bluuebunny/crossref_metadata_2025_split huggingface dataset:
Axisymmetric field generation within an ambient axial field
Authors: Darah A. A. , Sarson G. R. 
Published: January 2007

AbstractThe generation of magnetic field in a homogeneous, electrically conducting fluid – as required for the dynamo generation of the fields of many astrophysical bodies – is normally a threshold process; the dynamo mechanism, applicable to such bodies in unmagnetised environments, requires motions of sufficient strength to overcome the innate magnetic diffusion. In the presence of an ambient field, however, the critical nature of the field generation process is relaxed. Motions can distort and amplify the ambient field for all amplitudes of flow. For motions with appropriate geometries, an internal ‘dynamo‐like’ field of appreciable strength can be generated, even for relatively weak flows. At least a minority of planets, moons and other bodies exist within significant external astrophysical fields. For these bodies, the ambient field problem is more relevant than the classical dynamo problem, yet it remains relatively little studied. In this paper we consider the effect of an axial ambient field on a spherical mean‐field α 2ω dynamo model, through nonlinear calculations with α ‐quenching feedback. Ambient fields of varying strengths, and both stationary and oscillatory in time, are imposed. Particular focus is placed on the effects of these fields on the equatorial symmetry and the time dependence of the preferred solutions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Contribution to the study of composite spectra: XI. Orbital elements of some faint systems
Authors: Carquillat J.‐M. , Prieur J.‐L. 
Published: January 2007

AbstractWe present the results of a radial‐velocity study of nine new faint SB1 spectroscopic binaries with composite spectra: HD 137975‐6, 177984, HDE 226489, 231613‐4, 255387‐8, 256138‐9, 264997‐8, 276787 and 293041‐2. The observations were made at Haute‐Provence and Cambridge observatories with CORAVEL instruments between 1982 and 2006. From the radial‐velocity measurements of the cool components, we derive the orbital elements of those spectroscopic binaries for the first time. Using all the available data, we propose a model for each system that describes the nature of the individual components, with an estimation of the angular separation and orbital inclination. Finally we discuss the rotation–revolution synchronism of the cool components. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Discovery of magnetic fields in three He variable Bp stars with He and Si spots
Authors: Briquet M. , Hubrig S. , Schöller M. , De Cat P. 
Published: January 2007

AbstractIt is essential for the understanding of stellar structure models of high mass stars to explain why constant stars, nonpulsating chemically peculiar hot Bp stars and pulsating stars co‐exist in the slowly pulsating B stars and β Cephei instability strips. We have conducted a search for magnetic fields in the four Bp stars HD55522, HD105382, HD131120, and HD138769 which previously have been wrongly identified as slowly pulsating B stars. A recent study of these stars using the Doppler Imaging technique revealed that the elements He and Si are inhomogeneously distributed on the stellar surface, causing the periodic variability. Using FORS 1 in spectropolarimetric mode at the VLT, we have acquired circular polarisation spectra to test the presence of a magnetic field in these stars. A variable magnetic field is clearly detected in HD55522 and HD105382, but no evidence for the existence of a magnetic field was found in HD131120. The presence of a magnetic field in HD138769 is suggested by one measurement at 3σ level. We discuss the occurrence of magnetic B stars among the confirmed pulsating B stars and find strong magnetic fields of order kG and oscillations to be mutually exclusive. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrogen‐Bonded Dendronized Polymers and Their Self‐Assembly in Solution
Authors: Xie Dang , Jiang Ming , Zhang Guangzhao , Chen Daoyong 
Published: January 2007

AbstractFrechet‐type benzyl ether dendrons of second and third generations with a carboxyl group (G2, G3) at the apex site could attach to poly(4‐vinylpyridine) (PVP), forming hydrogen‐bonded dendronized polymers (HB denpols) in their common solvent, chloroform. The HB denpols show unique self‐assembly behavior, forming vesicles in the common solvent under ultrasonic treatment. The structure and morphology of the vesicles were characterized by dynamic light scattering (DLS), static light scattering (SLS), SEM, TEM, and AFM. The size of the vesicles decreases and the thickness of the vascular membrane increases as the molar ratio of Gx/PVP increases. The hydrogen bonding, π–π aromatic stacking of the dendrons, and the considerable difference in architecture between the dendron Gx and PVP are the main factors facilitating the assembly of the HB denpols in the common solvent.
Modelling a sequencing batch reactor to treat the supernatant from anaerobic digestion of the organic fraction of municipal solid waste
Authors: Dosta Joan , Galí Alexandre , Macé Sandra , Mata‐Álvarez Joan 
Published: January 2007

AbstractIn this study, a lab‐scale sequencing batch reactor (SBR) has been tested to remove chemical oxygen demand (COD) and NH4+‐N from the supernatant of anaerobic digestion of the organic fraction of municipal solid waste. This supernatant was characterized by a high ammonium concentration (1.1 g NH4+‐N L−1) and an important content of slowly biodegradable and/or recalcitrant COD (4.8 g total COD L−1). Optimum SBR operating sequence was reached when working with 3 cycles per day, 30 °C, SRT 12 days and HRT 3 days. During the time sequence, two aerobic/anoxic steps were performed to avoid alkalinity restrictions. Oxygen supply and working pH range were controlled to promote the nitrification over nitrite. Under steady state conditions, COD and nitrogen removal efficiencies of more than 65% and 98%, respectively, were achieved. A closed intermittent‐flow respirometer was used to characterize and model the SBR performance. The activated sludge model ASM1 was modified to describe the biological nitrogen removal over nitrite, including the inhibition of nitrification by unionized ammonia and nitrous acid concentrations, the pH dependency of both autotrophic and heterotrophic biomass, pH calculation and the oxygen supply and stripping of CO2 and NH3. Once calibrated by respirometry, the proposed model showed very good agreement between experimental and simulated data. Copyright © 2007 Society of Chemical Industry
Rapid quantification of sucrose esters in oriental tobacco by liquid chromatography‐ion trap mass spectrometry
Authors: Ding Li , Xie Fuwei , Zhao Mingyue , Wang Sheng , Xie Jianping , Xu Guowang 
Published: January 2007

AbstractA rapid and sensitive LC‐MS/MS method was developed for the quantitative determination of sucrose esters (SEs) in Oriental tobacco samples. The sample preparation involved a 10‐min sonication extraction procedure with acetone and five‐fold dilution of the extract with methanol. The experiment was carried out in positive ion mode by ESI IT mass spectrometer. Because of lack of authentic standards of SEs, sucrose octa‐acetate (internal standard, IS) was used as a surrogate to validate the proposed method. Matrix‐matched standard calibration was used for quantification of IS in the spiked samples. Under optimized MS/MS conditions, an LOQ of 3.9 μg/g was achieved for IS, with an LOD of about 1.2 μg/g. Recoveries for IS were 95–97%. Among 19 monitored SEs, the contents of 11 SEs had RSDs lower than 13.7%. The method, with very little sample handling and good sensitivity, was applied to the rapid quantification of SEs in four Oriental tobacco samples. It appears that the sum of contents of the five SEs with MW 650, 664, and 678 Da occupied approximately 80% of the total content of SEs.
Low‐cost data communication network for rural telecom network management
Authors: Jagadish C. , Jammula Vinod Kumar , Gonsalves Timothy A. 
Published: January 2007

AbstractThe backbone networking infrastructure of rural telecom networks is often costly and is of limited bandwidth. The availability of connectivity such as DSL or leased lines is scarce. In order to keep operational costs low, these rural telecom networks are often kept unmanned and are managed from a centralized network management station (NMS). This often requires a low‐cost, efficient and reliable data communication network (DCN) between the rural telecom equipment and the central NMS. The conventional DCN used for telecom management consists either of leased lines or Internet connectivity. These are often costly and not freely available in rural areas. We have developed a new DCN model, based on dial‐up, which is easily available. Using mathematical models and measurements we show that this DCN meets the QoS requirements of a telecom network at an affordable cost. We have implemented this DCN in corDECT networks. This is in use in India and Tunisia, and is under implementation in other similar countries. Copyright © 2007 John Wiley & Sons, Ltd.
Differential radioactive quantification of protein abundance ratios between benign and malignant prostate tissues: Cancer association of annexin A3
Authors: Wozny Wojciech , Schroer Klaus , Schwall Gerhard P. , Poznanović Slobodan , Stegmann Werner , Dietz Klaus , Rogatsch Hermann , Schaefer Georg , Huebl Heidi , Klocker Helmut , Schrattenholz André , Cahill Michael A. 
Published: January 2007

AbstractA differential quantitative protein expression study, comparing matched prostate cancerous and benign tissues from 31 patients, revealed proteins newly associated with prostate cancer. Average effects for 17 proteins whose abundance was significantly different (p<0.01) across patients ranged from 1.5‐ to 6.1‐fold, and included a number of known cancer markers. The most differentially abundant proteins between cancer and benign samples were isopeptidase T, serum amyloid P (SAP), annexin A3 (ANXA3) and mitochondrial enoyl coenzyme‐A hydratase. SAP is restricted to stroma in healthy tissue, and the lower abundance in tumours may be explained by the reduced stromal content. ANXA3 is present in healthy epithelial cells, exhibits strong staining in precancerous prostatic intraepithelial neoplasia, and is relatively less abundant in individual tumour cells of increasing Gleason pattern (GP), despite exhibiting higher overall tissue abundance in tumours. ANXA3 staining was predominantly cytoplasmic, yet nuclear localization was also observed. Strongly staining single cells, possibly phagocytes, were interspersed in highly dedifferentiated GP5 tumour areas among tumour cells without measurable ANXA3. Local recurrent androgen ablation therapy‐resistant tumours exhibit heterogenous low levels of ANXA3 staining. Results are discussed focussing on the potential implications for tumour tissues.
Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry for metabolic flux analyses using isotope‐labeled ethanol
Authors: Hollemeyer Klaus , Velagapudi Vidya R. , Wittmann Christoph , Heinzle Elmar 
Published: January 2007

AbstractWe describe a novel method for the determination of the concentration and labeling degree of ethanol originating from 1‐13C‐labeling experiments. This method is suitable for high‐throughput metabolic flux analysis because of the possible parallel sample preparation and fast final analysis using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS). In a closed vial containing culture supernatant, ethanol is enzymatically oxidized to acetaldehyde. The acetaldehyde formed evaporates and is readily trapped in a second enclosed but open vial containing acidified 2,4‐dinitrophenylhydrazine (DNPH). The 2,4‐acetaldehyde dinitrophenylhydrazone (Ac‐DNPH) that is formed is insoluble under these conditions. This leads to a constant conversion rate of the acetaldehyde produced from ethanol after 14 h minimum incubation time. MALDI‐TOFMS was used to quantify the formed Ac‐DNPH with [13C2]‐ethanol as internal standard. The relative signal intensities of the unlabeled ethanol derivative as well as of [1‐13C]‐ethanol were linearly related to the ethanol concentration within a range of 1 to 50 mM with a limit of detection of 0.6 mM, a range which is sufficient for flux analysis in microtiter plate fermentation experiments. The method allows the estimation of the [1‐13C]‐ethanol originating from 1‐13C‐labeling experiments of Saccharomyces cerevisiae strains. In experiments where the expected flux range was exceeded, unlabeled ethanol was determined with a linear range from 30 to 500 mM. Ethanol quantification using this method was compared with enzymatic analysis and exhibited differences of less than 3.3% on average. Comparison of flux partitioning ratios between glycolysis and the pentose‐phosphate pathway (PPP) based on MALDI‐TOFMS and gas chromatography (GC)/MS methods showed good agreement, with differences for ethanol and alanine labeling of only 4.3%. Copyright © 2007 John Wiley & Sons, Ltd.
The specific refraction of fatty oils
Authors: Tels M. , Kruidenier A. J. , Boelhouwer C. , Waterman H. I. 
Published: January 2007

SummaryIt is shown that atomic and group refractions, obtained from data on hydrocarbons, may be used in calculating the Lorenz‐Lorentz molar refraction of fatty acid esters.By assuming that the various atomic and group refractions are additive in mixtures of fatty acid esters, a relation between the iodine value, the saponification value, and the specific refraction of fatty oils is derived. The validity of this relation is confirmed by comparing the calculated and the experimentally determined specific refractions of a number of fatty oils and their hydrogenation products.From this relation a diagram for the graphical‐statistical analysis of glycerides of nonconjugated, nonpolymerized, straight‐chain fatty acids is developed.
The preparation and properties of surface‐active N‐acylamino‐methanesulfonates
Authors: Falk Robert A. , Gerecht J. Fred , Krems Irving J. 
Published: January 2007

SummaryThe preparation and properties of aminomethanesulfonic acid and several of its lower and higher N‐alkyl derivatives have been studied. The acylation of these compounds was investigated, and the optimum conditions were determined. Measurements of the surface‐active properties, including pour foam, soil removal, and redeposition, of several of the acylated derivatives are described, with reference to Igepon T.
Detergent bars from salts ofa‐sulfonated tallow acids
Authors: Weil J. K. , Stirton A. J. , Maurer E. W. , Ault W. C. , Palm W. E. 
Published: January 2007

Summary and ConclusionsExperimental detergent bars were based entirely on selected salts of α‐sulfonated saturated tallow acids. Some compositions appear to merit further investigation for the production of finished detergent bars, and an opportunity exists for the discovery of favorable combinations with soap. General conclusions are these.
Attractive detergent bars can be made from the monosodium or monoammonium salt [RCH (SO3M)CO2H] by partial neutralization with an amine or mixture of amines. Representative bars had the following compositions in mole percentage, anhydrous basis: a) 72 monosodium, 20 sodium ammonium, 8 sodium triethanolammonium salts; b) 85 monoammonium, 15 ammonium ethanolammonium salts.
Hardness and solubility can be controlled by water content and particularly by choice of the amine and the extent of the partial neutralization. Triethanolamine, isopropanolamine, and triethylamine tend to produce softer and more soluble bars than do ethanolamine or ethylamine.
The following compositions were suitable for detergent bars useful in sea water: a) 80 mole percentage of disodium 20 acid triethanolammonium; b) 20 monosodium, 50 sodium ammonium, 30 sodium triethanolammonium.
Effects of double bond configuration on lecithin synthesis
Authors: Lands W. E. M. 
Published: January 2007

AbstractStearyl‐CoA, oleyl‐CoA and elaidyl‐CoA were prepared and tested as substances in synthesizing lecithin from 1‐ and 2‐acyglycerol‐3‐phosphorylcholine. The rates of acyltransfer were followed by a continuous spectrophotometric assay. The enzyme(s) used to catalyze esterification at the 2‐position did not discriminate appreciably between thecis andtrans isomers of octadecenoate and transferred them more rapidly than the saturated acid, octadecanoate. However, the enzyme(s) which acted at the 1‐position discriminated markedly between the geometric isomers and rapidly transferred totrans‐ octadecenoate and octadecanoate.
General safety in handling solvents
Authors: Smalling J. W. 
Published: January 2007

AbstractThere are two major requirements for safety in plant operations: 1) convince everyone that it is smart to be safe, and 2) make it easier to be safe than unsafe. The most important method of instituting a workable and reliable safety program is that the general safety philosophy must be truly believed by management and promoted by them. It is only in this atmosphere that plant personnel will be able to progress to an outstanding safety record. The procedures for safer plant operations and general safety is a continuing program, and must be reviewed and revised, when required, in order to enhance safer operations.
Analytical techniques for hydroxy acids in fats and oils
Authors: Applewhite T. H. 
Published: January 2007

AbstractRecent work on separation techniques such as column, thin‐layer, gas‐liquid, and liquid‐liquid partition chromatography; chemical and physical characterization techniques, e.g., derivatization, X‐ray, infrared, nuclear magnetic resonance and mass spectrometry; and the possibilities for qualitative and quantitative analysis using these and other methods are discussed.
Determination of copper in edible soybean oils
Authors: List G. R. , Hoffmann R. L. , Kwolek W. F. , Evans C. D. 
Published: January 2007

AbstractSoybean oils have been analyzed for their copper content before and after hydrogenation with copper‐containing catalysts. A low‐temperature dry asher, an apparatus in which oxygen plasma is generated in a radio frequency field under high vacuum, was adopted for ashing glyceride oils. The residues were analyzed by a colorimetric procedure using zinc dibenzyldi‐thiocarbamate as the reagent. Identical samples were analyzed without ashing by neutron activation and atomic absorption techniques. The accuracy of the methods was determined by adding known amounts of copper at four different levels to two different soybean salad oils. Plots of copper found versus added copper showed that results were consistent over the range 0.04–5.0 ppm for all three methods, but that the atomic absorption results were low. The relative error of a single determination was ±13% and that of the mean of duplicate determinations ±9%. Analysis of natural soybean oils showed a copper content of about 0.03–0.10 ppm, whereas the same oils hydrogenated with cooper‐containing catalysts and without metal removal treatments had levels of 3–5 ppm.
Laboratory investigations on the extraction of oil from vegetable oil‐cakes with ethanol
Authors: Kaparthi Ramalingam , Chari K. S. 
Published: January 2007

Conclusions
Undue dilution of alcohol can be prevented by employing oleaginous materials of moisture content less than 1.0% for ethanol extraction.
The residual oil content of the meal depends on the particle size of the cake for a constant period of extraction.
Better quality oil in respect to color and F.F.A. is obtained with 95.6% ethanol extraction though the temperature of extraction is higher than the temperature employed with 98.6% ethanol.
F.F.A. of the extracted oils is low and within 1.0% for most of the oils, hence a reduction of refining loss. The color of safflower and peanut oils compares with the color of the screw‐press oils.
In the case of cottonseed meats extraction, the cooking of meats results in a lighter color oil and increases the yield for the same period of extraction. Cottonseed extraction also illustrates the advantages of ethanol as the solvent for oil extraction.
Reaction of ethylene oxide or propylene oxide with long‐chain fatty acids. Mono‐ and diester formation
Authors: Wrigley A. N. , Smith F. D. , Stirton A. J. 
Published: January 2007

SummaryThe alkali‐catalyzed reaction of ethylene oxide or propylene oxide with fatty acids was shown to be complex. Mono‐ and diesters were formed in comparable amounts even at an early stage when only about one equivalent of the cyclic ether had been condensed.The following compounds were isolated in a pure state: ethylene glycol monolaurate, ethylene glycol dilaurate, diethylene glycol dilaurate, ethylene glycol distearate, 1,2‐propylene glycol dilaurate, and 1,2‐propylene glycol distearate. A monoester from propylene oxide was shown to be a mixture of the 1‐and 2‐monolaurate [C11H23CO2CH2CHOHCH3 and C11H23CO2CH(CH3)CH2OH].
Biological utilization of fatty acid isomers
Authors: Melnick Daniel , Deuel Harry J. 
Published: January 2007

SummaryA review of the literature has shown that in the hydrogenation of vegetable oils, positional and stereoisomers of the unsaturated fatty acids are formed in appreciable quantities and that some isomers are intermediates in the development of others as hydrogenation proceeds. Using a microbiological assay technique, it was demonstrated that the iso‐oleic acids formed during hydrogenation are not antimetabolites for natural oleic acid but are utilized as nutrients. Fatty acids with conjugated double bonds are not antimetabolites for the essential fatty acids but are readily metabolized to carbon dioxide and water. Hydrogenated fats compare favorably with a natural fat of comparable firmness in serving as a source of essential fatty acids. In hydrogenating vegetable oils, isomers of linoleic acid can be formed which resist spectrophotometric detection but exhibit essential fatty acid activity.
Selective gas chromatographic determination of cholesterol in eggs
Authors: Guardiola F. , Codony R. , Rafecas M. , Boatella J. 
Published: January 2007

AbstractA selective gas‐chromatographic method is proposed for the determination of cholesterol in egg samples. The method consists of extraction of the lipid fraction and cold saponification prior to determination on a glass capillary column. The absence of cholesterol oxidation during the process was checked, and the conditions in which oxidation is avoided are discussed. The method also showed good precision (coefficient of variation=1.39%). Applying this method to different fresh and frozen egg samples, we obtained a mean content of 392 mg of cholesterol/100 g of edible portion. These values are clearly lower than the majority of results published for eggs.
Estimation of the sharma constant and thermoacoustic properties of vegetable oils
Authors: Subrahmanyam M. S. R. , Vedanayagam H. Sumathi , Venkatacharyulu P. 
Published: January 2007

AbstractThe density and volume of four Indian edible vegetable oils, sunflower, rice bran, groundnut and coconut, and one Indian nonedible oil, castor oil, have been experimentally determined. The values obtained were used to estimate the volume expansivity α, hence the thermoacoustic parameters, such as the Sharma constantS0, the isochoric temperature coefficient of internal pressure, the isochoric temperature coefficient of volume expansion, reduced volume, reduced compressibility and the Huggins parameter F. The results obtained show that the Sharma constantS0 has the same characteristic value of 1.11±0.01 for the five oils, thus establishing the constancy of the Sharma parameter. All the other parameters are of the expected order of magnitude; however, in all cases there is a uniform deviation at 293°K, which can be attributed to the behavior of density and volume at this temperature.