bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies in the production of penicillin, respiration and growth of penicillium chrysogenum in submerged culture, in relation to agitation and oxygen transfer
Authors: Calam C. T. , Driver N. , Bowers R. H. 
Published: July 2010

AbstractThe submerged‐culture process for the production of penicillin by Penicillium chrysogeman was investigated in the laboratory. An attempt was made to determine whether there was any rigid relationship between the growth and respiration of the mould and the yield of penicillin, and whether the rate of transfer of oxygen to the liquid phase always limited the yield of penicillin. With these objects in view fermentations were carried out with different types of fermenter, concentrations of medium and strains of the mould. The results indicated that there was no rigid relationship between the various processes. This view was supported by a study of the effect of temperature on the different reactions. With any particular set of conditions, however, changes in the speed of stirring produced effects on growth, respiration and yield of penicillin which appeared to be related. This was doubtless due to the effect of changes in agitation on parallel but relatively independent processes. Our results suggest that the yield of penicillin depends mainly on the suitability of the agitation for its particular enzyme system, and that at present improvements can best be sought by empirical means. Fermenters and fermentation‐systems will show different responses to changes in conditions depending on which part of the enzyme system producing penicillin is limiting its production.
An improved type of vapour‐liquid equilibrium still
Authors: Thornton John D. 
Published: July 2010

AbstractA design is presented for a new type of vapour‐liquid equilibrium still. This incorporates separate liquid‐ and vapour‐sample traps, the latter being vacuum‐jacketed. The apparatus has proved satisfactory for investigating the type of system encountered in the extractive distillation process, where heterogeneous condensates occur a few degrees below the equilibrium temperature.
Commercial production of polystyrene
Authors: Samaras N. N. T. , Perry E. 
Published: July 2010

AbstractThe commercial production of polystyrene is limited by engineering considerations of heat transfer rather than by rate of chemical reaction. Mass polymerization has been developed for batchwise and continuous operation. Suspension polymerization was developed to overcome the limitations of the mass process by reducing the heat‐transfer distances to small values and by keeping the reacting mixture at a low viscosity. Emulsion polymerization can be considered an extreme case of suspension polymerization in which the droplet size is less than Im̈.A consideration of relative capital and conversion costs shows that there are not large differences between the three processes, and the final choice as to which plant to install is a matter of specific circumstances.Future developments on commercial polystyrene operation will be directed toward reducing capital costs required.
Copolymerization
Authors: Melville H. W. , Bonsall E. P. , Valentine L. 
Published: July 2010

AbstractThe mechanism of the copolymerization of two components in addition‐polymerization has been examined in detail for the systems styrene‐methyl methacrylate, styrene‐butyl acrylate, and styrene‐p‐methoxystyrene. In such reactions nine elementary‐radical processes are involved. By kinetic analysis of the problem combined with measurements of the rate, composition, and molecular weight of the copolymers and measurements of the rate‐coefficients for the polymerization of individual components, all the nine rate‐coefficients may be determined with reasonable accuracy.One of the unusual factors which comes out of this study is that in the reaction of methyl methacrylate and butyl acrylate the velocity with which dissimilar radicals interact with each other is very much greater than the geometric mean reactivity of the separate radicals. On the other hand with the p‐methoxystyrene system completely normal behaviour is obtained and the rate of the interaction of dissimilar radicals is exactly equal to the geometric mean of the reactivity of the separate radicals.
Mineral oil as a wool lubricant; emulsification of blends of mineral oil and wool‐wax alcohols
Authors: Truter E. V. 
Published: July 2010

AbstractWool wax contains alcohols which, when mixed with a suitable mineral oil, give blends that are stable at 0° c. and are easily removable from wool. The flash points are well above the necessary minimum laid down by the fire insturance companies (340° F.), and there is no tendency for spontaneous oxidation to take place, nor do the blends become discoloured if exposed to very strong light for considerable periods of time. The isolation of these alcohols from several sources is described, and data on their performance are given.
Developments in the theory of cationic polymerization
Authors: Plesch P. H. 
Published: July 2010

AbstractThe polymerization of olefins by metal halides is discussed with special emphasis on the role of the co‐catalyst in these reactions. A new extension of the existing theory is proposed to account for some hitherto inexplicable observations, especially those relating to the effect of hydrogen halides on various polymerization systems. It is suggested that the carbonium ion which starts the polymerization may be formed by either of two essentially different reactions, depending on the nature of the catalyst, co‐catalyst and monomer. In one class of reactions the monomer reacts with a catalyst/co‐catalyst complex in the other the co‐catalyst reacts with a monomer/catalyst complex. In both cases a carbonium ion and a complex anion are formed.
Dynamic testing of road constructions
Authors: Van Poel C. Der 
Published: July 2010

AbstractThe deformations of various roads under alternating load were measured. The amplitude of the loading force ranged from 300‐2000 kg.‐force, and the frequencies from 5‐60 cycles/sec. The results give a good impression of the mechanical rigidity of the constructions and of the stresses and strains raised in the carpet.In addition, the rates of propagation of the vibrations were measured at various frequencies. From these rates the dynamic Young's moduli of the various construction layers could be accurately calculated.
X‐ray investigation of 2 : 2′‐dihydroxy‐5 : 5′‐dimethyl‐diphenylmethane and its 3‐, 4‐, and 5‐ring polymers and p‐cresol novolak resins
Authors: Hunter R. F. , Vand V. 
Published: July 2010

AbstractThe X‐ray diffraction of 2 : 2′‐dihydroxy‐5 : 5′‐dimethyldiphenylmethane and its 3‐, 4‐, and 5‐ring polymers, two p‐cresol‐formaldehyde resins of known average molecular weight, and the 1 : 1‐addition complex of the 4‐ring polymer and ethylene dichloride have been examined using a Frevel focusing camera of high resolving‐power. Each pattern of a crystalline individual, however, proved different from the others and the number of repeating units in the polymer chain of the p‐cresol series is insufficient to lead to regularities of the type observed in other homologous series. There is a definite change from the crystalline to the amorphous state on passing from the 4‐ring to the 5‐ring polymer and the latter gives a photograph showing that the compound is approaching the condition of p‐cresol—formaldehyde resins. No polymorphism was observed in specimens of 2 : 2′‐dihydroxy‐5 : 5′‐dimethyldiphenylmethane prepared by crystallizing from different solvents and by drying under different conditions.
The formation of scale from hard waters at temperatures below the boiling point
Authors: Howland A. H. , Simmonds W. A. 
Published: July 2010

AbstractIn order to obtain information on the mechanism by which scale is formed from natural waters at temperatures below the boiling point, an investigation has been carried out into the formation of calcium carbonate by the thermal decomposition of calcium bicarbonate solutions. It has been shown that the rate of formation appears to be unaffected by the presence of glass surface but is greatly increased by the presence of various finely divided materials, particularly calcium carbonate powder. A quantitative estimate of the influence of calcium carbonate surface has been obtained and it has been shown that its effect increases with increasing temperature.The experimental results indicate that the thermal decomposition of calcium bicarbonate solutions may be represented by the relation where C represents the calcium concentration at a time t and GE is the equilibrium concentration. The quantity m is a function of the initial supersaturation (CI ‐ CE) and for the temperature range 75°‐90° c. is given by m = 1.99 × 10−8 (CI ‐ CE)2.5.The experimental results have also been applied to the formation of scale from natural waters and graphs are supplied from which it is possible to calculate amounts of scale deposition under various conditions.
A modified method for the determination of total penicillin in procaine penicillin
Authors: Wild A. M. 
Published: July 2010

AbstractA method is described for the chemical assay of total penicillin (salt) in procaine penicillin [penicillin (procaine salt)]. The method depends on the conversion of procaine penicillin to sodium penicillin [penicillin (sodium salt)] by precipitation with sodium silicotungstate, the sodium penicillin being assayed iodimetrically.
An electron‐microscope study of plasticized nitrocellulose
Authors: Ames J. , Sampson Avis M. D. 
Published: July 2010

AbstractThe surfaces of films of (a) castor oil plasticized (b) dibutyl phthalate plasticized and (c) unplasticized nitrocellulose were examined in the electron microscope, using an atomic‐replica technique. The castor oil‐nitrocellulose plastic was relatively granular in texture, whereas the remainder were almost structureless. No evidence of the presence of plasticizer could be obtained, and it is concluded that the degree of dispersion of the plasticizer is finer than the resolving limit of the microscope. Some possible plasticization mechanisms are discussed on the basis of the observations made.
The recovery of organic material from cobalt 1‐nitroso‐2‐naphtholate
Authors: Dargaville A. D. , Ingles D. L. , Polya J. B. 
Published: July 2010

AbstractThe decomposition of cobalt i‐nitroso‐2‐naphtholate by sodium hydrosulphite (dithionite) gives cobalt sulphide and I‐amino‐2‐naphthol in good yields. Attempts at the electrolytic oxidation of I‐amino‐2‐naphthol to I‐nitroso‐2‐naphthol were unsuccessful.
Rapid electrolytic method for the determination of zinc in aluminium‐zinc alloys
Authors: Norwitz George 
Published: July 2010

AbstractA rapid and accurate electrolytic method is described for determining zinc in aluminium‐zinc alloys. The sample is dissolved in sodium hydroxide, and then sulphuric acid and hydrogen peroxide are added to dissolve the copper. The peroxide is destroyed by boiling, and the solution buffered with tartaric acid. The zinc, copper and iron are quantitatively plated out together and the zinc found by difference. Nickel, lead and tin interfere with the determination.
Colorimetric determination of copper in aluminium alloys
Authors: Shrager S. A. , Norwitz George 
Published: July 2010

AbstractA very rapid method for the colorimetric determination of copper in aluminium alloys is described. The sample is dissolved in hydrochloric and nitric acids, and an excess of ammonia is added to precipitate the aluminium, iron and silica. The solution is diluted to 500 ml. and a portion is filtered and read with a colorimeter at 580 m μ. A small correction is necessary for samples containing nickel.
Continuous polycondensation : The development of a practical method
Authors: Sunderland E. 
Published: July 2010

AbstractThe fundamental features of polycondensation reactions which have a bearing on methods of production are discussed. It is deduced that where reversible heterogeneous reactions are involved a film reactor will provide optimum production‐conditions.Laboratory work has confirmed this deduction in several cases, notably where the reaction is a polyesterification, as in the production of oil‐modified alkyd resins.In the light of the laboratory results a factory‐scale production unit has been designed and the salient features of this unit are described.
The influence of oxygen upon polymerization reactions
Authors: Abere J. , Mark H. , Hohenstein W. P. 
Published: July 2010

AbstractInvestigations were carried out to measure the influence of varying initial concentrations of oxygen upon the rate of polymerization during the early stages of polymerization of styrene in toluene solution. Likewise, the viscosity‐average molecular weights of the polymers produced were determined and correlated with the changes of the amounts of oxygen initially present.In order to evaluate properly the differences in the length of the inhibition periods caused by the varying amounts of oxygen added, polymerizations of styrene were first carried out in the absence of oxygen. No inhibition period was observed then. The influence of varying amounts of oxygen is shown by an appearance of inhibition periods, the length of which is dependent upon the initial oxygen concentration. The viscosity‐average molecular weights of the resulting polymers also are related to the same quantity. It too can be observed that the velocity of the reactions immediately following the inhibition period is dependent on the amount of oxygen added at the beginning of the reaction.In accordance with evidence produced by other investigators it is assumed that formation of polyperoxides takes place during the inhibition period. All the observed experimental facts can be explained by this assumption. It also is assumed that the decomposition of these polyperoxides causes a decrease in the length of the inhibition periods by producing radicals which can start new polyperoxide chains. The increase in the rate of the polymerizations after the end of the inhibition period above the rate of a thermal polymerization is of course also due to the decomposition of the polyperoxides at that period of the reaction.Thus it is proposed to change the equation, suggested by Bolland and Gee for the relationship between initial oxygen concentration and inhibition period to P = Kt + a where a is a factor dependent on the rate of decomposition of the polyperoxides during the inhibition period, as well as on possible side‐reactions consuming oxygen.
The influence of carbon smokes on the corrosion of metal surfaces exposed to flue gases containing sulphur trioxide
Authors: Kear R. W. 
Published: July 2010

AbstractFurther work has been carried out to assess the effect of the presence of carbon smokes on the corrosion of a mild‐steel surface by flue gases containing sulphur trioxide. The results obtained have confirmed the view that a peak rate in corrosion obtains at temperatures of 20‐45°c. below the dew‐point of the gas and that the presence of carbon smokes can profoundly affect the extent of corrosion. As the smoke concentration is increased from zero there is an initial increase in corrosion but eventually the dew‐point of the gases and their corrosive properties are substantially reduced.Comparison of the behaviour of filtered and unfiltered smoke‐laden gases would indicate that carbon reduces the sulphur trioxide content of flue gases by a process of physical adsorption.
The spectrographic determination of hafnia in mixtures of hafnium and zirconium oxides
Authors: Kingsbury G. W. J. , Temple R. B. 
Published: July 2010

AbstractA general method for the quantitative analysis of non‐conducting solids has been developed, and its application is described for the particular problem of the determination of hafnium oxide in mixtures of hafnia and zirconia over the concentration range 0.01‐55%. The advantage of the method is that not more than 10 mg. of the oxides is required for the preparation of the electrodes, the material being attached to the end of flat graphite electrodes by a drop of Bakelite varnish and excited by means of an impulse are of a new type.A number of line pairs have been examined to discover the most suitable, and it has been found possible to obtain good results by the use of two, namely. A standard deviation of = 6% has been obtained by this method. Some estimations of the residual zirconia of very pure hafnium oxide have been made using the lines Zr II 2387. i8A., HfII 2385.78A.
The insoluble matter of coal tar. VII. Dilution of tars
Authors: Green S. J. , Olden M. J. F. 
Published: July 2010

AbstractPrevious application of surface‐tension rules to dilution of coal tars is criticized and it is considered that the surface tension of the mixture of diluent with the oils of the tar must be considered rather than the surface tension of the diluent alone. Maximum insolubles in a tar‐diluent system occur at lower ratios of diluent to tar for both horizontal‐ and vertical‐retort tars. The relation of maximum insolubles to the surface tension of the diluents has been examined and generally it is shown that diluents with surface tensions above that of the tar behave quite differently from those of lower surface tension. The results are interpreted to mean that flocculation and precipitation, followed by solution or redis‐persion, occur when diluent of surface tension lower than the tar is added in increasing amounts.
Identification of and tests for homogeneity of alcohols by means of the nitrophenylhydrazones of their acetoacetates
Authors: Carroll M. F. 
Published: July 2010

AbstractA new method for identifying alcohols by the determination of the melting points of the p‐nitro‐phenylhydrazones of their acetoacetates is described and shown to be of fairly general application. The method may also be used to give an approximate estimate of the homogencity of commercial alcohols.A selection of melting points of the derivatives of purified alcohols normally used in commerce is given and some results for the ordinary commercial products are shown for comparison.
The hydrolysis of wool wax and related high molecular weight esters. I. Homogeneous reactions
Authors: Truter E. V. 
Published: July 2010

AbstractThe homogeneous alkaline hydrolysis of the acetates, caprylates and palmitates of n‐octadecanol and cholesterol in the four lowest normal alcohols has been studied. It is shown that the various constants for the reactions are within the range recorded for similar reactions of low molecular weight esters, no anomalies of any sort being observed.
Estimation of impurities in aluminium alloys by means of arc spectra
Authors: Janiec J. 
Published: July 2010

AbstractTo estimate the impurities in aluminium alloy a d.c. arc is used. An aluminium‐alloy rod, 12 mm. in diameter and faced up on the lathe, is employed as the positive electrode and a graphite rod pointed to 60° as the negative one. Analysed samples and suitable standards are spread over the photographic plate as in spark exposures. They are energized in an arc under defined conditions, i.e. 4‐mm. gap between the electrodes, potential difference 220 v., current 7 amp., etc. Ilford thin‐film half‐tone plates are used and are developed according to the maker's instructions. The spectra registered are then measured and evaluated in a similar manner to that used for the spark spectra; an internal comparison method is used. In arc spectra registered under these conditions the densities of the analysed samples are similar, and on this account the same standards may be used for all unknown samples which pass through the spectroscopic laboratory. This method properly used gives accurate and reproducible results.
Automatic distilling apparatus for continuous production of conductivity water
Authors: Bieber Roman C. , Ibl Norbert 
Published: July 2010

AbstractA simple laboratory device is described which allows the double distillation of water in a continuous and automatic way in order to produce particularly pure water. The water thus obtained has a mean specific conductivity of 0.5 × 10‐6 ohm‐1cm.‐1 at 25° c.
Organic adsorbents from Indian tannins. II. Adsorption of acids, bases and salts
Authors: Bhatnagar M. S. , Nigam P. C. 
Published: July 2010

AbstractThe adsorption of homologous series of monobasic and dibasic aliphatic acids by katha and cutch resins has been studied. The adsorption decreases with the increase in the molecular weight. This reversal of Traube's rule is explained on the basis of orientation of molecules at the resin‐water surface according to the theory of Langmuir and Harkins. The influence of substituted hydroxyl groups has also been studied. The adsorption of barium, strontium and calcium has been studied. The order of adsorption is explained on the basis of the polar concept.
Formaldehyde condensations with phenol and its homologues. XII. The dehalogenation of halogenated diphenylmethanes having halogen substituents in the nucleus
Authors: Finn S. R. , Lewis G. J. 
Published: July 2010

AbstractThe preparation of I‐hydroxy‐2 : 6‐bis‐(2‐hydroxybenzyl)benzene by dehalogenation of the corresponding trichloro compound was described in Part X of this series (Finn, Lewis & Megson, 1950). The removal of the chlorine was effected by treatment of the boiling amyl alcohol solution of the compound with sodium. The yield was poor and amounted to only 5% of theory.It has now been found that the dehalogenation can be achieved more satisfactorily by treatment of a solution of the diphenylmethane derivative in aqueous sodium hydroxide with Raney nickel‐aluminium alloy. A yield of about 50% of theory is obtained.2 : 2′‐Dihydroxydiphenylmethane may be obtained from 2 : 2′‐dihydroxy‐5 : 5′‐dichloro‐diphenylmethane by the same means and the method has been used to prepare 2 : 2′‐dihydroxy‐3 : 5‐dimethyldiphenylmethane, 2 : 2′‐dihydroxy‐3 : 3′ : 5 : 5′‐tetramethyldiphenylmethane, and I‐hydroxy‐3 : 5‐dimethyl‐2 : 6‐bis‐(2‐hydroxybenzyl)benzene.
‘β‐Phellandrene’ from Canada‐balsam oil
Authors: Davenport J. B. , Sutherland Maurice D. , West T. F. 
Published: July 2010

AbstractIt has been found that, contrary to earlier reports, the β‐phellandrene obtainable from Canada‐balsam oil by fractional distillation is very impure, being contaminated with about an equal amount of (—)‐limonene. A much purer β‐phellandrene may be separated from the hydrocarbons resulting from the dehydration of neopiperitol.
THE extraction and refining of germanium and gallium
Authors: Powell A. R. , Lever F. M. , Walpole R. E. 
Published: July 2010

AbstractSources of germanium and gallium are discussed and descriptions are given of processes for the recovery of these elements from flue dusts and from germanite. The flue‐dust process involves smelting to recover the rare elements in a metallic regulus, dissolution of this regulus in ferric chloride solution with the aid of chlorine, distillation of crude germanium tetrachloride from the resulting solution, fractional distillation of the crude product to remove the bulk of the arsenic, and final rectification through a column packed with copper turnings to remove the remainder. After hydrolysis of the resulting tetrachloride germanium oxide is obtained with less than 0.1 p.p.m. of arsenic. Gallium is recovered from the acid liquor in the first still by treatment with aluminium to remove heavy metals and to reduce the iron to ferrous chloride, followed by extraction of the gallium chloride in a continuous process with isopropyl ether, removal of the ether by distillation, purification of the aqueous phase with hydrogen sulphide, and conversion of the gallium into sodium gallate for electrolysis.The germanite process is a modification of that recommended by Sebba & Pugh (1937), combined with similar refining stages to those used in the treatment of flue dust.