bluuebunny/crossref_metadata_2025 huggingface dataset:
Dislocations of Burgers vector c /2 in graphite
Authors: Suarez‐Martinez I. , Savini G. , Haffenden G. , Campanera J.‐M. , Heggie M. I.
Published: May 2007

We report calculations in support of the application of LDA within DFT to graphite and go on to report the inner core structure and energetics of prismatic dislocations with Burgers vector c/2: two types of edge and one of screw type. We find the screw dislocations preserve sp2 hybridisation and graphite bonding, whereas one edge type (zigzag) gives rise to interlayer single bonds and sp3 hybridisation, while the other type (armchair) does not, preferring instead to rehybridise towards sp and form bonds with itself approaching triple character. For computational and physical reasons these calculations were based on AA graphite, rather than Bernal (AB) graphite. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and recombination properties of extended defects in the dislocation slip plane in silicon
Authors: Eremenko V. , Yakimov E. , Abrosimov N.
Published: May 2007

It is shown, that moving 60° dislocations in Si as well as in SiGe generate high density of extended defects in their slip plane. As a result, the plastic deformation introduces in the crystal volume in addition to the dislocations a very dense system of extended defects, spatially separated from dislocations. The EBIC imaging revealed strong recombination contrast associated with these extended defects. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of bulk photovoltaic effect and photovoltaic barrier effect distributions in multicrysta lline silicon
Authors: Jung W. , Piotrowski T. , Sikorski S. , Lipinski M. , Panek P. , Zieba P.
Published: May 2007

Photoelectric voltage distribution on mc‐Si wafers subjected to phosphorus gettering processes was investigated. It was demonstrated, that the measured photoelectric voltage results from bulk photovoltaic effect and photoelectric voltage connected with potential barriers occurring on grains boundaries. It was shown that sample illumination results in reduction of bulk photoelectric effect enabling better visualization and investigation of potential barriers. Relations determining photoelectric voltage distribution on single barrier are given. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of defect levels in 6H‐SiC single crystals
Authors: Kamiński P. , Kozłowski R. , Kozubal M. , Miczuga M. , Palczewska M. , Pawłowski M. G. , Pawłowski M.
Published: May 2007

Defect levels in the n‐type bulk 6H‐SiC have been investigated by deep level transient spectroscopy (DLTS) and photoinduced transient spectroscopy (PITS). From the DLTS spectra, four electron traps at Ec ‐ 0.53 eV (T1), Ec ‐ 0.64 eV (T2), Ec ‐ 0.67 eV (T3) and Ec ‐ 0.69 eV (T4) with concentrations of 6.4x1015, 1.1x1016, 3.0x1016 and 1.6x1016 cm–3, respectively, were revealed. The centers T1, tentatively identified with carbon vacancies, were found to be located in the vicinity of dislocations. The centers T2 and T3 were assigned to the known deep‐level defect Z1/Z2 occurring both in 4H and 6H SiC polytypes. The PITS measurements revealed two shallow traps with activation energies 20 and 60 meV, as well as a deep trap at 0.66 eV. The origin of the first trap still remains unclear. The latter two traps are tentatively identified with a nitrogen atom in hexagonal site and a complex involving a boron atom and silicon antisite, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scanning probe studies of the electrical activity at interfaces formed by silicon wafer direct bonding
Authors: Ratzke M. , Vyvenko O. , Yu X. , Reif J. , Kittler M. , Reiche M.
Published: May 2007

In order to investigate the electrical properties at the surface of dislocation rich silicon, we conducted Electrostatic Force Microscopy on cross‐sections of samples prepared by Wafer Direct Bonding. The applied methods, namely Scanning Kelvin Probe Microscopy and non‐contact Scanning Capacitance Microscopy, yield a distinct contrast at the position of the dislocation area, i.e. the bonding interface, indicating strong electrical activity. For an explanation of the explicit electrostatic potential extracted from the experiment a simple model taking into account only an intrinsic charge distribution at the dislocation area appears to be insufficient. Instead, a more complex approach has to be used considering carrier generation and recombination by additional, dynamic mechanisms. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical levels of nanoscale NiSi2 precipitates in silicon band gap
Authors: Trushin M. V. , Vyvenko O. F.
Published: May 2007

Electric levels of NiSi2 nanoprecipitates in n‐ and p‐type Si were studied by means of deep level transient spectroscopy (DLTS) and minority carrier transient spectroscopy (MCTS) The shapes of MCTS spectra of as‐quenched as well as annealed p‐type samples were found to be similar whereas they differ qualitatively in n‐type samples. Experimental results are discussed using energetic diagram of electrical levels of NiSi2 nanoprecipitates in the Si band gap. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tautomerism of monochalcogenosilanoic acids CH3Si(O)XH (X = S, Se, Te) in the gas phase and in the polar and aprotic solution: An ab initio computational investigation
Authors: Li Qiang‐Gen , Deng Chao , Ren Yi , Wong Ning‐Bew , Chu San‐Yan , Wang Xin
Published: May 2007

Computational investigations by an ab initio molecular orbital method (HF and MP2) with the 6‐311+G(d,p) and 6‐311++G(2df, 2pd) basis sets on the tautomerism of three monochalcogenosilanoic acids CH3Si(O)XH (X = S, Se, and Te) in the gas phase and a polar and aprotic solution tetrahydrofuran (THF) was undertaken. Calculated results show that the silanol forms CH3Si(X)OH are much more stable than the silanone forms CH3Si(O)XH in the gas‐phase, which is different from the monochalcogenocarboxylic acids, where the keto forms CH3C(O)XH are dominant. This situation may be attributed to the fact that the SiO and OH single bonds in the silanol forms are stronger than the SiX and XH single bonds in the silanone forms, respectively, even though the SiX (X = S, Se, and Te) double bonds are much weaker than the SiO double bond. These results indicate that the stability of the monochalcogenosilanoic acid tautomers is not determined by the double bond energies, contrary to the earlier explanation based on the incorrect assumption that the SiS double bond is stronger than the SO double bond for the tautomeric equilibrium of RSi(O)SH (RH, F, Cl, CH3, OH, NH2) to shift towards the thione forms [RSi(S)OH]. The binding with CH3OCH3 enhances the preference of the silanol form in the tautomeric equilibrium, and meanwhile significantly lowers the tautomeric barriers by more than 34 kJ/mol in THF solution. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Iteration domainH∞‐optimal iterative learning controller design
Authors: Moore Kevin L. , Ahn Hyo‐Sung , Chen Yang Quan
Published: May 2007

This paper presents anH∞‐based design technique for the synthesis of higher‐order iterative learning controllers (ILCs) for plants subject to iteration‐domain input/output disturbances and plant model uncertainty. Formulating the higher‐order ILC problem into a high‐dimensional multivariable discrete‐time system framework, it is shown how the addition of input/output disturbances and plant model uncertainty to the ILC problem can be cast as anH∞‐norm minimization problem. The distinctive feature of this formulation is to consider the uncertainty as arising in the iteration domain rather than the time domain. An algebraic approach to solving the problem in this framework is presented, resulting in a sub‐optimal controller that can achieve both stability and robust performance. The key observation is thatH∞synthesis can be used for higher‐order ILC design to achieve a reliable performance in the presence of iteration‐varying external disturbances and model uncertainty. Copyright © 2007 John Wiley & Sons, Ltd.
High‐order sliding mode for an electropneumatic system: A robust differentiator–controller design
Authors: Smaoui M. , Brun X. , Thomasset D.
Published: May 2007

This 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

At 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

Despite 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

Von 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

Zur 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

Die 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

Nach 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

Es 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

Short 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

Freshly 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

The 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

Multigram 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

The 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

A 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

Data 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

The 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

More 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

Panel 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

1‐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

The 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

A 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

Alkali‐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

Seed 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

The 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.

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The 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.
Stability of coconut oil in food products
Authors: Fritsch C. W. , Weiss V. E. , Anderson R. H.
Published: May 2007

The active oxygen method (AOM) stability of refined coconut oil is generally 250 hr; however, samples with as low a stability as 30 hr have been obtained. The addition of BHA, BHT and citrate increased the AOM stability to about 350 hr even though the initial stability was 30 or 250 hr. Refined coconut oil samples which hydrolyzed from 2 to 10 times as rapidly as normal oils have been encountered. Such samples are undesirable for food production as soapy off‐flavors may be produced. The rate of hydrolysis of coconut oil samples was evaluated by a simple laboratory test. Coconut oil free fatty acids produced a soapy off‐flavor at a lower level in sweet foods than in salty ones. Soapy off‐flavors were produced in a low moisture food containing coconut oil by the lipase activity of cinnamon.
Extraction of N‐compounds of rapeseed meal in relation to pH and temperature
Authors: Korolczuk J. , Rutkowski A.
Published: May 2007

Nitrogen compounds were extracted from defatted rapeseed meal with 0–0.1 N aqueous sodium hydroxide or hydrochloric acid. Extractions were carried out for 30 min in water bath at 20, 40, 60, 80 or 100 C. Samples were centrifuged and concentrations of nitrogen and pH were measured. The highest extractability of N‐compounds (more than 80% of total N) was at pH 9.5–10 and 30–45 C. The lowest extractability (20–25% of total N) was at pH 6.5–8, and 80–100 C, the region of heat denaturation, and at pH 3.8–4 at 20 C (35% of total N).
Oxidation of lipids in fish meal
Authors: Waissbluth Mario D. , Guzman Lucy , Plachco Florencio P.
Published: May 2007

Oxidation of lipids in fish meal has been studied. The course of the reaction has been followed by means of oxygen absorption, peroxide values and chromatographic analyses. The latter has been used quantitatively, because the method of methylation of the unreacted fatty acids obtained by hydrolysis of the glyceryl esters has proved to the quantitative. The results indicate: (a) there are other oxygen‐consuming reactions which account for up to 10 times the oxygen consumed by simple peroxidation of the polyunsaturated lipids; (b) increasing moisture content has a marked prooxidant effect in all the oxidative reactions; (c) the overall rate of reaction is apparently independent of the peroxide concentration in the lipid, possibly due to the fact that there is some resistance to the diffusion of oxygen which produces deviations from the normal autocatalytic path of the reaction occurring when oxygen is fully available.
Aminimides: I. Antimicrobial effect of some long chain fatty acid derivatives
Authors: Kabara Jon J. , McKillip William J. , Sedor Edward A.
Published: May 2007

Aminimides are a new class of surface active agents which have antimicrobial activity. These bipolar compounds have activity against both gran‐positive and yeast organisms. Their activity against gram‐negative organisms is low or absent. The acyl derivatives tested showed maximum activity at chain lengths of C14 and C16. Fatty acid derivatives, shorter (C16), were less active. Unsaturation was an important factor contributing to aminimide activity. Their low toxicity and wide spectrum of antimicrobial activity make aminimides ideal candidates for further investigation.
The viscosities of nonaqueous solutions of magnesium caprate and laurate
Authors: Bose A. N. , Dixit Virendra K.
Published: May 2007

The viscosities of nonaqueous solutions of magnesium caprate and magnesium laurate have been determined at different concentrations and temperatures. Because Arrhenius' equation was found to be applicable to these solutions, it has been concluded that the size of the micelles does not change with the increase in temperature.

The variation of relative viscosity with temperature was also calculated. The fact that the value of d/dt (νs/νo) does not change much with temperature further supports the conclusion that the molecular aggregation of the soap molecules in the solvent is not affected by the temperature.

The equation of Schulze and Blaschke is not applicable to these solutions within the concentration range studied in the present work, probably because the size of the micelles changes with the increasing concentration of the soaps.
Note on gossypol and its relation to color fixation in cottonseed oil
Authors: Castillon Berardi Leah , Frampton Vernon L.
Published: May 2007

The crude oils studied contained from 0.00 to 0.04% gossypol.

Much of the gossypol added to crude cottonseed oils disappeared in one hour.

The disappearance of gossypol from refined, bleached, and deodorized cottonseed oil, from highly purified tripelargonin, and from ethyl acetate is demonstrable after the lapse of one hour.

It is suggested that the initial reaction of gossypol in the oils is an ester exchange reaction.

It is further suggested that secondary reactions result in the production of a red coloration product that is not removable from the oil by the standard refining and bleaching methods.
Methods of analysis for functional groups in earth (mineral) waxes
Authors: Sundgren A. , Rauhala Veikko T.
Published: May 2007

The potentiometric titration method is superior to color‐indicator methods in the determination of acid and saponification values of earth waxes.

The saponification reaction in determining saponification values of earth waxes is a balanced one; therefore the equilibrium depends on conditions under which it is run.

Hydroxyl and carbonyl value methods have been modified to make them suitable for earth (mineral) waxes.

The values obtained on high‐molecular weight peat waxes are not absolute, but rather they serve to characterize and identify these products.

The methods explained in this report may perhaps be found suitable for other natural products, such as montan wax.
Preliminary report on the nutritional significance of bound gossypol in cottonseed meal
Authors: Baliga B. P. , Lyman Carl M.
Published: May 2007

A procedure is described by which bound or inactivated gossypol can be removed from cottonseed meal without the application of heat which might damage the protein. The removal of bound gossypol increased the nutritional value of the protein as determined by chick feeding tests, rat protein‐repletion tests, and lysine availability tests. A procedure is described for the preparation of a gossypol‐cottonseed protein complex without heating the materials. As a result of the combination of the protein with gossypol, marked reduction in nutritional value occurred. The nitrogen solubility of the complex was only about half that of the original protein. The results are in accord with the concept that the inactivation of gossypol during the processing of cottonseed meal is accomplished through the formation of an insoluble, inert gossypol‐protein complex which results not only in rendering the gossypol harmless but also in the loss of part of the nutritional value of the protein.
Dilatometric errors and an application to volume changes for the solid state of methyl stearate
Authors: Craig B. M.
Published: May 2007

The dilatometric curves representing heating and cooling cycles for methyl stearate between‐38°C. and +35°C. are the same shape as found in the previous study. Cooling cycles which are started from points on the heating curve yield curves which are different from each other and from curves representing the complete heating and cooling cycles. Curves for heating cycles which are started from points on the curve representing the complete cooling cycle will also be different from the curves representing either the heating or cooling cycles in the same temperature region. The specific volumes at any temperature in the solid region depend on the previous history of the sample even though the sample is not melted between determinations. A continual reduction in specific volume was found for successive runs after equilibration at+35°C. This reduction had no apparent effect on the coefficient of expansion of the solid state but did increase the melting dilation. Using the present Vycor dilatometers, the standard error of measurements in the solid state are around ±0.00005 ml. per gram in terms of specific volume. The use of a platinum resistance thermometer and Mueller bridge did not significantly improve the precision of the measurements.
A review of ethylene oxide condensation with relation to surface‐active agents
Authors: Fine R. D.
Published: May 2007

A limited presentation has been made in the preceding discussion of some of the more important aspects of ethylene oxide condensation with respect to surface‐active agents. As a commercial process it is an economical means of introducing hydrophilic ethoxy groups to achieve the desired balance with lipophiles. The hydrophilic characteristics of ethoxy groups result from hydration of ether‐linked oxygen atoms. The condesation of ethylene oxide with compounds having active hydrogen atoms is carried out commercially at moderate temperatures and pressures in the presence of catalysts with careful regard to safe operating procedures. Nonionic agents having a variety of properties and uses are formed by condensing ethylene oxide with alkyl phenols, higher aliphatic alcohols, polyhydric alcohol partial esters, carboxylic acids, higher alkyl amides, alkyl mercaptans, and polypropylene glycols. Condensation of ethylene oxide with higher alkyl amines yields cationic agents.

In recent years a considerable volume of literature has been published on the subject of ethylene oxide and nonionic surface‐active agents. The references cited should serve as a source of more complete and detailed information.
Optical bleaches in soaps and detergents
Authors: Villaume F. G.
Published: May 2007

In this discussion a brief history of optical bleaches and some chemical aspects of brightener structures have been presented. A description has been given of the behavior of optical bleaches in soaps and detergents and of several methods by which they are evaluated. It has been attempted to show the various choices a soap or detergent manufacturer has with the current commercially available brighteners. The differences between these brighteners as to substantivity, degree of exhaustion, fastness properties, etc., have been pointed out. Also it has been shown that certain brighteners differ in behavior with variations in the detergent formulation and washing procedures.
Composition of the oil of asphodelus fistulosus (piazi) seeds
Authors: Khan Shafiq Ahmad , Qureshi Muhammad Ilyas , Bhatty Muhammad Khurshid , Karimullah
Published: May 2007

The seed oil ofAsphodelus fistulosus (piazi) contains 0.5% myristic, 5.7% palmitic, 3.6% stearic, 33.1% oleic, and 54.9% linoleic acids.

The 1.8% nonsaponifiable matter appeared to contain fucosterol and a yellow, unidentified substance.
Feed value and protein‐quality determinations on cottonseed meals
Authors: Eagle Edward , Davies Donald L.
Published: May 2007

Twenty‐four cottonseed meals fed to chicks in practical feeding rations for eight weeks led to good growth performance and favorable feed efficiency in many cases, despite the unusually high free gossypol content of the rations.

The results from replicated, protein‐quality evaluations in chicks fed for eight weeks at the 15% protein level were closely parallel to those from similar experiments in rats fed at the 9% protein level and showed that the percent nitrogen solubility in 0.02N sodium hydroxide of cottonseed meals is a poor indicator of protein quality.

Constant gossypol levels of 0.1%, supplied by additions of different amounts of cottonseed pigment glands, caused greater body‐weight depressions than did the same gossypol level supplied by pure gossypol.

The toxicity of cottonseed pigment glands and of cottonseed meals cannot be accounted for solely on the basis of analyzed gossypol content.
Studies on guar seed oil (cymmopsis psoralioides)
Authors: Mehta D. R. , Ramakrishnan C. V.
Published: May 2007

The properties of guar seed oil (Cyammopsis Psoralioides) were studied, and it was found that it may be satisfactory for edible purposes. An interesting observation has been made that the unsaponifiable fraction of guar oil may be used as a stabilizer for oils.
Some laboratory investigations of degummed cottonseed oil
Authors: Sikes James K.
Published: May 2007

In the foregoing we have set forth our views and findings on possible ways of handling degummed cottonseed oil in the laboratory. Foreseeing the day when degummed cottonseed oil will come into prominence, we offer these suggestions and findings as an incentive to spur collaborative efforts in a search for a better laboratory method. Two possibilities have been explored. One is a centrifuge method of refining, approximating actual refining conditions in present‐day refineries. The other is a chromatographic determination of total neutral oil. It is indeed heartening to know that the A.O.C.S. total neutral oil subcommittee is actively engaged in a collaborative program of work on such methods as the chromatographic loss method. This is good evidence that we are making a realistic approach to the problem of better laboratory methods.
Solidification points of some binary mixtures of derivatives of stearic acid
Authors: Sasin George S. , Butte Walter A. , Sasin Richard
Published: May 2007

The solidification points of binary mixtures of stearic acid‐stearamide, stearic acid‐stearonitrile, stearic acid‐1‐octadecanol, and stearonitrile‐stearamide were determined.
Effect of milk fat fractions on fat bloom in dark chocolate
Authors: Lohman Myung H. , Hartel Richard W.
Published: May 2007

Anhydrous milk fat was dissolved in acetone (1∶4 wt/vol) and progressively fractionated at 5°C increments from 25 to 0°C. Six solid fractions and one 0°C liquid fraction were obtained. Melting point, melting profile, solid fat content (SFC), fatty acid and triglyceride profiles were measured for each milk fat fraction (MFF). In general, there was a trend of decreased melting point, melting profile, SFC, long‐chain saturated fatty acids and large acyl carbonnumbered triglycerides with decreasing fractionation temperature. The MFFs were then added to dark chocolate at 2% (w/w) addition level. In addition, two control chocolates were made, one with 2% (w/w) full milk fat and the other with 2% (w/w) additional cocoa butter. The chocolate samples were evaluated for degree of temper, hardness and fat bloom. Fat bloom was induced with continuous temperature cycling between 26.7 and 15.7°C at 6‐h intervals and monitored with a colorimeter. Chocolate hardness results showed softer chocolates with the 10°C solid fraction and low‐melting fractions, and harder chocolates with high‐melting fractions. Accelerated bloom tests indicated that the 10°C solid MFF and higher‐melting fractions (25 to 15°C solid fractions) inhibited bloom, while the lowermelting MFFs (5 and 0°C solid fractions and 0°C liquid fraction) induced bloom compared to the control chocolates.
Thermal analysis of palm mid‐fraction, cocoa butter and milk fat blends by differential scanning calorimetry
Authors: Md.Ali A. R. , Dimick P. S.
Published: May 2007

Commercial samples of anhydrous milk fat (AMF), Ivory Coast cocoa butter (CB) and palm mid‐fraction (PMF) were blended in a ternary system. The melting characteristics of the blends were studied by differential scanning calorimetry (DSC). Results suggest that in the studies of interaction involving more than two fats, partial area (Ai) under the melting peak should be converted to partial enthalpy (ΔHi) rather than to solid fat index. The ΔH values of the blends decreased as the amount of AMF was increased and increased as the amount of CB was increased. In general, the effect of PMF was less pronounced compared to the effect of the other two fats. Eutectic effects within the ternary system could be detected by measuring the deviation of melting enthalpy by DSC, and from the corresponding values that were calculated for the thermodynamically ideal blends. The deviation reached a maximum when the amount of AMF was about 33%. On the binary line of CB/PMF, the eutectic effect was maximum at about 50–75% PMF. The interaction effect in the system was more noticeable at 30 and 20°C than at lower temperatures. Evaluation at 30°C was preferred because both the effect of AMF in the ternary system and the effect of PMF on the binary line were more readily observed.