bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐order sliding mode for an electropneumatic system: A robust differentiator–controller design
Authors: Smaoui M. , Brun X. , Thomasset D. 
Published: May 2007

AbstractThis paper deals with the robust control problem of a pneumatic actuator subject to parameter uncertainties and load disturbances. The control strategies are based on second‐ and third‐order sliding mode approaches. These controllers require measurements of acceleration for feedback. However, accelerometer is seldom used in practical drive systems, because of the complexity they add to the overall process as they are mounted to the load in displacement. For this, a robust differentiatorviasliding mode is used to estimate the acceleration. A comparative study between the robust differentiator and a classical one is presented. Implementation results of the proposed sliding mode differentiator–controller design on an experimental set‐up are given to illustrate the developments. Copyright © 2007 John Wiley & Sons, Ltd.
A mesohabitat method used to assess minimum flow changes and impacts on the invertebrate and fish fauna in the Rhône River, France
Authors: Harby Atle , Olivier Jean‐Michel , Merigoux Sylvie , Malet Emmanuel 
Published: May 2007

AbstractAt the 8 km bypass section of Chautagne in the Rhône River, most of the flow is diverted due to hydropower production. The environmental flow to the bypass section of the Rhône River was increased from 10 m3 s−1 (winter) and 20 m3 s−1 (summer) to 50 m3 s−1 (winter) and 70 m3 s−1 (summer) in July 2004. A Norwegian mesohabitat method of classifying the river into physical mesoscale morphological (mesohabitat) classes by visual observation was applied at 10 and 70 m3 s−1. The results show that the dominating classes at both flows are deep and low velocity pools, but a higher physical diversity occurs at 70 m3 s−1, quantified by indices from Simpson (1949) and Shannon and Weaver (1962). In total, 6 per cent of the depth measurements and 0.3 per cent of the velocity measurements were outside the expected range at low flow. At high flow, 16.2 per cent of the depth measurements and 19.6 per cent of the velocity measurements were outside the expected range. The change in mesohabitats gives impacts on the composition and abundance of fish and invertebrates. Rheophilic taxa are favoured by the increased flow while more limnophilic species will find less amount of suitable habitat at 70 m3 s−1. Other studies show that population densities of grayling, brown trout, nase and dace have decreased greatly and become endangered since hydropower development, while densities of gudgeon, minnow and stone loach have increased. Fish habitat preferences from Lamouroux et al. (1999a) and Mallet et al. (2000) were used. Most of the endangered species need high velocity mesohabitats and both high and low depths during all life stages. The increase of such mesohabitat proportions at 70 m3 s−1 indicates that their population should recover soon. The method may be a useful tool to compare different flow situations and their impact on the invertebrate and fish population structure even in large rivers. Copyright © 2007 John Wiley & Sons, Ltd.
Life in the ice lane: the winter ecology of stream salmonids
Authors: Huusko Ari , Greenberg Larry , Stickler Morten , Linnansaari Tommi , Nykänen Mari , Vehanen Teppo , Koljonen Saija , Louhi Pauliina , Alfredsen Knut 
Published: May 2007

AbstractDespite the common view that conditions in winter strongly influence survival and population size of fish, the ecology of salmonids has not been as extensively studied in winter as in other seasons. In this paper, we review the latest studies on salmonid winter survival, habitat use, movement and biotic interactions as they relate to the prevailing physical and habitat conditions in rivers and streams. The majority of research conducted on the winter ecology of salmonids has been carried out in small rivers and streams, where temperatures are above zero and where there is no ice. Investigations in large rivers, regulated and dredged rivers, and under conditions of different ice formations are almost totally lacking, presumably related to sampling difficulties with these systems. The studies‐at‐hand indicate that a multitude of physical and biological factors affect the survival, behavior, and habitat use of salmonids in winter. The general concept that winter functions as a critical period for the survival of young salmonids is not well supported by the literature. Instead, overwinter survival of juvenile fish appears to be context‐dependent, related to specific habitat characteristics and ice regimes of streams. In general, over wintering salmonids prefer sheltered, low velocity microhabitats, are mainly nocturnal, and interact relatively little with conspecifics or interspecifics. Specific descriptions of microhabitat preferences of salmonids are difficult to make due to highly disparate results from the literature. We suggest that future research should be directed towards (1) being able to predict the dynamics of freezing and ice processes at different scales, especially at the local scale, (2) studying fish behavior, habitat use and preference under partial and full ice cover, (3) evaluating the impacts of man‐induced environmental modifications (e. g. flow regulation, land‐use activities) on the ecology of salmonids in winter, and (4) identifying methods to model and assess winter habitat conditions for salmonids. Copyright © 2007 John Wiley & Sons, Ltd.
Das statistische Problem der Korrelation als Variations‐ und Eigenwertproblem und sein Zusammenhang mit der Ausgleichsrechnung
Authors: Gebelein Hans 
Published: May 2007

AbstractVon einem voll befriedigenden Korrelationsmaß ist zu verlangen, daß es durch sein Verschwinden mit Sicherheit anzeigt, wenn die beiden Veränderlichen unabhängig voneinander sind, und daß es anderseits mit Sicherheit den Wert Eins annimmt, wenn zwischen ihnen vollständige Abhängigkeit besteht. Die Aufgabe, ein solches Korrelationsmaß zu gewinnen, führt auf ein Variationsproblem und kann zurückgeführt werden auf die Frage nach dem kleinsten Eigenwert einer homogenen Fredholmschen Integralgleichung. Bei der Untersuchung dieses Variationsproblems wird auch der Zusammenhang mit den bisher üblichen Korrelationsmaßen und mit dem Problem der Ausgleichsrechnung ersichtlich.
Bemerkungen zur Theorie der freien Turbulenz .
Authors: Prandtl L. 
Published: May 2007

AbstractZur Einführung für den nachfolgenden Aufsatz von H. Görtler wird ein Überblick über den derzeitigen Stand der Grundformeln der turbulenten Ausbreitung gegeben. Es wird dabei auch zu den von H. Reichardt vorgeschlagenen Ansätzen Stellung genommen.
Der schwimmende Balken .
Authors: Schiel Friedrich 
Published: May 2007

AbstractDie Behandlung des Balkens, der auf dem gleichmäßig federnden (= elastisch isotropen) Halbraum aufliegt, ist mit großen mathematischen Schwierigkeiten verbunden. Wieghardt hat einen Näherungsansatz vorgeschlagen, um die Schwierigkeiten zu verringern. Im folgenden wird gezeigt, daß das mechanische Modell dieses Ansatzes eine schwere, nichtbenetzende Flüssigkeit ist. Die Berechnung eines auf einer solchen Flüssigkeit schwimmenden Balkens ist als Näherungsverfahren zur Behandlung von Bauwerken auf nachgiebigem Baugrund geeignet.
Die „ähnlichen”︁ Lösungen der Prandtlschen Grenzschichtgleichungen
Authors: Mangler Werner 
Published: May 2007

AbstractNach einer Diskussion der Körperformen, and denen „ähnliche”︁ laminare Geschwindigkeitsprofile auftreten können, werden die Lösungen der gewöhnlichen Differentialgleichung, der diese „ähnlichen”︁ Geschwindigkeitsprofile genügen müssen, näher untersucht, insbesondere ihre Abklingen gegen die äußere Potentialströmung. Es zeigt sich, daß es außer den schon von Hartree [3] berechneten noch weitere „ähnliche”︁ Lösungen der Grenzschichtgleichungen gibt.
Differenzenverfahren zur numerischen Integration von gewöhnlichen Differentialgleichungen n=ter Ordnung
Authors: Collatz L. 
Published: May 2007

AbstractEs werden zur numerischen Berechnung von Anfangswertaufgaben bei gewöhnlichen Differentialgleichungen n‐ter Ordnung zwei Extrapolationsverfahren und zwei Interpolationsverfahren angegeben, welche die meisten bisher bekannten Arten der Differenzenverfahren für Differentialgleichungen erster und zweiter Ordnung als Spezialfälle enthalten. Unter den verschiedenen Verfahren zeichnet sich auch bei Differentialgleichungen höherer Ordnung das Verfahren der zentralen Differenzen durch einfache Koeffizienten und günstigere Konvergenzbedingungen aus.
A rapid engine test to measure injector fouling in diesel engines using vegetable oil fuels
Authors: Korus Roger A. , Jo Jaiduk , Peterson Charles L. 
Published: May 2007

AbstractShort engine tests were used to determine the rate of carbon deposition on direct injection diesel nozzles. Winter rape, high‐oleic and high‐linoleic safflower blends with 50% diesel were tested for carbon deposit and compared to that with D‐2 Diesel Control Fuel. Deposits were greatest with the most unsaturated fuel, high‐linoleic safflower, and least with winter rape. All vegetable oil blends developed power similar to diesel fueled engines with a 6 to 8% greater fuel consumption.
Evaluation of self degumming properties of phospholipids in soybean oil using HPLC
Authors: Ragan J. E. , Handel A. P. 
Published: May 2007

AbstractFreshly extracted crude soybean oil was obtained from a commercial soybean oil refinery, divided into aliquots, stored at 24 C and 5 C for varying lengths of time up to two weeks, and analyzed for total phosphorus. The concentrations of phosphatidylethanolamine (PE), phosphatidic acid (PA), phosphatidylinositol (PI) and phosphatidylcholine (PC) were determined by phosphorus analysis following separation by HPLC. Portions of the aliquots were degummed, and total phosphorus and individual phospholipids were determined as described above. Total phosphorus decreased 41% in crude oil stored at 24 C and 34% in crude oil stored at 5 C over two weeks. PE and PC precipitated more readily than PI and PA. Total phosphorus remaining in degummed oil was least after 12 hr storage of the crude oil and increased as the storage period became longer. The PE, PI and PA concentrations showed similar trends in degummed oil; however the PC concentration was least at 0 hr and increased thereafter. These results are discussed in terms of phospholipid‐phospholipid interactions and possible interactions between phospholipids and other compounds present in the oil.
Antioxidant efficacy of water washed gums as a function of relative humidity in peanut oil
Authors: Gopalakrishna A. G. , Prabhakar J. V. 
Published: May 2007

AbstractThe stability of raw peanut oil to autoxidation at 40 C increased with ambient relative humidity, reaching a maximum stability at 90.5% RH (KM × 10−3 2.54, 1.83, 0.50 meq O2/kg/hr at RH of 2, 47.5, 90.5%, respectively). Degumming with water or with phosphoric acid accelerated autoxidation at all test humidities. The trend in the rate of autoxidation was opposite that of the raw oil, increasing with relative humidity. It reached its maximum at 90.5% RH (KM × 10−3 of 3.93, 3.16, 6.65 meq O2/kg/hr at RH of 2, 47.5, 90.5% respectively for phosphoric acid degummed oil). Adding back the water washed gums removed during degumming to the water degummed peanut oil substantially restored the stability of the oil to autoxidation. These studies indicate that water washed gums retain most of their native state antioxidant activity. Hence, the gums removed during processing of oils could be added back to the oil after final processing to impart increased stability to the oil in some applications. The antioxidant efficacy of water washed gums was as good as that of synthetic antioxidants. These have an advantage over synthetic antioxidants in that they are natural components of most oils and fats.
The isolation of omega‐3 polyunsaturated fatty acids and methyl esters of fish oils by silver resin chromatography
Authors: Adlof R. O. , Emken E. A. 
Published: May 2007

AbstractMultigram quantities of the highly unsaturated ω3 component from samples of fish oil fatty acids and esters were isolated by silver resin chromatography. An XN1010 resin column saturated with silver ions was utilized. Polyunsaturated fatty acid (PUFA) esters from fish oil concentrate (FOC) were fractionated based on the number of double bonds by using solvent programming (acetonitrile in methanol). Larger samples (4–9 g) of FOC acids and esters and menhaden acids and esters were enriched in ω3 polyunsaturates to 82–99% (95–99% total PUFA) by use of a large 100% silver resin column and isocratic elution with 30, 35 or 45% acetonitrile in acetone.
Tocopherol contents of nine vegetable frying oils, and their changes under simulated deep‐fat frying conditions
Authors: Yuki E. , Ishikawa Y. 
Published: May 2007

AbstractThe tocopherol contents and active oxygen method values of nine vegetable oils were determined and compared before and after the oils were treated under simulated deep‐fat frying conditions. The saturated oils, coconut and palm, had much higher initial active oxygen method values than the unsaturated oils, soybean, safflower, etc., but the treatments caused a much sharper decrease of the active oxygen method value in saturated oils than in unsaturated ones. The ratio of tocopherol loss after treatment is also much greater in the saturated oils than the unsaturated ones. A similar tendency was observed when the saturated oils enriched with commercial tocopherol mixture were treated under the same conditions.
Quantitative determination of polyethylene glycols in nonionic surfactants by high pressure liquid chromatography
Authors: Turner L. P. , McCullough D. , Jackewitz A. 
Published: May 2007

AbstractA method employing high pressure liquid chromatography has been developed for the quantitative determination of polyethylene glycols in ethoxylated fatty alcohols and alkylphenols. This technique overcomes many of the limitations encountered in previously‐reported methods. The polyethylene glycols are separated from the ethoxylated product and other sample components using a 65/35 acetonitrile/water mobile phase and a Bondapak C18/Corasil reversephase column system. The response factor of the differential refractometer detector is determined using Carbowax standards of appropriate molecular weights. The molecular weight of the polyethylene glycols in each sample is approximated using thin layer chromatography prior to the high pressure liquid chromatography calibration and analysis. The precision of this method for the determination of polyethylene glycols is ± 4% relative or better, and the recovery of added polyethylene glycols is quantitative. Application of this method to a wide variety of commercial ethoxylated fatty alcohols and alkylphenols is presented.
Jojoba seed: Phenotypic within plant variability in wax content and composition
Authors: Yermanos D. M. , Duncan C. 
Published: May 2007

AbstractData are presented on the wax content and composition and seed weight of 7 individual plants in Aguanga, California. Mean wax content was 48.5% and average range 17.6 percent units. Mean seed weight was 0.38 g and mean range 0.43 g. The range in seed weight wax content and composition among seeds within single plants was comparable in magnitude to that found among single plant means. It appears that most of that variability is due to environmental factors. Thus, selection for these traits should be based on single plant performance; propagation should not be based on analyses of single seeds harvested in bulk from several plants. Correlations between fatty acids and alcohols among seeds within plants were the same as those found among single plant samples. Seeds of jojoba can be cut in half transversely without impairing germination of the basal half including the embryo axis. The upper half can be used to obtain a wax sample for single‐seed analyses.
Assessing detergent safety: A comparison of a nonphosphate laundry detergent with phosphate detergents
Authors: Williams James B. , Taber David 
Published: May 2007

AbstractThe potential hazard of a carbonate‐based, phosphate‐free detergent was compared with that of a variety of granular and liquid phosphate detergents. Evaluations were made using methods prescribed by the Federal Hazardous Substances Act (FHSA) and others designed to more closely approximate exposure in actual use. Some phosphate products produced esophageal and gastric mucosal irritation similar to that produced by the nonphosphate detergent, while others caused varying, lesser degrees of injury. The nonphosphate detergent, as well as several phosphate products, was seriously irritating to the unwashed eye at required FHSA test levels. Under more realistic conditions, eye irritation was reduced significantly. Skin irritation by the nonphosphate product was comparable to that by phosphate detergents, and in some cases was lower. In skin irritation tests with human subjects, results with the carbonate detergent were equal to or lower than those obtained with phosphate detergents. The carbonate detergent was found not to be phototoxic, nor a contact‐ nor photo‐sensitizer. Total alkalinity was shown not to correlate with the severity of tissue injury in either test animals or in man.
Various interactions in chocolate flavor
Authors: Keeney P. G. 
Published: May 2007

AbstractMore than 300 volatile compounds have been identified in roasted cocoa beans and its products, making chocolate one of the most complicated natural flavors. Most beans, after harvesting, are subjected to a fermentation that is an important step in the formation of flavor precursors. Roasting is essential to the development of chocolate flavor both with respect to the loss of undesirable volatiles and the generating of key aroma compounds. Flavor is modified to meet demand using blends of beans and through variation in roasting conditions and the mechanical treatments employed to process beans into chocolate liquor and coating. The effect of fermentation and roasting on certain chemical properties related to flavor in chocolate is reviewed. Particular attention is given to monocarbonyls, headspace volatiles, pyrrole aldehydes and alkylpyrazines.
Room odor evaluation of oils and cooking fats
Authors: Evans C. D. , Warner Kathleen , List G. R. , Cowan J. C. 
Published: May 2007

AbstractPanel evaluations have been made of room odors developed by edible oils and cooking fats heated to frying temperatures. Vegetable and mixed fat shortenings, as well as oils of different iodine value and from special processing, were investigated with and without added stabilizers. When silicones were added to frying fats, room odor scores improved markedly. Certain added autoxidative cleavage products had little effect on odor scores at levels where they were detected easily in taste tests. To be discernible in room odors, these additives had to be present at levels ca. 100‐fold greater than their taste thresholds. Panel results show that the undesirable frying odors contributed by unhydrogenated soybean oil in mixtures with other oils could be detected readily at 25% levels. As the level of soybean oil was lowered further, the room odor scores of oil mixtures improved perceptibly.
Alcohols from ozonolysis products of unsaturated fatty esters
Authors: Pryde E. H. , Thierfelder C. M. , Cowan J. C. 
Published: May 2007

Abstract1‐Nonanol and alkyl 9‐hydroxynonanoates were more readily prepared by hydrogenation of the respective isolated aldehydes than by direct hydrogenation of products from reductive ozonolysis of oleate esters. Hydrogenation with nickel catalysts and aprotic solvents reduced the isolated aldehydes in good yield with a minimum of side reactions. Although the noble metal catalyst and hydroxylic solvent systems frequently used in similar reductions were also effective, they required a promoter that fortuitously catalyzed hydrolysis of acetals that formed during hydrogenation. Direct hydrogenation of the ozonolysis products resulted in side reactions and a mixture of products difficult to separate.
Effect of liquid fat on melting point and polymorphic behavior of cocoa butter and a cocoa butter fraction
Authors: Lovegren N. V. , Gray M. S. , Feuge R. O. 
Published: May 2007

AbstractThe polymorphic behavior of cocoa butter and a high‐melting fraction of cocoa butter (CBF) was investigated by differential scanning calorimetry. The effect of liquid fat on melting point and polymorphic behavior was established for six mixtures: 83.5% cocoa butter and 16.5% of a low‐melting fraction of cocoa butter (CBF‐LM), 90% cocoa butter and 10% olive oil, and four mixtures of CBF and olive oil containing 10%, 20%, 30%, and 50% olive oil. Six polymorphs were found for cocoa butter and at least five for CBF. The melting points for cocoa butter and CBF were 35 and 38 C, respectively. Addition of CBF‐LM to cocoa butter reduced the observable polymorphs to four and the melting point to 32.5 C. In cocoa butter, 10% olive oil reduced the observable polymorphs to three and the melting point to 31.5C. Similarly, 10% olive oil in CBF reduced the observable polymorphs to three and the melting point to 37 C. Amounts of 20%, 30%, and 50% olive oil in CBF reduced the polymorphs to two and the final melting point to 34.5, 33, and 32 C, respectively. Possible explanations for the observed polymorphic behavior are advanced. Changes in the rates of tempering of cocoa butter and CBF on addition of various amounts of liquid fat are discussed.
Phase behavior of triglyceride mixtures involving primarily tristearin, 2‐oleyldistearin, and triolein
Authors: Lutton E. S. 
Published: May 2007

SummaryA study of binary systems involving SSS with PPP, PSP, LLL, SOS, or OOO, also SOS with OOO shows, for these triglycerides, agreement of liquidus position with the Hildebrand solubility law. Solid solution is essentially absent in LLL‐SSS and OOO‐SSS and OOO‐SOS but definitely occurs with PPP‐SSS, PSP‐SOS, and SOS‐SSS, where it is clearly shown by x‐ray and dilatometric evidence. Solid solutions are particularly evident with metastable forms. Possibility of wide departure from equilibrium behavior is shown for “stabilized” samples in the SOS‐SSS case; low melting components melted out of solid solution below the system's complete melting point are able to reenter the solid solution phase only to a limited extent.
Chemical and nutritional evaluation of chili (Capsicum annum) seed oil
Authors: Reddy B. Sarala , Sarojini G. 
Published: May 2007

AbstractAlkali‐refined red chili (Capsicum annum) seed oil was analyzed for free fatty acids, iodine value, saponification value, peroxide value and fatty acid composition, and the values were found to be close to those of edible oils. The alkali‐refined chili oil (5% of diet), alcohol‐treated chili oil (5%) and a mixture of alcohol‐treated chili oil and peanut oil (5%+5%) were fed to adult male albino rats in natural diets for eight weeks. Digestibility was normal in all experimental animals and was on par with the peanut oil control. Serum lipid levels in the group fed alcohol‐treated chili oil were slightly high compared to those in groups fed alkali‐refined chili oil and peanut oil. Liver structure revealed no abnormalities.
Cyclopropenoid fatty acids in leguminosae oils
Authors: Daulatabad C. D. , Hosamani K. M. , Desai V. A. , Alagawadi K. R. 
Published: May 2007

AbstractSeed oils ofCassia grandis, Linn andDelonix elata, Gamble, Syn.Poinciana elata, Linn, belonging to the Leguminosae family contain small amounts of sterculic and malvalic acids as determined by conversion of esters with AgNO3/MeOH, NMR and IR.
Enol esters XIII: Synthesis of isopropenyl esters by addition of carboxylic acids to propyne
Authors: Rothman Edward S. , Serota Samuel 
Published: May 2007

AbstractThe addition of long chain carboxylic acids to propyne under conditions of elevated temperature and pressure takes place in the presence of the zinc salt of the corresponding acid as indicated by the following equation.imageThe reactor apparatus is described and the properties of a series of enol esters are listed. this series shows examples with chain length variations of the carboxylic acid moiety of the ester from 8 to 22 carbon atoms.