bluuebunny/crossref_metadata_2025_split huggingface dataset:
The recovery of the lanthanides from phosphate rock
Authors: Habashi Fathi 
Published: July 2010

AbstractPhosphate rock contains up to 1% lanthanide (rare earths) oxides present in isomorphous substitution for Ca2+. Lanthanum, cerium and neodymium form about 80% of the total. When the rock is leached with H2SO4 the lanthanides are mostly (about 70%) lost in the gypsum residue. When the rock is leached with HNO3 or HC1, more than 80% can be recovered without interference with fertiliser production. At an annual production of 130 million tons, phosphate rock represents an important source of lanthanides. The different methods of recovery are reviewed.
The extraction of platinum from Pt(II) chloride solution by a quaternary ammonium compound
Authors: Hoh Ying‐Chu , Chuang Wen‐Shou , Yueh Peng‐Shiung 
Published: July 2010

AbstractThe fundamental aspects of the extraction and stripping of platinum (II) from its chloride solution by Aliquat 336 diluted with toluene have been studied. The extraction and stripping was at 99.5 and 97.6% equilibrium within 30 s and 20 min respectively. The percentage extraction increased slightly with decreasing hydrochloric acid concentration. In 0.1 mol dm−3 hydrochloric acid, 1.0 volume percent Aliquat 336 in toluene could load 9.8 mmol dm−3 of platinum (II). The percentage stripping of platinum (II) from Pt(II)‐load organic solvent increased with increasing sodium bisulphite concentration. The enthalpy changes of extraction and of stripping were 12.8 and 114.9 kJ mol−1 respectively. Both of the reactions were endothermic.
A convenient preparative method for mintlactone and isomintlactone
Authors: Fujita Tsutomu , Watanabe Shoji , Miharu Kenji , Itoh Kazunori , Sugahara Kotoji 
Published: July 2010

AbstractVarious 2‐(2′‐hydroxy‐4′‐methyl‐1′‐cyclohexylidene) carboxylic acid lactones were synthesised in good yield from carboxylic acids and 4‐methylcyclohexanone. For example, mintlactone (VI) and isomintlactone (VII) were prepared from 2‐(1′‐ hydroxy‐4′‐methylcyclohexan‐1′‐yl) propanoic acid (III) which was obtained by reaction of propanoic acid (I) with 4‐methylcyclohexanone (II) using lithium naphthalenide in the presence of diethylamine. Compound (VI) could be separated from compound (VII) by silica gel column chromatography. Several new 2‐(2′‐ hydroxy‐4′‐methyl‐1′‐cyclohexylidene) carboxylic acid lactones which may be used as perfumery materials, were obtained in good yield by this method.
Fluorocarbon microemulsions
Authors: Ceschin C. , Roques J. , Malet‐Martino M. C. , Lattes A. 
Published: July 2010

AbstractThe microemulsification of various perfluorinated (or almost completely fluorinated) oils with different perfluorinated (or almost completely fluorinated) surfactants with or without cosurfactant is described. Ternary or pseudoternary phase diagrams are discussed. The sizes of the monophasic areas are related to surfactant and cosurfactant nature, weight ratio surfactant/cosurfactant and oil.
A microcomputer‐controlled facility for the analysis of phases from the AKUFVE mixer‐centrifuge unit
Authors: Waterman M. J. 
Published: July 2010

AbstractAn AKUFVE mixer‐centrifuge unit is used to collect distribution data for plutonium and uranium in a nitric acid/tributyl phosphate system under various conditions. The equipment necessary to make on‐line measurements in both phases and to perform off‐line titrations of the nitric acid is described. An explanation is given or the design of the Control Program. Written in BASIC with a few machine code subroutines, the program executes blocks of code of ‘sequences’ corresponding to particular functions. There are a dozen sequences which may be called in any order or individually to perform these functions.
The catalytic oxidation of organic air pollutants. Part 3. Catalysts from manganese and copper sulphates
Authors: Heyes Christopher J. , Irwin James G. , Moss Ronald L. 
Published: July 2010

AbstractManganese sulphate and copper sulphate were evaluated as the basis of catalysts for the control of organic air pollutants responsible for malodorous process emissions. Tests were made with low concentrations, 100 volumes × 10−6 in air, (i.e. 100 parts × 10−6 by volume), of methyl mercaptan or mercaptan + n‐butanal as a function of temperature and time to determine efficiencies for destructive oxidation. The complex pattern of odorant removal and product formation observed using manganese sulphate is discussed in terms of active sites which convert mercaptan to SO2 but are inhibited by the onset of dimethyl disulphide formation at higher temperatures; reactions between the odorants may also occur. Copper sulphate formed dimethyl disulphide at the lower temperatures but only SO2, SO3, CO and CO2 were detected above 300°C; after a 100 h durability test at 400°C, the odour removal efficiency determined by dynamic dilution olfactometry was 99.9%. Hence copper sulphate is preferable to manganese sulphate and is equal in performance to the copper oxide tested previously (Part 1) but with the advantage of a stable performance from the outset under sulphating conditions.
Adsorption and 13C N.m.r. studies of ethene, ethane and carbon monoxide on zn‐ and cd‐exchanged A‐zeolites
Authors: Emesh Ismail T. A. , Gay Ian D. 
Published: July 2010

AbstractThe adsorption of C2H4, C2H6 and CO has been studied on Zn2+‐exchanged A‐zeolites. Partial exchange with Zn2+ or Cd2+ increases the adsorption capacity for C2H4 and CO. Complete Zn2+ exchange leads to a decrease, indicating a complicated variation of cation positions with exchange level. N.m.r. measurements are consistent with adsorption of C2H4 as weak π‐complexes on the divalent cations. Weak specific adsorption complexes are also demonstrated for CO.
Spontaneous emulsification aspect of enhanced oil recovery
Authors: Egbogah Emmanuel O. , Dawe Richard A. 
Published: July 2010

AbstractRecent studies have suggested the possibility of spontaneous emulsification as a mechanism for enhanced oil recovery (EOR). The discussions have, however, remained essentially qualitative. A study was therefore undertaken to estimate quantitatively the contribution of spontaneous emulsification as an EOR mechanism. The tests were conducted on several bulk liquid/liquid systems as well as by displacement experiments in unconsolidated synthetic sand packs. Spontaneous emulsification was found to be a mechanism for EOR: the estimated extra contribution to EOR due to this mechanism was found to be significant in laboratory scale displacement experiments. Tertiary recovery was always greater when spontaneous emulsification was evident than otherwise. Results of tests on bulk liquid/liquid systems indicate that the occurrence or absence of spontaneous emulsification can be correlated with the values of ‘partition parameter’. It may be concluded that higher oil recoveries may be achieved in chemical EOR processes where interface mass transfer (and the accompanying spontaneous emulsification) occurs. The evaluation of efficiency of residual oil mobilisation through the capillary number theory (with and without spontaneous emulsification) is also discussed. Displacement tests with spontaneously emulsifying systems showed that residual oil left behind a conventional waterflood was mobilised in a range of capillary numbers much less than that which applies to low‐tension waterfloods.
The concentration of rubidium chloride in carnallite and its preparative separation by ion‐exchange
Authors: Ratner Rachel , Mittelman Judith , Kohn David H. 
Published: July 2010

AbstractA two‐stage process for the preparative separation of rubidium chloride from carnallite from the Dead‐Sea Works, Israel, is described. In the first stage rubidium chloride is enriched by successive decompositions and recrystallisations of carnallite from an Rb+ content of 0.02% up to about 4%. In the second stage pure rubidium chloride is obtained by means of displacement development chromatography using a polystyrene‐sulphonic acid resin followed by a rubidium‐selective cation exchange resin.
Polymeric additives for pour point depression of residual fuel oils
Authors: Naga Hamdi H. Abou El , Azim Wedad M. Abou El , Ahmed Mohamed M. 
Published: July 2010

AbstractEsters of styrene‐maleic anhydride copolymers were synthesised by reacting styrene with maleic anhydride and esterifying the product with fatty alcohols. The resulting copolymers were purified and tested as pour point depressants for residual fuel oils. Comparative evaluation of these esters of styrene‐maleic anhydride copolymers with some commercial additives showed their good activity.
A computer study of liquid‐liquid stage‐wise calculations in typical and new countercurrent contacting
Authors: Hughes Michael A. , Parker Nicholas 
Published: July 2010

AbstractA new scheme for contacting aqueous metal solutions with organic extractants in liquid‐liquid systems is described. The method is shown to give advantages in organic chemical usage under certain conditions. The application to the CuSO4/ H2SO4/LIX64N system is described.
Phase transfer catalysed esterification of phenols with aliphatic acid chlorides
Authors: Direktor D. , Effenberger R. 
Published: July 2010

AbstractThe phase transfer catalysed esterification of phenols with aliphatic acid chlorides was carried out in a basic bi‐phasic aqueous‐organic medium. Unhindered phenols, i.e. having at least one free ortho position, gave good to quantitative yields of ester while ortho disubstituted phenols gave low to moderate yields of ester only with the higher, less water soluble acyl homologues (≧C5). Phenol‐free ester was easily obtained by simple phase separation and evaporation of the organic phase.
Thermal and textural characteristics of modified silica
Authors: Selim Suzy A. , Hanafi Said , Abd‐El‐Khalik Mohamed , Ismail Mohamed 
Published: July 2010

AbstractA silica gel characterised as predominently microporous, with the remaining pores of limited dimensions which do not permit capillary condensation, is modified with aqueous solutions of acetic acid, glycine and β‐alanine. The modified samples are investigated and compared with a water soaked sample by means of differential thermal analysis, thermogravimetry and i.r. spectroscopy. Textural measurements are also carried out on the parent samples and those produced in the temperature range 110–600°C. Acetic acid is both physically and chemically adsorbed; a surface ester is formed. Both amino acids are physically adsorbed but no chemical interaction has been detected. Glycine and β‐alanine decompose differently when adsorbed on to the silica surface than when in the pure state. The specific surface area decreases upon modification, reaching half the value of the pure silica for the β‐alanine modified sample. Pore structure analysis, shows that the microporous nature of the modified samples decreases in the modifier order acetic acid < glycine < β‐alanine. The adsorbed β‐alanine molecules block most of the micropores present.
The influence of apex diameter on the pattern of solid/liquid ratio distribution within a hydrocyclone
Authors: Ahmed A. A. , Ibraheim G. A. , Doheim M. A. 
Published: July 2010

AbstractKnowledge of the pattern of solid/liquid ratio distribution within a hydrocyclone is very important for reliable design and efficient operation. This pattern was examined using a 100mm hydrocyclone for a wide range of apex diameters at high solid contents of the feed pulp. The measurements were taken along orbit radii at several horizontal level positions along the cyclone length. The results give a complete pattern of pulp‐solid content distribution for the studied parameters. An empirical equation relating the pulp solid/liquid ratio with all the studied variables was established. The predicted data show good agreement with the experimental results.
The influence of physico‐chemical and operating parameters on the filtration of the precipitate of hydrated Zr(IV) oxide
Authors: Kawalec‐Pietrenko Boz̊enna , Ruszel‐Lichodzijewska Barbara 
Published: July 2010

AbstractAn experimental investigation of the filtration of the colloidal precipitate of hydrated Zr(IV) oxide is presented. The influence of pH over the range from 3 to 12, of the ageing time of the suspension and of the procedure for the precipitation of hydrated Zr(IV) oxide on the course of its filtration under the constant pressure was studied.
A continuous process for dye removal from liquid effluents using carbonised wool waste
Authors: Malmary Guy , Périneau Francis , Molinier Jaques , Gaset Antoine 
Published: July 2010

AbstractIndustrial dyeworks are often conspicuous due to discoloration of rivers and streams into which they discharge waste materials. The adsorption process put forward for the treatment of such effluent makes use of wool‐carbonising waste made up of carbonised keratinic fibres and a hydrolysed vegetable material rich in ionic groups. This agro‐industrial by‐product showed a remarkable capacity for fixing surfactants, metallic cations and dyes. The current pilot project studied the removal of Maxilon Red from aqueous solutions by adsorption of the dye into the vegetable part of waste from the carbonising process. The operation was carried out continuously in a series of mixers. An examination of the hydrodynamic behaviour of a particular type of extractor established operating conditions favouring efficient removal of dyes from the effluent. A maximum dye removal rate of around 98% was possible.
Alkylation of phenol with isobutene catalysed by cation exchange resin: A kinetic study
Authors: Unni P. N. , Bhatia S. 
Published: July 2010

AbstractAlkylation of phenol with isobutene catalysed by Amberlyst 15 (cation exchange resin) was carried out in a batch reactor in the liquid phase. The reaction rate increased with increase in catalyst concentration and reaction temperature. Resin particle size and stirrer speed had virtually no effect on the rate under the experimental conditions. The rate data were correlated with a kinetic model based on homogeneous reaction. The apparent activation energies were found to be 57.7, 51.5 and 46.4 kJ mol‐1 for the formations of o‐alkylate, p‐alkylate and dialkylate respectively. The resin was found to have higher selectivity than the sulphuric acid catalyst.
Synthesis of some new thiophene derivatives with antimicrobial activity. part I
Authors: El‐Maghraby Ahmed A. , Mohamed Nour A. 
Published: July 2010

AbstractFor possible antimicrobial activity, thiophene‐2‐sulphonyl chloride was condensed with primary or secondary amines, phenols and hydrazine hydrate. Thiopene‐2‐sulphonhydrazones and thiophene‐2‐sulphoniminoazo derivatives were obtained. The constitution of some of the prepared products is discussed in the light of their infrared spectra. The biological activities of all prepared compounds were tested.
A convenient preparative method for carboxylic acids containing the dichlorocyclopropane ring system
Authors: Sugahara Kotoji , Fujita Tsutomu , Watanabe Shoji , Suga Kyoichi 
Published: July 2010

AbstractVarious carboxylic acids containing the dichlorocyclopropane ring system were prepared from the direct reaction of unsaturated carboxylic acids with dichlorocarbene. For example, 2‐(2,2.dichloro‐1‐methylcyclopropyl)‐ethanoic acid (II) was prepared from 3‐methyl‐3‐butenoic acid (I), 50% aqueous sodium hydroxide solution and benzyltriethylammonium chloride (BTEAC) in 80% yield. Similarly, 3‐(2,2‐dichloro‐3,3‐dimethyIcyclopropyl)‐2,2‐diethyl propanoic acid (IV) was obtained in 80% yield from 2,2‐diethyl‐5‐methyl‐4‐hexenoic acid (III). The dichlorocyclopropane compounds, (II) and (IV), are potent insecticides against houseflies (Takatsuki strain in Japan).
Recovery of chromium from waste electroplating liquors by ion‐exchange on casein. part 1. pilot plant studies
Authors: Davey Peter T. , Houchin Martin R. , Winter George 
Published: July 2010

AbstractThe ion‐exchange properties of cross‐linked caesin were used to selectively recover Cr(VI) from waste electroplating solutions. Acidic solutions containing Cr(VI), Cr3+, Zn2+ and Cd2+ were passed through an ion exchange column containing 35 kg of + 60 mesh casein. The casein had been previously cross‐linked using a 2% w/w formaldehyde solution. The anionic Cr(VI) was adsorbed by the casein while the cationic Cr(III), Zn(II) and Cd(II) passed through the column. Cr(VI) was eluted with ammonia. The casein was then washed, regenerated with sulphuric acid and the cycle repeated. The eluant for each cycle consisted of the (NH4)2 CrO4 eluate from the preceeding cycle with added ammonia.
The adsorption of dyestuffs from aqueous solutions using activated carbon. iii. intraparticle diffusion processes
Authors: Mckay Gordon 
Published: July 2010

AbstractThe rate of dye removal from aqueous solution has been found to vary linearly with the square root of time for much of the adsorption period. A rate parameter, k, has been defined to explain intraparticle diffusion on a quantitative basis. This rate parameter has been correlated against the process variables thus providing useful design data.
Discrimination of rival kinetic models in heterogeneous catalysis by the dynamic behaviour of products
Authors: Kobayashi Masayoshi , Maeda Yasuo , Takahashi Nobuo 
Published: July 2010

AbstractThe transient response method has been applied to discriminate between rival kinetic models derived from the conventional Hougen‐Watson procedure in heterogeneous catalysis, by using some old data for the NO‐CO reaction, dehydrogenation of sec‐butanol, hydrogenation of phenol, and dehydrogenation of tert‐butanol. A computer technique is commonly used for the simulation of the transient response curves of products caused by the concentration jump of reactants in a flow type reactor. The shapes of the calculated response curves are of various characteristic types (depending on the given model) which allow for easy discrimination between rival kinetic models. The difficulty of the discrimination in some particular models is also discussed.
Medium effect on the reaction of gibb's reagent with sodium thiosulphate
Authors: Harfoush A. A. 
Published: July 2010

AbstractRates of the reaction between Gibb's reagent and sodium thiosulphate have been measured in water‐glycerol mixtures over the temperature range 25–40°C. Log(k) varies linearly with the reciprocal of the dielectric constant. The energy of activation and the thermodynamic parameters of activation are calculated and discussed in terms of solvent properties.
Electrochemical reduction of some 5‐substituted‐4‐thiohydantoins at the dme
Authors: Aboutabl M. A. , Fahmy H. M. , Abdel Aziz M. A. , Abdel Rahman H. 
Published: July 2010

AbstractThe polarographic behaviour of a series of 5‐arylidene‐4‐thiohydantoin derivatives is reported and discussed. The reduction proceeds via a CECE mechanism in acid media with the formation of a 5‐benzyl‐4‐thiohydantoin and other products. The mechanism is confirmed through pKa determinations and Hammett's σ‐E1/2 relations.
High‐purity mercuric iodide
Authors: Nicolau Y. F. 
Published: July 2010

AbstractTwo methods of obtaining high purity HgI2 by wet‐synthesis are described: one by direct synthesis from the elements and the other by a double exchange reaction. Further purification of the synthesised HgI2 by recrystallisation, electrolysis and sublimation is described. The efficiency of the purification methods is tested by emission spectroscopy and by mass spectrometry analyses.
A procedure for quantitative 13c‐n.m.r. application to the characterisation of the naphtha fraction of petroleum crude
Authors: Srivastava Shanti P. , Bhatnagar Ajay K. , Joshi Girish C. 
Published: July 2010

AbstractA method for optimising the conditions for the quantitative 13C‐n.m.r. measurement is suggested and has been applied to the compositional studies of naphtha fractions (50–100°C and 100–150°C) of Darius crude oil. The novelty of the method is that we can pre‐estimate the pulse repetition time for unknown samples. It has been shown that the various compositional parameters thus obtained are in satisfactory agreement with those obtained from the elemental analysis, fluorescent indicator adsorption (FIA) and 1H‐n.m.r. spectrometry.
Retention of some non‐mercurial fungicides in paint films
Authors: Hughes Clifford A. , Taylor Colin G. , Thamaung Anek 
Published: July 2010

AbstractThe fungicides, 3,5‐dimethyltetrahydro‐1,3,5‐thiadiazine‐2‐thione (DTTT) and 4‐tolyldiiodomethylsulphone (TDMS) have been prepared labelled with 14C and incorporated into polyvinylacetate emulsion (PVA), styrene/acrylic emulsion (acrylic) or alkyd gloss (alkyd) paints. Test plates prepared from these paints have been exposed in both tropical and temperate conditions and losses of fungicides have been followed radiometrically. In outdoor conditions, DTTT is rapidly lost from all the paints. Indoors, DTTT is retained well (50% after 150 days) only by alkyd paint. TDMS is well retained in indoor conditions by all the paints. Outdoors however, retention in PVA and acrylic films is less than 50% after 150 days and is poorer in tropical conditions. About 90% of the TDMS is retained in alkyd films for an indefinite period in temperate conditions: in tropical conditions, 80% is retained after 150 days. Comparisons of losses from paint films of mercurial and non‐mercurial fungicides show that TDMS is a satisfactory substitute for the more commonly used mercurials.
Reduction of nitric oxide with ammonia on silica‐supported vanadium oxide catalysts
Authors: Shikada Tsutomu , Fujimoto Kaoru , Kunugi Taiseki , Tominaga Hiro‐O 
Published: July 2010

AbstractHighly active catalysts for the reduction of nitric oxide with ammonia can be obtained by supporting vanadium oxide, more than 15% by weight, on a silica gel with micropores of a mean diameter larger than 10 nm, followed by calcining it in the temperature range from 250 to 350°C. Both pre‐impregnation with a small amount of titania and addition of ammonium bromide increased the activity markedly. The catalyst gave an NO conversion level of 100% at 150°C. A series of life tests of the catalysts, which was performed at 230°C using a simulated flue gas containing 700 parts/106 of sulphur dioxide, demonstrated that their activities were stable for more than 300 h. Little irreversible change in the catalyst properties was observed after the test.
Denaturing of single electrospun fibrinogen fibers studied by deep ultraviolet fluorescence microscopy
Authors: Kim Jeongyong , Song Hugeun , Park Inho , Carlisle Christine R. , Bonin Keith , Guthold Martin 
Published: July 2010

AbstractDeep ultraviolet (DUV) microscopy is a fluorescence microscopy technique to image unlabeled proteins via the native fluorescence of some of their amino acids. We constructed a DUV fluorescence microscope, capable of 280 nm wavelength excitation by modifying an inverted optical microscope. Moreover, we integrated a nanomanipulator‐controlled micropipette into this instrument for precise delivery of picoliter amounts of fluid to selected regions of the sample. In proof‐of‐principle experiments, we used this instrument to study, in situ, the effect of a denaturing agent on the autofluorescence intensity of single, unlabeled, electrospun fibrinogen nanofibers. Autofluorescence emission from the nanofibers was excited at 280 nm and detected at ∼350 nm. A denaturant solution was discretely applied to small, select sections of the nanofibers and a clear local reduction in autofluorescence intensity was observed. This reduction is attributed to the dissolution of the fibers and the unfolding of proteins in the fibers. Microsc. Res. Tech., 2010. © 2010 Wiley‐Liss, Inc.