bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intrinsic kinetics of nickel/calcium aluminate catalyst for methane steam reforming
Authors: Soliman M. A. , Adris A. M. , Al‐Ubaid A. S. , El‐Nashaie S. S. E. H. 
Published: July 2010

AbstractA new catalyst for steam reforming of methane based on nickel/calcium aluminate is prepared. The new catalyst has shown stability and high activity at low steam to methane ratios. In this paper the intrinsic rate equations are derived and parameters estimation made. The rate equations show non‐monotonic dependence on steam partial pressure. The rate equations also show that the primary product is CO2 while CO is formed via the reverse water‐gas shift reaction. The mechanism proposed and the rate equations obtained indicate that it may be essential to propose specific rate models for any given catalyst rather than generalized mechanism and rate models.
Optimisation of the synthesis of 5‐chloromethyl‐2‐furancarboxaldehyde from D‐fructose dehydration and in‐situ chlorination of 5‐hydroxymethyl‐2‐furancarboxaldehyde
Authors: Sanda Komla , Rigal Luc , Gaset Antoine 
Published: July 2010

AbstractA stepwise method for the conversion of D‐fructose into 5‐chloromethyl‐2‐furancarboxaldehyde is described. The sugar was first subjected to acid‐catalysed dehydration in N,N‐dimethylformamide to give 5‐hydroxymethyl‐2‐furancarboxaldehyde as an intermediate. The latter was then chlorinated in situ with phosphorylchloride, to give the named chloro‐compound in an 85% overall yield, in the absence of any humic matter or tarry product.
Synthesis and application of some new oxazole derivatives as antimicrobial agents
Authors: Bakhite Etify A. , Mohamed Thana A. , Abdel‐Rahman Abdu E. 
Published: July 2010

Abstract5‐(p‐Acetylphenyl)‐2‐phenyloxazole (I) was condensed with aromatic aldehydes to furnish chalcones 2a‐e. Cyclocondensation of 2a‐e with hydrazine hydrate and with phenyl hydrazine led to the formation of pyrazoline derivatives 3a‐e and 4a‐e respectively. Similarly, 2a was interacted with hydroxylamine to give isoxazoline (5). On the other hand, condensation of 1 with phenyl hydrazine yielded hydrazone 6 which on treatment with Vilsmeier reagent (DMF/POCl3) gives 5‐[p‐(4‐formyl‐1‐phenylpyrazol‐3‐yl)phenyl]‐2‐phenyloxazole (7). Also, a few derivatives of 7 have been prepared. Moreover, all compounds were screened for their antimicrobial activity against some strains of bacteria and fungi.
The use of modified divinylbenzene‐polystyrene resins in the separation of fermentation products. A case study utilizing amino acids and a dipeptide
Authors: Casillas J. L. , Addo‐Yobo F. , Kenney C. N. , Aracilxs J. , Martínez M. 
Published: July 2010

AbstractThe adsorption of phenylalanine, aspartic acid, asparagine and aspartame from phosphate‐buffered aqueous solutions with modified divinyl‐benzene‐polystyrene resins has been investigated using high pressure liquid chromatography (HPLC). The pH studied was 2.8, the temperature range was 293‐313 K and the ionic strength was maintained at 1.0 mol dm−3. Over the range of variables investigated, the adsorption isotherms are linear and may be characterized by temperature and pH‐dependent apparent adsorption equilibrium constants, characteristic of the resin‐adsorbate system. By studying the dependence on temperature of this adsorption constant, heats of adsorption and entropy of adsorption have been estimated. In terms of the heat liberated on adsorption, the amino acids and a dipeptide can be ranked thus: aspartame > phenylalanine > aspartic acid > asparagine.
Artificial lighting system design for photosynthetic studies
Authors: Mouget Jean‐Luc , De La Noüe Joël , Legendre Louis , Jean Yves , Viarouge Philippe 
Published: July 2010

AbstractMost artificial lighting systems operate with a 100‐120 Hz flickering, an undesirable condition for studies on photosynthesis, requiring a fluctuating (flashing light effect) as well as a constant light flux. The amplitude of this flickering depends on the type of lamps and on the power supply. Selected lamps and related power supplies providing a flickering‐free light source are critically reviewed. A new system is proposed, that combines a high intensity discharge lamp (simulating natural sunlight) with a high‐frequency (>40kHz) ballast. This power supply provides a flickering‐free light flux, and offers such advantages as the use of lamps with high energy output and long life expectancy.
Spiroheterocyclic system. Part IV: Novel azo dye sulpha drugs of spiroheterocyclic naphthenes
Authors: Awad Ibrahim M. A. , Hafez Ali A. Abdel , El‐Zohry Mahr F. 
Published: July 2010

AbstractNovel azo‐dyes have been synthesized by diazotization of 4‐amino benzene‐4′‐(substituted heterocyclo) sulphonamide derivatives and coupling with 1‐oxa‐4‐thia‐spiro[4,4]nonan‐2‐one (I) and/or with l‐oxa‐4‐thia‐spiro[4,5]decan‐2‐one (I′) in acid medium to give the corresponding 3‐azo‐(4′‐substituted benzenesulphonamido)‐l‐oxa‐4‐thia‐spiro[4,4]nonan‐2‐one (II‐IX) and/or l‐oxa‐4‐thia‐spiro[4,5]decan‐2‐one (II′‐IX′] as spiro‐ligands. Treatment of these ligands with metal salts of iron (Fe3+), copper (Cu2+) and mercury (Hg2+) as chlorides in ethanolic solution furnished the corresponding metal chelates (IIa‐c‐IXa‐c) and/or (II′a‐c‐IX′a‐c). The compounds were tested in vitro for antimicrobial activity to study the structure‐activity relationship.
Synthesis and biological study of some pyrrolopyridine derivatives
Authors: Mohamed Thana A. 
Published: July 2010

AbstractQuinoline dicarboxylic anhydride (1) reacted with p‐aminoacetophenone to give a pyrrolopyridine derivative (2). The compound produced (2) reacted with hydrazine hydrate, hydroxyl amine hydrochloride, semicarbazide and thiosemicarbazide to produce pyrrolopyridine derivatives (3‐6). Compound 3 reacted with aromatic aldehyde, PhNCS or PhNCO to produce compounds 7‐9. Compound 4 reacted with PhNCO to give the carbamate ester 10. When compound 5 was boiled with SOC12, the thiadiazolo compound (11) was obtained. When compound 6 was allowed to react with α‐haloesters and α‐haloketones, the thiazolo compounds (12‐14) were produced. All the synthesized compounds were tested against some Gram‐positive and some Gram‐negative bacteria and they gave satisfactory results.
Synthesis and surface activity of sodium salts of branched perfluorocarboxylic acids and their analogs containing one chlorine atom
Authors: Meissner Egbert , Myszkowski Jerzy , Szymanowski Jan , Sobczyńska Anna 
Published: July 2010

AbstractIndividual sodium salts of branched perfluorocarboxylic acids, (CF3)2CF(CF2CF2)nCOONa, and their analogs containing one chlorine atom, CF3CF(CF2CI)(CF2CF2)nCOONa, were synthesized by telomerization of 2‐iodoheptafluoropropane and l‐chloro‐2‐iodohexafluoropropane with tetrafluoroethene, the addition of ethylene to both types of iodides considered, HI elimination and the oxidation of perfluoroalkylethylenes with potassium bichromate. The surface tension measurements demonstrated the high surface activity of sodium salts containing 9 and 11 carbon atoms in the hydrophobe. Perfluorocompounds were more surface active than their analogs having one chlorine atom but the differences were not great.
Ultrafiltration membranes for the separation of catalyst and products in homogeneous catalysis systems
Authors: Halligudi S. B. , Khan M. M. Taqui , Desai N. V. , Rangarajan R. , Rao A. V. 
Published: July 2010

AbstractResults of preliminary studies on concentration by ultrafiltration and reuse of a Ru(III)EDTA complex in homogeneous catalysis are reported. A method of preparation and selection of conditions of making cellulose acetate membranes for concentrating Ru(III)EDTA is described. At an operating pressure of 75 psig (517 kPa), the above catalyst can be concentrated to seven to eight times its initial concentration. The membrane used exhibits a separation of about 97.5 % for the complex with a permeate flow rate of about 3–6 gallons per sq. ft per day. The catalyst activities were determined for two reactions, viz. hydroformylation of 1‐hexene and carbonylation of ammonia for five cycles of concentration followed by reuse. The experimental data indicated that the catalyst concentration by ultrafiltration for subsequent reuse is simple and attractive and can provide potentially energy saving alternative to the cumbersome conventional separation processes associated with the recovery of catalysts in homogeneous catalysis.
A comparative study of the performance of solid supported and soluble urease for the enzymatic hydrolysis of urea
Authors: Demirel Günay , Akovali GÜNeri , Tanyolac Abdurrahman , Hasirci Nesrin 
Published: July 2010

AbstractThe performance of both free and solid supported urease for the enzymatic hydrolysis of urea was studied. Kinetic analysis of reaction rate data shows that the kinetic data were consistent with the proposed model. Statistical tests validated the model. Despite the deactivation of ureases, the immobilized enzyme could be the choice for a technological process aiming at the detoxification of blood in haemoperfusion columns.
Nitriles in heterocyclic synthesis. Part III: New sulpha drugs related to cyanopyridine derivatives
Authors: Hafez Ali A. Abdel , Awad Ibrahim M. A. , Monem Maisa I. Abdel 
Published: July 2010

Abstract4‐Hydroxyacetophenone (1) was reacted with cinnamonitrile derivatives (2–6) to give 3‐cyano‐4‐(substituted phenyl)‐6‐(p‐hydroxyphenyl)‐pyridines (7–11). Interaction of compounds 7–9 with 4‐substituted heterocyclo‐benzenesulphonyl diazoniura chloride gave the corresponding 3‐cyano‐4‐(sub‐stituted phenyl)‐6‐(3′‐azobenzene sulphonamido‐4′‐hydroxyphenyl) pyridines (12–29). The corresponding iron (III) copper (II) and mercury (II) chelates were also prepared in a 1:2 metal‐to‐ligand ratio. All the synthesized compounds were characterized on the basis of microanalysis, IR and 1H‐NMR spectrometry.
Contributions of the crosslinked and noncrosslinked moieties to the solvent‐induced swelling of brown coals
Authors: Jones J. C. , Lim G. S. H. , Sananikone D. S. 
Published: July 2010

AbstractA suite of brown coals from different sources was examined for solvent‐induced swelling in two forms: oven‐dried whole coal and pyridine‐extraced coal. This enabled the swelling to be resolved into the component due to imbibition of solvent by the crosslinked part and the component due to the non‐crosslinked part.
Experiments to promote colour changes in wool
Authors: Cottle D. J. , Zhao W. , Jones J. C. 
Published: July 2010

AbstractWool colour is not stable and it changes during storage. This study developed wool challenge methods by using a one‐week water bath incubation at 40°C or incubation overnight at a higher temperature to promote colour changes in wool. The study showed that the bacteria present in raw wool play a significant role in colour biodegradation during challenge (storage). A stable wool colour could be obtained for wool specification after a challenge treatment before colour measurement.
Zirconium‐based intermetallics as heterogeneous catalysts for the fischer‐tropsch reaction: I. Zr‐Ni‐Co catalysts
Authors: Al‐Shammary A. F. Y. , Caga I. T. , Tata A. Y. , Winterbottom J. M. , Harris I. R. 
Published: July 2010

AbstractAlloys of the general formula Zr50NixCO50‐x, where 0 ≦x≧ 50, have been prepared and used in the temperature range 300–400°C, in the pressure range 1–9 barg in a microtubular reactor for the reaction of hydrogen with carbon monoxide to give hydrocarbons.The alloys or intermetallic materials were prepared by argon arc melting, powdered by hydrogen decrepitation and characterised by means of optical microscopy (metallography), scanning electron microscopy with surface analysis and magnetic susceptibility measurements.The selectivity towards higher hydrocarbons increased with (i) increase in the total pressure and (ii) decrease in hydrogen content of the feed gases. The kinetics were found to be of the form:

where m = 1.0 ± 0.2 and n = 0. The apparent energy of activation (Ea) lay in the range of 80–130 kJ mole−1 and there appeared to be a compensation effect between Ea and the pre‐exponential factor A.The turnover numbers for the reaction exhibited an activity maximum for alloys of composition around Zr50Ni40Co20 and Zr50Ni30Co20. Magnetic susceptibility measurements indicated that alloys changed their nature from moderately paramagnetic to strongly paramagnetic or even ferromagnetic after use and this is attributed to the conversion of zirconium to zirconium oxide during reaction with the attendant production of free 3d‐transition metals. Derived catalysts prepared by air treatment of the hydrogen‐decrepitated intermetallics behaved almost identically to the latter materials and gave similar magnetic susceptibility values to used hydrided materials.
Zirconium‐based intermetallics as heterogeneous catalysts for the fischer‐tropsch reaction: II. Zr‐Ni‐Cu catalysts
Authors: Al‐Shammary A. F. Y. , Caga I. T. , Tata A. Y. , Winterbottom J. M. , Harris I. R. 
Published: July 2010

AbstractIntermetallic alloys of the general formula Zr50NixCu50‐x (where 0 ⩽ × ⩽ 50) were prepared by argon arc melting and powdered by hydrogen decrepitation. These materials were used as catalysts for the H2/CO reaction in the temperature range 300–400°C, in the pressure range 1–9 barg and for H2/CO ratios in the range 1 to 5. Derived catalysts were prepared by air treatment of the hydrided alloys and were subjected to identical investigations to the latter.The hydrided and derived catalysts behaved in a very similar manner in terms of selectivity, which increased with respect to higher hydrocarbon production with (i) increasing total pressure, (ii) decreasing values of H2/CO and (iii) increasing copper to the extent where CH4 contents was < 50% of the products. Increased temperature gave rise to increasing methane production. The activity of the alloy system exhibited a sharp activity maximum at the nickel‐rich end of the series and the copper‐rich alloys were almost ten times less active. The initial rate equation was observed to be of the form:

However, whereas n = 0, m varied between 0.5 and 1.2 for both series of catalysts.The presence of copper promotes the formation of higher hydrocarbons, especially the formation of ethene. It is presumed that the presence of copper at the surface inhibits the polyerization of CHX species and favours the CO insertion.
Zirconium‐based intermetallics as heterogeneous catalysts for the fischer‐tropsch reaction: III. Zr‐Co‐Ni‐Cu and Ru catalysts
Authors: Al‐Shammary A. F. Y. , Caga I. T. , Tata A. Y. , Winterbottom J. M. , Harris I. R. 
Published: July 2010

AbstractIntermetallic alloys of the general type Zr50MxN50‐x, where 0 ≦x≧ 50, were prepared by argon arc melting of the constituent elements. M and N are combinations of cobalt, nickel, copper and ruthenium. The alloys were powdered by hydrogen decrepitation, which yielded hydrided species of the general composition Zr50MxN50‐′H150‐x′ in which form they were used as catalysts.The reactions were carried out in a semi‐micro‐tubular flow reactor at 1 barg, 350°C and a H2/CO feed ratio of 3. It was observed that, while methane (CH4) was the dominant product, there was clear indication that intermetallic alloys containing Cu and Ru gave larger quantities of higher hydrocarbons and one alloy Zr50Ru25Co25 was 102‐103 times more active than any of the others, based on turnover number (TON) calculations; its activity was also observed to decline rapidly. The study of catalysts derived from intermetallic compounds provides a useful means of investigating alloy effects, due to the precise stoichiometry of the starting compounds which have long‐range order in respect of crystal structure. However, they can be rendered unstable by involvement with reactants, especially with oxygen.
Thermal decomposition of azobisisobutyronitrile dissolved in xylene in the presence of tin(IV) chloride
Authors: Juang Ruey‐Shin , Liang Ji‐Feng 
Published: July 2010

AbstractThe rate of thermal decomposition of azobisisobutyronitrile (AIBN) dissolved in xylene was investigated alone and in the presence of tin(IV) chloride over the temperature range of 90–107°C. It was found that the decomposition rate of AIBN increases linearly with increasing concentration of tin(IV) chloride, which suggests the formation of an activated complex between AIBN and tin(IV) chloride. A parallel reaction mechanism is proposed to describe the kinetic behavior. The Arrhenius relationships of rate constants were also obtained.
Uptake of benzenecarboxylate ions by magnesium aluminium oxides
Authors: Sato Tsugio , Kato Kenji , Yoshioka Toshiaki , Okuwaki Akitsugu 
Published: July 2010

AbstractThe behaviour of uptake of the benzenecarboxylate ions, C6H6‐n(COO)nn (n = 1–6), in aqueous solutions by rock‐salt type magnesium aluminium oxide, Mg(1‐x)(2+x)Al2x/(2+x)O (x = 0.17, 0.30, 0.33) was investigated at 0.70°C. All the benzenecarboxylate ions were taken up from solution competitively with OH‐ to form the hydrotalcite‐like layered double hydroxides. The uptake rate could be adequately described by a surface chemical reaction controlled shrinking core model, and the apparent activation energy was c. 60 kJ mol−1. The selectivity of anion uptake increased with increasing the charge density of the benzenecarboxylate ions. The amount of benzenecarboxylate ions incorporated in the interlayer of hydrotalcite and the selectivity of uptake for benzenecarboxylate possessing higher electric change increased with increasing aluminium content in the magnesium aluminium oxide.
Reduction of aqueous carbonate photocatalysed by treated semiconductors
Authors: Khalil Laila B. , Youssef Nabil S. , Rophael Magdy W. , Moawad Mona M. 
Published: July 2010

AbstractHeterogeneous photocatalysed reduction of aqueous Na2CO3 solution (1 m) was achieved by using phthalocyanine‐coated semiconductor powders (1–3% coating) as well as bare semiconductors. The suspensions were irradiated with 254 nm light from a low‐pressure mercury lamp in a nitrogen atmosphere. The phthalocyanine dyes (Fe2+‐Pc or Co2+‐Pc) absorb > 80% of the 254 nm radiation and thus sensitize the semiconductor. The products of reduction (CH3OH and HCHO) were determined spectrophotometrically. The CH3OH yields obtained are much higher than the HCHO yields, due to a photocatalysed reduction of HCHO to CH3OH. The CH3OH yields from coated titania increased linearly with irradiation time over the period 6–18 h. However, the straight line does not pass through the origin, and it seems that a slowing‐down occurs at times > 6 h. Titania coated with both dyes gave an optimum CH3OH yield at 2% surface coating. At higher coating percentages, phthalocyanine screens the surface, thus reducing the light reaching the semiconductor. Changing the redox potential of the phthalocyanine dye by changing its central metal from Fe to Co affects the CH3OH yields. The bare MoS2 photocatalyst gave a much higher CH3OH yield due to the characteristic behaviour of the semiconducting layer‐type disulphide, distinguished from that of classical semiconducting materials. In the various semiconductors studied, it seems that there is no correlation between the position of the conduction band and the yield of CH3OH. Such correlation was argued. Generally, a decrease in the yield of CH3OH was observed as the band gap width of the semiconductor increased. The yields of the photoproduced CH3OH generally increased with the percentage of light absorbed at 254 nm by the various semiconductors. Irradiation leads to the production of electrons in the conduction band of the semiconductor. It is likely that the photoproduced electrons reduce CO32‐ initially to HCOO‐ and then to HCHO and CH3OH.
An examination into the structure of stable foams formed on activated sludge plants
Authors: Foot R. J. , Kocianova E. , Forster C. F. , Wilson A. J. 
Published: July 2010

AbstractAlthough stable foams on activated sludge plants have been under discussion for about 25 years, their structure and the reasons for their structure are still unresolved. The paper describes a study, based on cryogenic electron microscopy and rheology, into foam structure. The results have shown that a foam consists of air bubbles held in a dense matrix of filamentous microbes and that the individual bubbles were surrounded by a film which contained cellular material. Rheology measurements showed that foams had an appreciable viscosity which varied with the concentration of solids in the foam. A significant difference occurred between the foam viscosities and those of non‐foaming activated sludge that had been thickened to similar concentrations of solids.
Selective extraction of metal ions through liquid surfactant membranes
Authors: Shiau Ching‐Yeh , Jung Shou‐Wen 
Published: July 2010

AbstractSelective separation of metal ion from a liquid solution with the help of different permeation rate of solutes through liquid membranes was performed. The salts used were ZnCl2, CdCl2, NiCl2. D2EHPA and LIX64N were used as carrier to study the extraction rate of the solutes. The results show that at low pH value of external phase the order of degree of extraction by D2EHPA or LIX64N is Zn > Cd > Ni, while at high pH value with the presence of ammonia in the feed solution the order of degree of extraction is reversed to Ni > Cd > Zn. The results also indicate that when the mixed carrier is used an enhanced effect on the extraction was observed. Synergistic effect was also noted when comparing the cases with mixed carriers to those with pure carriers.
Production of the enzyme dihydrofolate reductase by methotrexate‐resistant bacteria isolated from soil
Authors: Nigam Poonam , Marchant Roger 
Published: July 2010

AbstractSix bacterial cultures isolated from soil were capable of growing in the presence of methotrexate (MTX). Two strains, PFR‐1 and 3, developed resistance to 500 μg cm−3 MTX in the medium and produced elevated levels of the enzyme dihydrofolate reductase (EC 1.5.1.3): 2580 and 2702 U dm−3 compared to the sensitive parent strains (28 and 35 U dm−3). Isolate PFR‐3 showed maximum enzyme production (4950 U dm−3, specific activity 12.56 U mg−1 in flasks and 5737 U dm−3, specific activity 14.80 U mg−1 in 5‐dm3 fermenter) during exponential phase of growth (6 h) at 37°C and pH 7.0.
Studies on the fungicidal properties of some triphenyltin(IV) compounds
Authors: Chandra Shubhra , Gioskos Sam , James Bruce D. , Macauley Barry J. , Magee Robert J. 
Published: July 2010

AbstractThe results are reported for an investigation into the fungicidal properties of six triphenyltin(IV) compounds representing metal coordination numbers of four through six. These experiments were conducted against a number of soil and plant pathogenic fungi and compared with the results obtained from triphenyltin chloride. While all the compounds examined proved to be effective fungicides, differences at the concentration levels tested were not sufficiently pronounced to relate the degree of toxicity to the molecular structure.
Recovery of epichlorohydrin and dichloropropanols from waste
Authors: Milchert Eugeniusz , Goc Waldemar , Myszkowski Jerzy 
Published: July 2010

AbstractA method of recovery of the organic compounds: dichloropropanols, epichlorohydrin, 1,2,3‐trichloropropane from epichlorohydrin plant waste has been performed. The method depends on the adsorption of organic compounds in the active carbon and their desorption by allyl chloride. Allyl chloride is desorbed by steam. After desorption the solutions are recirculated to the epichlorohydrin plant.