bluuebunny/crossref_metadata_2025 huggingface dataset:
Composition and pozzolanic properties of pulverised fuel ashes. II. Pozzolanic properties of fly ashes, as determined by crushing strength tests on lime mortars
Authors: Thorne D. J. , Watt J. D.
Published: July 2010

The pozzolanic activities of 14 representative British fly ashes have been compared by determining the crushing strengths of their lime mortars cured for periods of 7–730 days. The mortars differed considerably both in the crushing strengths attained and in the rates at which these strengths were developed. The relations between the crushing strengths and the carbon content, glass content, silica and alumina content, density, and specific surface of the ashes have been examined, as such factors have been suggested in the literature as parameters of pozzolanic activity. For short periods of cure, none of these factors was found to correlate closely with crushing strength; the best correlation was that given by the specific surface of the ashes, as determined from the particle size analysis. For long periods of cure, the best correlation was given by the SiO2 or the (SiO2 + Al2O3) content of the ashes. The activity of an ash was found to reside in its siliceous particles and was determined by their particle size characteristics. The chemical compositions of these particles lay within a fairly narrow range and differences in composition within this range were found to have no significant influence on activity.
Batch and continuous ion‐flotation of hexavalent chromium
Authors: Grieves R. B. , Schwartz S. M.
Published: July 2010

An experimental investigation is presented of the flotation of dichromate ion using a cationic surfactant, ethylhexadecyldimethylammonium (EHDA) bromide. Dichromate ion forms a colloidal complex with EHDA ion in a molar ratio of 1 : 2, which may be efficiently floated from solution and concentrated in a stable foam produced by excess surfactant. Batch experiments with feed solutions containing 5–100 mg/l of dichromate ion produced residual dichromate concentrations ranging from 0.004 to 0.198 of that of the feed, depending upon the concentration of surfactant in the feed. The effects of pH and of possible interfering anions were determined. Continuous experiments indicated the reduction of dichromate from 50 to 15 mg/l, producing a foam stream containing 450 mg/l of dichromate. The influence of retention time is discussed.
Evaluation of low‐temperature coal tars by a rapid, detailed assay based on chromatography
Authors: Karrjun C. , Comberiati J. R. , McCaskill K. B. , Estep Patricia A.
Published: July 2010

A rapid, detailed assay, based largely on both liquid and gas chromatography, was developed for low‐temperature coal tars. With the use of this assay, the pounds per ton of coal of various compounds of commercial interest could be determined, thus supplying the information needed for an economic evaluation of the tars and the carbonisation processes. The amounts of about 100 individual compounds of several classes were involved, including light oil components, tar acids and bases, and neutral‐oil components such as naphthalenes and straight‐chain paraffins and olefins, and the total amounts of these classes in the entire tar. The results for six different tars from the same coal were chosen as examples.
The composition and pozzolanic properties of pulverised fuel ashes
Authors: Watt J. D. , Thorne D. J.
Published: July 2010

The pozzolanic activities of the fly ashes and other materials examined in previous papers1,2 have been determined by two chemical methods based on estimating the amount of acid‐soluble material that is produced when a pozzolan reacts with lime. The conclusions reached from these results, on the relative importance of the factors that determine the activity of an ash, agree with those previously based on the crushing strengths of fly ash mortars, as already presented. There was a close relation between the amount of chemical reaction taking place in a mortar and the strength it developed, but short‐term chemical assessments showed no relation to long‐term crushing strengths. It was concluded that chemical methods were unlikely to have any practical value for predicting the long‐term strength of a mortar in the field.
The electrical resistance of sodium aluminate solutions
Authors: Glastonbury J. R.
Published: July 2010

Specific resistance data for sodium aluminate solutions at 25° have been obtained. The equation: p = 6.353 + 3.466 R‐5.0185 S × 10−2 + (1.517 + 1.154 R)S2 × 10−4 where p = specific resistance (ohm‐cm) S = Na2O concentration (g/l) R = mass ratio Al2O3/Na2O expresses the effect of sodium hydroxide and alumina concentrations on the specific resistance. The effects of: (a) presence of carbonate and (b) temperature are also discussed. In association with density measurements, specific resistance provides a rapid and continuous means of determining the composition of sodium aluminate solutions.
Foam separation: The principles governing surfactant transfer in a continuous foam column
Authors: Newson I. H.
Published: July 2010

Surface‐active agents have been removed from solution by foaming in a continuous flow foam column and the results have been analysed in terms of a mass balance and the surface adsorption equilibrium. The analysis permits the prediction of column performance at other operating conditions.

The analysis was tested during foaming experiments with the surfactant sodium dodecylbenzenesul‐phonate in dilute aqueous solution. The maximum value of the surfactant surface adsorption determined by experiment agreed well with predictions from surface tension measurements. It is possible also to predict the effect of the operating variables, such as feed‐liquid and air‐flow rates, and of feed concentration on the quantitative removal of surfactant. The predictions were confirmed by experiment.

The foam column as operated for these experiments with feed injection into the liquid pool of the column (‘pool feed’) was shown to represent a single equilibrium stage and the derived working equation to be that of an operating line. It follows that there is greater advantage to be gained from multi‐stage operation if this can be simply accomplished. Column operation where feed liquid is injected into the foam phase, so‐called ‘foam feed’, can provide a multi‐stage system.
Extraction of uranium (VI) and thorium from hydrochloric acid solutions by tri‐n‐butyl phosphate
Authors: Sato Taichi
Published: July 2010

The partitions of uranium (vi) and thorium between hydrochloric acid solutions and solutions of tri‐n‐butyl phosphate (TBP) in benzene or kerosene have been investigated at different concentrations of hydrochloric acid and solvent, and at different temperatures. An infra‐red spectral study has also been made of the organic solutions obtained in the extraction of uranium. The effect of organic solvent on the extractions has also been examined.
Dimensional stabilisation of wood
Authors: Gibson E. J. , Laidlaw R. A. , Smith G. A.
Published: July 2010

The dimensional stabilisation of timber by impregnation with methyl methacrylate and polymerisation by γ‐radiation has been studied. Treatment with pure monomer yielded a product wherein the voids in the wood were filled with homopolymer, but introduction of the monomer in a solvent which swells wood enabled the methacrylate to penetrate the cell walls, giving a product which was not entirely extractable with polymer solvents such as chloroform. Both methods gave products with improved strength and stability, but it was shown that, at low polymer loadings, use of a swelling solvent for impregnation caused some breakdown of the more ordered regions of the cell wall, and could lead to swelling greater than that of the untreated wood.

There is some evidence to suggest that, if graft copolymerisation is achieved at all under these conditions, it may be to the lignin rather than to the carbohydrate portions of the wood.
Aeration mass‐transfer related to reynolds number
Authors: Iberall A. S. , Cardon S. Z.
Published: July 2010

A study of aeration rate data for streams and laboratory channels shows that the aeration rate can be correlated with Reynolds number and Schmidt number by a suitable dimensionless mass‐transfer parameter which varies only slowly over a wide range of Reynolds number. This parameter, analogue to similar correlations in the heat‐ and mass‐transfer fields, has two different near‐constant levels, one in the low Reynolds number regime corresponding to molecular diffusivity, and another in the high Reynolds number regime corresponding to eddy diffusivity. The Schmidt number dependence has been found by comparison of gas into water data with vapour into gas data.
The reactivity of calcium sulphate hemihydrate
Authors: Ridge M. J. , Surkevicius H.
Published: July 2010

Studies were made of the effects of temperature, duration of heating and intergranular movement during the dehydration of gypsum in vacuo, on the reactivity of the resultant calcium sulphate hemihydrate. The formation of orthorhombic anhydrite was not associated with a significant increase in reactivity. The results are discussed in terms of variations in the population of seeding nuclei for the growth of gypsum.

The kinetics of the formation of orthorhombic anhydrite from soluble anhydrite formed from gypsum in vacuo are significantly different from those found when soluble anhydrite has been formed by dehydrating calcium sulphate hemihydrate.
The pyrolysis of cellulose and the action of flame‐retardants
Authors: Byrne G. A. , Gardiner D. , Holmes F. H.
Published: July 2010

In further work on the vacuum pyrolysis of cotton cellulose, alone or with flame‐retardants, at temperatures usually near 420°, products have been identified and determined. In the tar, laevoglucosan has been determined by an infra‐red absorption method, and by gas‐liquid chromatography of its trimethylsilyl ether; 5‐(hydroxymethyl)furfural and 1,6‐anhydro‐β‐D‐glucofuranose have been identified and determined similarly by gas‐liquid chromatography. By thin‐layer chromatography of the 2,4‐dinitrophenylhydrazones, 19 carbonyl compounds have been identified in the products from pure cotton; fewer were found from cotton treated with flame‐retardants.

The distribution of boron, nitrogen, phosphorus and chlorine from appropriate flame‐retardants has been determined among the products of pyrolysis of cotton. It is concluded that borax/boric acid, and APO‐THPC, act predominantly in the solid phase; Proban appears to act partly in the vapour phase. Mechanisms of pyrolysis are proposed. In a pure cotton cellulose, 1,2‐anhydroglucoses are regarded as important intermediates.
Studies on desalination by reverse osmosis: II. The relation between the fabrication procedure and the structure of cellulose acetate desalination membranes
Authors: Banks W. , Sharples A.
Published: July 2010

The special structure of Loeb‐type desalination membranes has been considered in relation to the complex casting and immersion procedures by which they are fabricated. The role of each procedure in determining ultimate structure has been elucidated. This has enabled the rigid conditions which previously governed casting to be modified, so that the fabrication can be carried out at ambient temperatures rather than the low temperatures previously employed.
Solvent extraction study of a whole, low‐temperature tar
Authors: Ahmed M. S. A. , Vahrman M.
Published: July 2010

A low‐temperature tar was sub‐divided, entirely by solvent extraction, into the following fractions: crude phenols and bases; hydrocarbons of different types—aliphatic, hydroaromatic and aromatic; and a neutral, oxygen‐containing aromatic fraction. The three hydrocarbon materials and the last‐named were obtained from the neutral tar oil (light petroleum‐soluble) by a series of partition extractions with the solvent pair, furfural/light petroleum, petroleum, using definite ratios of tar/solvents. These four fractions corresponded closely to those previously obtained by adsorption chromatography.
High‐temperature studies in the extraction of beryllium
Authors: Bayliss R. K. , Derry R.
Published: July 2010

The recrystallisation behaviour of melts and glasses derived from beryl ores, flotation concentrates and synthetic oxide mixtures was examined and two new hybrid beryllium aluminium silicate phases were discovered. Beryllium extraction from the various products was correlated with their heterogeneous structure and conditions were established which enabled more than 95% of the beryllium to be extracted from all the ores and concentrates examined.
The reaction of kaolin with fluorides: I. Effect of neutral and acid sodium fluoride solutions
Authors: Semmens B. , Meggy A. B.
Published: July 2010

The reaction between kaolinite and neutral and acid sodium fluoride solutions was investigated at different temperatures and over the acid pH range.

The stoicheiometric replacement of hydroxyls in the kaolinite crystal lattice by fluoride ions, as reported by earlier workers, was not confirmed. The release of hydroxyl ions into solution was due predominantly to the disruption of the kaolinite crystal lattice. In the presence of sodium ions and at pH < 7, sodium fluoro‐silicate and cryolite were found as solid phases. At pH > 7, only cryolite was found as a solid phase. Small, spherical, particles were observed in all cases. These particles were believed to be amorphous silica, formed as an intermediate phase in the disruption process.
The reaction of kaolin with fluorides. II. Effect of aqueous hydrofluoric acid
Authors: Semmens B. , Meggy A. B.
Published: July 2010

The dissolution of kaolinite in aqueous solutions of hydrofluoric acid was investigated at different temperatures and fluoride concentrations. The percentage dissolution of kaolinite was greater than was to be expected from a theoretical consideration of the reaction. The percentage dissolution was less for Na‐kaolinite than for a H‐kaolinite under the same experimental conditions. Two reaction rates were observed. The relative intensities of the 001 and 002 basal reflections decreased with reaction time, temperature and hydrofluoric acid concentration. The decrease was probably due to an amorphous phase. Although kaolinite samples after treatment at the lower temperature showed very little change in their infra‐red absorption spectra, a marked change in the spectra was observed at the higher temperature. The disruption of the kaolinite crystal lattice is believed to be due to the preferential extraction of aluminium from the lattice leaving an intermediate silica phase, which dissolves to form fluorosilicic acid.
The surface tension of coal tar distillates
Authors: Briggs D. K. H. , Speak K. E.
Published: July 2010

The surface tensions of coal tar distillates have been measured along with their densities and average boiling points. As in the case of most organic liquids, the surface tension for any one oil varies as the fourth power of the density when temperature is altered. The value of the surface tension y20 of an oil at 20° in dynes/cm is given by the following equation:.

y20 = 93.8 d20‐0.0496 tb‐47.5 where d20 is the density of the oil in g/cm3 at 20° and tb is the average boiling point in °c.

A method for calculation of y at other temperatures is suggested.
Extraction of uranium (VI) from hydrochloric acid solutions by long‐chain aliphatic amines
Authors: Sato Taichi
Published: July 2010

The partition of uranium (vi) between hydrochloric acid solutions and organic solutions of long‐chain aliphatic amines has been investigated at different concentrations of hydrochloric acid, solvent and aqueous uranium, and at different temperatures. The effects of amine structure and of organic solvent and the mechanism of uranium extraction are discussed on the basis of the results obtained. From infra‐red spectral measurements it is postulated that a chloro complex of uranium (vi) is formed in the extraction of uranium (vi) from hydrochloric acid solution by tri‐n‐dodecylamine in benzene.
The early hydration of tricalcium silicate and β‐dicalcium silicate in neat portland cement pastes
Authors: Hurley F. R. , Angstadt R. L.
Published: July 2010

Quantitative X‐ray diffraction analysis was used to study the early hydration of the tricalcium silicate and β‐dicalcium silicate phases in neat Portland cement pastes. There is an initial ‘dormant’ period during which these phases hydrate only very slowly. In the case of the Ca3SiO5 phase in the cement used, this ‘dormant’ period lasts 3–4 hours. Of the Ca3SiO5 originally present 5% hydrated in 5 h; 22% in 10 h; 34% in 15 h; 45% in 24 h; and 63% in 72 h. No conclusive evidence of any β‐dicalcium silicate hydration during the seventy‐two hour period investigated was found.
Activation of emulsion polymerisation by a hydrocarbon‐soluble vanadium compound
Authors: Waterman J. A.
Published: July 2010

A hydrocarbon‐soluble vanadium‐activated system consisting essentially of vanadyl di‐isopropylsalicylate and phenylcyclohexane hydroperoxide proved to be an active initiation system for the low‐temperature emulsion copolymerisation of butadiene and styrene. Mercaptans were observed to have a promoting as well as a modifying effect in this system. Whereas complete omission of the mercaptan resulted in a very low conversion, high conversions were obtained with as little as 0‐01 g per 100 g of monomer. No initiation took place when the polymerisation was carried out in a homogeneous phase, e.g. in benzene.
The preparation of lead dioxide for X‐ray diffraction studies
Authors: Bagshaw N. E. , Clarke R. L. , Halliwell B.
Published: July 2010

Lead dioxide is the active constituent of the positive electrode in the lead‐acid battery. Both the α‐ and the β‐modifications are present in battery electrodes and X‐ray diffraction techniques must be used to differentiate the role of each in the reactions occurring in the lead‐acid battery system. Standard samples of the two forms of lead dioxide are necessary for this purpose, and samples prepared by various methods have been studied. Powder patterns of electrodeposited samples of both α‐ and β‐lead dioxide showed preferred orientation effects which could not be removed by grinding. Chemically prepared samples of the two forms were well crystallised and did not produce preferred orientation effects. α‐Lead dioxide prepared by the oxidation of yellow lead monoxide (using a fused mixture of sodium chlorate and sodium nitrate) and β‐lead dioxide prepared by hydrolysis of lead tetra‐acetate were chosen as standard samples for X‐ray studies and their diffraction patterns have been recorded. A mechanism of nucleation has been proposed for the formation of α‐lead dioxide in alkaline and neutral media, and the β‐form in acid media.
Hydrothermal precipitation of uranium dioxide from uranyl nitrate solutions
Authors: Robins R. G.
Published: July 2010

Uranium dioxide of high purity has been precipitated directly from acid uranyl nitrate solutions by hydrogen in a stainless steel autoclave at temperatures in the region of 300° and pressures up to 40 atmospheres. The thermodynamics of the reaction are discussed.
Ion‐exchangers containing phosphorus in their functional group. Sorption of cations from nitric acid solutions and from acetate medium
Authors: Marhol Milan
Published: July 2010

A selective sorption of uranyl ions on organic ion‐exchangers containing ‐OPO(OH)2 or ‐PO(OH)2 groups from dilute nitric acid solution and the affinity of various divalent cations to these groups in acetate medium were studied. Practical applications of these ion exchangers for the separation are described.
Influence of stabilisers on bitumen durability
Authors: Martin K. G.
Published: July 2010

Combinations of eight asphaltic bitumens and twelve selected antioxidants have been examined for susceptibility to oxidative hardening. Bitumen films 40μ thick were oxidised at 300 psi in the dark and by simple exposure to solar radiation. Subsequent changes were determined with the sliding plate microviscometer. Many combinations exhibited improved stability and their behaviour is discussed in relation to current theory of autoxidation of hydrocarbons.
Reaction of ketohexoses with acid in certain non‐aqueous sugar solvents
Authors: Moye C. J. , Goldsack R. J.
Published: July 2010

Ketohexoses or potential ketohexoses react rapidly with acids at high temperatures in non‐aqueous solvents (containing the grouping R·O·C·C·OH in their structures1) to produce 5‐hydroxymethyl‐furfural (HMF). HMF reacts further to give the solvent ether (e.g., II, III or IV) in a slow reaction. Several of these ethers have been reduced partially to mono‐ethers of 2,5‐di(hydroxymethyl)furan (V, VI or VII) and fully to mono‐ethers of 2,5‐di(hydroxymethyl)tetrahydrofuran (VIII, IX or X).
The reactions occurring during the refining of benzene with concentrated sulphuric acid
Authors: Roberts D. , Gore P. H.
Published: July 2010

It is shown that the two‐phase system, benzene/sulphuric acid, follows a different pattern of sulphonation of benzene to that observed for homogeneous systems by earlier workers. This is ascribed to the diluting effect on the sulphuric acid of the sulphonation reaction, and the establishment of equilibrium conditions.

Important results have been obtained on the loss of benzene associated with removal of thiophen in the benzene refining process. The results presented show that effective loss of benzene can be reduced in the presence of hexene, provided no cyclohexene is present. It is also shown that loss of benzene can be minimised by the employment of the lowest practicable reaction temperature.
Spray tower performance. Extraction of propionic acid from dispersed toluene to water: Effect of number of nozzles and flow rates on mass‐transfer coefficient
Authors: Subbarao B. V. , Venkatarao C.
Published: July 2010

Experimental investigations were carried out for extracting propionic acid from dispersed toluene to water in a spray extraction tower to ascertain the effect of number of nozzles and flow rates on mass‐transfer coefficient. The effect of the number of nozzles on the mass‐transfer coefficient was negligible when the number of nozzles was increased from 12 to 37. Mass‐transfer coefficients increased with either of the flow rates at a constant value of the other.
Differences in molecular species present in aqueous potassium silicate solutions and their efficiency as adhesives for phosphors on glass
Authors: Walker A. J. , Whitehead N.
Published: July 2010

Potassium silicate liquors of very similar composition (SiO2/K2O ratios approximately 3.mD4:1) prepared from Aerosil, acid‐washed silica‐gel fines or potash glass have been examined by (a) light scattering, (b) reaction with molybdate and (c) use of the metachromatic effect with pinacyanol chloride. Definite differences between the molecular weights of the samples were obtained from the light‐scattering results. These differences correlated well with the interaction observed between the silicate and pinacyanol chloride and the wet adhesion shown by the silicate; the samples containing more of the very high molecular weight polysilicate showing poor adhesion. The actual molecular weights have been estimated, but the determination of these involved dilutions of the silicate liquors and, over the range of dilution used, the reaction with molybdate showed that rapid depolymerisation of the silicate polyanion occurred on dilution. The results indicate that liquors prepared from potash glass contain more high‐molecular‐weight material than liquors prepared from silica gel or Aerosil.
A low pressure vapour‐liquid equilibrium still
Authors: Taylor K. H. , Ellis S. R. M. , Hands C. H. G.
Published: July 2010

An equilibrium still, based on the Jones still has been developed to determine vapour‐liquid equilibrium data at low pressures. Results are presented for the system 2‐methylnaphthalene‐n‐decanol at 1.5 mm and 3.0 mm Hg abs. This system can be used for testing vacuum distillation columns operating at low pressures.
The recovery of uranium from zircaloy‐uranium alloy
Authors: Jenkins I. L. , Keen N. J. , Robson J.
Published: July 2010

A process has been studied in which Zircaloy‐uranium alloy is dissolved in a mixture of hydrofluoric acid and potassium fluoride. The uranium can be precipitated with an efficiency of 99.9%, as a complex potassium uranium fluoride, together with some of the zirconium in analogous complexes. These precipitates, when dissolved in a mixture of aluminium nitrate and nitric acid, give stable solutions from which uranium may be recovered by solvent extraction with an overall efficiency of 99.7%.
Film evaporation of drops
Authors: King P. J. , Scully D. B.
Published: July 2010

Experiments have been carried out on the film evaporation of drops from a heated surface, and time‐weight curves for various liquids for different hot surface temperatures have been obtained. It is shown that the experimental results may be correlated in terms of heat conduction through the supporting vapour film.
The relationship between lattice parameter and chemical constitution of spinel oxide phases formed during the oxidation of austenitic steels
Authors: Francis J. M.
Published: July 2010

A detailed classification of spinels in the Fe/Cr/Ni/O system is described. These phases are important constituents of the surface oxide formed during the high‐temperature oxidation of austenitic steels. The effect of minor alloying elements in the steel on the spinel structure is also included.

It is shown that spinels produced on stainless steels cannot in general be unambiguously interpreted by lattice parameters alone; some additional form of chemical analysis is required before the identity of any spinel phase can be specified with certainty.
Effect of manganese dioxide on the thermal decomposition of ammonium perchlorate
Authors: Kishore Kaushal , Verneker Vencatesh R. Pai , Sunitha Munipalli R.
Published: July 2010

Thermal decomposition of powdered ammonium perchlorate, catalysed by manganese dioxide (MnO2), has been studied in the low concentration ranges of the catalyst. MnO2 sensitises the thermal decomposition of ammonium perchlorate. The activation energy estimations of catalysed ammonium perchlorate show that the value is about 30 kcal/mol throughout the low and the high temperature regions whereas uncatalysed ammonium perchlorate gives two activation energies, 20 kcal/mol in the low temperature region (280–320°C) and 60 kcal/mol in the higher temperature region (350–390°C). This behaviour has been explained on the basis of an electron transfer process. The effectiveness of MnO2 in the thermal decomposition further increases on pre‐heating the sample at 50°C for two weeks; manganese ions enter the ammonium perchlorate lattice during the process of pre‐heating.
Alkylation of benzene to propyl and isopropyl benzenes over ZSM5 zeolites
Authors: Chandavar Kalpana H. , Hegde Sooryakant G. , Kulkarni Suneeta B. , Ratnasamy Paul
Published: July 2010

The alkylation of benzene with isopropanol over pure and modified (with phosphorous and boron) HZSM5 zeolites is reported. Isopropylbenzene is the primary reaction product. In the presence of strong acid sites, it isomerises to n‐propylbenzenes. The isomerisation reaction is also facilitated by the shape‐selective nature of the ZSM5 zeolite. Poisoning of the strong acid sites with bases such as pyridine enhances the selectivity to isopropyl benzene.
Purification and utilisation of iron‐contaminated sulphuric acid
Authors: Hutchings Graham J. , Fraser‐Bell Graeme
Published: July 2010

The purification and utilisation of sulphuric acid contaminated with iron is discussed in detail. It is found that treatment of the acid with FeSO4·7H2O resulted in complete removal of the iron impurity. Partial removal of the iron was affected by treatment with acetone and ammonium sulphate. Treatment with activated carbon was not found to be effective. The study shows that the contaminated sulphuric acid can be utilised to prepare sodium sulphate and calcium sulphate.
Neue Arten aus Raubmilbengattungen der Gamasina LEACH (Acarina, Parasitiformes) mit Indikationen zum Entwicklungsalter
Authors: Karg Wolfgang
Published: July 2010

From New Caledonia 30 new species are described and documented by differential diagnoses (as determination keys mostly) and by figures. The species belong to 16 different genera. The zoogeography of the genera is analysed and related to palaegeographical events to obtain indications of their origin and of the former conditions of ecosystems. Obviously above all the palaeogeographic events of the Jurassic have caused the origin of groups of genera.
Transcobalamin deficiency caused by compound heterozygosity for two novel mutations in the TCN2 gene: a study of two affected siblings, their brother, and their parents
Authors: Nissen Peter H. , Nordwall Maria , Hoffmann‐Lücke Elke , Sorensen Boe S. , Nexo Ebba
Published: July 2010

Transcobalamin (TC) deficiency (OMIM# 275350) is a rare, autosomal recessive disorder that presents in early infancy with a broad spectrum of symptoms, including failure to thrive, megaloblastic anemia, immunological deficiency, and neurological symptoms. Here we report a study of a family (parents and three children) with two children suffering from TC deficiency caused by two different mutations in the TCN2 gene. Initially, molecular genetic analysis of genomic DNA revealed a heterozygous mutation in the +1 position of exon 7 (c.1106+1 G > A) in the father and all three children. Bioinformatic analysis indicates that this mutation causes exon skipping, and further experiments supported this hypothesis and suggested that the mutant allele undergoes nonsense‐mediated messenger RNA (mRNA) decay. We did not identify further mutations in genomic DNA that could explain TC deficiency in the two children. However, further efforts using complementary DNA (cDNA) derived from RNA from blood leukocytes identified a large deletion removing the entire exon 8, resulting in a frameshift and a premature stop codon (p.E371fsX372) in the mother and the two affected children. Our data indicate that if exon‐by‐exon DNA sequencing of genomic DNA does not uncover mutations corresponding to the phenotype, a systematic search for other mutations should be initiated by sequencing cDNA or using semiquantitative methods to detect large deletions in TCN2.
Biodegradable Photo‐Crosslinked Thin Polymer Networks Based on Vegetable Oil Hydroxy Fatty Acids
Authors: Kim Han‐Min , Kim Hak‐Ryul , Hou Ching T. , Kim Beom Soo
Published: July 2010

Novel crosslinked thin polymer networks based on vegetable oil hydroxy fatty acids (HFAs) were prepared by UV photopolymerization and their mechanical properties were evaluated. Two raw materials, castor oil and 7,10‐dihydroxy‐8(E)‐octadecenoic acid (DOD) were used as sources of mono‐ and di‐HFAs, respectively. Poly(ethylene glycol) (PEG) diacrylate and poly(ε‐caprolactone) diacrylate were synthesized and used as crosslinking agents to form crosslinked polymer networks by UV‐initiated free‐radical polymerization with acrylated castor oil or acrylated DOD. The synthesis of acrylate derivatives was confirmed using FT‐IR and 1H‐NMR spectroscopic techniques. The composition of the reaction mixture and the type/length of crosslinking agent were changed to obtain crosslinked polymer networks with various mechanical properties. For polymers prepared from high molecular weight (20,000) PEG, a 58–60% of the initial weights decreased in 35 days in phosphate buffer solution (pH 7.2) containing lipase enzyme. These potentially biodegradable polymers based on vegetable oil HFAs can be used as eco‐friendly materials for various applications to replace the existing petroleum‐based polymers currently used.
Adolescents’ beliefs about sources of help for ADHD and depression
Authors: Swords Lorraine , Hennessy Eilis , Heary Caroline
Published: July 2010

The peer group begins to become a source of support during late childhood and adolescence making it important to understand what type of help young people might suggest to a friend with an emotional or behavioral problem. Three groups of young people participated in the study with average ages of 12 (N = 107), 14 (N = 153) and 16 years (N = 133). All participants were presented with vignettes describing fictional peers, two of whom had symptoms of clinical problems (ADHD and depression) and a third comparison peer without symptoms. Results indicate that all participants distinguished between clinical and comparison vignette characters and they believed that the characters with clinical symptoms needed help. The 16‐year‐olds were more likely to differentiate between the two clinical vignettes in terms of the type of help suggested. The results are discussed in light of previous research on adolescents’ understanding of sources of help for mental health problems.
Recession or Mutation? Post-Recovery Appeal of Major Consumer Brands
Authors: Tixier Daniel
Published: July 2010

This article questions whether once the world recovers from the Global Financial Crisis of the late 00's, major Fast Moving Consumer Goods will return to the same playfield as before. If the GFC is essentially riding a recession, marketers and retailers could expect their old successful approaches to the consumers to work again well. If the GFC is essentially revealing a hidden and ripening mutation of the socio-economic environment which once having come out will not go back in hiding, then the marketing world of FMCGs will have durably changed and marketers, both on the manufacturing and retailing fronts, will need to deeply change their approaches to the consumers’ pocketbooks. The article contends that a mutation is indeed what the world is currently living through.
Influence of training in the use and generation of evidence on episiotomy practice and perineal trauma
Authors: Ho Jacqueline J. , Pattanittum Porjai , Japaraj Robert P. , Turner Tari , Swadpanich Ussanee , Crowther Caroline A.
Published: July 2010

Objective

To examine episiotomy practices before and after a multi‐component intervention designed to support the use and generation of research evidence in maternal and neonatal health care.

Methods

Set in 9 centers across 4 Southeast Asian countries, a retrospective survey was performed for 12 recommended pregnancy/childbirth practices and 13 outcomes of women in each center before and after intervention. Qualitative interviews were conducted to assess staff awareness and experience in evidence‐based practice.

Results

There were significant decreases in the rate of episiotomy, from 64.1% to 60.1% (risk difference [RD] –4.0; 95% confidence interval [CI], –5.8 to –2.2) for all women and from 92.2% to 80.7% (RD –11.5; 95% CI, –13.4 to –9.6) for nulliparous women. Severe trauma decreased from 3.9% to 1.9% (RD –2.0; 95% CI, –2.7 to –1.4) for all women and from 6.7% to 3.0% (RD –3.7; 95% CI, –4.9 to –2.5) for nulliparous women. The frequency of intact perineum increased from 12.4% to 15.6% (RD 3.2; 95% CI, 1.9–4.6) for all women and from 1.7% to 8.0% (RD 6.3; 95% CI, 5.0–7.5) for nulliparous women.

Conclusion

An intervention based on understanding and using the best available evidence can result in significant improvements in care and health outcomes.
Prevention of nausea and vomiting during termination of pregnancy
Authors: Fujii Yoshitaka
Published: July 2010

Background

Postoperative nausea and vomiting (PONV) is common in women undergoing dilatation and curettage under general anesthesia for pregnancy termination, and many studies suggest treating these women prophylactically for PONV.

Objectives

Reviewing the antiemetics used over the past 20 years for this indication and comparing their efficacy.

Search strategy

We performed MEDLINE and EMBASE searches for articles published from January 1980 through June 2009. The search terms were complications, nausea, vomiting, antiemetics, anesthetics, surgery, dilatation, curettage, pregnancy, and women.

Selection criteria

We selected the studies of the antiemetics droperidol, metoclopramide, hydroxyzine, propofol, dexamethasone, ondansetron, and ramosetron when used for the stated indication. When assessing drug efficacy, we compared the antiemetics used at the time the article was written.

Data collection and analysis

We reviewed the selected studies, presented the reported incidence rates of PONV for each drug, and presented and interpreted the P values reported for the different comparisons.

Main results

Although all antiemetics assessed decreased the incidence of PONV, the combination of dexamethasone and droperidol seems to be the most effective in preventing PONV.

Conclusions

All antiemetics used in the last 20 years to prevent PONV are effective (some more than others) in women undergoing dilatation and curettage for pregnancy termination. However, there is a need for benefit and risk analyses of the different treatments.
Patientenmanipulation durch Patienteninformationen
Authors: Mühlhauser Ingrid
Published: July 2010

Einleitung

Irreführende Patienteninformationen sind die Regel. Sie werden systematisch genutzt, um gesundheitsorientierte Maßnahmen umzusetzen. Sie können zu schwerwiegenden Trugschlüssen führen. Irreführung entsteht durch Unvollständigkeit der Information und missverständliche Präsentation von Daten. Den Bürgern fehlt die notwendige kritische Gesundheitsbildung die Botschaften gezielt zu hinterfragen. Die Folgen sind Fehleinschätzungen von Risiken und des Nutzen-Schaden Verhältnisses von Interventionen.
Incidence and Identification of Intrathecal Baclofen Catheter Malfunction
Authors: Dvorak Eric M. , McGuire John R. , Nelson Mary Elizabeth S.
Published: July 2010

Objective

A retrospective chart review was undertaken of cases of intrathecal baclofen (ITB) pump/catheter malfunction and the diagnostic tests performed to identify the problem. An internal review was performed to develop a diagnostic flow chart to have a systematic method for identifying ITB pump and catheter complications.

Design

Retrospective chart review.

Setting

Tertiary care hospital.

Participants

A total of 167 adult patients currently followed in outpatient clinic with intractable spasticity and ITB pump implanted between January 1994 and May 2009.

Interventions

None.

Main Outcome Measures

Catheter malfunction was identified either by anterior/posterior and lateral thoracic/lumbar radiographs, fluoroscopic guided side port access, contrast agent injection followed by CT (fluoro/CT) scan, or indium radionuclide studies.

Results

During the study period, 33 patients had 37 catheter revisions. Radiographs were obtained in all cases; fluoro/CT studies in 22, and indium studies in 6. Four cases had both fluoro/CT and indium studies. A total of 13 cases (35.1%) were diagnosed with radiographs; 9 cases (24.3%) were diagnosed by inability to withdraw cerebral spinal fluid from the side port; 13 cases (35.1%) were diagnosed with fluoro/CT studies; and 2 cases (5.4%) were diagnosed with indium studies. Fluoro/CT studies demonstrated subdural catheter location in 7 cases. A total of 2 of 4 cases with both fluoro/CT and indium studies had normal‐appearing indium scans and an abnormal fluoro/CT study confirming subdural catheter placement.

Conclusions

On the basis of an internal review of the diagnostic studies used to identify patients with suspected ITB pump/catheter malfunction, a troubleshooting flow chart was developed. Timely identification and correction of potential ITB complications could improve the clinical effectiveness of ITB and may reduce unnecessary health‐care costs.
Accuracy of Ultrasound‐Guided versus Unguided Pes Anserinus Bursa Injections
Authors: Finnoff Jonathan T. , Nutz David J. , Henning Philip T. , Hollman John H. , Smith Jay
Published: July 2010

Objective

To compare the accuracy of ultrasound (US)‐guided versus unguided pes anserinus bursa injections in a cadaveric model.

Design

Single blind, prospective study.

Setting

Academic institution procedural skills laboratory.

Participants

Twenty‐four unembalmed, unpaired adult cadaveric lower extremity specimens.

Methods

A single investigator performed 12 US‐guided and 12 unguided pes anserinus bursa injections using colored liquid latex into 24 unembalmed adult cadaveric lower extremity specimens. The order of the injection techniques was randomized. The specimens were subsequently dissected by a co‐investigator blinded to the injection technique used for each injection.

Main Outcome Measures

The injections were graded for accuracy as follows: accurate (all injectate contained within the pes anserinus bursa), accurate with overflow (injectate within the pes anserinus bursa, but also located in adjacent structures), or inaccurate (injectate not within the pes anserinus bursa). The accuracy of the 2 approaches was compared using Pearson χ2 test with Williams' correction for the small sample size (P = .05).

Results

The accuracy rate was 92% (11 of 12 specimens) in the US‐guided condition and 17% (2 of 12 specimens) in the unguided condition. One US‐guided injection was considered accurate with overflow, whereas 4 unguided injections were accurate with overflow. The US‐guided injection technique was significantly more accurate than the unguided technique (Williams‐corrected χ2 = 12.528, P < .01).

Conclusions

Despite its superficial location, unguided pes anserinus bursa injections rarely place the injectate within the pes anserinus bursa, whereas US‐guided pes anserinus bursa injections have a high degree of accuracy. Therefore, clinicians should consider using US‐guidance for diagnostic or therapeutic pes anserinus bursa injections when indicated.
Non-equilibrium effects in capillarity and interfacial area in two-phase flow: dynamic pore-network modelling
Authors: JOEKAR-NIASAR V. , HASSANIZADEH S. M. , DAHLE H. K.
Published: July 2010

Current macroscopic theories of two-phase flow in porous media are based on the extended Darcy's law and an algebraic relationship between capillary pressure and saturation. Both of these equations have been challenged in recent years, primarily based on theoretical works using a thermodynamic approach, which have led to new governing equations for two-phase flow in porous media. In these equations, new terms appear related to the fluid–fluid interfacial area and non-equilibrium capillarity effects. Although there has been a growing number of experimental works aimed at investigating the new equations, a full study of their significance has been difficult as some quantities are hard to measure and experiments are costly and time-consuming. In this regard, pore-scale computational tools can play a valuable role. In this paper, we develop a new dynamic pore-network simulator for two-phase flow in porous media, called DYPOSIT. Using this tool, we investigate macroscopic relationships among average capillary pressure, average phase pressures, saturation and specific interfacial area. We provide evidence that at macroscale, average capillary pressure–saturation–interfacial area points fall on a single surface regardless of flow conditions and fluid properties. We demonstrate that the traditional capillary pressure–saturation relationship is not valid under dynamic conditions, as predicted by the theory. Instead, one has to employ the non-equilibrium capillary theory, according to which the fluids pressure difference is a function of the time rate of saturation change. We study the behaviour of non-equilibrium capillarity coefficient, specific interfacial area, and its production rate versus saturation and viscosity ratio.

A major feature of our pore-network model is a new computational algorithm, which considers capillary diffusion. Pressure field is calculated for each fluid separately, and saturation is computed in a semi-implicit way. This provides more numerical stability, compared with previous models, especially for unfavourable viscosity ratios and small capillary number values.
Turbulent plumes with internal generation of buoyancy by chemical reaction
Authors: CAMPBELL A. N. , CARDOSO S. S. S.
Published: July 2010

Turbulent plumes, which are seen in a wide number of industrial and natural flows, have been extensively studied; however, very little attention has been paid to plumes which have an internal mechanism for changing buoyancy. Such plumes arise in e.g. industrial chimneys, where species can react and change the density of the plume material. These plumes with chemical reaction are the focus of this study. An integral model describing the behaviour of a plume undergoing a second-order chemical reaction between a component in the plume (A) and a component in the surrounding fluid (B), which alters the buoyancy flux, is considered. The behaviour of a reactive plume is shown to depend on four dimensionless groups: the volume and momentum fluxes at the source, the parameter ϵ which indicates the additional buoyancy flux generated by the reaction and γ which is a dimensionless rate of depletion of species B. Additionally, approximate analytical solutions are sought for a reactive plume rising from a point source of buoyancy when species B is in great excess. These analytical results show excellent agreement with numerical simulations. It is also shown that the behaviour of a reactive plume in the far field is equivalent to an inert plume issuing from a virtual source downstream of the real source, and the dependence of the location of the virtual source on ϵ and γ is discussed. The effects of varying the volume flux at the source and the Morton source parameter Γ0 are further investigated by solving the full governing equations numerically. These solutions indicate that ϵ is important in determining the buoyancy generated by the reaction, and the length scale over which this reaction occurs depends on γ when γ > 1. It is also shown that when the dimensionless buoyancy ϵ < − 1, the reaction can cause the plume to collapse.
A fibre-reinforced fluid model of anisotropic plant cell growth
Authors: DYSON R. J. , JENSEN O. E.
Published: July 2010

Many growing plant cells undergo rapid axial elongation with negligible radial expansion. Growth is driven by high internal turgor pressure causing viscous stretching of the cell wall, with embedded cellulose microfibrils providing the wall with strongly anisotropic properties. We present a theoretical model of a growing cell, representing the primary cell wall as a thin axisymmetric fibre-reinforced viscous sheet supported between rigid end plates. Asymptotic reduction of the governing equations, under simple sets of assumptions about the fibre and wall properties, yields variants of the traditional Lockhart equation, which relates the axial cell growth rate to the internal pressure. The model provides insights into the geometric and biomechanical parameters underlying bulk quantities such as wall extensibility, and shows how either dynamical changes in wall material properties or passive fibre reorientation may suppress cell elongation.