bluuebunny/crossref_metadata_2025_split huggingface dataset:
Über die Lösbarkeit der Feldgleichungen des Zweiflüssigkeitsmodells für ein staubbeladenes Gas
Authors: Förste J. 
Published: June 2007

AbstractDie Strömung eines staubigen Gases in einem beschränkten räumlichen Gebiet wird durch das Zweiflüssigkeitsmodell beschrieben. Mit Hilfe eines Iterationsverfahrens wird gezeigt, daß es ein Zeitintervall gibt, dessen Länge von den Anfangs‐werten der Geschwindigkeiten und der Dichtegradienten und den äußeren Kräften abhängt, in dem die Feldgleichungen lösbar sind. Es wird bewiesen, daß diese Lösung eindeutig bestimmt ist.
Lösung inkonsistenter linearer Gleichungssysteme und Bestimmung einer Pseudoinversen für rechteckige Matrizen durch Spaltenapproximation
Authors: Maess Gerhard , Peters Wolfgang 
Published: June 2007

AbstractDie auf Kiesewetter und Albrand zurückgehende Methode der Spaltenapproximation, eine Variante der von Householder und Bauer untersuchten Klasse von Projektionsverfahren, eignet sich zur iterativen Lösung über‐und unter‐bestimmter linearer Gleichungssysteme. Sie führt die Lösung großer Systeme auf die wiederholte Lösung kleiner Teilsysteme zurück, ist also auch anwendbar, wenn die Koeffizientenmatrix zu groß für den Kernspeicher der Rechenanlage ist. In der vorliegenden Arbeit wird das Verfahren im Fall inkonsistenter Gleichungssysteme analysiert. Die Näherungen konvergieren gegen eine Pseudolösung, die beste Approximation im Sinne der Methode der kleinsten Quadrate ist. Mit Hilfe einer verallgemeinerten Inversen ((1, 2, 3)‐Inversen) X der Ausgangsmatrix kann die allgemeine Lösung bzw. Pseudolösung explizit angegeben werden. Hat die Ausgangsmatrix maximalen Spaltenrang, so ist X identisch mit der Moore‐Penroseschen Pseudoinversen A+, und mit dem Startvektor x= o konvergiert die Iteration gegen die normkleinste Lösung bzw. Pseudolösung A+b.
P‐Boundedness of Inverses of Nonlinear Operators
Authors: Bohl Erich 
Published: June 2007

AbstractThe central result of this paper reads as follows: Let T be a P‐bounded operator on a linear distance space. If I — P has a monotone inverse then I — T has a (I — P)−1‐bounded inverse. This Theorem is being applied to various special situations (e.g. nonlinear systems, nonlinear ordinary differential operators) to yield known and new results.
Existenz und Eindeutigkeit eines linearen hyperbolischen Anfangs‐Randwertproblems und die praktische Anwendung auf Probleme aus der Hydraulik. Teil I: Zur Existenz und Eindeutigkeit des linearen hyperbolischen Anfangs‐Randwertproblems
Authors: Iben H. ‐K. 
Published: June 2007

AbstractFor a linear hyperbolic mixed boundary value problem frequently occurring in the engineering science, the existence and uniqueness of a solution are proved. The complete, self‐contained and analytical solution of the problem are explicitly given. With a view to a correct indication of the problem, only such boundary conditions are permitted which are not in contradiction with the defined compatibility conditions.
Zur Konvergenzbeschleunigung bei Summen strikt kontraktiver Operatoren
Authors: Schneider K. R. 
Published: June 2007

AbstractLet T1 and T2 be strictly contractive operators whose Lipschitz constants satisfy the relation x1 + x2 < 1. The aim of the paper is to give conditions under which there exist iteration procedures whose speed of convergence is higher than that one of the usual procedure (*) xn = T1xn‐1 + T2xn‐1 and whose complexity (expense of computer time) is less than that one of (*).
A Parabolic Control Problem with a Boundary Condition of the Stefan‐Boltzmann Type
Authors: Sachs Ekkehard 
Published: June 2007

AbstractIn this paper we consider a one‐dimensional nonlinear boundary control problem occuring in heat conduction with a boundary condition governed by the Stefan‐Boltzmann law. For L∞‐inputs we prove the existence and uniqueness of non‐negative solutions. Furthermore we show for a class of cost functionals that there exist optimal controls. We also give necessary conditions for optimal controls in form of a certain type of bang‐bang‐principle.
Magnetohydrodynamic Stability of Boundary Layers along a Flat Plate in the Presence of a Transverse Magnetic Field
Authors: Watanabe T. 
Published: June 2007

AbstractThe purpose of the paper is to consider theoretically first the behavior of two‐dimensional steady laminar boundary layer flow of an incompressible, electrically conducting fluid past a semi‐infinite flat plate in the presence of a transverse magnetic field by using the difference‐differential method. The neutral stability curves for wavelike disturbances of Tollmien‐Schlichting type are then presented for the velocity profiles obtained above in the wide range of magnetic parameter (mx). The results show that the skin friction and the critical Reynolds number decrease with increasing mx, so that the MHD boundary layer becomes less stable.
Creep Transition in Thick‐Walled Cylinder under Internal Pressure
Authors: Gupta S. K. , Dharmani R. L. 
Published: June 2007

AbstractTransitional stresses for thick‐walled cylinder under internal pressure for the three stages of creep has been derived. For stationary stage of creep, the stresses and the assumed stress‐strain rate relations are the same as those given by Bailey, Odquist and others.
Über die Grundgleichungen der Plasmadynamik auf der Basis der Zweiflüssigkeitstheorie
Authors: Förste J. 
Published: June 2007

AbstractFür die linearisierten Bewegungsgleichungen eines vollionisierten Plasmas wird ein Anfangs‐Randwertproblem formuliert und ein Existenz‐ und Einzigkeitssatz bewiesen.
Analysis of fat acid oxidation products by countercurrent distribution methods. V. Low‐temperature decomposition of methyl linoleate hydroperoxide
Authors: Johnston A. E. , Zilch K. T. , Selke E. , Dutton H. J. 
Published: June 2007

AbstractMethylcis, trans diene conjugated linoleate hydroperoxide isolated by counterenrrent distritbution from 4ŶC, auatoxidation of methyl linoleate was stored in atmospheres of oxygen and of nitrogen at 4ŶC. in darkenss. Besides manometric changes, infrared and ultraviolet characteristics, peroxide value, diene conjugation, and molecular weights were followed on samples removed at various periods of storage up to 53 days. These same analyses were obtained on fractions obtained by counter‐current distributions.Evidence for the reaction that occurs on storage in oxygen may be summarized thus: 1 mole oxygen absorbed by linoleate hydroperoxides destroys 1 molecis, trans diene conjugation, 1/2 mole peroxide group, and 1 mole linoleate hydroperoxide; dimers of varying polarities, scission acids, and isolatedrans bonds are formed.Since to volume changes were observed in the nitrogen storage of methyl linoleate hydroperoxide, changes in chemical and physical characteristics can only be related to time of storage. Storage in nitrogen at 4ŶC, destroys diene conjugation, peroxides, and linoleate hydroperoxide and produces dimers of varying polaritics, seission neids, and isolatedrans bonds. Destruction of diene conjugation was one‐fourth as rapid in a nitrogen atmosphere as in oxygen. While differences in reactions and products were observed between oxygen and nitrogen storage, particularly in rates and in countereurrent distribution patterns, the similarity of products from oxygen and nitrogen storage is remarkable. One methyl linoleate hydroperoxide is formed regardless of storage atmosphere, dimirization and attendant destruction of double bonds and peroxides proceed.
In vitro hydrolysis of natural and synthetic γ‐linolenic acid‐containing triacylglycerols by pancreatic lipase
Authors: Huang Yung‐Sheng , Lin Xiaorong , Redden Peter R. , Horrobin David F. 
Published: June 2007

AbstractThe present study compared thein vitro hydrolysis of two 18:3n‐6‐rich oils—evening primrose oil (EPO) and borage oil (BO)—and different synthetic 18:3n‐6‐containing triacylglycerols (TG). Incubation of EPO and BO with pancreatic lipase lipolyzed 18:3n‐6 from the TG species. The rate of lipolysis of TG species containing two or three molecules of 18:3n‐6, which comprised 36% of total 18:3n‐6 in BO and only 7% in EPO, was significantly slower than those containing only one molecule of 18:3n‐6. This was found especially in those with two molecules of linoleic acid, which constituted 20% of total 18:3n‐6 in BO, whereas over 80% were present in EPO. In a separate study, various synthetic 18:3n‐6‐containing TG were also subjected toin vitro hydrolysis by pancreatic lipase. Results showed that release of 18:3n‐6 from thesn‐1/sn‐3 positions was significantly slower when two other stereospecific positions in the same TG molecule were occupied by either palmitic acid (16:0) or monounsaturated (18:1 and 20:1) fatty acids than when occupied by 18:2n‐6. The rate of hydrolysis ofsn‐2‐γ‐linolenyl‐sn‐1(3)‐diacylglycerol to formsn‐2‐mono‐γ‐linolenyl glycerol was also significantly slower when both thesn‐1 andsn‐3 positions in TG molecules were occupied by either saturated fatty acids (16:0 and 18:0) or long‐chain monounsaturated fatty acids than when occupied by 18:2n‐6. These findings suggest that the stereospecific position of 18:3n‐6 in TG molecules and the constituent of its neighboring fatty acids modulated availability of 18:3n‐6 from 18:3n‐6‐containing TG or 18:3n‐6‐rich oils.
Enzymatic synthesis of phosphatidylcholine with fatty acids, isooctane, carbon dioxide, and propane as solvents
Authors: Härröd Magnus , Elfman Inger 
Published: June 2007

AbstractPhosphatidylcholine (PC) was synthesized from lyso‐PC and long polyunsaturated fatty acids (PUFA) with phospholipase A2. In previous investigations, performed in small glass tubes, the enzymatic synthesis reaction was optimized. This paper presents results from experiments performed in a high‐pressure reactor filled with an immobilized enzyme (Im.E.). Fatty acids were used as the main solvent while isooctane, CO2, or propane was used as an additional solvent. The water content was carefully controlled over wide ranges. The temperature was kept constant at 45°C for up to 50 h. The highest initial reaction rate was attained with pure fatty acids under relatively humid conditions (water=35% of dry Im.E.). The reaction rates were more than three times as high in the high‐pressure reactor than in previous experiments in glass tubes. In all solvent systems, the best yield was attained after long times under dry conditions (water <15% of dry Im.E.). Addition of CO2 to the PUFA reduced the yield, while addition of isooctane or propane increased the yield. After 20 h at 45°C, the best yield (25%) was attained at a solvent composition of 91% PUFA and 9% propane.
Competitive adsorption among sesame oil components in a concentrated miscella system
Authors: Toro‐Vazquez Jorge F. , Mendez‐Montealvo Guadalupe 
Published: June 2007

AbstractCompetitive adsorption of free fatty acids and carotenoids adsorption from sesame oil miscellas on vegetable carbon was studied by regression analysis. The equations obtained indicated that unsaturated carbonyls, free fatty acids (FFA0), and carotenoids interacted to determine fatty acid and carotenoid adsorption. The driving force for carotenoid adsorption, the carotenoid concentration (C0), was affected by a quadratic function of free fatty acid concentration [i.e., (FFA0/C0)2]. As FFA0/C0 increased, carotenoid adsorption efficiency was reduced, possibly because the accessible adsorption sites for carotenoids were occupied by fatty acids. Unsaturated carbonyls promoted free fatty acid adsorption, probably in the pores that were readily accessible for fatty acids. However, when the carbonyl concentration increased in the oil miscella, carbonyls were adsorbed instead of fatty acids. The results indicated how different oil molecules interact and affect adsorption (i.e., free fatty acids and carotenoids). Therefore, the adsorption process of vegetable oils (i.e., bleaching) has to be considered a multicomponent adsorption system.
Thermoacoustic properties of methyl esters ofn‐alkanoic acids
Authors: Cole Sandya , Rao J. V. , Venkatacharyulu P. 
Published: June 2007

AbstractA number of thermoacoustic parameters, including the Sharma constant S0, the isochoric temperature coefficient of volume expansivity (d Inα/d InT)V, the isochoric temperature coefficient of internal pressure (d InPi/d InT)V, reduced volume V, reduced compressibility β and the Huggins parameter F, are estimated by using only the volume expansivity α from the density temperature data for a number of methyl esters ofn‐alkanoic acids. The methyl esters give excellent separation of saturated fatty acid mixtures. The Sharma constant, which relates the molecular constantn and other thermoacoustic parameters, is a constant with a characteristic value of 1.11+0.01 for all these esters.
Crystal morphology of mixtures of tripalmitin and butterfat
Authors: Fairley Peter , Krochta John M. , German J. Bruce 
Published: June 2007

AbstractBlends of butterfat and tripalmitin are of interest for use as moisture barriers in edible films. Tripalmitin was blended with butterfat in the ratios 100:0, 90:10, 80:20, and so on through to 10:90 and 0:100. Crystal morphologies of squash and smear preparations were determined by polarizing light microscopy. Samples were stored at 19–22°C and re‐examined after 6 d and after 30 d. Morphology was strongly dependent on composition and the presence of a coverslip. Morphology was less dependent on polymorphic form and age. Barrier properties depend more strongly on morphology than on polymorphic form.
Allylic hydroxy fatty compounds with Δ5‐, Δ7‐, Δ8‐, and Δ10‐Unsaturation
Authors: Knothe G. , Bagby M. O. , Weisleder D. , Peterson R. E. 
Published: June 2007

AbstractSeveral novel allylic mono‐ and dihydroxy fatty compounds were synthesized from Δ5, Δ7‐, Δ8‐, and Δ10‐monounsaturated fatty acids with the selenium dioxide/tert‐butyl‐hydroperoxide. Chainlengths were C19 for Δ7 and Δ10, and C20 for Δ5 and Δ8 compounds. With a full range of Δ5‐ to Δ11‐unsaturated allylic monohydroxy fatty compounds available, position‐dependent effects in the13C‐nuclear magnetic resonance spectra of these compounds are discussed. The olefinic carbon shift differences in monohydroxy compounds, where the OH group is located between the double bond and the terminal methyl group, were plotted as a function of double‐bond distance from C1. This plot is presumably a rational function. During SeO2‐based hydroxylation, lactonization of the hydroxy groups, located between the double‐bond and the carboxyl group, also occurs for Δ5 unsaturation.
Chromatographic characterization of internal polar lipids from wool
Authors: Coderch L. , de la Maza A. , Soriano C. , Erra P. , Parra J. L. 
Published: June 2007

AbstractWool internal polar lipids were isolated and separated into different fractions based on polarity. Qualitative and quantitative analyses of the different fractions were performed by thin‐layer chromatography and thin‐layer chromatography coupled to flame‐ionization detection, respectively. Cholesterol esters, free fatty acids, sterols, ceramides, glycosylceramides, and cholesterol sulfate were the main components, with ceramides being in the highest proportion. The fatty acid composition of ceramides and glycosylceramides was determined by gas chromatography/mass spectrometry. As for other keratinized tissues, long‐chain fatty acids predominated in comparison to either free fatty acids or phospholipid‐linked fatty acids; in both cases, stearic and lignoceric acids were the most abundant fatty acids, and a low amount of 18‐methyleicosanoic acid was found. This work opens new avenues in the study of lipid rearrangement in more complex and realistic vesicle structures than conventional liposomes.
Structures of ozonolysis products of methyl oleate obtained in a carboxylic acid medium
Authors: Nishikawa Naoki , Yamada Kaoru , Matsutani Shigeaki , Higo Moriaki , Kigawa Hitoshi , Inagaki Takeo 
Published: June 2007

AbstractHigh‐performance liquid chromatography‐mass spectrometry (LC‐MS) and nuclear magnetic resonance spectrometry (NMR) were applied to the analysis of organic peroxide mixtures, which were labile and tended to decompose during analysis. The ozonolysis reaction of methyl oleate gives a peroxide mixture, and, finally, mono‐ and dibasic acids are obtained by subsequent oxidation. In this study, methyl oleate was ozonized in a nonanoic acid medium, one of the final reaction products. The reaction products were directly analyzed by LC‐MS equipped with a frit‐fast atom bombardment interface. The molecular ion peak of each peroxide was clearly observed, and its molecular weight was readily determined. On the other hand, each peroxide was fractionated by high‐performance liquid chromatography and submitted to structural analysis by NMR. Both results indicated that the reaction products include four peroxidic species: 1,2,4‐trioxolaneI, peroxide oligomerII, 1‐acyloxyalkyl‐1‐hydroperoxideIII, and 1‐acyloxyalkyl‐1′‐hydroxyalkyl peroxideIV, as well as an aldehydeV. Ozonolysis of methyl oleate in the absence of solvent produces mainlyI, while that in the presence of a carboxylic acid solvent characteristically produces mainlyIII andIV derived from the solvent.Bis(1‐acyloxyalkyl‐1‐alkyl) peroxide, which was reported previously as a ozonolysis product of methyl oleate, was concluded to beIV in this study.
Thermal stability ofThevetia peruviana juss seed oil
Authors: Ibiyemi A. Samuel , Bako S. S. , Ojokuku G. O. , Fadipe V. O. 
Published: June 2007

AbstractThevetia peruviana seed showed characteristic changes in physicochemical properties when heated at 180, 200, and 220°C over a period of 15 h. There is no striking significant difference in the five parameters (iodine value, acid value, peroxide value, saponification value, and polar compounds) studied for the three working temperatures. Thevetia seed oil showed good thermal stability and will be a good frying and cooking oil.
Phenylethyl esters of fatty acids for the analytical resolution of petroselinate and oleate
Authors: Liu Linsen , Hammond E. G. 
Published: June 2007

Abstract2‐Phenylethyl esters of fatty acids were prepared readily by esterification of free fatty acids or transesterification of other lipids. Compared with methyl esters, phenylethyl esters greatly improve the resolution of oleate and petroselinate by both gas and high‐performance liquid chromatography, and the ultraviolet absorption of the phenylethyl esters facilitates detection of the derivatives by high‐performance liquid chromatography (HPLC) ultraviolet detectors. The fatty acid compositions of corn and soybean oil obtained by analysis of phenylethyl esters agreed with those obtained with methyl esters. The phenylethyl esters were resolved and eluted on C‐18 HPLC columns with much smaller solvent volumes than those reported for other aromatic esters.
Co‐metathesis reaction of crude palm oil and ethene
Authors: Ahmad F. B. H. , Hamdan S. , Yarmo M. A. , Alimunir A. 
Published: June 2007

AbstractThe co‐metathesis reaction of crude palm oil with ethene in the presence of WCL6/Me4Sn, followed by termination of this reaction with methanol, gives terminal alkenes. The major metathesis products are 1‐decene and methyl 9‐decenoate.
A wide line NMR R‐F saturation method to measure fat in moist samples of defatted corn germ
Authors: Conway T. F. 
Published: June 2007

AbstractA wide‐line NMR radio‐frequency (r‐f) saturation technique has been applied to measurement of residual fat (1–6%) in defatted corn germ process samples containing significant amounts (4–11%) of moisture. Since NMR relaxation times for protons associated with the fat differ from those associated with the water, it is possible to use these differences as a basis for discrimination. In process samples where these differences are sometimes marginal, they can often be enhanced by milling the moisture‐containing sample at high speed in carbon tetrachloride to alter the relaxation times of protons associated with the fat. The fat content is derived from NMR signals obtained at two r‐f levels. At the lower r‐f level, energy absorbed is proportional to the number of protons associated with both water and fat. At the higher r‐f level, signals from fat are saturated preferentially. This reduction in signal intensity, due to r‐f saturation, is proportional to the amount of fat in the sample and can be used as a quantitative measurement. Examples of this methodology for laboratory‐prepared and process samples are given. Experimental data for approximately 40 random process samples indicate that the method is accurate to within ±0.3% fat, absolute, 95% confidence limits.
Automated determination of protease for laundry compounds
Authors: Detmar D. A. , Vogels R. J. 
Published: June 2007

AbstractFor the determination of the activity of protease for laundry washing compounds preference is given to casein as substrate and measurement of the supernatant at 275 nm after precipitation with trichloro‐acetic acid. Since sampling rate and precision with the AutoAnalyzer are in this case very low, an automated system based on the principle of the mechanized test tube has been developed. The sampling rate is one sample per minute; the coefficient of variation of a single sample is 2.3% without relation to a standard solution and 1.6% if results are related to a standard solution run simultaneously. If the activity of a sample is determined in threefold, the coefficients of variation are 1.6% resp. 1.1%.
High levels of acetone found in male Turkey skin
Authors: Thomas C. P. , Dimick P. S. , Macneil J. H. 
Published: June 2007

AbstractInvestigation of the carbonyl compounds in the hexane extractable lipid of raw poultry skin revealed that the only monocarbonyl present was acetone. Furthermore, in male turkeys the level of acetone was significantly greater than the level observed in either chickens or female turkeys. During maturation, increased acetone concentrations were accompanied by low lipid deposition in the tissue.
The contribution of saturated acyl groups to the volatiles of oxidized soybean oil
Authors: Michalski S. T. , Hammond E. G. 
Published: June 2007

AbstractU‐14C‐Stearic acid was interesterified into soybean oil and the resulting oil was oxidized to high peroxide values at 25 C and at 125 C. Volatile oxidation products were isolated and found to have a count that was not significantly above background.
Modification of quantity and quality of safflower oil through plant breeding
Authors: Knowles P. F. 
Published: June 2007

AbstractLess than 20 years have passed since safflower was established commercially in the southwestern area of the United States. Already hybrid varieties are available, oil and protein contents have been raised greatly, and oil quality has been modified sufficiently to constitute another oil crop for American agriculture. It is hoped that the next 20 years will be equally productive in terms of improvements and modifications of the oil and protein of this crop.
Heats of fusion for some triglycerides by differential scanning calorimetry
Authors: Hampson J. W. , Rothbart H. L. 
Published: June 2007

AbstractHeats of fusion of tristearin, tripalmitin, trimyristin, trilaurin and several standards were determined by the relatively new technique of Differential Scanning Calorimetry. The data obtained on the standards shows good precision and accuracy. The results obtained for the triglycerides are 1–10% lower than values which have been reported elsewhere.