bluuebunny/crossref_metadata_2025_split huggingface dataset:
Schweißen ermüdungsbeanspruchter Altstahlkonstruktionen – Untersuchungen zum Einfluss der Vorbelastung auf die Lebensdauer der Schweißkerbdetails
Authors: Lüddecke Falk , Mehdianpour Milad , Graße Wolfgang 
Published: August 2007

AbstractFür die Sanierung und Ertüchtigung bestehender, vorwiegend nicht ruhend beanspruchter Stahltragwerke mittels Schweißen ist bei der ingenieurmäßigen Bemessung neu eingebrachter Schweißverbindungen der Nachweis der Betriebsfestigkeit zu führen. Um für die Restlebensdauerermittlung den Anteil der vergangenen ermüdungsrelevanten Belastung abschätzen zu können, wurden experimentelle Untersuchungen durchgeführt. Hierbei erfolgte u.a. die Einprägung einer definierten Vorbelastung in einen äußerlich ungekerbten Grundwerkstoff, anschließend die Kerbung und die Ermüdungsbeanspruchung der Probe bis zum Bruch. Dieses Vorgehen repräsentiert einen bereits vorbelasteten Altstahl, an dem nachträglich eine Reparatur durchgeführt wurde. Aus den Ergebnissen lässt sich ableiten, dass die aufgebrachten Vorbelastungen in der Regel keinen signifikanten Einfluss auf die erreichbare Lebensdauer ausüben, wenn eine Oberflächenbearbeitung durchgeführt und ein ausreichender Einbrand gewährleistet wird. Dies bedeutet, dass die eingeprägte Vorgeschichte bestehender Konstruktionen beim Nachweis der Betriebsfestigkeit von neu eingebrachten Schweißkerbdetails vernachlässigt werden kann.
Doppelwaagebalkenbrücke – Vorschlag für einen innovativen Klappbrückentyp
Authors: Saul Reiner , Humpf Karl 
Published: August 2007

AbstractWaagebalkenbrücken wurden bisher immer als Einfeldträger ausgeführt, wobei sich die Überspannung wegen der gelenkigen Lagerung des Waagebalkens nur an der Abtragung der ständigen Last beteiligt. Wird dagegen die Verdrehung durch ein zweites Lager blockiert, wirkt die Überspannung auch an der Abtragung der Verkehrslasten mit. Dies ermöglicht es, Waagebalkenbrücken mit zwei Klappen auszuführen und damit den Stützweitenbereich zu verdoppeln.
Bemessung von strukturellen Silikon‐Klebungen
Authors: Hagl Anneliese 
Published: August 2007

AbstractWas ist erforderlich, wenn die Fügetechnik Kleben im konstruktiven Glasbau anwendet wird? Was sind die Gründe dafür, dass – obwohl der Werkstoff Silikon seit 40 Jahren bekannt ist – noch immer von einer Innovation gesprochen wird, wenn tragend mit Silikon geklebt wird? Was muss ein Ingenieur wissen, der sich an eine Bauaufgabe wagt, bei der er die Möglichkeit einer tragenden Verklebung ins Auge fasst?Offensichtlich fehlt hier das Wissen über die Tragmechanismen komplexerer Verklebungen, und es fehlen einfache Dimensionierungsmethoden, die helfen, bereits im Vorfeld einer genaueren Berechnung und/oder Versuchsdurchführung mit Hilfe einer einfachen Handrechnung das Tragpotential einer Verklebung abzuschätzen.Dieser Aufsatz hat das Ziel, an Hand von aktuellen Ergebnissen des Forschungsvorhabens “Geklebte Verbindungen im Glasbau” [1] der Fachhochschule München die Wirkungsweise komplexerer Verklebungsgeometrien aufzuzeigen und ein einfaches überschlägiges Bemessungskonzept vorzustellen.
“Instantaneous” sulfation of fatty alcohols
Authors: Whyte David D. 
Published: July 2007

ConclusionsA continuous process has been developed for sulfating fatty alcohols with sulfuric acid up to 100% H2SO4concentration.The success of the process depends on maintaining a proper balance among the factors of temperature, reaction time, acid strength, and acid usage.In general, best results accrue from use of as strong acid as is permissible (99% in plant operations), about 160°F. and 10 seconds reaction time.Neutralization is quite simple, requiring only efficient mixing and adequate heat removal.
Sesamin, sesamolin, and sesamol content of the oil of sesame seed as affected by strain, location grown, ageing, and frost damage
Authors: Beroza Morton , Kinman Murray L. 
Published: July 2007

SummaryThe effect of strain and location grown on the sesmin, sesamolin, and sesamol content of oils from sesame seed chosen to represent a wide variety of genetic material is reported. Only differences in sesamin content due to strain were significant.Three of four oils exposed as the oil to 100°F. became rancid in two to three months. Rancidity of the oil was accompanied by lesser sesamin and sesamolin contents, and the ultraviolet spectrum of the oil was much altered. Oil from seed exposed as the seed to the same conditions for six months did not become rancid even though most of the seeds were damaged in threshing. The sesamol content of all the oils subjected to the accelerated ageing procedure increased, but the increase was greatest in the rancid oils.Frost damage of sesame seed markedly diminished the sesamin and sesamolin content of the oil.
A rapid method for the estimation of unsaturation of fats and oils by use of hypochlorous acid reagent
Authors: Mukherjee S. 
Published: July 2007

SummaryA rapid method for the determination of unsaturation of oils and fats containing non‐conjugated ethylenic linkages has been developed, using hypochlorous acid as the reagent. The method has several advantages,viz., that the estimation is conducted with an aqueous solution of sodium hypochlorite reagent, and moreover no oil solvent is required for the estimation. In all the methods currently employed, the reagents used must be perfectly anhydrous otherwise incomplete addition will take place, giving low results. Since a reaction time of 4 to 5 min. is recommended, the estimations are much more rapid than the customary Wijs or Hanus methods. No discrimination as to time factor need be made for oils possessing different degree of saturation. All oils, whether belonging to non‐drying or drying groups, give accurate results within the specified time. There is no secondary reaction except in the case of castor oil, but even in that case the secondary reactions are not appreciable within the first hour of reaction. The present method compares favorably with the standard procedures currently employed for determination of unsaturation.
Low temperature solubilities of fatty acids in selected organic solvents
Authors: Kolb Doris K. , Brown J. B. 
Published: July 2007

SummaryA number of highly purified fatty acids have been prepared and their solubilities determined in six common organic solvents within the temperature range from 10° to −70°. The acids studied were palmitic, stearic, oleic, elaidic, petroselinic, petroselaidic, linoleic, stearolic, arachidic, eicosenoic, behenic, erucic, and brassidic. The solvents used were methanol, ethyl acetate, diethyl ether, acetone, toluene, and n‐heptane, representing six different solvent types. A limited study was also made with a series of hydrocarbon solvents in order to note any effects of solvent structure on fatty acid solubility. Data are discussed with respect to their application in separating various fatty acid mixtures by low temperature crystallization.
Vicinally unsaturated hydroxy acids in seed oils
Authors: Morris L. J. , Holman R. T. , Fontell K. 
Published: July 2007

SummaryThe interference of certain unsaturated hydroxy acids in the Durbetaki method of epoxide determination has been demonstrated. The concentrations of these constituents were determined concurrently with those of epoxy components by measurement of the near infrared spectra of samples before and after treatment with anhydrous ethereal hydrogen chloride. The individual hydroxy esters were separated and isolated from samples of mixed esters by thinlayer chromatography. GLC of these esters resulted in their alteration to conjugated trienoates and gave proof of their conjugated diene hydroxyl structure. Thin‐layer chromatographic and infrared studies verified theTrans‐trans diene unsaturation of the acid fromDimorphotheca aurantiaca oil and showed that the other hydroxy compounds examined have acistrans diene system. These data suggest that the seed oils ofArtemisia absinthium, Calliandra eriophylla, Balanites aegyptica, Cosmos bipinnatus, and Helianthus annuus contain 9‐hydroxy‐trans‐10‐cis‐12‐ and 13‐hydroxy‐cis‐9‐trans‐11‐octadecadienoic acids.
Chromatographic isolation of the original constituents of natural waxes. The composition of ouricuri wax
Authors: Cole Leslie J. N. , Brown J. B. 
Published: July 2007

SummaryA chromatographic method was developed which separated a known mixture of alleged wax constituents into four groups,viz., dotriacontane, octadecyl stearate and stearone, octadecanol, and stearic acid on especially prepared alumina. This adsorbent, when prepared fresh, did not give a satisfactory separation of spermaceti wax. On re‐use after regeneration by exhaustive washing with methanol and water, spermaceti wax was resolved into esters (95.4%), alcohols (2.6%), and acids (1.2%). A resolution of ourieuri wax into four major classes (nine fractions) was obtained on alumina (M. Woelm, aniontrophie, pII4) of lesser adsorptive activity than the two previous preparations. Two of the latter fractions were further resolved on silica gel. There isa priori evidence that the constitutents of natural plant waxes do not conform rigidly to the pattern of mixtures of simple normal esters. An estimated composition of ouricuri wax (in per cent) is hydrocarbons 1.3, simple esters 23.5, hydroxy‐mono‐esters 22.4, hydroxy‐di‐esters 17.2, hydroxy‐aeidie‐poly‐esters 5.4, free acids 8.7, free alcohols 3.0, resins 14.8, moisture 1.4, and ash 0.4.
Gas‐liquid chromatography of fatty derivatives
Authors: Link W. E. , Morrissette R. A. , Cooper A. D. , Smullin C. F. 
Published: July 2007

SummaryThe separation of fatty amines has been carried out with nonpolar substrates on solid supports of Chromosorb and Chromosorb W, which were previously treated with potassium hydroxide to overcome adsorptivity. In this manner well‐resolved symmetrical peaks are obtained. Untreated supports give peaks which trail and prohibit precise quantitative measurements. Both Apiezon L on Chromosorb W and Silicone Grease on Chromosorb have proved effective, the latter at 176°C. and the former at 225°C. Relative detector sensitivity factors have been determined for the amines C8 to C18, thus permitting accurate analyses. The relative response for primary alkyl fatty amines is a linear function of molecular weight.
Acidolysis of vegetable and marine oils with phthalic acids
Authors: Carlston E. F. 
Published: July 2007

SummaryThe interchange reaction of the three phthalic acid isomers with triglyceride oils at high temperatures was studied. Orthophthalic acid dehydrates to the anhydride before any interchange occurs, but isophthalic and terephthalic acids are heat‐stable and react easily with oils in the temperature range of 260–300°C. Isophthalic acid reacts more rapidly than terephthalic acid and is ideal for use in acidolysis processes of alkyd‐resin manufacture. Various methods of application of the acidolysis reaction to isophthalic alkyd resin preparation were studied, and the minimum of oil conversion to monobasic acids that is required for successful alkyd preparation was found. Under certain conditions the acidolysis reaction occurs simultaneously with esterification; use is made of this fact to improve the process. Commercial use of the acidolysis reaction in alkyd‐resin manufacture is economically attractive because it is noncatalytic; therefore no catalyst residues need to be removed by pressure filtration. Another advantage is that glycerol is readily pumped into hot acidolysis‐reaction mixtures without opening the kettle, and this eliminates the disagreeable and toxic fumes that escape from hot kettles when they are opened after alcoholysis for addition of solid phthalic anhydride or isophthalic acid.Applications of acidolysis in conjunction with oil polymerization, fish oil upgrading, and castor oil dehydration were studied briefly, and the results suggest that further work in these fields is desirable.
Conversion of some C14‐labelled compounds into the neutral lipid ofNeurospora crassa
Authors: Krzeminski Leo F. , White Harold B. , Quackenbush F. W. 
Published: July 2007

SummaryConidia‐free mycelia ofNeurospora crassa converted C14‐acetate into neutral lipid more efficiently than C14‐labelled mevalonic acid or six other compounds tested. Pyruvate, glucose, and alanine contributed little to the neutral lipid fraction, but that contribution was mainly as fatty acids. Substantial losses of C14 as carbon dioxide indicated that all of the labelled compounds participated in cell metabolism.Analysis of the fatty acids esterified to the neutral lipid of unlabelled mycelia showed that palmitic, oleic, and linoleic acids each comprised nearly one‐third of the total while stearic, palmitoleic, and a small amount of unidentified acids contributed the remainder.
Polymerization of linseed oil in an electric discharge
Authors: Boelhouwer C. , Hoekstra T. , Waterman H. I. , Westerdijk J. B. , Van Dam J. , Kruidenier A. J. 
Published: July 2007

SummaryThe treatment of linseed oil by the action of electric discharges (voltolization) in a hydrogen atmosphere (80 mm. Hg, 70°C.) is described.It has been known for a long time that voltolization of linseed oil brings about a polymerization of the oil. Now it has been proven that the nature of the polymerization product thus obtained is absolutely different from that of thermally or catalytically polymerized linseed oils.In contrast to the latter, voltolized linseed oils contain only small amounts of cyclic compounds. Their viscosity is relatively low, even at a high polymerization degree, and considerably less than that of thermally polymerized oils of a corresponding degree of polymerization.Atomic hydrogen seems to play an important part in the voltolization process. Coupling of fatty acid chains is made possible by combining radicals, formed primarily by the action of hydrogen atoms. Coupling reaction occurs almost exclusively intermolecularly.The possibility of transforming linseed oil and other drying oils into polymerization products of a completely different chemical structure, depending on the applied polymerization process, opens new possibilities for their manufacture.
Marketing and economics of fatty alcohols
Authors: Houston Colin A. 
Published: July 2007

AbstractAlcohols represent 35% of the world's major surfactant intermediates, with natural alcohols accounting for one‐third of that percentage. Present trends suggest, however, that alcohols will become increasingly important in the detergent industry (the primary market for surfactants) during the next 10 years. Moreover, natural alcohols will frequently have an economic advantage over synthetics. Factors contributing to the growth of alcohols as surfactant intermediates include: better derivative biodegradability (especially compared to alkylbenzenes), better solubility (for use in low‐temperature washing and in liquid detergents), better hard‐water tolerance (for use in unbuilt liquid detergents), and a reputation for better detergency on synthetic fabrics. Factors favoring the natural alcohols (as opposed to the synthetics) include: frequently favorable raw material economics (especially as supplies of lauric oils increase), and integration of major manufacturers.
Marketing and economics of oleochemicals to the oil patch
Authors: LaSusa C. D. 
Published: July 2007

AbstractOleomines represent the largest class of oleochemicals used in the oil patch and are used in virtually all phases of the oil industry. Although the largest volume is used in production and refining, many amines are used prior to production in drilling operations and well completions, as well as postprocessing as additives in finished products. Other oleochemicals widely used include various surfactants made by ethoxylation and sulfation of fatty acids as well as polymerized fatty acids. The amines of interest start with simple primary amines and include secondary, tertiary and quaternary amines. They extend into higher amines such as diamines, triamines and beyond as well as all of these further reacted with other chemical species. Oleoamines in a generic sense also include amino amides, amphoteric amines, cyclic amidines, ether amines, as well as some high molecular weight polymeric materials. The oleoamines are used per se in suitable solvent systems, or as components in a wide variety of finished products containing several chemical entities to obtain specified product properties. Oleoamines, their derivatives, and other oleochemicals are used to prevent corrosion, inhibit and kill bacteria, condition waters for improved injectivity, emulsify, deemulsify, foam, gel, remove deposits, disperse solids, wet solids, solubilize or disperse otherwise incompatible liquids, produce or stabilize foaming systems, lubricate and produce detergent properties in liquid systems. They are used in drilling fluids. well completion fluids, oil and gas wells, water source wells, injection wells, gathering systems, filters, storage tanks, pipelines, refineries, and in finished products for all of the purposes listed above. This paper covers the oil patch operating parameters that determine the need for using oleochemicals, and describes for each system appropriate oleochemicals whose properties satisfy those needs.
Partial hydrogenation of polyunsaturated fatty materials
Authors: Draguez de Hault E. , Demoulin A. 
Published: July 2007

AbstractFor many applications involving the use of polyunsaturated triglycerides such as soybean oil, a liquid product having an improved stability to oxidation is required. The partial hydrogenation of soybean oil into a liquid product containing less oxidizable materials can be achieved with selective nickel catalysts. A soybean oil containing ca. 5% solid matter at 10 C, 1% linolenic acid and 0.5% conjugated dienes is obtained with a nickel/titanium oxide catalyst or with nickel‐zirconium oxide/kieselguhr catalyst treated wity fatty amines such as lauric or coco primary amines. In the frame of this work, ca. 100 heterogenous Ni catalysts have been tested under standard operating conditions for the partial hydrogenation of soybean oil.
Influence of various catalyst poisons and other impurities on fatty acid hydrogenation
Authors: Klimmek Helmut 
Published: July 2007

AbstractThe effect of various impurities which reduce the activity of nickel catalysts during fatty acid hydrogenation has been studied. It is here proposed to divide the compounds which negatively influence the nickel‐based fatty acid hydrogenation process into three categories, namely, catalyst poisons, inhibitors and deactivators, each group acting according to a different mechanis. The deleterious effect of typical catalyst poisons, such as S, N, P or Cl, is more or less independent of the chemical nature of the individual organic compounds containing these elements. There is good correlation between these element contents and the required nickel catalyst loading level. Other typical impurities present in technical fatty acids, such as oxidized fatty acids, soaps and water, also diminish the catalyst activity considerably. A number of experiments were designed to study the influence of various pretreatments of fatty acids on the catalyst loading levels needed for hydrogenation. In view of the high cost of nickel catalysts, considerable savings can be obtained by pretreatment of fatty acids prior to hydrogenation. Such pretreatment steps may include sulfuric acid washing, application of spent catalysts, and/or distillation. The most economical method will depend on local circumstances.
Fatty acid fractionation by column distillation: Purity, energy consumption and operating conditions
Authors: Stage Hermann 
Published: July 2007

AbstractThis paper discusses the optimal process conditions for production of individual fatty acids of any desired purity up to higher than 99% and describes especially the influences of column internals as well as exchange numbers, reflux ratios and fatty acid residence times at distillation temperatures. The new process conditions are characterized by degasification at low temperatures followed by efficient dehydration together with separation of first cuts at high reflux ratios by short‐time dephlegmation. The design of columns for efficiency and low pressure drop is influenced by the thermal properties of crude acids and the quality demands on distillate fractions. Environmental requirements can be met by working without open steam. Bottom temperatures should not exceed 250 C, to prevent thermal degradation of fatty acids as well as corrosion of stainless steel.
Supercritical CO2extraction of lipid‐bearing materials and characterization of the products
Authors: Friedrich J. P. , Pryde E. H. 
Published: July 2007

AbstractSupercritical fluid extraction has recently become a reality in the petroleum, coal and food industries and is rapidly increasing in importance as its advantages become known. Advantages of carbon dioxide as a supercritical fluid include its low toxicity, low cost, lack of flammability, lack of reactivity, wide range of solvent properties at different pressures and temperatures, and improved properties of separated components in certain cases. Disadvantages of such extractions include high capital costs for batch extraction and lack of engineering hardware technology for continuous operation. In the supercritical CO2extraction of oil from soybeans, equilibrium solubility and high flow rates are readily achieved in a short‐path batch reactor. The oil has a lighter color, less iron and ca. 1/10 of the phosphorus contained in hexane‐extracted oil. The lower phosphorus content results in lower refining losses. During extraction, some fractionation is observed to take place, with some more polar and/or higher molecular weight compounds having a tendency to increase in the later fractions. In a long cylindrical batch extractor, the flakes perform much like the stationary phase of a chromatographic column. The same advantages that result from extraction of soybeans also apply to the extraction of oil from cottonseed and corn germ. Cottonseed oil obtained by supercritical CO2extraction has a lower gossypol content and requires less alkali for refining. In the extraction of wheat germ and bran, the oil has a lighter color, a milder odor and less unsaponifiables than that obtained by hexane. Free fatty acid contents were comparable, but tocopherol was higher in the supercritical CO2extract.
New developments in the fatty acid industry in America
Authors: Sonntag Norman O. V. 
Published: July 2007

AbstractAlthough acquisition, divestiture and other organizational changes within the American oleochemical industry are still the most startling and attention‐attracting, the development of new technology continues to be of paramount scientific interest. Noteworthy among the new developments are (a) the continuing development of new vegetable oil raw materials like 90% erucic acid rapeseed oil and 80% oleic acid sunflower; (b) the intense process development under way in some areas for the minimization of thermal energy requirements of certain reactions like polymerization (dimer acids), glycerolysis (mono‐ and diglycerides) and fat splitting; (c) the ever‐increasing substitution of methyl esters for fatty acids in the production of a whole series of oleochemicals; (d) development of new esterification catalysts; (e) lipase catalysis of interesterification; (f) development of new corrosion‐resistant materials of construction; (g) the use of irradition sulfoxylation as a preferred production route to randomly sulfonated methyl esters; and (h) superemulsification as an aid to hydrophobic/hydrophilic liquid chemical reactions. Continued attention to alternative feedstocks, biotechnology, microprocessor technology, pollution control and lower energy consumption are certain to receive considerable attention for the next several years.