bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rate Type Plastic Material with General Work‐Hardening
Authors: Tokuoka T. 
Published: June 2007

AbstractA rate type plastic material is proposed. A scalar internal variable and a symmetric tensor internal variable are introduced. The constitutive and the evolutional equations are invariant for the change of time‐scale. Two sets of equations are assumed for the loading and the unloading state. Three material functions which define equations in the loading state are assumed to depend on the translated stress, to be pressure insensitive, and to have some symmetricities which imply no Bauschinger effect with respect to the translated stress. Three constant material functions are assumed in the unloading state. The yield criterion and the flow rule which are defined by the rate type constitutive equation may show the kinematic as well as the isotropic workhardening. Two special materials are presented, one has a generalized Huber‐von Mises yield criterion and the other has a generalized Tresca yield criterion. They are a generalization of the materials proposed by the author in the preceding paper.
Symmetrische Koppelkurven mit sechspunktig berührendem Scheitelkrümmungskreis
Authors: Jank Walther 
Published: June 2007

AbstractFür die Synthese von gleichschenkeligen Gelenkvierecken, die eine symmetrische Koppelkurve mit bestapproximierendem Scheitelkrummungskreis erzeugen, werden einfache Formeln abgeleitet. Zur ersten Auswertung derselben wird überdies eine bequem verwendbare Kurventafel bereitgestellt.
Monotone Einschließung der Moore‐Penrose Pseudoinversen einer Matrix
Authors: Mönch W. 
Published: June 2007

AbstractEs werden Iterationsverfahren vom Schulz‐Typ angegeben, die eine monotone Einschließung der Moore‐Penrose Pseudoinversen A+ einer vorgegebenen Matrix A erzeugen. Die Verfahren konvergieren überlinear gegen A+.
On Plane Plastic Flow of Compressible Solids
Authors: Telega J. J. 
Published: June 2007

AbstractEquations of plane compressible flow of perfectly‐plastic solids are derived from a three‐dimensional, tensorially nonlinear theory of Sawczuk and Stutz. In plane flow the flow rule reduces to a linear relation. The flow law is, in general, not associated with the yield condition. The system of stress and velocity equations may be hyperbolic, parabolic or elliptic depending upon the material constants and dilatancy. The second order effects manifest in the expressions describing the stress and velocity fields, the yield condition and the power of dissipation.
Ein Modell für eine Klasse von Aufgaben optimaler Steuerung
Authors: Bittner Leonhard 
Published: June 2007

AbstractIn dieser Arbeit wird eine abstrakte Steuerungsaufgabe formuliert. Dafür werden notwendige Optimalitätsbedingungen hergeleitet. Das untersuchte Modell stellt eine um zusätzliche Nebenbedingungen erweiterte Fassung des in [1] betrachteten dar und hat eine gewisse Ähnlichkeit zu einem nichtlinearen Optimierungsproblem in Banach‐Räumen. Es ergeben sich notwendige Optimalitätsbedingungen in Form von Variationsungleichungen, die bei passender Konkretisierung Maximumprinzipe und Transversalitätsbedingungen liefern.
Auxiliary Functions for Non‐Stationary One‐Dimensional Diffusion under Forced Convection. Basic Properties and Applications
Authors: Kahlig P. 
Published: June 2007

AbstractIn the first part, basic properties of a class of functions (called Omega‐functions) are investigated, e.g. series representation, recurrence relation, asymptotic behavior. In the second part, beginning with Section 12, the solution of some versions of the diffusion equation by a series of Omega‐functions is treated. Omega‐functions may be used as auxiliary functions in the case of onedimensional non‐stationary diffusion under forced convection with or without removal process.
Sprungrelationen und zugehörige Transportgleichungen für die Bachschen Feldgleichungen
Authors: Günther Paul 
Published: June 2007

AbstractIn a general curved space‐time, for which the Bach‐field‐equations are fulfilled, the jump‐relations for the jumps of the fourth derivatives of the fundamental tensor on a characteristic surface are considered. In contrast to the Einstein equations in general the jump‐tensor has not only pure transversal, but also longitudinal‐transversal components. The jump‐tensor satisfies a linear transport equation of second order, the longitudinal‐transversal components satisfy a separate transport equation of first order.
Bestimmung der Temperaturverteilung in einem stromdurchflossenen Körper
Authors: Gröger K. , Schleiff M. 
Published: June 2007

AbstractThe present paper is concerned with a system of equations describing the stationary interaction of temperature and electrical tension in a 3‐dimensional body in the case that the electrical conductivity depends on the temperature. It is shown that this system is solvable. This is achieved by reduction of the system to an equation with a pseudo‐monotone operator. A short report is given on attempts to determine temperature and tension in an electrode numerically.
Liquid C‐18 saturated acids derived from linseed oil
Authors: Friedrich J. P. , Teeter H. M. , Cowan J. C. , McManis G. E. 
Published: June 2007

AbstractLiquid C‐18 saturated monocarboxylic acids that fail to crystallize at 蜢70ŶC. have been prepared from linseed oil, linolenic acid, and tung oil. Heating one part of linseed oil in three parts of glycol (weight‐volume ratio) at 295ŶC. for 1 hr. with 25% excess sodium hydroxide, followed by distillation and hydrogenation of the resulting free fatty acid monomers and separation of the straight‐chain components by low temperature crystallization from acetone, yielded these liquid acids.The relative proportions of cyclic acids, straight‐chain monomeric acids, and polymer varied with the type of starting material and with the conditions employed. Cyclic acids in excess of 30% yields were obtained from linseed oil. Some hydroxylation of the fatty acids apparently takes place during cyclization; the amount increases with ascending temperatures, as evidenced by a rise in polyester content of the polymer fraction.Evidence indicates that the bulk of the unhydrogenated cyclic acids are vicinal disubstituted cyclohexadienes. Gas chromatography of the cyclic acids hydrogenated to an iodine value <1 shows that there are several components. These have not as yet been separated and positively identified.
Solubilization of fatty soils by a radiotracer technique
Authors: Ginn M. E. , Brown E. L. , Harris J. C. 
Published: June 2007

AbstractA technique for measurement of solubilized radiotagged triolein and tristearin fatty soils is described. By using surfactant solutions under standardized conditions of temperature and agitation, the solubilized soils are removed from emulsified materials by filtration through 0.1 and 0.01 micron‐pore size of filters. The radiotagged fat is recovered by solvent extraction from the clear filtrate by salting‐out under centrifugal force and is measured by conventional counting technique.The nonionic alkanol‐ and alkylphenol‐ethylene oxide (EO) adducts solubilized up to 0.058% triolein (weight percentage at 75ŶC.) while anionic surfactant and sodium tripolyphosphate solubilization was negligible. These findings suggest for these nonionics that solubilization is one of the main, if not the controlling factor in the mechanism of soil removal. Nonionic solubilization was at a maximum for 10 molar EO adducts and at near cloud‐point temperatures.For the same surfactant more triolein than tristearin was solubilized, possibly on account of spatial considerations. For tridecanol‐10 EO at 0.25% the heat of solubilization of triolein, खHs, was 15 kcal/mole while the heat of micellization of the adduct was 1.3 kcal/mole of adduct. Differences in the colloidal ion lengths of the micelles and their aggregation numbers may explain the differences in solubilization between the anionic and nonionic surfactants tested.
Carbonyls in oxidizing fat. V. The composition of neutral volatile monocarbonyl compounds from autoxidized oleate, linoleate, linolenate esters, and fats
Authors: Gaddis A. M. , Ellis Rex , Currie G. T. 
Published: June 2007

AbstractThe steam volatile monocarbonyl compounds in mildly autoxidized esters of oleic, linoleic, linolenic acids, and animal and vegetable fats were quantitatively estimated. The major aldehydes in oleate and linoleate were those that might be expected from the scission of reported monomeric hydroperoxide isomers. The predominance of hept‐2,4‐dienal and propanal in linolenate suggested that the major monomeric hydroperoxides were 12‐and 16‐hydroperoxy conjugated dienoic isomers. The number of minor aldehydes increased with degree of unsaturation of the fatty acid. The amounts of monocarbonyl compounds in the fats examined generally agreed with their average fatty acid composition. Appreciable amounts of heptanal in lamb and beef fat and heptanal and decanal in butterfat, under the conditions of oxidation, could not have come from the three unsaturated acids. Heating at 165ŶC. in all samples increased the proportions of the most unsaturated major aldehydes.
Enzymatic transesterification of palm olein with nonspecific and 1,3‐specific lipases
Authors: Ghazali H. M. , Hamidah S. , Che Man Y. B. 
Published: June 2007

AbstractThe enzymatic transesterification of palm olein was conducted in a low‐moisture medium with nonspecific and 1,3‐specific lipases from microbial sources. The enzymes were first immobilized on Celite, lyophilized for 4 h and then added to a reaction medium that consisted of 10% (wt/vol) palm olein in water‐saturated hexane. The catalytic performance of the enzymes was evaluated by determining the changes in triglyceride (TG) composition and concentrations by reverse‐phase high‐performance liquid chromatography (HPLC) and the formation of free fatty acids by titration. Studies with lipase fromCandida rugosa showed that the degree of hydrolysis was reduced by drying the immobilized preparation and that the best drying time was 4 h. In all cases, the transesterification process resulted in the formation of PPP, a TG initially undetected in the oil, and increases in the concentrations of OOO (1.3–2.1‐fold), OOL (1.7–4.5‐fold), and OLL (1.7–4.3‐fold), where P, O, and L are palmitic, oleic, and linoleic acids, respectively. SOS (where S is stearic acid), another TG not detected in the oil, was synthesized byRhizomucor miehei andPseudomonas lipases, with the latter producing more of this TG. There was a corresponding decrease in the concentrations of POP, PLP, POO, and POL. PPP concentration ranged from 1.9% (w/w) forMucor javanicus lipase to 6.2% (w/w) forPseudomonas lipase after 24 h. The greatest degree and fastest rate of change were caused byPseudomonas lipase, followed by the enzymes fromR. miehei andAspergillus niger. The effects of transesterification and hydrolysis of palm olein by the various lipases resulted in changes in the overall degree of saturation of the triglyceride components. There seems to be no clear correlation between the enzyme positional specificity and the products formed. Possible mechanisms for the formation of PPP, OOL, OLL, OOO, and SOS are discussed.
Alternative hydrocarbon solvents for cottonseed extraction: Plant trials
Authors: Wan P. J. , Hron R. J. , Dowd M. K. , Kuk M. S. , Conkerton E. J. 
Published: June 2007

AbstractHexane has been used for decades to extract oil from cottonseed and is still the solvent of choice for the edible‐oil industry. Due to increased regulations as a result of the 1990 Clean Air Act and potential health risks, the edible‐oil extraction industry urgently needs an alternate hydrocarbon solvent to replace hexane. Based on laboratory‐scale extraction tests, two hydrocarbon solvents, heptane and isohexane, were recommended as potential replacements for hexane. A cottonseed processing mill with a 270 MT/day (300 tons/day) capacity agreed to test both solvents with their expander‐solvent process. Extraction efficiencies of isohexane and heptane, judged by extraction time and residual oil in meal, refined and bleached color of miscella refined oil, and solvent loss, were comparable to that of hexane. However, fewer problems were encountered with the lower‐boiling isohexane than with the higher‐boiling heptane. With isohexane, the daily throughput increased more than 20%, and natural gas consumption decreased more than 40% as compared to hexane.
n‐fatty acids: Comparison of published densities and molar volumes
Authors: Fisher Charles H. 
Published: June 2007

AbstractBecause some publishedn‐fatty acid densities and molar volumes disagree significantly with others, an attempt was made, based primarily on the principle of homology, to distinguish between reasonably accurate and inaccurate data. Literature densities compatible with each other and with requirements of homology (including limiting densities) were identified. These densities, considered to be at least reasonably accurate, were used as standards and compared with other published densities. Most publishedn‐fatty acid densities, judged by these criteria, appear to be reasonably accurate.
Determination of oxidation stability of soybean oil with the oxidative stability instrument: Operation parameter effects
Authors: Hill Steven E. , Perkins Edward G. 
Published: June 2007

AbstractOperation parameters of the oil stability index instrument were evaluated to determine their effect on the oxidative stability of commercial soybean oil. A factorial design was developed to evaluate the following three parameters, each at two levels, sample weight (2.5 or 5.0 g), conductivity tube temperature (20 or 30°C), and air flow rate (12 or 20 L/h), for a total of eight observations. Significance testing indicated that sample size and air flow rate affected oil oxidative stability independently (P<0.001), but not in combination. The conductivity tube temperature did not affect the oxidation stability index.
Carica papaya latex lipase:sn‐3 stereoselectivity or short‐chain selectivity? Model chiral triglycerides are removing the ambiguity
Authors: Villeneuve P. , Pina M. , Montet D. , Graille J. 
Published: June 2007

AbstractShort‐chain fatty acids are usually located at positionsn‐3 in natural triglycerides, particulary in dairy fats. As a result, it is extremely difficult to differentiate betweensn‐3 stereospecificity and short‐chain typoselectivity in many lipases and acyltransferases that perform in this way. This ambiguity can be removed through successive use of a chiral triglyceride with a short fatty acid in positionsn‐1 and of its racemic in controlled hydrolysis reactions. After checking that the proposed method effectively confirmed the type of activity of control biocatalysts (Candida cylindracea nonspecific lipase andMucor miehei 1–3 regiospecific lipase), we confirmed thatCarica papaya latex has a strictsn‐3 stereospecificity.
Measurement and assessment of substrates containing fluorescent whitening agents
Authors: Anders G. , Daul C. 
Published: June 2007

AbstractWhite, as a color sensation, can be determined by colorimetric methods of measurement. With other than colorimetric methods, no satisfactory correlation between measured value and visual assessment can be expected. The contribution of hue, saturation and luminosity to the degree of whiteness as found by six formulas widely used in industry was analyzed and the results were plotted in the form of a graph. An easy‐to‐use nomogram for whiteness determination was developed, based on the CIE 1931 2°‐color system. Another nomogram is presented which provides an easy means to determine the hue of a sample treated with fluorescent whiteining agents (FWAs). The new whiteness determination is based on the measurement of true tristimulus values for fluorescent samples using the new International Commission on Illumination standard illuminant D 65. The magnitude of the just perceptible difference in whiteness was determined in a panel test using 11 samples and 22 observers. The results were evaluated statistically. Pending standardization of an illuminant, not only for colorimetric measurements, but also for visual assessment of white samples containing FWAs, it would scarcely seem possible to arrive at a more accurate determination of degrees of whiteness. All visual rankings of fluorescent white substrates are widely scattered around a mean value for the different phases of natural daylight. The relative energy emitted by artificial daylight lamps in the near UV region is insufficient in many cases. Xenon lamps are quite satisfactory for instrumental evaluation. In an internationally approved system, with a known hue preference, it would be possible to compare an objective measured value with each subjective result obtained by visual evaluation.
Oxidation at intermediate moisture contents
Authors: Labuza T. P. , Heidelbaugh N. D. , Silver M. , Karel M. 
Published: June 2007

AbstractIn the study of the oxidation rate of methyl linoleate in protein and cellulose systems, a prooxidant effect was found at intermediate moisture contents. At low water content, water hydrates metals and hydrogen bonds with peroxides, and an overall decrease in the rate of lipid oxidation results. With an increase in the water content to the region with a water activity of 0.6 to 0.7, the water predominantly acts as a solvent to dissolve and mobilize previously unavailable trace metals with the result of increased oxidation rates. Use of chelating agents such as ethylenediaminetetraacetic acid and citric acid reduced oxidation significantly although some antioxidant activity was also observed for butylated hydroxyanisole. These results have important implications in the preparation of intermediate moisture foods.
A simplified method for the evaluation of antioxidants
Authors: Miller H. E. 
Published: June 2007

AbstractA procedure is described for rapid evaluation of antioxidants. Dilute aqueous emulsions of an antioxidant, carotene and lipid were prepared in spectrometer tubes. The oxidative destruction of carotene in the emulsion was observed directly with a colorimeter. The antioxidants were then evaluated according to their effect on the rate of carotene decolorization.
Some problems in altering the gossypol content of cottonseed through breeding
Authors: Lee Joshua A. 
Published: June 2007

AbstractCultivated cottons have small, pigment‐bearing glands in their embryonic tissues or seed meats. These glands contain gossypol, a polyphenolic substance toxic to various animals. The presence of glands in cottonseed is controlled by alleles at two loci. Substitution of mutant alleles for active alleles at both loci produce cottons that are devoid of glands and gossypol. Glandlessness is thus a character of great potential worth, and breeders seek to develop glandless varieties of cotton which give high yields of quality fiber. Although some success has been achieved, recent work shows that both glandless genes are linked to factors which reduce yield of fiber. Methods for ameliorating these difficulties are discussed.
Hydroformylation of unsaturated fatty esters
Authors: Frankel E. N. , Metlin S. , Rohwedder W. K. , Wender I. 
Published: June 2007

AbstractUnsaturated fatty esters and vegetable oils were hydroformylated with H2 and CO (3500–4600 psi) and Co2(CO)8 to give fatty aldehydes at 100–110 C and fatty alcohols at 175–190 C. Yields of distillable C19 oxo products varied from 42% to 84%. Distilled products contained from 50% to 90% branched isomers and from 4% to 16% linear isomers. The proportion of linear isomers increased at higher reaction temperatures and in the presence of tributylphosphine‐cobalt carbonyl complex. Linear and branched hydroxy products were separated by silicic acid column, thin‐layer, and gas‐liquid chromatography. The linear hydroxy product (from oleate and linoleate) was identified as methyl 19‐hydroxynonadecanoate by nuclear magnetic resonance and mass spectrometry. Isomeric branched products were analyzed by mass spectrometry as the diester derivatives. They were identified as a mixture of 5‐ to 13‐carbomethoxy methyl octadecanoate.
Hydrogenation of unsaturated fatty acids to unsaturated fatty alcohols: II. Kinetics and mechanism of the reaction using Cu and Cd oleates as catalysts
Authors: Richter J. D. , van den Berg P. J. 
Published: June 2007

AbstractThe kinetics and mechanism of the Cu and Cd‐soap‐catalyzed hydrogenation of oleic acid have been studied. The reaction is first order in Cd and H2, and also first order in Cu if the double bond is completely preserved during reduction of the carboxyl group to the hydroxyl group. It will deviate from this order if the selectivity is lower owing to an increased Cu concentration. The reaction rate‐determining step is independent of the Cd concentration. Its activation energy, of 13.4 kcal/mole, corresponds to that of the chemisorption of hydrogen on Cu. Unsaturated and saturated fatty acids of the same chain length have the same reaction rate. A decrease of the chain length causes a decrease in the reaction rate and in the final degree of conversion. Water and low molecular weight acids have an inhibitory effect on the reaction. A reaction mechanism is proposed which is based on the assumption that cadmium oleate plays a double role: it stabilizes the copper sol and is intermediate for the hydrogenation.
Oxidative stability of safflower oil
Authors: Bratcher Sharon S. , Kemmerer A. R. , Rubis D. D. 
Published: June 2007

AbstractOils from a number of varieties of safflower (Carthamus tinctorius L.) seeds (achene) were measured for oxidative stability by the gain in weight method. The induction periods of oils containing 75% to 80% linoleic acid ranged from 288 to 715 hr. Safflower oils containing 79% to 80% oleic acid and only 11% to 15% linoleic acid had induction periods ranging from 1274 to 2374 hr. No correlation between induction period and total tocopherol content was observed. However, there were indications that oils from pigmented seeds were less stable than oils from pigmentless seeds. Blending of an oil containing a high amount of linoleic acid with an oil containing a high amount of oleic acid gave a blend with an induction period intermediate between the two. However, the induction period was considerably less than the theoretical average calculated for the mixture.
The formation of 1‐octen‐3‐ol in soybeans during soaking
Authors: Badenhop A. F. , Wilkens W. F. 
Published: June 2007

AbstractThe soaking of soybeans in water as a pretreatment for soy milk manufacture was found to result in the production of significant quantities of 1‐octen‐3‐ol. The amount of this compound formed at a soak temperature of 50 C increased with length of soak time and reached a maximum after approximately 6 hr. The rate of formation had a pH optimum of 6–7. A pure fraction of 1‐octen‐3‐ol, isolated by a preparative GLC technique, was found to be levorotatory ([a]D17 = −11.7; [a]D13 = −11.8). Based on these findings, the mode of formation of 1‐octen‐3‐ol in this case is presumed to be enzymatic. The flavor threshold of 1‐octen‐3‐ol in soy milk was determined to be between 0.5 and 1.0 ppm.