bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a hybrid EPR/NMR coimaging system
Authors: Samouilov Alexandre , Caia George L. , Kesselring Eric , Petryakov Sergey , Wasowicz Tomasz , Zweier Jay L.
Published: July 2007

Electron paramagnetic resonance imaging (EPRI) is a powerful technique that enables spatial mapping of free radicals or other paramagnetic compounds; however, it does not in itself provide anatomic visualization of the body. Proton magnetic resonance imaging (MRI) is well suited to provide anatomical visualization. A hybrid EPR/NMR coimaging instrument was constructed that utilizes the complementary capabilities of both techniques, superimposing EPR and proton‐MR images to provide the distribution of paramagnetic species in the body. A common magnet and field gradient system is utilized along with a dual EPR and proton‐NMR resonator assembly, enabling coimaging without the need to move the sample. EPRI is performed at ∼1.2 GHz/∼40 mT and proton MRI is performed at 16.18 MHz/∼380 mT; hence the method is suitable for whole‐body coimaging of living mice. The gradient system used is calibrated and controlled in such a manner that the spatial geometry of the two acquired images is matched, enabling their superposition without additional postprocessing or marker registration. The performance of the system was tested in a series of phantoms and in vivo applications by mapping the location of a paramagnetic probe in the gastrointestinal (GI) tract of mice. This hybrid EPR/NMR coimaging instrument enables imaging of paramagnetic molecules along with their anatomic localization in the body. Magn Reson Med 58:156–166, 2007. © 2007 Wiley‐Liss, Inc.
Whole‐heart coronary magnetic resonance angiography at 3 Tesla in 5 minutes with slow infusion of Gd‐BOPTA, a high‐relaxivity clinical contrast agent
Authors: Bi Xiaoming , Carr James C. , Li Debiao
Published: July 2007

T1‐shortening contrast agents have been used to improve the depiction of coronary arteries with breath‐hold magnetic resonance angiography (MRA). The spatial resolution and coverage are limited by the duration of the arterial phase of the contrast media passage. In this study we investigated the feasibility of acquiring free‐breathing, whole‐heart coronary MRA during slow infusion of the contrast media (0.3 ml/s) for prolonged blood signal enhancement time. Ultrashort TR (3 ms) and parallel data acquisition were used to allow the whole‐heart MRA in approximately 5 min. A newly approved gadolinium (Gd)‐based high T1 relaxivity contrast agent, gadobenate dimeglumine ([Gd‐BOPTA]2–), was used and coronary MRA was performed on a whole‐body 3 Tesla (T) system to improve the signal‐to‐noise ratio (SNR). Results from eight volunteers demonstrate that this coronary MRA method is capable of imaging the whole heart in 4.5 ± 0.6 min. Major coronary arteries are well depicted with high SNR (42.4 ± 12.5) and contrast‐to‐noise ratio (CNR; 27.1 ± 7.6). Magn Reson Med 58:1–7, 2007. © 2007 Wiley‐Liss, Inc.
In vivo 13carbon metabolic imaging at 3T with hyperpolarized 13C‐1‐pyruvate
Authors: Kohler S.J. , Yen Y. , Wolber J. , Chen A.P. , Albers M.J. , Bok R. , Zhang V. , Tropp J. , Nelson S. , Vigneron D.B. , Kurhanewicz J. , Hurd R.E.
Published: July 2007

We present for the first time dynamic spectra and spectroscopic images acquired in normal rats at 3T following the injection of 13C‐1‐pyruvate that was hyperpolarized by the dynamic nuclear polarization (DNP) method. Spectroscopic sampling was optimized for signal‐to‐noise ratio (SNR) and for spectral resolution of 13C‐1‐pyruvate and its metabolic products 13C‐1‐alanine, 13C‐1‐lactate, and 13C‐bicarbonate. Dynamic spectra in rats were collected with a temporal resolution of 3 s from a 90‐mm axial slab using a dual 1H‐13C quadrature birdcage coil to observe the combined effects of metabolism, flow, and T1 relaxation. In separate experiments, spectroscopic imaging data were obtained during a 17‐s acquisition of a 20‐mm axial slice centered on the rat kidney region to provide information on the spatial distribution of the metabolites. Conversion of pyruvate to lactate, alanine, and bicarbonate occurred within a minute of injection. Alanine was observed primarily in skeletal muscle and liver, while pyruvate, lactate, and bicarbonate concentrations were relatively high in the vasculature and kidneys. In contrast to earlier work at 1.5T, bicarbonate was routinely observed in skeletal muscle as well as the kidney and vasculature. Magn Reson Med 58:65–69, 2007. © 2007 Wiley‐Liss, Inc.
Perfusion mapping with multiecho multishot parallel imaging EPI
Authors: Newbould Rexford D. , Skare Stefan T. , Jochimsen Thies H. , Alley Marcus T. , Moseley Michael E. , Albers Gregory W. , Bammer Roland
Published: July 2007

Echo‐planar imaging (EPI) is the standard technique for dynamic susceptibility‐contrast (DSC) perfusion MRI. However, EPI suffers from well‐known geometric distortions, which can be reduced by increasing the k‐space phase velocity. Moreover, the long echo times (TEs) used in DSC lead to signal saturation of the arterial input signal, and hence to severe quantitation errors in the hemodynamic information. Here, through the use of interleaved shot acquisition and parallel imaging (PI), rapid volumetric EPI is performed using pseudo‐single‐shot (ss)EPI with the effective T blur and susceptibility distortions of a multishot EPI sequence. The reduced readout lengths permit multiple echoes to be acquired with temporal resolution and spatial coverage similar to those obtained with a single‐echo method. Multiecho readouts allow for unbiased R mapping to avoid incorrect estimation of tracer concentration due to signal saturation or T1 shortening effects. Multiecho perfusion measurement also mitigates the signal‐to‐noise ratio (SNR) reduction that results from utilizing PI. Results from both volunteers and clinical stroke patients are presented. This acquisition scheme can aid most rapid time‐series acquisitions. The use of this method for DSC addresses the problem of signal saturation and T1 contamination while it improves image quality, and is a logical step toward better quantitative MR PWI. Magn Reson Med 58:70–81, 2007. © 2007 Wiley‐Liss, Inc.
Fast spin‐echo triple‐echo dixon (fTED) technique for efficientT2‐weighted water and fat imaging
Authors: Ma Jingfei , Son Jong Bum , Zhou Yuxiang , Le‐Petross Huong , Choi Haesun
Published: July 2007

Previously published fast spin‐echo (FSE) implementations of a Dixon method for water and fat separation all require multiple scans and thus a relatively long scan time. Further, the minimum echo spacing (esp), a time critical for FSE image quality and scan efficiency, often needs to be increased in order to bring about the required phase shift between the water and fat signals. This work proposes and implements a novel FSE triple‐echo Dixon (fTED) technique that can address these limitations. In the new technique, three raw images are acquired in a single FSE scan by replacing each frequency‐encoding gradient in a conventional FSE with three consecutive gradients of alternating polarity. The timing of the three gradients is adjusted by selecting an appropriate receiver bandwidth (RBW) so that the water and fat signals for the three corresponding echoes have a relative phase shift of −180°, 0°, and 180°, respectively. A fully automated postprocessing algorithm is then used to generate separate water‐only and fat‐only images for each slice. The technique was implemented with and without parallel imaging. We demonstrate that the new fTED technique enables both uniform water/fat separation and fast scanning with uncompromised scan parameters, including applications such asT2‐weighted separate water and fat imaging of the abdomen during breath‐holding. Magn Reson Med 58:103–109, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis and properties of a well‐defined glycopolymer via living radical polymerization
Authors: Miura Yoshiko , Koketsu Daisuke , Kobayashi Kazukiyo
Published: July 2007

A well‐defined glycopolymer was synthesized to investigate its properties. The glycopolymer was obtained with a narrow polydispersity by nitroxide‐mediated radical polymerization of styrene carrying acetylated lactose and by the subsequent deprotection. The cylindrical structure and helical conformation of the polymer were measured by circular dichroism (CD) spectra. The affinities of the polymers towards lectins depended on the degree of polymerization (DP), and the polymers with higher DP showed stronger affinity. Copyright © 2007 John Wiley & Sons, Ltd.
Influence of organic modifiers on morphology and crystallization of poly(ϵ‐caprolactone)/synthetic clay intercalated nanocomposites
Authors: Kiersnowski Adam , Gutmann Jochen S. , Pigłowski Jacek
Published: July 2007

ε‐caprolactone was polymerized in the presence of neat montmorillonite or organomontmorillonites to obtain a variety of poly(ε‐caprolactone) (PCL)‐based systems loaded with 10 wt % of the silicates. The materials were thoroughly investigated by different X‐ray scattering techniques to determine factors affecting structure of the systems. For one of the nanocomposites it was found that varying the temperature in the range corresponding to crystallization of PCL causes reversible changes in the interlayer distance of the organoclay. Extensive experimental and literature studies on this phenomenon provided clues indicating that this effect might be a result of two‐dimensional ordering of PCL chains inside the galleries of the silicate. Small angle X‐ray scattering and wide angle X‐ray scattering investigation of filaments oriented above melting point of PCL revealed that polymer lamellae were oriented perpendicularly to particles of unmodified silicate, while in PCL/organoclay systems they were found parallel to clay tactoids. Calorimetric and microscopic studies shown that clay particles are effective nucleating agents. In the nanocomposites, PCL crystallized 20‐fold faster than in the neat polymer. The crystallization rate in nanocomposites was also significantly higher than in microcomposite. Further research provided an insight how the presence of the filler affects crystalline fraction and spherulitic structure of the polymer matrix in the investigated systems. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2350–2367, 2007
Free‐volume and crystallinity in low molecular weight poly(ethylene oxide)
Authors: Machado José C. , Silva Glaura G. , Oliveira Fernando C. de , Lavall Rodrigo L. , Rieumont Jacques , Licinio Pedro , Windmöller Dario
Published: July 2007

Positron annihilation lifetime spectroscopy (PALS), differential scanning calorimetry, X‐ray diffraction, and polarized light optical microscopy were used to study six low molar mass poly(ethylene oxide) samples with average molar masses ranging from 1 × 103 to 10 × 103 g mol−1. Dynamic light scattering was used to determine molar mass and polydispersity rigorously. Polymer samples with 70–95% crystallinity, which is an unusual range in PALS studies, were prepared by molten material quenching. The ortho‐positronium pick‐off lifetime (τ3) and relative fractional free volume (fv), determined by the free volume model, correlated well with the average molar mass and crystallinity of the polymers. X‐ray diffraction and polarized light optical data support the interpretation of positron annihilation results. PALS parameter, I3, which is associated with high cavity content, remained approximately constant at 20–22% for all samples. The cavities are present as crystallite defects in the spherulitic open texture and the amorphous phase for the low crystallinity sample (e.g., for Mw = 1390) and at the interfaces and in interlamellar spherulite regions of the more crystalline materials. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2400–2409, 2007
Shear‐enhanced crystallization of a thermoplastic polyimide derived from 3,3′,4,4′‐oxydiphthalic dianhydride and 4,4′‐oxydianiline
Authors: Zhao Guiyan , Zhang Min , Men Yongfeng , Ding Mengxian , Jiang Wei
Published: July 2007

The aim of this work is to investigate the effect of consecutive shear on the crystallization of an amorphous aromatic polyimide (PI) derived from 3,3′,4,4′‐oxydiphthalic dianhydride (3,3′,4,4′‐ODPA) and 4,4′‐oxydianiline (ODA). At 260 °C, the increase of shear rate or shear time leads to the increase of crystallinity. Indeed, increasing shear rate can also accelerate the crystallization behavior. Moreover, it was found that a new melting peak appeared at higher temperature for long time or high rate sheared sample. The enhancement of crystallization behavior appears directly linked to the increase of crystal thickness. Particularly, the effect of shear temperature was investigated, and the results revealed that the crystallization of the PI was more sensitive to shear at 260 °C, which was 10° above the glass transition temperature (250 °C) of the PI. Possible mechanism was proposed to illustrate the effect of consecutive shear on the crystallization of the PI polymer. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2344–2349, 2007
Flonicamid, a novel insecticide with a rapid inhibitory effect on aphid feeding
Authors: Morita Masayuki , Ueda Tsuyoshi , Yoneda Tetsuo , Koyanagi Tohru , Haga Takahiro
Published: July 2007

Flonicamid (IKI220; N‐cyanomethyl‐4‐trifluoromethylnicotinamide), a pyridinecarboxamide compound, is a novel systemic insecticide with selective activity against hemipterous pests, such as aphids and whiteflies, and thysanopterous pests. The purpose of this study is to clarify the biological properties of flonicamid against aphids. Flonicamid is very active against aphids, regardless of differences in species, stages and morphs. This compound inhibited the feeding behaviour of aphids within 0.5 h of treatment without noticeable poisoning symptoms such as convulsion, and this antifeeding activity was not recoverable until death. The nymphs born from adults exposed to flonicamid for 3 h showed high mortality. The effect of flonicamid on the feeding activity of an individual aphid was studied using electronic monitoring of insect feeding behaviour (EMIF). Although the treated aphid attached the head of its proboscis to the leaf surface, salivation and sap feeding were strongly inhibited. These results suggest that the main insecticidal mechanism of flonicamid is starvation based on the inhibition of stylet penetration to plant tissues. Copyright © 2007 Society of Chemical Industry
Effectiveness of insecticide‐treated and non‐treated trap plants for the management of Frankliniella occidentalis (Thysanoptera: Thripidae) in greenhouse ornamentals
Authors: Buitenhuis Rosemarije , Shipp J Les , Jandricic Sarah , Murphy Graeme , Short Mike
Published: July 2007

The effectiveness of trap cropping as an integrated control strategy against western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), was explored in potted chrysanthemum, Dendranthema grandiflora (Tzvelev), greenhouse crops. The efficacy of flowering chrysanthemum trap plants, either treated with the insecticide spinosad or untreated, to regulate F. occidentalis populations was tested at different spatial scales (small cage, large cage and commercial greenhouse) and for different time periods (1 or 4 weeks). It was demonstrated that flowering chrysanthemums as trap plants lower the number of adult F. occidentalis in a vegetative chrysanthemum crop and, as a result, reduce crop damage. In the 4 week large‐cage trial and the commercial trial, significant differences between the control and the trap plant treatments started to appear in the third week of the experiment. Larvae were only significantly reduced by the presence of trap plants in the 1 week small‐cage trials. There were no significant differences between treatments with spinosad‐treated and untreated trap plants in the number of F. occidentalis on the crop. This suggests that there was minimal movement of adult F. occidentalis back and forth between the trap plants and the crop to feed and oviposit. It is concluded that the trap plant strategy is a useful tool for integrated pest management against F. occidentalis in greenhouses. Copyright © 2007 Crown in the right of Canada. Published by John Wiley & Sons, Ltd
Ab initio study of elastic, thermal physical properties and electronic structure of Fe–Ga alloys
Authors: Chen K. , Cheng L. M.
Published: July 2007

Ab initio spin polarized calculations were carried out to study the elastic, thermal physical properties and electronic structures of Fex Ga1–x alloys. To evaluate the elastic properties, dilute supercell models were constructed for Fe–6.25 at% Ga and Fe–12.5 at% Ga alloys. In addition, possible atomic models were explored for Fe–18.75 at% Ga, in which one model that contains a pair of Ga atoms forming a cluster was suggested to represent the quench state of the alloy. The experimentally observed softness of the tetragonal shear modulus 1/2(C11 – C12) in Fe–Ga alloys was reproduced in the calculations. The ductility of Fe–Ga alloys was analyzed in terms of the ratio G /B, where G and B are the shear and bulk modulus, respectively, and the Cauchy pressure 1/2(C12 – C44). The results show that the ductility of Fe–Ga was enhanced with increasing Ga concentration. The relation between linear thermal expansion coefficients α (T) and Ga content was also examined. It was demonstrated that both bulk modulus B and the Grüneisen parameter γ play a major role in determining the trend in thermal expansion coefficients. The electronic structures of Fe–Ga alloys were investigated, and the characteristics of electronic density of states were analyzed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemical and nutritional studies on the seed oil ofAcacia arabica
Authors: Maity C. R. , Mandal B.
Published: July 2007

The seeds ofAcacia arabica contain 5.2% oil. Physicochemical constants and fatty acid composition of the refined seed oil were determined. The seed oil was rich in linoleic acid (39.2%) and oleic acid (32.8%). Trace quantities of epoxy and hydroxy fatty acids were present in the seed oil. Nutritional evaluation of the refined seed oil was done by rat bioassay with peanut oil as control. The animals fed 10% seed oil showed poor growth performance and low feed efficiency ratio. The digestibility of the seed oil was 90% compared to 94% for peanut oil. The seed oil in the diet of rats for 4 wk did not produce any abnormal serum lipids or histopathological findings.
Temperature effects on the extraction of rubber and melon seed oils
Authors: Ibemesi J. A. , Attah J. C.
Published: July 2007

Oils were extracted from the seeds of rubber [Hevea brasiliensis (Kunth) Muell. Arg.] and melon (Colocynthis vulgaris Schrad) using different solvents at varying temperatures. The objective was to determine temperature coefficients (n) for enhanced oil removal and the enthalpy changes accompanying the extraction process.

Values of n, obtained from the slopes of the plots of the natural logarithm of equilibrium oil yield vs T/10, were on the order of 1.10, showing that oil, yield increased by a factor of about 1.10 for every 10° rise in temperature. Also, n values were used to predict oil yields at other temperatures by knowing the oil yield at a given temperature.

Enthalpy changes (ΔH) in the extraction of both oils were determined using the Arrhenius equation. The ΔH values obtained were in the range of 4–13.5 kJ mol−1, indicating the physical nature of oil extraction by a solvent.
Surfactants & detergents: Influence of alkanols on the micellar behavior of samarium soaps
Authors: Mehrotra K. N. , Chauhan Mithlesh , Shukla R. K.
Published: July 2007

The critical micelle concentration, degree of ionization, and ionization constant of samarium caproate in alcohols (methanol, ethanol, propanol‐1, butanol‐1 and pentanol‐1) were determined by using conductometric measurements. The results show that the soap behaves as simple electrolyte in dilute solutions below the CMC. The viscosity results of samarium soap have been explained in terms of equations proposed by Einstein, Vand, Moulik and Jones‐Dole. The critical micelle concentration (CMC) was found to decrease with increasing dielectric constant of the solvent.
Component fatty acids in body fats of some marine fishes
Authors: Karkhanis Y. D. , Magar N. G.
Published: July 2007

The component fatty acids of the body fats of three typical species of Bombay marine fish were investigated. The saturated acid contents of pala and black pomfret oil were about the same. The black pomfret oil was abnormally high in palmitoleic acid. Linoleic acid was found to be remarkably low in pala and black pomfret oils. In white pomfret the amount of it present was about the same as that of linolenic. Polyunsaturated acids were present in black and white pomfret oils but only present in traces in pala oil.
Phase behavior in the solvent winterization of crude cottonseed oil in 85–15 acetone‐hexane mixture as related to reduction in refining loss and color
Authors: Boucher Richard E. , Skau Evald L.
Published: July 2007

Fundamental physical chemical data have been obtained which indicate on a laboratory scale the feasibility and advantages of solvent winterization of crude cottonseed oil in 85–15 acetone‐hexane mixture. The results show the effect of oil‐solvent ratio, chilling temperature, duration of chilling, and the addition of adsorbents on the degree of winterization, the refining loss, and the color of the winterized oil. Crystallization is markedly inhibited by the presence of a phosphatide‐rich material in the crude oil, but this can be overcome by the proper control of the oil‐solvent ratio and temperature and by the addition of adsorbents. Winterization in this solvent with or without adsorbents results in the separation of a large proportion of the phosphatides, and a marked reduction in refining loss and color. The advantages of winterizing hexane‐extracted cottonseed oils before refining are discussed.
An investigation of the oil from the seed of sebastiana lingustrina
Authors: Hanks D. P. , Potts W. M.
Published: July 2007

The seed ofSebastiana lingustriana have been collected and investigated. They contain about 37% oil, the physical and chemical characteristics of which were determined.

Analyses of the component fatty acids were made by interesterification to form esters, which were separated into principally saturated and unsaturated fractions by low temperature crystallization. Each of these fractions was fractionated on a Todd column. The resulting fractions were examined spectrophotometrically and the percentage of each acid was calculated.

The oil ofSebastiana lingustrina contains an unusual fatty acid, probably 2,4‐dodecadienoic acid.
The chronic toxicity of lauryl gallate
Authors: Allen Shannon C. , DeEds Floyd
Published: July 2007

Summary and Conclusions

Long‐term feeding experiments with albino rats involving concentrations of lauryl gallate as high as 0.5% in the daily diet produced no deleterious effects as judged by food intake, rate of growth, gross observations at time of autopsy, and histopathological examination of tissues. Diets containing 1.0% lauryl gallate definitely inhibited growth of male rats and retarded growth of females slightly. Levels of 2.5 and 5% lauryl gallate caused no histopathological changes in various organs but decreased the food intake to a point where starvation was an obvious factor in death of the animals. Lauryl gallate produced skin irritation but did not produce skin sensitization. The property of skin irritation might be of importance to workers engaged in the production and handling of lauryl gallate. There is no evidence to indicate that ingestion of slight amounts, such as might be encountered in edible fats and oils protected against oxidation, would produce harmful effects.
A colorimetric method for determining small amounts of trichloroethylene in vegetable oils
Authors: Eisdorfer I. , Mehlenbacher V. C.
Published: July 2007

An accurate method for determining small amounts of trichloroethylene in vegetable oils has been presented. The method employs a distillation procedure to separate the trichloroethylene from the oil and a colorimetric procedure based on the Fujiwara reaction to determine the trichloroethylene in the distillate. The method has been tested on known samples of crude and refined soybean and cottonseed oils varying in trichloroethylene content from 0.001% to 0.6% with excellent results.
Phase investigations of fats. III. Systems containing oleic and palmitic acids and an organic solvent
Authors: Singleton W. S.
Published: July 2007

The ternary systems, oleic acid‐palmitic acid‐commercial hexane and oleic acid‐palmitic acid‐acetone, containing varying amounts of the three components have been equilibrated at 0°C., −10°C., −20°C., −30°C., and −40°C.

From compositional data of the liquid and solid phases in equilibrium at each isothern, ternary phase diagrams have been constructed. From these diagrams it is possible to predict the degree of separation which can be obtained with any given mixture of oleic and palmitic acids, using either acetone or commercial hexane as solvent.

The liquid phase boundaries have been established for each isotherm investigated and have been constructed on an enlarged scale.

The intersolubilizing effect of oleic acid on palmitic acid is greater in commercial hexane than in acetone although each acid is more soluble in acetone than in commercial hexane.
An esr study of radical intermediates formed by γ ‐ radiolysis of tripalmitin and dipalmitoyl phosphatidylethanolamine
Authors: Sevilla C. L. , Swarts S. , Sevilla M.D
Published: July 2007

Radicals resulting from the 7‐radiolysis at 77 K of neat tripalmitin and neat dipalmitoyl phosphatidylethanolamine were investigated by electron spin resonance spectroscopy (ESR). Analyses of the spectra of these complex lipids were aided by ESR studies of their components phosphorylethanolamine, palmitic acid and hexa‐decane. Concentrations of various radicals were followed as a function of temperature after γ‐irradiation at 77 K. Both tripalmitin and dipalmitoyl phosphatidylethanolamine show anion radicals formed by electron addition to the ester groups and aliphatic side‐chain radicals (‐CH2‐CH‐CH2‐) which are thought to be the result of deprotonation of the original positive hole. Computer analyses of the spectra as the temperature increases show loss of the anion radicals with an increase in a new radical produced by the abstrac‐tion of a hydrogen atom from the α carbon on an acyl side chain. In the case of dipalmitoyl phosphatidylethanolamine, a radical of the phosphorylethanolamine portion of the molecule is detected as an intermediate. Mechanisms for the formation and decay of the free radical intermediates are discussed.
Interpreting the appearance of dispersed systems: I. Model dispersions of polymer latex microspheres
Authors: Franses E. I. , Scriven L. E. , Miller W. G. , Davis H. T.
Published: July 2007

Measurements of total absorbance at wavelengths 350–780 nm of aqueous dispersions of polymer latex microspheres of diameters 0.091 μm, 0.254 gmm, 0.325 μm, and 1.10 μm were used to interpret systematic observations of them. Light scattering dissymmetries and scattering ratios of dispersions of the 0.091 μm microspheres were measured at varying concentration and path length at 546 nm and 436 nm. Spectroturbidimetry and observations were also made in binary mixtures of the above particle sizes and in dispersions of microspheres with added dye, the sodium salt of methyl red. For ab‐sorbance due to scattering, Ascat, exceeding 0.04 but not 2, the ab‐sorbance and its wavelength dependence yield reliable estimates of particle size, even though the dissymmetry and the scattering ratio do not. Observations of nonabsorbing systems under ordinary illum‐ination are most reliably interpreted with 0.1 < Ascat < 1, i.e., when the systems look translucent to translucent‐turbid, even though multiple scattering predominates in this range. That the Tyndall effect, or a variant of it when absorption is important, is visible im‐plies that particles smaller than 0.1 μm are present. To estimate particle sizes in milky dispersions in which A > 2, it is necessary to decrease the path length — or the concentration, if tolerable — so that the absorbance falls in that optimal range. Outside this range, the literature rules are unreliable. Because observers and illumination conditions vary among laboratories, it seems essential that model systems such as the microspheres and the dye employed here be used to simulate scattering and absorption features of dispersed systems. By direct comparisons of model systems to systems of interest, observations can be standardized and interpretation of appearances can become less subjective. Moreover, combining obser‐vations with spectroturbidimetry provides a much more potent tool for estimating sizes simply and quickly.
Seeding effects on solidification behavior of cocoa butter and dark chocolate. I. Kinetics of solidification
Authors: Hachiya Iwao , Koyano Tetsuo , Sato Kiyotaka
Published: July 2007

Effects of seeding of fat crystals on the crystallization kinetics of cocoa butter and dark chocolate were examined with a rotational viscometer. The seed crystals employed were cocoa butter, 1,3‐distearoyl‐2‐oleoylglycerol (SOS), 1,3‐dibehenoyl‐2‐oleoylglycerol (BOB) and 1,2,3‐tristearoylglycerol (SSS). The seed powders were prepared by pulverization below —50°C, the dimensions being in a range from 20–70 μm. Particular attention was paid to the influence of polymorphism of the seed crystal. We found that all of the above seed materials accelerated the crystallization, the degree of acceleration being in a following order; SOS (β1) > cocoa butter (Form V) > SOS (a mixture ofβ’ andβ2) > BOB (β2) > BOB (pseudo‐β’) > SSS (β). Precise measurements of the crystallization kinetics showed that the most influential factors in the seeding effects are the physical properties of the seed materials—above all, thermodynamic stability, and similarity in the crystal structure to cocoa butter are the most determinative.
Lipid and hardness characteristics of cocoa butters from different geographic regions
Authors: Chaiseri Siree , Dimick Paul S.
Published: July 2007

Twenty‐four commercially pressed cocoa butters and 39 laboratory solvent extracted cocoa butters were evaluated. A rapid method using differential scanning calorimetry (DSC) was used to evaluate the hardness of small quantities of cocoa butter. In the DSC thermogram of a quenched sample, the percentage area under the polymorph II endotherm had a positive correlation (r=0.74) with the mechanical hardness. Soft cocoa butters were characterized by high POO, SOO content (P=palmitic acid, O=oleic acid, S=stearic acid), high iodine value, low percentage, area under the polymorph II endotherm from the DSC scanning, and low SOS. Hard cocoa butters displayed opposite characteristics. In general, South American cocoa butters were the softest and had a 37.03 iodine value, a total of 9.1% POO and SOO, and a 26.4% area under the polymorph II endotherm. Cocoa butters from Asia and Oceania were the hardest and had a 34.74 iodine value, a total of 4.1% POO and SOO, and a 35.65% area under the polymorph II endotherm. North and Central American and African cocoa butters were intermediate in hardness characteristics.
Polymorphic stability of hydrogenated canola oil as affected by addition of palm oil
Authors: Yap P. H. , deMan J. M. , deMan L.
Published: July 2007

Palm oil was added to canola oil before and after hydrogenation and the effect of this addition on the polymorphic stability of the hydrogenated oils was investigated. Palm oil was added to canola oil at two levels to produce hydrogenated canola and palm oil blends containing 5 and 10% palm oil. The levels of palm oil added to hydrogenated canola oil were 5, 10 and 15%. Samples were subjected to temperature cycling between 5 and 20°C as well as storage at 5°C up to 56 days. X‐ray diffraction and polarized light microscopy were used to follow the changes of polymorphic form and crystal growth, respectively, during cycling and storage. Theβ‐crystal contents of the oils were quantified based on the relative density of the characteristic short spacings using a Soft Laser Scanning Densitometer. The delaying effect of palm oil on phase transition was observed using Differential Scanning Calorimetry. Palm oil showed no effect on the polymorphic stability of the temperature cycled selectively hydrogenated oil, however, it delayed the transition rate at a constant temperature of 5°C. Addition of palm oil at the 10% level before hydrogenation and the level after hydrogenation proved to be effective in delaying polymorphic instability of nonselectively hydrogenated canola oil. Theβ′ stabilization effect of palm oil on the polymorphic stability of hydrogenated canola oil is most likely due to a decrease of fatty acid chain length uniformity.
Biodegradability of alkylbenzene sulfonates
Authors: Sweeney W. A. , Anderson R. G.
Published: July 2007

This article puts in perspective various questions concerning the environmental impact of alkybenzene sulfonates (ABS). Several points which are frequently overlooked or misunderstood are clarified:

Except for the nuisance aspects of its foaming tendency, ABS entering the environment as a component of household sewage is insignificant relative to other pollutants.

Any negative impact that ABS has—foaming, possible interaction with living organisms—comes from its surface active character. When it biodegrades sufficiently to lose its surface active character, it becomes innocuous. Hence, only “primary” biodegradation rates are important.

Linear ABS (LAS) biodegrades much faster than highly branched ABS (BAS). However, they both eventually completely degrade in an aerobic environment.

Neither BAS nor LAS degrade when the sewage does not receive adequate aerobic sewage treatment either in a treatment plant or in the receiving water. Therefore, in localities without adequate aerobic sewage treatment, there is no environmental incentive to use LAS in preference to BAS.

Realistic laboratory tests mirror the sewage treatment process. It is not reasonable, except for screening purposes, to run biodegradation tests in the absence of sewage.

Slight variations in the LAS structure—isomer distribution, modest branching—do not affect its biodegradation in realistic tests.

The important criteria for a country contemplating a switch from BAS to LAS are the concentration of ABS found in receiving waters and the adequacy of sewage treatment.
Conjugated dienes of crude soy oil: Detection by UV spectrophotometry and separation by HPLC
Authors: Brown H. G. , Snyder H. E.
Published: July 2007

A study of crude soy oils by ultraviolet spectrophotometry showed E1cm1% values at 233 nm ranging from 1.6 to 2.0. These E1cm1% values can be used as a measure of the conjugated diene compounds of soy oil. E1cm1% values for purified triglycerides were 0.78 (tristearin), 1.1 (triolein), and 0.71 (trilinolein). For the triglyceride fraction of crude soy oil after separation by high performance liquid chromatography (HPLC) the E1cm1% was 0.98. HPLC separation of components in crude soy oil led to a tentative identification of a triglyceride fraction, a carotene fraction, 2 tocopherol fractions, and 4 conjugated diene fractions.
Analytical chain to monitor vegetable oil hydrogenation
Authors: Bitner E. D. , Snyder J. M. , Mounts T. L. , Dutton H. J. , Baker G.
Published: July 2007

Three analyses were automated to monitor a laboratory continuous hydrogenator. Attenuated total reflectance infrared was used to followtrans isomer formation, refractive index for iodine value change and gas liquid chromatography for fatty acid composition. The instant response of the infrared spectrometer was confirmed by the later responses of the refractometer and gas chromatograph. All 3 operations were used to follow the progress of batch, continuous or semicontinuous hydrogenation.
Selective hydrogenation of soybean oil: XII. Trialkyl aluminum‐copper stearate homogeneous catalysts
Authors: Koritala S.
Published: July 2007

The reaction of copper stearate with triethylaluminum (TEAL) formed a soluble catalyst that promoted the selective hydrogenation of the linolenyl groups in soybean oil. This homogeneous catalyst was more active than copper‐chromite. The activity was enhanced by the addition of silica, alumina or titania. Ethyl alcohol accelerated the hydrogenation when it was added in small amounts and retarded hydrogenation when increased amounts were added. More active and, in some cases, more selective catalysts were formed when TEAL was replaced by trialkylaluminum compounds containing longer chain length in the alkyl groups. Among other organometallics tested, diethylmagnesium and diisobutylaluminum ethoxide formed catalysts with activity comparable to heterogeneous catalysts (KLe/KLo=2.8~5.2) was less than that obtained with copper‐chromite (12~14), but greater than that of commercially used nickel catalysts (2). Isomerization, as measured by the percentage oftrans isomers formed, was similar to that of heterogeneous copper catalysts (%trans/ΔIV=0.6~0.7).
Polyglycerol esters composition: Theoretical random distribution versus HPLC analysis
Authors: Garti N. , Aserin A.
Published: July 2007

Product composition of polyglycerol esters, prepared from a direct alkaline polymerization of glycerol followed by esterification with stearic or oleic acids, has been studied. The internal product composition, as analyzed by high performance liquid chromatography (HPLC), shows clearly that in contradiction to what has been published recently, the fatty acid radicals arenot distributed at random among all available hydroxyl groups, and thus, any theoretical calculation on the product composition could not be correct. The product composition of the crude material indicates clearly that the internal positions (secondary hydroxyls) of the glycerol polymer are esterified with greater difficulty than the primary hydroxyl groups.
On the application of supercritical fluid extraction to the deacidification of olive oils
Authors: Gonçalves M. , Vasconcelos A. M. P. , Gomes de Azevedo E. J. S. , Chaves das Neves H. J. , Nunes da Ponte M.
Published: July 2007

A recent suggestion on the applicability of supercritical fluid extraction to the deacidification of olive oils of high acid content was based on solubility data in clear disagreement with the results of other authors. In this work, we measured the solubilities of substances chosen for their importance in that extraction process, namely pure glycerol trioleate, the most abundant triglyceride in olive oil, and of a husk oil with a high acid content. Our results agree well with some of the previous reports on this subject. These seem to be a trustworthy data base, but more results are needed for a definite conclusion about the technical feasibility of the process.
Fatty acid and oil diversity of cupheaviscosissima: A source of medium‐ chain fatty acids
Authors: Knapp S. J. , Tagliani L. A. , Roath W. W.
Published: July 2007

Cuphea viscosissima Jacq. is being developed as a commercial source of caprylic, capric, lauric, and myristic acids. Germplasm resources for characterizing the genetic diversity of this species became available following explorations by the United States Department of Agriculture (USDA) in 1986 and 1987. In this paper, we describe the fatty acid and oil percentage diversity of forty‐ two populations ofC. viscosissima collected from seven states within the United States. Caprylic (18.0%) and capric acid (69.9%) were the major fatty acids of these populations. The fatty acid percentage ranges were narrow for every fatty acid,e.g., 16.4 to 20.4% for caprylic acid and 66.6 to 71.3% for capric acid. The maximum lauric acid percentage was 3.4%. Oil ranged from 27.3 to 33.4%. Although the populations surveyed cover a fairly wide geographic range, they display limited fatty acid diversity. Surveys of germplasm from other parts of the range are needed to further characterize the fatty acid diversity of this species.
Chemical evaluation of egyptian citrus seeds as potential sources of vegetable oils
Authors: Habib M. A. , Hammam M. A. , Sakr A. A. , Ashoush Y. A.
Published: July 2007

Seeds of the citrus fruits orange, mandarin, lime and grapefruit were analyzed. Petroleum ether‐extracted oils of such seeds amounted to more than 40% of each. Physical and chemical properties of the extracted oils are presented. Samples of the extracted oils were saponified and the unsaponifiables and fatty acid fractions isolated. The isolated unsaponifiables and fatty acids were analyzed by GLC. GLC analysis of the unsaponifiables revealed compositional patterns differ‐ent in number, type and relative concentration of fractions according to type of citrus seed oil, depending on the solvent system used for oil extraction and unsaponifiable matter isolation. The compositional patterns of the unsaponifiables were similar to that of cottonseed oil. Mandarin and grapefruit oils are free of cholesterol. The data demonstrate that the fatty acid compositional patterns of the oils differ; Mandarin seed oil contains the largest number of fatty acids, and grapefruit seed oil contains the lowest. The total amounts of volatile fatty acids in these oils are generally higher than those of other edible oils. Lime seed oil is similar, in the degree of unsaturation, to soybean oil. The orange oil pattern is similar to cottonseed oil. The amount of total essential fatty acids in lime seed oil is the highest of the oils studied.
A comparison by warburg respirometry and die‐away studies of the degradability of select nonionic surface‐active agents
Authors: Garrison L. J. , Matson R. D.
Published: July 2007

The relative biodegradability of several classes of nonionic surfactants have been determined by Shake Flask, Die‐Away and Warburg Respirometer tests. Analytical techniques used to follow the degradation processes involved the measurement of loss of surfactant properties (surface tension or foamability), colorimetric determinations and oxygen uptake studies. Nonionic products prepared from naturally occurring or synthesized straight chain hydrophobes were shown to exhibit based upon branched chain materials. A good correlation of data by the various analytical techniques was obtained on the straight chain based products.
Surfactants containing ethylene oxide: Relationship of structure to biodegradability
Authors: Steinle E. C. , Myerly R. C. , Vath C. A.
Published: July 2007

Anionic ethoxy sulfate and nonionic ethoxylate surfactants were prepared from the following straight‐chain hydrophobes: fatty or Ziegler primary alcohols, oxo alcohols derived from straight‐chain olefins, secondary straight‐chain alcohols and straight‐chain alkylphenols. These were studied to relate biodegrability to the following elements of structure: the nature of the connecting link, its position of attachment to the hydrophobe, the chain length of the hydrophobe, and the length of the ethylene oxide chain used. Previously described methods were used to estimate both rate and completeness of degradation in river water as well as activated sludge environments.

Data are presented to support the following conclusions.

All surfactants derived from straight‐chain primary and secondary alcohols are rapidly and completely degraded with loss of surfactant properties. The length of the ethylene oxide chain from zero up to ten units has no effect on the rate or the completeness of degradation. In such surfactants, the ethylene oxide chain is completely degraded.

In contrast, surfactants from straight‐chain alkylphenols are not as rapidly or as completely degraded as those described above. The position of attachment of the phenol ring to the straight‐chain has a large effect on degradability; normal or primary attachment leads to a faster rate of disappearance than secondary attachment. Nonionic surfactants from straight‐chain alkylphenols containing ten to twelve moles of ethylene oxide are not completely degradable.
Straight‐chain alkylbenzenes: Structure and performance property relations
Authors: Rubinfeld J. , Emery E. M. , Cross H. D.
Published: July 2007

An intensive study of the mass spectral characteristics of straight‐chain alkylbenzenes has been made in conjuction with their ultimate performance as sulfonates in heavy duty formulations. Two variables of the alkylates, carbon‐chain length distribution (which fixes the mean mol wt) and phenyl position on the chain, have been successfully related to the observed dishwashing performances. Formulas are given which allow accurately predicting this performance criteria. The important role of phenyl position is illustrated by a detailed study of each phenyl isomer in the tetradecylbenzene series.
A colorimetric procedure for the estimation of fat acidity in peanuts and peanut meals
Authors: Bains G. S. , Rao S. V. , Bhatia D. S.
Published: July 2007

Modification of a colorimetric method for the estimation of free fatty acids in peanuts and its products is described. The material is extracted with benzene and a measured aliquot shaken with aqueos cupric acetate. The absorbance of the filtered coloured benzene layer is measured spectrophotometrically at 670 mॖ.

The concomitant presence of peanut oil in the benzene solution of copper oleate has a negligible effect on the intensity of colour. The procedure can also be used for determining the fat acidity in sesame meals.
Quality assessment of used frying fats: A comparison of four methods
Authors: Billek G. , Guhr G. , Waibel J.
Published: July 2007

The level of petroleum ether insoluble oxidized fatty acids in used frying fats is one of the recommended criteria for assessing their quality in Germany; however, the method of determination is time consuming and inaccurate. Gel permeation chromatography (GPC) allows the determination of dimeric and oligomeric triglycerides in a heated fat irrespective of the presence of oxidized material. An indication of the total amount of polar and oxidized compounds can be obtained by liquid chromatography (LC) on a silica gel column in connection with a moving‐wire detector. A comparatively simple and quick method is the separation of polar and unpolar components in a used frying fat by means of column chromatography (CC) on silica gel. Over a large number of investigations, a good correlation was seen between the results obtained with GPC, LC, and CC and the amount of petroleum ether insoluble oxidized fatty acids isolated from used frying fats. Limits of the analytical data obtained by the new methods are proposed which indicate deterioration of used frying fats.
Cationic surf ACE‐active agents
Authors: Gawish S. M. , Hazzaa A. A. B. , Gebril B. EL‐Din
Published: July 2007

A group of cationic surfactants of 2‐hydroxy‐3‐(2‐heptadecyl, pentadecyl or undecyl amido‐ethylamino) propane‐1‐triethyl ammonium hydro‐xides was prepared. These derivatives were purified and characterized by microanalysis, molecular weight determination, infrared, nuclear magnetic resonance, and mass spectra studies. Their surface and interfacial tensions were determined.
New non‐ionic surfactants: Alkyl polyoxyethylene diethers of isomeric dimethylxanthines
Authors: Sax Philip , Donbrow M.
Published: July 2007

Novel isomeric nonionic surfactants of the poly‐oxyethylene (POE) ether type possessing terminal dimethylxanthine functions related to caffeine have been prepared using a polyoxyethylene cetyl mono‐ether as the starting material. The surface tension pro‐perties indicate that, compared to the parent com‐pound and its chloride derivative, these derivatives show pronounced changes in the critical micelle con‐centration (CMC) and pre‐CMC slope but relatively minor changes in the minimum surface tension value. The findings are discussed also in terms of efficiency and effectiveness of surfactants. The evidence indi‐cates that the structure of the terminal hydrophilic portion can have a significant effect on interfacial packing. The cloud points of the chloride derivative and the xanthine derivatives were considerably lower than that of the parent ether. Cloud point curves for the ether, the chloride, and the xanthines over the dilute concentration range show similar features.