bluuebunny/crossref_metadata_2025_split huggingface dataset:
Saturation effects in molecular spectroscopy using degenerate four‐wave mixing
Authors: Bultitude K. , Bratfalean R. , Ewart P. 
Published: December 2003

AbstractLineshapes of degenerate four‐wave mixing signals induced by both monochromatic and non‐monochromatic lasers are compared with predictions of the non‐perturbative model of Bratfalean, Lloyd and Ewart (BLE model) for the interaction of pump and probe beams of arbitrary intensity. Spectral lineshapes of isolated lines in DFWM spectra of OH in a methane–oxygen flame were recorded using a novel single‐mode tunable laser as a function of laser power. Power broadening of the lineshapes was found, in this case of an essentially monochromatic laser, to be well described by the BLE model. DFWM lineshapes of more complex molecular spectra were recorded in C2 in an oxy–acetylene flame using a standard, non‐monochromatic, dye laser. Lineshapes of closely spaced molecular resonances were found to be appreciably affected by saturation or power broadening effects. These effects were reasonably well approximated by the non‐perturbative BLE model when adapted to take account of the finite laser bandwidth. In contrast, the experimental lineshapes of the C2 spectra for saturating fields could not be modeled using the standard perturbative model of Abrams and Lind Copyright © 2003 John Wiley & Sons, Ltd.
Precision of single‐shot dual‐broadband rotational CARS thermometry with single‐mode and multi‐mode Nd:YAG lasers
Authors: Afzelius M. , Bengtsson P.‐E. 
Published: December 2003

AbstractThe precision of single‐shot coherent anti‐Stokes Raman spectroscopy (CARS) thermometry is an important characteristic for the application of CARS in various combustion devices such as internal combustion engines. It is generally assumed that the precision of CARS is directly related to the spectral noise of the interacting laser fields, and previous studies have presented a theoretical model describing the behaviour of the noise as a function of various experimental parameters. In this work, the aim was to test the results predicted by the previously developed model for dual‐broadband rotational CARS. We studied the precision of evaluated temperatures in pure nitrogen under different experimental conditions, namely the dependence of precision on the gas pressure and on the linewidth of the narrowband laser (the Nd:YAG laser). It was demonstrated that our experiments reproduce the main features of the model, and that a single‐mode Nd:YAG laser leads to better precision than a multi‐mode Nd:YAG laser for dual‐broadband rotational CARS thermometry. Copyright © 2003 John Wiley & Sons, Ltd.
Note on utilisation of peanut seed testa
Authors: Sobolev Victor S , Cole Richard J 
Published: December 2003

AbstractPeanut testae (skins, seed coats) are an extremely low value by‐product of peanut‐blanching operations. Their commercial value is $12–20 per ton and their limited use is only as a minor component of cattle feed. Based on world in‐shell peanut production of 29.1 million tons in 1999/2000 and an average skin content of 2.6%, world production of peanut skins can be estimated at over 750 000 tons annually. Research performed to find new uses for peanut skins demonstrated that up to 35% of the oil in the skins can be recovered. In some cases the oil can be a new potential source of behenic and lignoceric acids, which are used in body‐building formulations and as ingredients in shampoos. After removal of the oil the skins were useful for making brandy, liqueur and tea. Peanut skin oil extraction followed by tannin extraction also produces a protein‐enriched product that could find application in mixed feeds for cattle consumption at higher concentrations relative to existing practice. A simple technique was also offered to use the skins in finishing decorative panels. Published in 2003 for SCI by John Wiley & Sons, Ltd.
Changes in chemical quality indices during long‐term storage of palm‐olein oil under heated storage and transport‐type conditions
Authors: van der Merwe Gretel H , du Plessis Lourens M , Taylor John RN 
Published: December 2003

AbstractSix quality indices, namely free fatty acids (FFA), peroxide value (PV), anisidine value (AV), oxidative stability index (OSI), total tocopherols and headspace volatiles (hexanal, t‐2‐hexenal and t,t‐2,4‐decadienal), were evaluated in a long‐term storage trial of 52 weeks at 50 °C of palm‐olein, a monounsaturated oil. Three concentrations of copper (0.035, 0.17 and 0.69 mg kg−1) were added. FFA values for all the sample treatments increased slightly over the storage period but remained within acceptable limits. PV of the copper‐containing samples declined initially and then remained stable up to week 40, after which it increased slightly for the 0.035 and 0.17 mg kg−1 samples. However, PV of the control (no added copper) increased steadily to above the acceptable limit. AV of the copper‐containing samples increased much more than that of the control. OSI and total tocopherol values of the copper‐containing samples were markedly lower than those of the control. t‐2‐Hexenal did not increase during the storage period, whereas hexanal increased in the copper‐containing samples but at a slower rate than in the control. Conversely, the copper‐containing samples had high levels of t,t‐2,4‐decadienal but the control had none. AV, OSI and total tocopherols are the most valuable quality indices for assessing monounsaturated oil quality, whereas FFA, PV and headspace volatiles can be misleading. Copyright © 2003 Society of Chemical Industry
Structural and physical properties of dried Anaheim chilli peppers modified by low‐temperature blanching
Authors: Heredia‐Léon JC , Talamás‐Abbud R , Mendoza‐Guzmán V , Solís‐Martinez F , Jimenez‐Castro J , Barnard J , Quintero‐Ramos A 
Published: December 2003

AbstractThe effect of low‐temperature blanching and drying processes on the ultrastructural and physical properties of Anaheim chilli pepper was studied and optimum conditions to provide a final product with maximum firmness were determined. Lots of Anaheim pepper were blanched in water for 4 min at 48, 55, 65, 75 and 82 °C and maintained for hold times of 35, 45, 60, 75 and 85 min, blanched again for 4 min at 96 °C and dehydrated at 53, 60, 70, 80 and 87 °C. After treatment the samples were rehydrated in water at 30 °C. Rehydration ratio, texture and structural changes were evaluated. Optimisation used a second‐order rotatable central composite design. Texture and rehydration ratio were affected by blanching temperature and the interaction of blanching temperature with hold time (p ≤ 0.05); drying temperature did not show a significant effect. The best results, ie those which gave greatest firmness, were obtained by blanching at 64 °C for 4 min, holding for 55 min after blanching, followed by a second blanching at 96 °C for 4 min and then drying at 70 °C. Evaluation of the rehydrated dried pepper by microscopy showed that low‐temperature blanching close to the optimum conditions provided a protective effect in maintaining cell wall integrity. The results of processing increased firmness in the rehydrated product by a factor of 1.97. Copyright © 2003 Society of Chemical Industry
Processing of soybean hulls to enhance the distribution and extraction of value‐added proteins
Authors: Sessa David J 
Published: December 2003

AbstractSoybean hulls contain peroxidase (SBP) and Bowman–Birk type protease inhibitor (BBI). SBP is used in the European bread‐baking industry, and BBI isolated from dehulled, defatted soy flour possesses cancer‐preventive and anticarcinogenic properties. Because hulls possess a low percentage of nitrogen, with fibre and other carbohydrates being the major components, our objective was to determine whether air classification of milled hulls could be used to fractionate and enrich these value‐added proteins. Hulls were pin milled three times at 18 000 rpm, followed by air classification to yield fractions with particle size distributions ranging from <15 to >30 µm. The finely ground fractions with particle sizes ranging from <15 to 18 µm were enriched with nitrogen and lipid when compared with the more coarsely ground fractions. Yields of extractable nitrogenous components from aqueous extracts were quantified at a variety of pHs, homogenisation speeds and times. BBI and SBP were confirmed by polyacrylamide gel electrophoresis with known standards. Based on assays for SBP and BBI activities, BBI, though concentrated in the finer fractions, also appeared in the highest‐mass, coarsest fraction, whereas SBP resided mainly in the coarsest fraction. Dry milling and air classification of soybean hulls proved beneficial to distribute SBP into a product stream that facilitates its isolation and purification. Published in 2003 for SCI by John Wiley & Sons, Ltd.
Effect of high‐pressure processing on myofibrillar protein structure
Authors: Chapleau Nicolas , Mangavel Cécile , Compoint Jean‐Pierre , de Lamballerie‐Anton Marie 
Published: December 2003

AbstractModification of myofibrillar proteins induced by high‐pressure processing has been investigated at pressures ranging from 50 to 600 MPa for 10 min at 20 °C. Analysis by spectroscopic methods and circular dichroism of myofibrillar proteins in phosphate buffer pH 6.0 containing 0.6 M KCl showed no changes in the secondary structure of proteins. However, study of protein conformation by quasielastic light scattering and gel filtration chromatography proved the emergence of aggregation after treatment at pressures higher than 300 MPa. This aggregation was accompanied by enhanced binding of anilino‐1‐naphthalene‐8‐sulphonic acid, which indicated an increase in hydrophobic bonding of myofibrillar proteins. Modification of the tertiary and quaternary structures of proteins may induce a molten globule state. Copyright © 2003 Society of Chemical Industry
Solubilisation of proteins from rayfish residues by endogenous and commercial enzymes
Authors: Pastoriza Laura , Sampedro Gabriel , Cabo Marta L , Herrera Juan JR , Bernárdez Marta 
Published: December 2003

AbstractThe aim of the present study was to design methods for the digestion of fish proteins from processing wastes, leading to new possibilities for little‐used species or those generating a significant volume of residues. Residues of rayfish (Raja clavata) were used for the solubilisation of protein by hydrolysis treatment. The kinetics of hydrolysis was studied using rayfish enzymes, either by autolysis of the protein in a triturate of the raw material or by application of a multi‐enzyme preparation previously extracted from the viscera of the species. Their effectiveness was compared with that of two commercial enzymes, papain and pepsin. Optimum conditions of hydrolysis and enzymatic activity for digestion with rayfish enzymes were ascertained. The yield of material and the efficiency of digestion in each of the hydrolysis processes are reported. Copyright © 2003 Society of Chemical Industry
Nutritional quality of red shrimp, Aristeus antennatus (Risso), pink shrimp, Parapenaeus longirostris (Lucas), and Norway lobster, Nephrops norvegicus (Linnaeus)
Authors: Rosa Rui , Nunes Maria L 
Published: December 2003

AbstractThe proximate composition, amino acid and fatty acid profiles, lipid classes and cholesterol and glycogen contents were determined in the edible part of red shrimp, Aristeus antennatus (Risso), pink shrimp, Parapenaeus longirostris (Lucas), and Norway lobster, Nephrops norvegicus (Linnaeus), in two distinct periods of the year. The proximate composition did not vary significantly between species or between periods of sampling. Significant differences in glycogen content were obtained between winter and summer; the lowest values were attained in winter (1.2, 1.1 and 1.0% wet weight for red shrimp, pink shrimp and Norway lobster respectively). With the exception of Norway lobster, an opposite trend was obtained for cholesterol content, ie lower values in summer (60.8 and 57.8 mg per 100 g wet weight for red shrimp and pink shrimp respectively). The major essential amino acids (EAA) were arginine, lysine and leucine and the limiting amino acid was methionine in all three crustacean species. The most important non‐essential amino acids (NEAA) were glutamic acid, aspartic acid, proline and glycine. In respect to lipid classes, phospholipids and free cholesterol predominated. The major fatty acids were 16:0, 18:1n‐9, 20:5n‐3 and 22:6n‐3. The polyunsaturated fraction was dominant (42.1–48.4%), followed by the monounsaturated (26.3–34.6%) and saturated (22.9–27.4%) fatty acids. In conclusion, the nutritional quality of these shellfish species is similar, they are valuable protein and lipid sources for the human diet and are adequate elements of the traditional Portuguese diet. Copyright © 2003 Society of Chemical Industry
Fungal metabolism of butter and shea oils by Penicillium roquefortii in solid state cultures
Authors: Liu Qin‐Tao 
Published: December 2003

AbstractMonoacylglycerols (monoglycerides, MAGs) were produced from butter oil and shea stearin fraction (shea oil) by two strains of Penicillium roquefortii, FRR 2456 (isolated from a spoilt melon) and Wisbey PJ (a commercial dairy strain), at pH 7.0 at 10 and 25 °C. The system was designed as a model of cheese using modified Czapek medium in solid state cultures. Shea oil with its unique fatty acid profile (stearic, oleic and palmitic acids) was used for comparison with butter oil. Yields of MAGs, which ranged from 3 to 14 g kg−1 oil, were higher with butter than with shea oil and higher when the spoilage strain FRR 2456 was used. Monoacylglycerols produced by mycelium‐bound lipases from both fungal strains were mainly sn‐1(3) or α isomers (60–70 mol%). Monopalmitin was the major MAG produced from both butter and shea oils. The production and use of MAGs alone or in combination with free fatty acids (FFAs) as food preservatives are discussed. It is implied that sn‐1(3) MAGs together with free fatty acids may be part of a natural antimicrobial system in relatively high‐pH foods such as blue mould‐ripened cheese where growth of foodborne pathogens such as Listeria monocytogenes can be a problem. Copyright © 2003 Society of Chemical Industry
Studies on the Synthesis and Properties of Temperature Responsive and Biodegradable Hydrogels
Authors: Sun Li‐Fang , Zhuo Ren‐Xi , Liu Zhi‐Lan 
Published: December 2003

AbstractNovel linear poly(NIPA‐co‐CL) copolymers have been synthesized by radical copolymerization of N‐isopropylacrylamide (NIPA) and 2‐methylene‐1,3‐dioxepane (MDO). The structure of copolymers was confirmed by 1H NMR and IR spectroscopy. Cross‐linked poly(NIPA‐co‐CL) hydrogels have also been prepared in toluene using N,N′‐methylenebisacrylamide as cross‐linking agent. The hydrogels thus obtained exhibit good temperature response and are biodegradable in the presence of proteinase K.Temperature influence on the enzymatic degradation by proteinase K of poly(NIPA‐co‐CL) hydrogel (G‐60).magnified imageTemperature influence on the enzymatic degradation by proteinase K of poly(NIPA‐co‐CL) hydrogel (G‐60).
A Novel Gelatin–Carbon Nanotubes Hybrid Hydrogel
Authors: Li He , Wang Di Qiang , Chen Hua Lin , Liu Bai Ling , Gao Li Zhen 
Published: December 2003

AbstractThis letter focuses on the first result of the preparation and the swelling behavior of a novel hybrid gelatin hydrogel with carbon nanotubes. A novel hybrid gelatin hydrogel with carbon nanotubes was synthesized by a physical mixing method. The structure of the novel hydrogel obtained was characterized by SEM. Besides, the swelling behavior of the synthesized hydrogel was measured at two different temperatures. The results indicate that carbon nanotubes added could maintain the stability of the hybrid hydrogel without cross‐linking at 37 °C. This suggests that the hybrid gelatin hydrogel with carbon nanotubes could be used in biomedical field. Besides, its application in protein separation is discussed.SEM image of the gelatin‐MWNTs hybrid gel at 10 000 × magnification.magnified imageSEM image of the gelatin‐MWNTs hybrid gel at 10 000 × magnification.
A Wide‐Bandgap Semiconducting Polymer for Ultraviolet and Blue Light Emitting Diodes
Authors: Lu Ping , Zhang Haiquan , Shen Fangzhong , Yang Bing , Li Di , Ma Yuguang , Chen Xinfang , Li Jinghong , Tamai Naoto 
Published: December 2003

AbstractA novel wide‐bandgap conjugated polymer (PDHFSCHD) consisting of alternating dihexylfluorene and rigidly twisted biphenyl units has been synthesized. The new fluorene‐based copolymer composed of rigid twisting segments in the main‐chain exhibits an optical bandgap of as high as 3.26 eV, and a highly efficient ultraviolet emission with peaks at 368 nm and 386 nm. An electroluminescence device from PDHFSCHD neat film as an active layer shows UV emission which peaks at 395 nm with a turn on voltage below 8 V. By optimizing the device conditions, a peak EL quantum efficiency of 0.054% and brightness of 10 cd · m−2 was obtained. Furthermore, blending a poly(dihexylfluorene) in the PDHFSCHD host gave pure blue emission peaking at 417 nm and 440 nm without long wavelength emission from aggregated species. Efficient energy transfer from PDHFSCHD to PDHF was demonstrated in these blended systems. Depressed chain‐aggregation of PDHF in the PDHFSCHD host can correspond to pure blue emission behaviors.The structure of the copolymer PDHFSCHD.magnified imageThe structure of the copolymer PDHFSCHD.
Synthesis of Diene‐Functionalized Macromonomers via Functionalization with Hexa‐1,3,5‐triene
Authors: Quirk Roderic P. , Gomochak Deanna L. , Bhatia Rajeev S. , Wesdemiotis Chrys , Arnould Mark A. , Wollyung Kathleen 
Published: December 2003

AbstractThe reaction of poly(styryl)lithium (PSLi) with hexa‐1,3,5‐triene (HXT) was studied as a route to diene‐functionalized macromonomers. When PSLi was reacted with 1.5 molar equivalents of HXT for 2.5 h at −10 °C in toluene, it was found that the diene‐functionalized macromonomer was obtained in high yield; however, oligomerization of the HXT was observed by matrix‐assisted laser absorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). Oligomerization was eliminated by running the reaction with only 1.2 molar equivalents of HXT to PSLi and allowing the reaction to run for 15 min at −10 °C in toluene. The resulting polymer exhibited high diene chain‐end functionality and no oligomerization was observed by MALDI‐TOF MS. 13C NMR spectroscopy and the attached‐proton test (APT), along with calculated chemical shifts, showed the presence of both the 1,2‐ and 1,4‐addition chain‐end structures. Further analysis by the reaction of the functional polymer with maleic anhydride indicated that 18 wt.‐% of the product was unreactive, either because of a 1,4‐addition chain‐end structure or a nonfunctional polymer. The structure of the maleic anhydride‐modified polymer was determined by MALDI‐TOF MS and 13C NMR spectroscopy. Preliminary work on the reactivity of the diene‐functionalized macromonomers was performed by the addition of a large excess of PSLi to a solution of macromonomer followed by characterization by size‐exclusion chromatography (SEC).The formation of hexa‐1,3,5‐triene‐functionalized polystyrenes and their reaction with maleic anhydride.magnified imageThe formation of hexa‐1,3,5‐triene‐functionalized polystyrenes and their reaction with maleic anhydride.
Pyrromethene 567 Dye as Visible Light Photoinitiator for Free Radical Polymerization
Authors: García O. , Costela A. , García‐Moreno I. , Sastre R. 
Published: December 2003

AbstractIn the present work we report on the photochemistry and photopolymerization activity of a new bimolecular photoinitiator system, which exhibits maximum sensitivity at 518 nm, consists of a sensitizer dye, pyrromethene 567 (PM567), and a radical generating reagent 3,3′,4,4′‐tetra(tert‐butylperoxycarbonyl)benzophenone (BTTB). The photosensitization of BTTB through the excitation of PM567 induces high polymerization rates, while different experiences have revealed that PM567 or BTTB, separately, are unable of initiating the polymerization of 2‐hydroxyethyl methacrylate (HEMA) over extensive periods of time at 40 °C, either in the dark or under irradiation. The polymerization efficiency of this photoinitiator system, PM567/BTTB, was analyzed following the bulk polymerization kinetics of monomer HEMA by differential scanning photo‐calorimetry. Photopolymerization rates and quantum yields were observed under isothermal conditions (40 °C) for continuous illumination polymerizations (at 518 nm) at different incident light intensities and different BTTB concentrations.Scheme of the photosensitization process of the bimolecular photoinitiator system of PM567/BTTB.magnified imageScheme of the photosensitization process of the bimolecular photoinitiator system of PM567/BTTB.
Preparation of Monodisperse Crosslinked Organic‐Inorganic Hybrid Copolymer Particles by Dispersion Polymerization
Authors: Jun Jung‐Bae , Hong Jae‐Keun , Park Jin‐Gyu , Suh Kyung‐Do 
Published: December 2003

AbstractThis study presents a new method for producing monodisperse crosslinked organic‐inorganic hybrid polymer particles in micron‐size by using simple dispersion polymerization. Firstly, highly monodisperse hybrid copolymer particles were prepared by conventional dispersion polymerization of styrene and 3‐(trimethoxysilyl)propyl methacrylate (TMSPM) in a methanol/water medium. It was very interesting to find that slightly crosslinked hybrid polymer particles were formed by this simple dispersion polymerization due to a partial condensation reaction between the adjacent silanol groups of the TMSPM during the polymerization. Secondly, for the hydrolytic condensation of the remaining trimethoxysilyl groups, post treatment by sol‐gel process was carried out to form an inorganic siloxane network, which provides the particle with high crosslinking density. In the proper conditions, monodisperse crosslinked particles could be produced in high TMSPM concentrations, up to 20 wt.‐%. In addition, the size monodispersity of the hybrid polymer particles was maintained after the sol‐gel process. Crosslinking with inorganic networks formed by the sol‐gel process was confirmed by a thermal analysis and a 29Si NMR spectroscopy.Synthesis of crosslinked organic‐inorganic hybrid polymer particles by dispersion copolymerization and post sol‐gel process.magnified imageSynthesis of crosslinked organic‐inorganic hybrid polymer particles by dispersion copolymerization and post sol‐gel process.
Combustion Behaviour of Epoxide Based Nanocomposites with Ammonium and Phosphonium Bentonites
Authors: Hartwig Andreas , Pütz Dirk , Schartel Bernhard , Bartholmai Matthias , Wendschuh‐Josties Michael 
Published: December 2003

AbstractThe influence of different organobentonites on the decomposition and the combustion behaviour of an epoxy resin were examined. The epoxy resin is a cationically polymerised cycloaliphatic epoxy resin flexibilised with poly(tetrahydrofuran) (PTHF), with hydroxyl endgroups. The bentonite was modified with either an ammonium or a phosphonium salt. The thermal decomposition of the PTHF induced by the initiator, used for the cationic polymerisation, did neither take place for the nanocomposite based on the ammonium bentonite nor for that based on the phosphonium bentonite. This improved decomposition characteristic lead to a larger time to ignition for both kinds of nanocomposites compared to the not modified polymer, which is not the case for other polymer/clay nanocomposites described in the literature. The fire behaviour was investigated using limiting oxygen index (LOI), a horizontal burner test and a cone calorimeter. The forced flaming conditions in the cone calorimeter were varied using different external heat fluxes between 30 and 70 kW · m−2. The fire behaviour of the nanocomposites was improved in comparison to the polymer, and phosphonium bentonite was superior to ammonium bentonite. The main mechanism is a barrier formation resulting in a reduction of the fire growth rate, which was more pronounced in the case of high external heat fluxes.
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