bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iteration of Runge‐Kutta Methods with Block Triangular Jacobians
Authors: van der Houwen P. J. , Sommeijer B. P. 
Published: May 2007

AbstractWe shall consider iteration processes for solving the implicit relations associated with implicit Runge‐Kutta (RK) methods applied to stiff initial value problems (IVPs). The conventional approach for solving the RK equations uses Newton iteration employing the full righthand side Jacobian. For IVPs of large dimension, this approach is not attractive because of the high costs involved in the LU‐decomposition of the Jacobian of the RK equations. Several proposals have been made to reduce these high costs. The most well‐known remedy is the use of similarity transformations by which the RK Jacobian is transformed to a block‐diagonal matrix the blocks of which have the IVP dimension. In this paper we study an alternative approach which directly replaces the RK Jacobian by a block‐diagonal or block‐triangular matrix the blocks of which themselves are block‐triangular matrices. Such a grossly ‘simplified’ Newton iteration process allows for a considerable amount of parallelism. However, the important issue is whether this block‐triangular approach does converge. It is the aim of this paper to get insight into the effect on the convergence of block‐triangular Jacobian approximations.
Inequality Forms of D'Alembert's Principle in Mechanics of Systems with Holonomic Unilateral Constraints
Authors: Goeleven D. , Panagiotopoulos P. D. , Lebeau C. , Plotnikova G. 
Published: May 2007

AbstractThis paper concerns the study of superpotential laws in analytical mechanics which may be derived from generally non‐everywhere differentiable energy functions through subdifferentiation. A generalization of d'Alembert's principle is proposed dealing with problems involving unilateral constraints.
Optimal Design of an Elastic Plate with Unilateral Elastic Foundation and Rigid Supports, Using the Reissner‐Mindlin Plate Model. II: Approximate Problems
Authors: Hlaváček I. , Lovíšek J. 
Published: May 2007

AbstractApproximate optimal design and weight minimization problems are proposed, making use of mixed‐interpolated finite elements methods. The design variables — i.e., the thickness of the plate and the stiffness of the foundation are approximated by piecewise affine functions. The solvability of the approximate problems is proved and some convergence analysis is presented.
Magneto‐Micropolar Fluid Motion: On the Convergence Rate of the Spectral Galerkin Approximations
Authors: Rojas‐Medar M. A. 
Published: May 2007

AbstractIn this work we study error estimates and their respective convergence rates for approximate solution of spectral Galerkin type for the equations of motion of a magneto‐micropolar fluid in a bounded domain. We find error estimates that are optimal in the H1‐norm as well as estimates in the L2‐norm with improved rate with respect to the one immediately derived from the previous H1‐error estimate.
Thermal Buoyancy Convection in Vertical Zone Melting Configurations
Authors: Bárwolff G. , König F. , Seifert G. 
Published: May 2007

AbstractA numerical method has been performed to explain and interpret oscillating convection phenomena in the vertical zone melting technique. The governing equations are solved in a cylindrical coordinate system using the finite volume method. The thermal boundary conditions were taken from experimental data. The aspect ratio or was varied within the range of 1 ⩽ ar ⩽ 3. Two‐dimensional calculations with application of parabolic boundary temperature show always steady axisymmetric behaviour of the convection. Only the three‐dimensional calculation yields the transition to non‐axisymmetric, time‐dependent (unsteady) flow. Furthermore the necessity of using thermal boundary conditions by a heat flux density q instead of a fixed parabolic temperature profile was demonstrated. The torus‐like flow changes at ar ≃ 1.45…1.5 to a single roll flow pattern. This single roll shows an unsteady behaviour with increasing aspect ratios and Rayleigh numbers, respectively. The comparison of the numerical results with experimental data shows a good qualitative correlation.
Polymers derived from 9,10‐dihydroxystearic acid
Authors: Morriss F. V. , Bechtle G. F. , Gadberry H. M. 
Published: May 2007

AbstractA number of film forming polyester resins have been produced from 9,10‐dihydroxystearic acid. The resins cured readily at room temperature when crosslinked with 20% toluene diisocyanate to form flexible films. The properties of the films indicated that useful, internally plasticized polyester resins can be readily obtained from condensations of 9,10‐dihydroxystearic acid and polybasic acids. Maleic anhydride derived films gave the most desirable propertios.
Regeneration of carbonyl compounds from 2,4‐dinitrophenylhydrazones with sulfuric acid
Authors: Bassette Richard , Day E. A. 
Published: May 2007

AbstractA simple, rapid method employing sulfuric acid and water to regenerate earbonyl compounds from 2,4‐dinitrophenylhydrazones is presented. The method was evaluated by using a number of DNP‐hydrazones of alkanals, alkan‐2‐ones, and 2‐alkenals and was found to give recoveries ranging from 23 to 61%. The procedure makes possible rapid organoleptic observations and is well adapted for recovery of the free carbonyl compounds for other studies.
Preparation of petroselinic acid
Authors: Fore Sara P. , Holmes Raiford L. , Bickford W. G. 
Published: May 2007

AbstractPetroselinic acid of a grade which is suitable for most laboratory applications has been prepared by a single crystallization of the mixed fatty acids of parsley seed oil from 90% ethanol. A product of higher purity has been prepared from this acid by application of urea segregation techniques for the removal of saturated materials. No evidence of the presence of unsaturated fatty acids other than petroselinic acid was found in either of these samples when their ozonolysis products were examined chromatographically. On the basis of iodine values, assuming the absence of other unsaturated materials, the purities of the two preparations are 96.0 and 99.4%.
Evidence for cyclic monomers in heated linseed oil
Authors: Macdonald J. A. 
Published: May 2007

SummaryThe monomeric, non‐urea‐adduct‐forming material from the ethanolysis of heated linseed oil exhibits an infrared absorption band at 660 cm.−1 (15.2 μ). This absorption is not present in the spectrum of the esters of unheated linseed oil acids or in that of the adduct‐forming esters prepared from heated linseed oil. The monomeric, non‐urea‐adduct‐forming material, on aromatization and oxidation, yielded about 1% of phthalic anhydride, thus providing chemical evidence for the existence in this material of a compound containing an unsaturated six‐membered ring.
The chemistry of polymerized oils. V. The autoxidation of methyl linoleate
Authors: Sephton H. H. , Sutton Donald A. 
Published: May 2007

Summary1. The geometrical forms obtained during autoxidation of methyl linoleate at ordinary temperatures are largely conjugatedcis‐trans andtrans‐trans as shown by previous workers; there is a possibility that conjugatedcis‐cis forms are also produced.2. Thetrans‐trans molecules arise partly, at least, by thermal rearrangement of already formedcis‐trans peroxide.3. Some proportion, at least, of thecis‐trans molecules have theirtrans double bonds nearest to the hydroperoxide group.4. A partial separation of the geometrical forms can be accomplished by reversed phase partition chromatography both on methyl linoleate hydroperoxides and on the corresponding mixed hydroxy compounds; isolation of thetrans‐trans forms can be accomplished in the latter case by urea complex fractionation.5. No position isomers except the known 9‐ and 13‐isomers have been positively identified; there is a possibility that very minor amounts of the 2‐isomer are formed; the 9‐ and 13‐isomers are present in about equal amounts; the 11‐isomer was not detected by the methods applied.6. Various ways in which the linoleate autoxidation problem might be advanced further are suggested.
Semimicro determination of total fatty acids and unsaponifiable matter
Authors: Benedict James H. 
Published: May 2007

AbstractA semimicro method for determining both total fatty acids and unsaponifiable matter in fats, fatty acids, and soap is presented. The procedure involves saponification and recovery of the total fatty acids (which includes the unsaponifiables), removal of the fatty acids with anion exchange resins, and determination of the unsaponifiable matter by weight.The total fatty acid method was evaluated on seven samples and showed a standard deviation from the mean of 0.21%. The unsaponifiable matter determination gives good reproducibility with a standard deviation from the mean of 0.06%. Since this ion exchange is a direct determination of the nonionic components, the results obtained from it should be more accurate and more nearly the true values than the macro extraction method which is empirical.
Continuous refining of crude coconut oil in a pressure system
Authors: Sullivan Frank E. 
Published: May 2007

ConclusionA continuous proces for refining crude coconut oil has been described. This Hermetic system provides a means for continually controlling the variables of time, temperature, and reagent on a scientific, predictable basis. By utilizing the phase diagram as a guide for the correct conditions and employing a continuous process designed to maintain these conditions, it is always possible to obtain high yield refining results on crude coconut oil.
Reactions of tertiary butyl hypochlorite with vegetable oils and their derivatives. V. Dechlorination of chlorinated soybean oil with aqueous solutions of salts
Authors: Teeter H. M. , Myren R. A. 
Published: May 2007

SummaryDrying oils have been prepared by dechlorination of chlorinated soybean oil with aqueous solutions of basic salts such as sodium bicarbonate, sodium acetate, disodium hydrogen phosphate, and sodium tetraborate. These drying oils may prove useful in paints and varnishes.
Trends in the oilseed industry
Authors: Goss Warren H. 
Published: May 2007

ConclusionsIt is hardly feasible to mention here a host of additional trends now apparent in our industry. Neither is it possible to foresee with sufficient clarity the importance that will be attached one year or ten years hence to those trends which we have just discussed. By a thorough study of these however, including the economic situation responsible for them and the effects they will have on the oilseed and oil markets, we can formulate some insight into the course of the oilseed industry in the years ahead. We hope that this discussion, when viewed in retrospect next year or at a future date, will prove to have been accurate in at least some respects as an indieator of future developments.
Standardization of spectrophotometric methods for determination of polyunsaturated fatty acids using pure natural acids
Authors: Brice B. A. , Swain M. L. , Herb S. F. , Nichols P. L. , Riemenschneider R. W. 
Published: May 2007

SummarySpectrophotometric methods of analysis for the polyunsaturated constituents of oils and fats have been carefully restandardized for several conditions of alkali‐isomerization, using purified methyl esters of linoleic, linolenic, and arachidonic acids prepared by physical rather than by chemical means. A number of vegetable oil and animal fat samples were subjected to spectrophotometric analysis, and the results based on natural and on bromination‐debromination fatty acid standards were compared. The natural fatty acid standards lead to significantly higher accuracy and their use in the spectrophotometric analysis of natural fatty materials is strongly recommended. Results obtained under different conditions of isomerization were in satisfactory agreement. An isomerization time of 45 minutes is recommended rather than 25 or 30 minutes. The glycerol‐air technique is preferred for general use because of its simplicity and high precision. The ethylene‐glycol‐nitrogen technique is a close second choice because of the greater transparency of reagent blanks.
The chemistry of polymerized oils. I. Characteristics of some pilchard stand oil fractions
Authors: Joubert F. J. , Sutton Donald A. 
Published: May 2007

Summary

Present‐day knowledge of the composition and mode of formation of stand oils is briefly reviewed.

One pilchard stand oil of low viscosity has been separated by molecular distillation into non‐polymeric and polymeric triglycerides.

The non‐polymeric triglycerides contain, a very low proportion of fatty acid chains linked together in contradiction of a published hypothesis.

The polymeric triglycerides have been separated into three broad sub‐fractions, the number average molecular weights of which have been determined by an isothermal distillation method.

The polymeric triglyceride sub‐fraction of lowest molecular weight was shown to contain an appreciable proportion of linked fatty acid chains.
Carbohydrate constituents of soybean “lecithin”
Authors: Scholfield C. R. , Dutton Herbert J. , Dimler Robert J. 
Published: May 2007

SummaryThe carbohydrates present in commercial soybean lecithin consist of two types: free sugars which can be removed by extraction with 55% alcohol, and bound sugars which remain with the phosphatides. The free sugars consist mainly of sucrose and stachyose with a smaller amount of raffinose. Upon extraction of phosphatides with absolute alcohol, the sucrose is found mainly in the absolute alcohol‐soluble fraction, the stachyose in the insoluble fraction, and the raffinose in both fractions.The greater part of the bound sugars are found with that phosphoinositide fraction which is more hexane soluble. These bound sugars consist of galactose, mannose, and arabinose. The arabinose is easily freed by mild acid hydrolysis and all three sugars are freed by refluxing with 2 N H2SO4. The same three sugars together with a smaller amount of an unidentified sugar are found in the corresponding fraction of corn phosphatides. In the absolute alcohol‐soluble fractions of both soy and corn phosphatides the bound sugar consists of glucose and galactose.
Reactions of tertiary butyl hypochlorite with vegetable oils and their derivatives. VII. Partial chlorination of soybean oil
Authors: Teeter H. M. , Bell E. W. , Woods L. C. 
Published: May 2007

SummarySoybean oil has been partially chlorinated by treatment with from 0.1 to 1.0 equivalent oft‐butyl hypochlorite per equivalent of oil. The products were dechlorinated by autoclaving with aqueous sodium acetate solution, and the stability of the residual halogen in the dechlorinated oils was determined by a heat test.It was found that oils halogenated with 0.5 equivalent or less of hypochlorite were more completely dechlorinated than those halogenated with larger amounts of hypochlorite and that the residual halogen in the dechlorinated oils produced was more stable.
The centrifugal acetone foots test applied to crude soybean oil. II. Rapid method compared with other measures of phosphatides content and refining loss
Authors: Freyer Egbert , Shelburne Victor 
Published: May 2007

SummaryComparisons are made between eight methods of grading crude soybean oil with respect to a laboratory refining loss determination which closely simulates commercial wash kettle practice. This list of methods includes the five analysis factors, acetoneinsoluble, HCl heat break, centrifugal foots, phosphorus and ash contents, each combined with percentage of ffa and moisture and volatile. It includes the official A.O.C.S. cup loss, the Wesson loss, and the chromatographic absorption loss determinations. On 12 crudes on which laboratory wash extraction loss and losses determined from centrifugal foots values, from acetone‐insoluble contents, and from HCl break values were available, the centrifugal foots values best predicted the refining loss. The standard deviations of each method from the wash extraction loss were, respectively, 0.21%, 0.27%, and 0.29%. On seven of these crudes on which all nine determinations were available, acetone insoluble content showed the best correlation, followed by centrifugal foots and HCl heat break. The centrifugal foots test generally gives zero or trace results on degummed oil. By use of this method however the refining loss grade of crude soybean oils may be estimated in as little as one hour of elapsed time, and it requires only 5 to 10 minutes of the operator's time.
The iodine number of lanolin
Authors: Punnett P. W. , Rebarber A. 
Published: May 2007

ConclusionThe determination of the iodine value of U.S.P. anhydrous lanolin is an empirical one. Very close attention is necessary to the various factors concerned in the determination, sample weight, Hanus reagent strength, time, and temperature.The addition of mercuric acetate will speed up the iodination markedly, but again details of the determination will have to be determined.
Application of urea complexes in the purification of fatty acids, esters, and alcohols. I. Oleic acid from inedible animal fats
Authors: Swern Daniel , Parker Winfred E. 
Published: May 2007

SummaryUrea complex formation has been employed in the preparation of purified oleic acid (oleic acid content, 80–95%) from various grades of inedible animal fats and red oils. Since the urea complex of oleic acid forms in good yield at room temperature, low temperatures are not required in the isolation procedure. Yields of oleic acid are equal to or lower than those obtained by conventional low‐temperature crystallization procedures, but the preparation of a polyunsaturate‐free oleic acid is apparently not possible by urea complex formation alone. The separation of polyunsaturated acids from oleic acid by urea complex formation is more convenient than but not as efficient as by solvent crystallization, but separation of saturated acids from unsaturated acids is less convenient.Advantages and disadvantages in using urea in the preparation of purified oleic acid are briefly discussed.
Pilot plant desolventization of fine cottonseed meal
Authors: Graci A. V. , Gardner H. K. , Cucullu A. F. , Crovetto A. J. , Spadaro J. J. , Knoepfler N. B. 
Published: May 2007

Summary
The continuous desolventization of fine cotton‐seed meal has been successfully accomplished in a modified pilot‐plant meal dryer of the screw‐conveyor type under controlled conditions. The work should also have application in commercial solvent‐extraction where a general fines problem (1) exists.
Free gossypol content has been reduced as much as 69% during the desolventization operation without appreciably affecting the protein solubility of the meal.
A meal in granular form can be obtained, provided the feed material has certain physical characteristics. This granulation, or essentially pelleting, effect should have application particularly in nutritional work where the feeding of meal in pellet form of various sizes is required. It is believed that a number of conditions contributed to the granulation. The most important was probably the high density of the material which was fed in a compressed or extruded form. It is likely that the fineness of the material, the moisture content, and the solvent content contributed to this consolidation during desolventization, but the quantitative effect of these variables has not been determined. It is thought that any material that can be made to hold together during the initial part of the desolventization will tend to produce a granulated product at the end of the drying period.
Trans‐octadecenoic acid content of beef fat. Isolation of elaidic acid from oleo oil
Authors: Swern Daniel , Knight H. B. , Eddy C. Roland 
Published: May 2007

SummaryInfrared spectrophotometric examination of three samples of freshly‐rendered edible beef fat, and of edible oleo oil and oleo stearine obtained from one of them, has revealed the presence of substantial quantities (5 to 10%) of trans materials believed to the mainly, if not exclusively, monounsaturated. It has been concluded that the trans components are neither minor nor adventitious constituents but important naturally‐occurring components which may contribute to any unique properties which beef fat may have.It is proposed that trans‐octadecenoic acids arise in beef fat as a result of an oxidative cis‐trans isomerization coupled with double bond shift, reactions now known to occur in oxidizing fat systems, or by a simple oxidative cis‐trans isomerization without double bond shift of oleic or other isomeric cis‐octadecenoic acids which may be present in beef fat.Trans‐9‐octadecenoic (elaidic) and vaccenic acids have been isolated from oleo oil, the former‐acid apparently for the first time.
Pre‐treatment of peanut kernels for effective skin removal
Authors: Pominski J. , D'Aquin E. L. , Molaison L. J. , McCourtney E. J. , Vix H. L. E. 
Published: May 2007

SummaryA new method for the removal of skins from peanut kernels by water‐treatment, drying, and blanching in a standard split‐nut blancher has been developed on a pilot‐plant scale. Optimum conditions for approximately 98% skin removal from U. S. No. 1 shelled Spanish peanuts by this method are water‐treatment at room temperature, to gain not less than 20%, drying with forced circulated air at 120° to 125°F. to approximately 4.5% moisture in the peanuts, and blanching. The lipids and protein losses resulting from the water‐washing action on the kernels were relatively low and less than those losses obtained by lye treatment of the kernels. The method however did not give satisfactory results with either shelled U. S. No. 2 or oil mill stock kernels.Meal prepared by hexane extraction of de‐skinned (98%) water‐treated U. S. No. 1 kernels had color and flavor characteristics superior to other hexane solvent‐extracted peanut meals for food utilization. Protein prepared from this meal had a light color equal to that produced from peanut kernels treated with 0.5% lye solution.
Relation between fatty acid composition and iodine value of cottonseed oil
Authors: Stansbury Mack F. , Hoffpauir Carroll L. 
Published: May 2007

SummaryThe regularity in the increase in linoleic, and in the decrease in oleic and saturated acids with increase in iodine value of cottonseed oils has been shown by obtaining the regression equation for the glyceride of each acid on the iodine value by use of the compositional data on 48 samples of oil ranging from 89.8 to 117.0 in iodine value. These equations offer a ready means of approximating the fatty acid composition of cottonseed oils from their iodine values. Such approximations may prove useful in the segregation of oils for different end uses.The compositional pattern of cottonseed oils is compared with those reported in the literature for soybean and linseed oils.
The glycerolysis of fat in tertiary aromatic nitrogeneous bases to increase monoglyceride yield
Authors: Mattil Karl F. , Sims Rex J. 
Published: May 2007

SummaryA method has been described for producing monoglyceride concentrates containing up to 78% of monoesters. It involves the interaction of fat with glycerol in a tertiary aromatic nitrogenous base such as pyridine, β‐ or γ‐picoline, 2,6‐lutidine, quinoline, or iso‐quinoline, and employs an alkaline interesterifieation catalyst such as sodium methoxide.
Metabolic effects of selenium as related to vitamin E
Authors: Bieri J. G. , Andrews E. I. 
Published: May 2007

AbstractTrace amounts of dietary selenium, which prevent certain vitamin E deficiency symptoms, have been found to affect the composition of chick tissues. Both selenium and vitamin E increased liver coenzyme A levels to normal when cystine was omitted from the diet. Liver and plasma total fatty acids were unaltered by selenium but vitamin E increased the arachidonic acid content slightly. There was no effect of either selenium or vitamin E on total lipid, cholesterol, phopholipid or coenzyme Q in liver. Low dietary levels of either selenium or vitamin E, which were insufficient in preventing deficiency symptoms, completely eliminated mortality from toxic amounts of a dietary antioxidant. The ability of dietary selenium to reducein vitro lipid peroxidation in chick liver homogenates was not demonstrable with rat liver.