bluuebunny/crossref_metadata_2025 huggingface dataset:
Designer enzyme and cell applications in industry and in environmental monitoring
Authors: Wiseman Alan
Published: July 2010

Renewed world interest in enzyme biotechnological industries now derives from the expectation that many new biocatalysts will be created by genetic engineering associated with protein engineering designer techniques, or by chemical modification of existing enzymes by use of protein tailoring methods. The biocatalysts produced are mainly enzymes, abzymes (catalytic antibodies) and synthesis (synthetic analogues or mimics), and these will be used in industry, synthesis, therapy: and in bioanalysis of components of foodstuffs, and the environment including water, air and soil. The biocatalysts, including whole cells, are firstly incorporated into a particular bioreactor form by use of enzyme engineering techniques such as immobilization, and are then used, as appropriate, to modify their substrates. Improved processing or enhanced products are thereby achieved in the case of manufacturing industry: or monitoring signals are generated, often in the form of a measurable change in current flow, in the case of environmental biosensors. Designer enzymes and cells can be made now for identified applications where the presently available biocatalysts are inadequate, incompatible or uncompetitive.
Temperature effects on polyphenol oxidase activity in organic solvents with low water content
Authors: Estrada P. , Baroto W. , Castillon M. P. , Acebal C. , Arche Late R.
Published: July 2010

The effect of temperature studies on polyphenol oxidase immobilized on glass beads were carried out in organic solvents. The optimum temperature for catalysis depended on the solvent and varied in a range from 26°C for dichloromethane to 50°C for toluene, benzene and 1,1,1‐trichloroethane. Optimum temperature and activation energy were independent of the water content of the system whereas the inactivation energies decreased as the water content of the system was decreased. The enzyme was stable in toluene up to 50°C although residual activity depended on the water content of the system. Thermoinactivation of polyphenol oxidase in toluene gave an activation energy for enzyme decay of 111.5 kcal mol−1 which is consistent with a conformational process. Among the agents employed to protect the enzyme against thermal denaturation 1 % (w/v) short‐chain polyols added to the buffer and 0.5 mmol dm−3 p‐nitrophenol added to toluene more than doubled the half‐life of the enzyme.
Biodegradation of phenol: A comparative study with and without applying magnetic fields
Authors: Jung J. , Sanji B. , Godbole S. , Sofer S.
Published: July 2010

The objective of this work was to study the effect of magnetic fields on the rate of phenol biodegradation using immobilized activated sludge. A recirculation flow bioreactor employing immobilized bacterial beads was used with phenol as the substrate to study the biodegradation process. This study was conducted by applying separately the north pole and the south pole magnetic fields to the bioreactor. Rate of dissolved oxygen consumption, phenol concentration and extracellular protein concentration were the parameters monitored during the process.

It was observed that by applying a magnetic south pole to the process, biodegradation in the form of biological oxidation was enhanced. A 30% increase in biodegradation rate was obtained by applying a magnetic south pole of strength of 0.45 Tesla to the bioreactor with immobilized microbial beads as compared to the control. Magnetic north pole irradiation inhibited this type of biooxidation. This process has potential for biological treatment of organic wastes.
A comparison of adsorption characteristics of various activated carbons
Authors: Gergova K. , Petrov N. , Minkova V.
Published: July 2010

The physico‐chemical characteristics of activated carbons obtained from different agricultural by‐products by pyrolysis in a stream of water vapor have been investigated. It was established that under the same conditions of treatment the physico‐chemical and adsorption characteristics of activated carbons depend on the composition of the initial raw materials. Activated carbon obtained from apricot stones has the best properties. It is characterized by a large specific surface area and micropores volume and high iodine and methylene blue adsorption activity. The activated carbons produced from cherry stones and grape seeds are characterized by predominating meso‐ and macropores structure. It can be supposed this is related to the larger content of lignin in those materials.
Maximizing the production of acetone—butanol in an alginate bead fluidized bed reactor using clostridium acetobutylicum
Authors: Mollah Abdul H. , Stuckey David C.
Published: July 2010

Low volumetric solvent productivities are one of the characteristics of an acetone‐butanol fermentation by C. acetobutylicum. A calcium alginate immobilized continuous culture was used in a novel gas‐sparged reactor to strip the solvents from the aqueous phase and reduce their toxicity. A dilution rate of 0.07 h−1 was found to give maximum solvent productivity at 0.58 g dm−3 h−1, although at 0.12 h−1 the productivity was slightly lower. In order to increase glucose uptake by the culture, feed glucose concentrations were increased over time to attempt to acclimatize the culture. This resulted in a productivity as high as 0.72 g dm−3 h−1 although this production rate was found to be unstable.
Diels‐alder reaction: New antimicrobial pyrazolo‐chroman derivatives
Authors: Abd el Latif F. M. , Maghraby A. S. , Barsy M. A. , Badr M. Z. A.
Published: July 2010

Pyrazolo‐[2,3‐d]‐chroman dione derivatives were obtained via Diels‐Alder reaction of pyrazolone arylidenes and 1,4‐benzoquinone. The reaction rate and its yield have been found to be solvent and time dependent. The evaluation of the bactericidal and fungicidal screening showed significant inhibition effects against some thermophilic organisms grown and incubated at 55°C.
The preparation and properties of magnesia catalyst supports
Authors: Sidjabat O. , Trimm D. L. , Wainwright M. S.
Published: July 2010

The preparation of magnesia has been investigated with the object of preparing a catalyst support material that maintained high surface area after heating to high temperatures. The effect of precipitation, ageing, washing, drying and calcining on the surface area and porosity of magnesia has been studied. It was found possible to produce stable magnesia by washing with methanol or acetone, but the surface area was low for most catalytic applications.
Kinetic studies on dehydrogenation of butanol to butyraldehyde using zinc oxide as catalyst
Authors: Raizada V. K. , Tripathi V. S. , Lal Darshan , Singh G. S. , Dwivedi C. D. , Sen A. K.
Published: July 2010

Butyraldehyde is an important chemical for many industrial applications, especially in the production of polyvinylbutyral. A systematic study of its synthesis by catalytic dehydrogenation of butanol, using zinc oxide as catalyst has been carried out. The effect of the method of preparation of zinc oxide on its catalytic activity for the title reaction has also been studied. The optimum conditions for maximum yield have been worked out and on the basis of secondary electron micrograms the reasons for higher activity/selectivity in the case of zinc oxide calcined from zinc hydroxide is attributed to the presence of hexagonal morphology. A kinetic study for the best zinc oxide catalyst has been carried out and the rate equation has been determined.
Kinetics of carbonization of calcium sulfide in water suspension
Authors: Nishev T. , Pelovski Y.
Published: July 2010

The carbonization of CaS in water suspension was studied. The process takes place under diffusion control. The complicated process mechanism causes the appearance of a compensation effect. By increasing the carbon dioxide partial pressure, the probability of interaction is raised, which leads to the increase of the pre‐exponential factor. When the chemical reaction is faster then less porous CaCO3 is deposited and as a result the apparent activation energy is increased.
Kinetic properties of the periplasmic hydrogenase from Desulfovibrio desulfuricans NCIMB 8372 and use in photosensitized H2‐production
Authors: Eng Lars H. , Lewin Mona B.‐M. , Neujahr Halina Y.
Published: July 2010

The periplasmic hydrogenase (hydrogen: ferricytochrome‐c3 oxido‐reductase EC 1.12.2.1) from Desulfovibrio desulfuricans (NCIMB 8372) was isolated and the catalytic properties of the enzyme determined with different electron mediators.

In the direction of H2‐oxidation with the physiological electron mediator cytochrome c3, the value of the apparent second order rate constant (kcat/Km) is close to that expected for a diffusion‐controlled reaction. In H2‐production however, the value of kcat/Km with cytochrome c3 is almost 200 times lower. When methyl viologen is used as mediator, the value of kcat/Km is the same in both directions and is intermediate to the values obtained with cytochrome c3.

The close to optimum value of kcat/Km in H2‐oxidation with cytochrome c3 as electron acceptor is discussed with respect to the biological role of this and related hydrogenases.

H2‐production occurred with the hydrogenase in a system where the mediator was reduced with either of three photosensitizers (proflavin, 5‐deazariboflavin, Zn‐tetraphenyl porphyrin sulphonate) upon illumination. The efficiency of different mediators is discussed.
Recovery of lanthanides from kola apatite in phosphoric acid manufacture
Authors: Zielinski Stefan , Szczepanik Anna , Buca Marek , Kunecki Miroslaw
Published: July 2010

The paper presents the results of bench‐scale studies for the recovery of lanthanides from Kola apatite in the phosphoric acid production by a two‐stage hemihydrate‐dihydrate wet‐process. The second stage of the process (hydration of hemihydrate) provides the best conditions for the recovery of lanthanides. In the postulated recovery process use is made of solvent extraction for the removal of lanthanides during hydration of hemihydrate, and precipitation‐stripping for the removal of lanthanides from the solvent. Lanthanides are recovered in the form of Ln‐enriched concentrates with an efficiency of 80–85%. The process does not disturb the phosphoric acid production, and additionally purifies the by‐product gypsum, so that it can be utilized.
Sulphide inhibition of methanogenic activity at various pH levels at 55°C
Authors: Visser A. , Nozhevnikova Alla N. , Lettinga G.
Published: July 2010

The purpose of this study was to evaluate the toxic effect of sulphide on thermophilic methanogenic bacteria, pre‐cultivated in UASB‐reactors fed with and without sulphate, at 55°C and different pH levels. For granular sludge, precultivated in the presence of sulphate, the inhibition caused by hydrogen sulphide was dependent on the pH imposed. At alkaline pH the inhibitory effect of hydrogen sulphide was higher than at neutral or acidic pH. The effect of sulphide could not be described in terms of free hydrogen sulphide level only. For dispersed sludge, pre‐cultivated in the absence of sulphate, the inhibition caused by free hydrogen sulphide was independent of the pH, and the toxic effect of sulphide could be described in terms of free hydrogen sulphide.
A novel approach to the production of clinical‐grade dextran
Authors: Barker P. E. , Ganetsos G. , Ajongwen N. J.
Published: July 2010

Efficient unit operations for the production and purification of the enzyme dextransucrase and the biosynthesis and fractionation of dextrans have been developed and tested. An alternative process for the production of clinical‐grade dextran has been proposed by integrating these processes to achieve improved dextran product yield and the recovery of fructose as a valuable byproduct. The enzyme dextransucrase, which synthesizes dextran from sucrose, has been produced either by non‐aerated fed‐batch or continuous fermentations, purified by continuous ultracentrifugation and ultrafiltration and used in a bio reactor‐separator stage for the biosynthesis of dextran. High molecular weight dextrans have been biosynthesized on continuous counter‐current chromato‐graphic bioreactor‐separator systems. Membrane filtration and size exclusion continuous chromatography were used for the fractionation of the native dextran and production of clinical‐grade dextran. The advantages of the proposed process over the conventional process are related to cost reduction due to the elimination of ethanol usage and recovery, improved product quality control and the production and recovery of fructose as a by‐product.
Mechanistic study of cobalt, nickel and copper transfer across a supported liquid membrane
Authors: Marchese José , Campderrosa Mercedes E. , Acosta Adolfo
Published: July 2010

The mechanism of cobalt, copper and nickel transport through supported liquid membranes containing di(2‐ethylhexyl)phosphoric acid as a mobile carrier has been studied. An equation describing the permeation rate has been derived, taking into account stagnant layer aqueous diffusion, interfacial resistance due to solvatation reaction and liquid membrane diffusion as simultaneous controlling factors. The validity of this model is evaluated with experimental data of mass transfer coefficient measured employing a permeation cell. For these ions it was found that at low stirring conditions the stagnant layer resistance mainly controlled the processes, but it is controlled by diffusion of the ion complex through the supported liquid membrane when the stagnant layer resistance is negligible.
Synthesis and surface activity of nonionic surfactants containing fluorocarbon hydrophobes
Authors: Meissner Egbert , Myszkowski Jerzy , Szymanowski Jan , Barhoum Rakan
Published: July 2010

Nonionic surfactants having polydisperse polyoxyethylene chains and highly fluorinated hydrophobes were synthesized via a complex reaction route and their adsorption at water/air interfaces studied. They exhibit high surface activity and decrease both effectively and efficiently the surface tension of their aqueous solutions. The effect of the length of the polyoxyethylene chain upon surfactant surface activity is relatively low. Lower values of surface tension, below 30 mN m−1, are obtained for surfactants having a low degree of ethoxylation. Surfactants having two terminal highly fluorinated hydrophobes are less surface active than analogues with one terminal hydrophobe.
Removal of aldehydes by amino acids and their salts in ambient air
Authors: Sugiura Masahiro , Fukumoto Kazuhiro
Published: July 2010

The removal of gaseous aldehydes by amino acids and by their sodium salts and hydrochlorides was studied in ambient air with the relative humidity of 30% at 25°C. Amino acid sodium salts, diamino acids, sodium p‐aminobenzoate (PABANa), and o‐aminobenzoate (OABANa), and p‐aminobenzoic acid (PABA) on sepiolite, both having a carboxylato functionality (COO−) together with an amino (NH2) group, were highly reactive with aldehydes. In contrast, PABA which has free carboxylic acid functionality (COOH: dimeric) was not so reactive with aldehydes. Normal amino acids and their hydrochlorides having ammonio (NH2+) and COO− or COOH (dimeric) groups were less reactive with aldehydes. The reactivity was closely related to the degree of dissociation of carboxylate anion; as the degree of dissociation increases, the compound becomes more reactive. p‐Aminobenzoic acid hydrochloride (PABA · HCl), having NH3+ and COOH (monomeric) groups, was the most reactive (with ethanal) of all the amino acids and their salts examined. Amino acid sodium salts, diamino acid, PABANa, OABANa, and PABA on sepiolite are proved to be excellent removers of aldehydes in ambient air. Among them, PABA · HCl is particularly good for ethanal.
Simple method for the simultaneous evaluation of combustion and selective oxidation catalysts
Authors: Ramdasi Sudhakar S. , Kulkarni Suresh Y. , Gokarn Ashok N. , Pande Anita R.
Published: July 2010

The conventional rapid combustion technique used for microanalysis of organic compounds has been modified for the simultaneous evaluation of combustion and selective oxidation catalysts. Using this technique, MnO2 has been confirmed to be a good combustion catalyst. It was also possible to conclude that Fe2O3 and V2O5 are good selective oxidation catalysts at 250°C and 300°C, respectively. This simple and rapid method offers much scope for probing into the mechanism of oxidation of hydrocarbons.
Saccharification of modified starch to maltose in a continuous rotating annular chromatograph (CRAC)
Authors: Sarmidi M. R. , Barker P. E.
Published: July 2010

Simultaneous biochemical reaction and separation has been successfully carried out in a continuous rotating annular chromatograph (CRAC) by saccharifying liquefied starch to maltose using the enzyme maltogenase. Maltogenase is a thermostable, exo‐acting alpha‐amylase. A simple optimisation procedure involving both volume overload and concentration overload was used. For soluble potato starch, maltose conversions of up to 79% were achieved at feed flow rates of up to 400 cm3 h−1 and 15–5% w/v concentrations. The resolution between maltose and dextrin was 0.92.
Effect of acetate medium on the extraction of cobalt(II) with Di(2‐ethylhexyl)phosphoric acid dissolved in kerosene
Authors: Juang Ruey‐Shin , Lo Ru‐Huey
Published: July 2010

In this paper, the effect of acetate ion (OAc−) on the extraction of cobalt(II) from sulfate media with kerosene solutions of di(2‐ethylhexyl)phosphoric acid (D2EHPA, HR) was investigated at 25°C. In the absence of acetate ions, the composition of the extracted species was graphically determined to be CoR2(HR)2 at low loading of D2EHPA (α < 0.06). In the presence of acetate medium, the acetate ions were co‐extracted and the mixed complexes of the type Co2OAcqR4‐p(HR), were formed at a relatively higher loading of D2EHPA (0.10 < α < 0.34), where q = 0–4 and r = 2–4 depending on the concentration of acetate ions.
Synthesis and structural assignment of certain pyrimido[1,2‐a]benzimidazole derivatives
Authors: Ahmed Samia G. , Ahmed Abd‐El Hamid N. , Omar Nabil M. , El‐Gendy Mahmoud A.
Published: July 2010

The pyrimido[1,2‐a]benzimidazole derivatives compounds 1–8 were synthesized through cyclocondensation of 2‐aminobenzimidazole with the appropriate benzsubstituted benzoylacetone by fusion at 150–170°C for 5 h. Quaternary salts compounds 9–22 were obtained by quaternization of compounds 1–8 with dimethyl or diethyl sulfate and subsequent isolation as the relatively insoluble perchlorate salts. Assignment and confirmation of the structures of the newly synthesized compounds were based upon elemental microanalyses and other spectral evidence.
Covalent immobilization of aminoacylase to alginate for L‐phenylalanine production
Authors: Lee Pat M. , Lee Kong H. , Siaw Yew S.
Published: July 2010

Aminoacylase I (EC. 3.5.1.14) was immobilized by covalent crosslinking to alginate molecules with 1‐ethyl‐3‐(3‐dimethyl‐aminopropyl)‐carbodiimide HCl followed by calcium alginate bead formation for the production of L‐phenylalanine from the racemic mixtures of N‐acetyl‐DL‐phenylalanine. Different concentrations of the coupling reagent were tested and the coupling process was optimized. The immobilized and the partially purified aminoacylase were characterized in terms of the activity, operational stability, thermal stability, pH and temperature optima and kinetic constants, Km and Vmax. The activity of the enzyme covalently immobilized in calcium alginate beads was enhanced by about 75% compared to that of free enzyme. The beads showed stable activity under operational conditions, they lost about 40% of their activity after four reaction cycles. The immobilized aminoacylase was more stable over a broader pH range. Thus this simple method provides irreversible immobilization of aminoacylase to give a biocatalyst with good operational stability and enhanced activity.
Anaerobic digestion of alkaline black liquor using an up‐flow anaerobic sludge blanket reactor
Authors: Dangcong Peng , Qiting Jin
Published: July 2010

The anaerobic digestion of alkaline black liquor from a cereal straw pulping mill was studied in batch (serum bottles) and continuous systems (up‐flow anaerobic sludge blanket reactor—UASB). The batch digestion studies confirmed that lignin and related compounds (LRC) in the alkaline black liquor were the main inhibitory substances and could not be decomposed by anaerobic bacteria. At organic loading rates of 5–10 kg COD m−3 day−1, the UASB reactor achieved 50–60% COD removal efficiencies. Gas production was 2–3 dm3 per dm3 of alkaline black liquor. Two different sludge types were examined in the reactor: granular and cluster‐like sludges. Sludge in a cluster, which involved many small granules and flocs, tended to form larger aggregates and possessed good settling ability.
Extraction of gold from aqueous solution by carrier‐mediated process using kryptofix 22 DD
Authors: Uddin Mohammad S. , Hidajat Kus , Woo Fook‐Cheong
Published: July 2010

Reactive extraction of gold from alkaline aqueous cyanide solution into n‐decanol in the presence of Kryptofix 22 DD as complexing agent was studied using a stirred transfer cell. The study investigated the effects of carrier concentration and temperature on mass transfer rates. A two‐film model was proposed by considering film mass transfer resistances at the aqueous and organic phases. The model predicted adequately the experimental time‐concentration data at different carrier concentrations and temperatures. Experiments have also been carried out to extract gold in an emulsion system using the same carrier and a mixed solvent of kerosene and decanol.
Spectrophotometric study of the complexation equilibria of iron(III) with 3‐hydroxypicolinic acid and determination of iron in pharmaceutical preparations
Authors: Abu‐Bakr Mohamed S.
Published: July 2010

The complexation equilibria of iron(III) with 3‐hydroxypicolinic acid (hypa) have been studied spectrophotometrically in 40% (v/v) ethanol—water medium at 25°C and an ionic strength of 0.1 M NaClO4. The equilibria occurring in solution were established and the basic characteristics of the complexes formed were determined. The spectral study of the reaction solutions containing equimolar concentrations or an excess of one component in the pH range 1.5 to 10.5 gave the evidence for the formation of [FeLH]2+, [FeL]+ and [FeL2]− complex species, depending upon the pH of the medium (LH2 symbolising the molecular form of hypa). The possible complex transitions that occur in solution were demonstrated using graphical and logarithmic analysis of the absorbance—pH graphs. A simple, rapid, sensitive and selective method for spectrophotometric determination of trace levels of iron(III) was proposed based on the formation of Fe(hypa)2 complex at pH 5.5 (λ = 440 nm, ϵ = 1.5 × 104 dm3 mol−1 cm−1). The interference of a large number of foreign ions was investigated. The method has been applied successfully to the analysis of multivitamin and mineral preparations containing iron.
Effects of pH and temperature on the continuous production of amylolytic enzymes by bacillus amyloliquefaciens MIR‐41
Authors: Castro Guillermo R. , Baigorí Mario D. , Méndez Beatriz S. , Siñeriz Faustino
Published: July 2010

Bacillus amyloliquefaciens MIR‐41 produces three exocellular amylolytic enzymes: α‐amylase, pullulanase and α‐glucosidase. Physicochemical factors such as pH and/or temperature may affect the enzyme yield. Continuous culture at a dilution rate of 0.15 h−1 demonstrated that the maximum production of α‐amylase and α‐glucosidase occurred at 36°C and pH 6.8 and of pullulanase at 44°C and pH 5.6. The results indicated that combinations of temperature and pH might be used for the production of crude extracts of α‐amylase or pullulanase.
Evolution of the active surface of carbons produced from various raw materials by steam pyrolysis/activation
Authors: Gergova K. , Petrov N. , Butuzova L. , Minkova V. , Isaeva L.
Published: July 2010

A one step pyrolysis/steam activation was used to produce activated carbons from apricot stones, nuts, coconuts, almond shells and grape seeds, and Bulgarian lignite from Maritza Iztok and Chukurovo deposit. The evolution of the active surface of the carbons produced was investigated. The changes in the structure of activated carbons give evidence for the periodicity of the processes of oxidation and thermal destruction. It was established that the adsorption properties of activated carbons are dependent on the treatment temperature, soak time and the nature of the raw materials.

The activated carbons produced from various raw materials have a high concentration of surface functional groups, carboxyl and hydroxyl. Activated carbons with predominantly meso‐ and macropore structures showed high capacity for adsorbing Cu2+ ions from solutions.
Applicability of the simplified model for the correlation of vapour—liquid equilibrium in the CO2NH3H2o system
Authors: Ciric Gordana M. , Paunovic Ratomir N.
Published: July 2010

The applicability of the simple empirical model—previously derived by Paunovic et al.1 for correlating the VLE in the concentrated CO2—NH3—H2O system—to water‐rich mixtures, encountered in waste water treatment, has been tested. The new parameters of the model have been evaluated for concentrations of ammonia and carbon dioxide up to 16 and 7 molal respectively, for temperatures from 360 to 393 K, and total pressures up to 0.7 MPa. The limit of model applicability in terms of the minimal molality ratio of ammonia to carbon dioxide is established, and suggested to be 2.3. In the region of model applicability, the proposed correlations fit the experimental phase equilibrium constants of ammonia and water with average relative errors of 5.7% and 5.1% respectively, and the reaction equilibrium constant with 31% error.
Kinetics of the liquid phase esterification of acrylic acid with butanol catalysed by cation exchange resin
Authors: Darge Olivier , Thyrion Fernand C.
Published: July 2010

Esterification of butyl alcohol with acrylic acid catalysed by Amberlyst‐15 cation exchange resin was carried out in a batch reactor in the liquid phase in the temperature range 333 to 364 K and 1 atm. The reaction rate increased with an increase in catalyst concentration and decreased with an increase in water concentration. The rate data were correlated with a kinetic model based on inhibition by water. The apparent activation energy was found to be 59.5 kJ mol−1 for the formation of butyl acrylate.
Combustion profiles of a double‐base nitrocellulose propellant
Authors: Patai S. , Jordan J.
Published: July 2010

The form of combustion profiles of lamellae of a double‐base nitrocellulose propellant (referred to as plasticized nitrocellulose) was investigated. Experiments were performed both in air and in inert gases, using wrappings of different thermal conductivity. An interpretation of the various profiles obtained (inverted V, rectilinear, concave‐parabolic) is proposed. The factor mainly determining the geometry of the combustion profiles is heat transfer from the flame front to the solid lamellae, through the ambient media.
The saponification of α‐monomyristin, α‐monostearin and α‐mono‐olein
Authors: Jellinek H. H. G. , Gordon A.
Published: July 2010

The saponification of α‐monomyristin, α‐monostearin and α‐mono‐olein has been studied in 75% (v/v) aqueous alkaline acetone.

The reactions obey a second‐order law. The energies of activation for the three monoglycerides are very similar: α‐monomyristin, 9900; α‐monostearin, 11,100; α‐mono‐olein, 10,800 g.‐cal.

The glycerides show the general phenomenon of alcoholysis in aqueous alkaline ethanol solutions.
Itaconic acid. I. Production by aspergillus terreus from unrefined cane sugar
Authors: Van Der Westhuizen G. C. A. , Spruit C. J. P. , Sephton H. H.
Published: July 2010

Conditions for the formation from sucrose of itaconic acid by a strain of Aspergillus terreus have been examined. The optimum concentrations of certain mineral components of the medium and some other factors have been investigated. It has been shown that unrefined cane sugar contains substances favouring the formation of itaconic acid. This stimulating effect could be duplicated in solutions containing pure sucrose and dextrose, by adding small amounts of molasses or corresponding amounts of molasses ash. These additions gave better yields than those obtained by the corresponding use of corn steep liquor.
The corrosion of a steel surface by condensed films of sulphuric acid
Authors: Flint D. , Kear R. W.
Published: July 2010

An experimental technique is described which has been used to study the corrosion of a steel surface at elevated temperatures by condensed films of sulphuric acid. The results show that (a) the rate of corrosion of the steel increases with increasing sulphuric acid dew‐point, and (b) irrespective of the dew‐point temperature, the rate of corrosion reaches a maximum at a surface temperature of the steel lying between 20° and 45° c. below that of the dew‐point.
Organic derivatives of titanium. II. Preparation and properties of some ortho‐esters
Authors: Cullinane N. M. , Chard S. J. , Price G. F. , Millward B. B. , Langlois G.
Published: July 2010

Some further esters have been prepared by methods already described in Part I and also by a transesterification process (cf. Speer, 1949), e.g. Certain physical properties, for example boiling‐points at different pressures, densities, viscosities and molecular weights have been determined, and the action of heat and moisture investigated.

A modification of Burnop's (1938) expression has been devised by which the boiling‐points of the normal esters can be accurately predicted.

In general, the molecular weights, determined cryoscopically, have been found to give approximately double the values calculated from the molecular formulae, and structural formulae are suggested to account for these results.
Suppression of flame in explosive systems
Authors: Jones Elwyn
Published: July 2010

A method of preventing explosions in chemical manufacturing plants where inflammable bases or vapours are employed in the presence of air or oxygen is further elucidated and the principle extended to condensed explosives. The relative merits of various inhibitors in varying circumstances are reviewed and the conclusion drawn that the best inhibitors of flame are complex organic substances, often of a highly inflammable nature. The seeming paradox admits of a simple explanation based on thermochemical considerations.
Manufacture of algal chemicals. II. Laboratory‐scale isolation of mannitol from brown marine algae
Authors: Black W. A. P. , Dewar E. T. , Woodward F. N.
Published: July 2010

Methods for the isolation of mannitol from the common brown algae indigenous to Great Britain have been worked out on the laboratory scale with a view to the ultimate development of a process suitable for large‐scale production. These comprise (i) solvent extraction of the dried seaweed and (ii) dilute‐acid extraction of the fresh or dried seaweed, followed by evaporation of the extract to dryness and the isolation of mannitol from this extract by (a) solvent extraction (b) precipitation as a water‐insoluble derivative or (c) the use of ion‐exchange resins.
The hydrolysis of wool wax and related high molecular weight esters. II. Heterogeneous reaction: Oil‐in‐water emulsions
Authors: Truter E. V.
Published: July 2010

The aqueous alkaline hydrolysis of wool wax, n‐octadecyl caprylate and palmitate and cholesteryl acetate and caprylate as oil‐in‐water emulsions stabilized by various agents, has been examined. It is shown that the extent of reaction in a given time is not related to the quality of the emulsion, but is probably limited by the rate of penetration of the interface.
The elastic and viscous properties of polystyrene in the solid and liquid state
Authors: Mohrman H. W. , Buchdahl R. , Neilsen L. E. , Merz E. H.
Published: July 2010

Measurements on unfractionated and fractionated polystyrenes have provided data from which several fundamental conclusions can be drawn: (i) for a large class of mechanical properties, the value of the property is zero at low molecular weights, increases with increasing molecular weight, and finally approaches an asymptote; (ii) the details of the molecular weight distribution curve are immaterial in determining the value of the measured mechanical property as long as the number‐ and weight‐average molecular weights are above their respective limiting values; (iii) polystyrene contains a quasi‐permanent molecular network whose parameters determine the visco‐elastic response of the macroscopic specimen.
THE determination of the cement content of soil‐cement mixtures I. A laboratory method
Authors: Clare K. E. , Sherwood P. T.
Published: July 2010

Soil‐cement is being used increasingly in many aspects of civil engineering, and a method of determining the cement content is required both for research purposes and for checking the quality of soil‐cement construction. A description is given of the development and adoption in the U.S.A. of a method based on the determination of the calcium oxide content of the soil, the cement and the soil‐cement mixture. Adoption of this method in this country is described, and reference is made to the difficulty encountered in using it with soil‐cement made from heavy clay. Various modifications to the method have been investigated, and it was found that the most accurate results could be obtained with clay‐cement mixtures only when the acid extract containing the calcium was separated from the mixture by centrifuging.

Reference is made to a possible method of measuring the cement content of the soil‐cement by estimating the sulphate content which arises from the calcium sulphate contained in normal Portland cement. This method might be preferable for cement‐stabilized soil containing a large proportion of calcium carbonate but substantially free from sulphate.
Pre‐ignition reactions of some combustible substances with solid oxidants
Authors: Patai Saul , Hoffmann E.
Published: July 2010

Mixtures of solid inorganic oxidants (potassium chlorate, perchlorate and nitrate) with various combustible substances (carbon black, paraffin wax, starch and asphalt), when heated at relatively low temperatures, undergo an exothermal pre‐ignition reaction. This process, which is heterogeneous and in some cases a genuine solid‐solid reaction, elevates the temperature of the sample until ignition takes place. The plotting the natural logarithms of the time needed to the ignition point at various initiation temperatures, against 1/T°K. results in straight lines, permitting the evaluation of the critical increment of the Arrhenius equation.
Physico‐chemical studies on dusts. II. Nature and regeneration of the high‐solubility layer on silicious dusts
Authors: Clelland D. W. , Ritchie P. D.
Published: July 2010

It is shown that the high‐solubility layer previously demonstrated (Clelland, Cumming & Ritchie, 1951) on silicious dust‐particle surfaces is not a surface layer of hydrated silica; and evidence is adduced that it is a vitreous silica layer of the Beilby type, formed during the production of the dust by crushing and grinding. An important part of the evidence is the demonstration that prolonged grinding of quartz leads to a reduction in density. This reduction is attributed to partial conversion of the dust particles to vitreous silica: no conversion to other crystalline modifications of silica could be detected. Further, when the high‐solubility layer has been removed from silicious dust particles by solvents, it can be regenerated by a purely mechanical polishing process. The regenerated layer yields silica into aqueous media very largely in colloidal form.
The influence of formamide on the bactericidal action of certain substances against bacterium aerogenes
Authors: Cooper E. A. , Goddard A. E.
Published: July 2010

Aqueous formamide (20%) was found to exert a specific effect on the germicidal power of formic and acetic acids and also of ammonium hydroxide: bactericidal action against Bacr. aerogenes was increased six‐ to twelve‐fold. Certain other disinfecting substances were affected by formamide to a much less extent, e.g. phenols, isopropyl alcohol, acetone, oxalic acid, lactic acid, and various esters, while o‐chlorophenol and trichloracetic acid were actually diminished in germicidal activity. Possible explanations for the observed results are discussed.
The correlation of slot‐opening with flow rate for air bubbling into water
Authors: Cross C. A. , Ryder H.
Published: July 2010

When air flows through a slot in a vertical diaphragm into a tank full of water, the level on the air‐inlet side is depressed below the apex of the slot. This depression, defined as the slot‐opening, has been correlated with the air rate. Some 300 determinations have been made at air rates between 0·01 and 800 cu. ft. per min. for one rectangular and one triangular slot. A few further measurements have been made with slots of varied dimensions.

All these measurements are shown to fit with the simple hydrodynamic theory (Rogers & Thiele, 1934) when this is modified to take account of surface tension effects. The new theory requires that below a critical air rate the slot opening should be determined by surface tension effects alone, whereas above this rate the original hydrodynamic equations would apply. The values now found for the constants of these equations are significantly different from those proposed by the previous workers. In particular, the exponent of h (the slot opening) now corresponds with the theoretical values to within the limits of experimental accuracy. The larger values obtained in the earlier work (Roger & Thiele, 1934: Spells & Bakowski, 1950) were probably due to the inclusion of measurements below the critical rate.
The resistance of fire‐fighting foams to destruction by radiant heat
Authors: French R. J.
Published: July 2010

This note describes experiments that have been carried out to determine an index of the resistance of fire‐fighting foams to radiant heat and the development of an apparatus for this purpose. Results are given of experiments performed to find the manner in which this property is influenced by the intensity of the radiation and by the expansion factor and ultimate shear strength of the foam. It is shown that maximum resistance to radiant heat is obtained from a foam of low expansion and high shear strength and that the heat‐resistance index depends on the water content of the foam over the normal range of expansion factors.
Large‐scale filtration and purification of air supplies (with special reference to the electrostatic precipitator)
Authors: Munden D. L.
Published: July 2010

A description is given of the construction and principles of operation of the Precipitron and miniature Cottrell‐type electrostatic precipitators. Measurements have been made of the efficiency of these two types of precipitator in removing chemical dust from the air. Details are given of the experimental method and the efficiency values are compared with those obtained for a number of commercial dust‐filters tested under similar conditions.
Ultra‐violet irradiation of air supplies (with special reference to ultra‐violet intensity measurements)
Authors: Mellors H.
Published: July 2010

Methods of measuring bactericidal ultra‐violet intensity are outlined and details are given of a portable measuring instrument. Ultra‐violet irradiation of controlled air supplies is discussed and results are quoted for its effectiveness in the killing of different bacteria in an experimental air duct.
The prevention of corrosion in packaging. III. Vapour‐phase inhibitors
Authors: Stroud E. G. , Vernon W. H. J.
Published: July 2010

Of many compounds examined in vapour form in moisture‐laden air, a number will, in varying degrees, confer protection upon ferrous and some non‐ferrous metals when contained in the same enclosed space. Certain esters (e.g. n‐ and iso‐propyl benzoates, n‐butyl benzoates and methyl cinnamate) afford good protection to steel. Complete inhibition of the corrosion of steel and cast iron may be effected in moist air, even when heavily contaminated with sulphur dioxide, by certain amine carbonates, e.g. cyclohexylamine carbonate. These compounds also possess, in marked degree, the property of arresting the further corrosion of iron and steel surfaces that have already become rusted by exposure to moist polluted air.
A solvent method for the recovery of tar binder from road materials
Authors: Green E. H.
Published: July 2010

The paper describes a solvent method for the recovery of tar from road‐surfacing mixtures. The tar oils and tar resins are extracted from a sample of the road material using carbon disulphide. The fraction of the tar insoluble in this solvent, but soluble in pyridine, is recovered from an identical sample of the road material by extracting with pyridine and concentrating the solution, from which the fraction is precipitated by the addition of carbon disulphide. This material is added to the solution of oils and resins together with the required quantity of pyridine‐insoluble material (prepared beforehand from any suitable tar) and the carbon disulphide is removed by distillation. During this period the precipitated fractions redisperse in the tar oils. The method will recover the tar binder from any road‐surfacing mixture, either freshly mixed or after it has been on the road several years.

A small‐scale distillation test is described which is suitable for identifying the recovered tar in accordance with the requirements of B.S. 76.
The preparation of 1‐chloro‐2: 6‐dinitrobenzene
Authors: Gunstone F. D. , Tucker S. Horwood
Published: July 2010

1‐Chloro‐2: 6‐dinitrobenzene (4‐chloro‐3: 5‐dinitrobenzene) has been prepared by the following route: chlorobenzene → potassium 4‐chloro‐3: 5‐dinitrobenzenesulphonate (I) → potassium 4‐amino2 3: 5‐dinitrobenzenesulphonate (II) → 2: 6‐dinitroaniline (III) → 1‐chloro‐2: 6‐dinitrobenzene (IV).
Diffusion coefficients of ethanol in aqueous solutions
Authors: Smith I. E. , Storrow J. Anderson
Published: July 2010

Diffusion coefficients of ethanol in various ethanol–water solutions have been measured at temperatures up to 72.5°. At each temperature the product of diffusion coefficient and viscosity passes through a maximum at 8 mol.‐% ethanol and through a minimum at 32–37 mol.‐% ethanol with increasing concentration. From extrapolated values the variation of diffusion coefficient with composition at normal boiling point has been found.
Studies in coal‐tar bases. V. contaminants of pyridine
Authors: Coulson E. A. , Ditcham J. B.
Published: July 2010

Commercial samples of pyridine derived from coal tar show a variability in the ease with which they are catalytically hydrogenated that can be correlated with the amount of sulphur‐containing impurities. The non‐basic contaminants were separated from two typical samples of pyridine by passing steam through acidified aqueous solutions. From the first, which was a refined sample, there was obtained a small amount of o‐xylene: the second, a cruder technical grade, furnished an authenticated specimen of tetrahydrothiophen (thiophan), an individual which was thus recognized for the first time as a coal‐tar constituent. It is not difficult to reduce the sulphur content of a crude pyridine from about 0·022% by weight to less than 0·001% by the process described. Alternatively, if the sample is boiled with 1·5% by weight of potassium permanganate and redistilled, the sulphur content is reduced to about 0·0025%.
Tristrontium silicate—a new compound
Authors: Nurse R. W.
Published: July 2010

Tristrontium silicate, 3SrO,SiO2, was not discovered by previous investigators of the system SrO‐SiO2. The preparation of the new compound is described and optical properties and X‐ray spacings are given. A comparison is made between 3SrO,SiO2 and 3CaO,SiO2, the principal cementing compound in Portland cement. It is shown that the strontium compound has not the property of hardening under water, but the possibility remains that hardening may take place in sulphate solutions, and that cements in which strontium is wholly or partly substituted for calcium may be of value in resisting attack by sea‐water or soil sulphates.
The physical toxicity of chemicals. II. Factors affecting physical toxicity in aqueous solutions
Authors: McGowan J. C.
Published: July 2010

Evidence has been brought forward to show that a large number of simple organic compounds produce toxic symptoms in living organisms when they reach a definite concentration in some biophase. If this is so, for non‐associated compounds which do not participate in hydrogen‐bonding the equation — log10Ct = – log10C′ + k[P] is suggested by considerations of solubility. Here, Ct and C′ are the toxic concentrations in water and in the biophase respectively (g.‐mol./1.); [P] is the parachor (c.c.) and k is a constant. This equation was found to hold and examples are given. The constant k has been found to have the value o·012 and C′ is, of course, constant for any one manifestation of toxicity. Corrections can be applied for the presence in the molecules of the toxic compounds of groupings giving rise to association and hydrogen bonding.

The equation is useful for the prediction of toxicities of compounds which would be expected to be physically toxic and for the classification of data on toxicities of aqueous solutions.
The freezing and melting of some sulphur chloirdes
Authors: Whiting G. H.
Published: July 2010

Freezing and melting curves were obtained for pure sulphur dichloride and pure sulphur monochloride, and for mixtures of the two. Because the mixtures contained very little free chlorine, the usual deposition of higher chlorides did not obscure the phase behaviour, which showed that the following compounds were stable at low temperatures: SCl2, freezing and melting at 151° K.; S2Cl2, freezing and melting at 191° K.; and an intermediate compound, probably S2Cl3, freezing and melting at 145°k.

No compound corresponding to S3Cl4 was indicated; all mixtures containing from 20% to 50% of sulphur dichloride showed a rapid fall in temperature during freezing.

The phenomena associated with the freezings are described; and evidence for the formation and persistence of the intermediate compound at room temperature is discussed.
Sulphur in oil shale or torbanite
Authors: Mapstone Geo. E. , Nartsissov B.
Published: July 2010

Mott's rapid method for the determination of sulphate and pyritic sulphur in coal can be applied to oil shale or torbanite, the pyrites content being calculated from the iron extracted. The organic sulphur is best calculated by subtracting the pyritic sulphur from the total sulphur content of the hydrochloric acid‐extracted material as determined by the quartz‐tube method [I.P.63/42(T), 1949].

On the pyrolysis of the torbanite approximately only I% of added pyritic sulphur appears as organic sulphur in the oil. Similarly the addition of calcium carbonate had no effect and calcium hydroxide had only a slight effect on the organic sulphur content of the oil. None of these materials affected the oil yield significantly.
A note on the correlation of flooding rates for packed gas‐liquid columns
Authors: Dell F. R. , Pratt H. R. C.
Published: July 2010

The following equation, which is derived from an expression previously obtained for liquid‐liquid extraction columns by Dell & Pratt (1951), and which is basically similar to the equation of Bertetti (1942), is proposed for the correlation of flooding rates for packed absorption and distillation columns:
magnified image

This equation can be reduced to a form resembling the graphical correlation used by Sherwood, Shipley & Holloway (1938). A comparison with the available experimental data shows that agreement is good up to a critical value of the group on the right, beyond which the exponent changes sharply to to − 0·20. Derived values of the constants C2 are given for four types of packing, and the applications and limitations of the equation are discussed.