bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ti and Fe Speciation by X‐Ray Photoelectron Spectroscopy(XPS) and Mössbauer Spectroscopy for a Full Crystal Chemical Characterisation of Ti‐Garnets from Colli Albani (Italy)
Authors: Schingaro Emanuela , Scordari Fernando , Pedrazzi Giuseppe , Malitesta Cosimino 
Published: April 2004

AbstractDifferent analytical and structural methods (Electron Probe Micro‐ Analysis, Single Crystal X‐ray diffraction, X‐ray Photoelectron Spectroscopy, Mössbauer spectroscopy) were combined to fully characterise the crystal chemistry of natural Ti‐bearing garnets from Colli Albani (Lazio, Italy). The study of the relevant complex crystal chemistry (large number of cation substitutions affecting the three independent X(8‐fold), Y(6‐fold) and Z(4‐fold) crystallographic sites and Fe and Ti transition elements exhibiting several oxidation states and coordination environments) benefited from the multi‐technique approach.Electron probe microanalysis provided elemental composition of the analysed samples, which have low Ti‐content (TiO2 in the range 1.99 ‐ 3.48 wt %) and slightly different Fe/Al ratios. For all samples, two doublets were fitted to room temperature Mössbauer spectra and assigned to Fe3+(Y) (∼ 95%) and Fe2+(X) (∼ 5%). Up to three doublets (Ti3+(Y), Ti4+(Y), Ti4+(Z)) were fitted to XPS spectra and yielded direct evaluation of Ti site population. XPS technique confirmed its potential for the study of speciation of Ti in minerals.
Comparison of Different Calibration Methods for the Determination by FT‐NIR Spectroscopy of the Hydroxyl Number in Polyester Resins
Authors: Marengo Emilio , Soave Cristina , Gennaro Maria Carla , Robotti Elisa , Bobba Marco , Lenti Marcello 
Published: April 2004

AbstractDifferent calibration methods have been applied for the determination of the Hydroxyl Number in polyester resins, namely Partial Least Squares (PLS), Principal Component Regression (PCR), Ordinary Least Squares with selection of the variables by genetic algorithm (OLS‐GEN) and back‐propagation Artificial Neural Networks (BP‐ANN). The predictive ability of the regression models was estimated by splitting the dataset in training and test sets by application of the Kohonen self‐organising maps. The linear methods (OLS‐GEN, PLS and PCR) showed comparable results while artificial neural networks provided the best results both in fitting and prediction.
Chemical and Environmental Implications of Visible and Near‐Infrared Spectral Features of Salt Crusts Formed from Different Brines
Authors: Howari Fares M. 
Published: April 2004

AbstractThis work describes a laboratory experiment intended to study the formation and spectral reflectance properties of stratified salt crusts that cause severe environmental degradations to soil and water resources in arid regions. Salt crusts were prepared by evaporating three types of saline solutions consisting of i) NaCl ‐ Na2SO4, ii) Na2SO4 ‐ MgSO4, and iii) NaCl ‐ MgSO4 at an initial concentrations of 50 mmol L‐1. They were examined for evaporite mineralogy using X‐ray diffraction, optical and reflected microscopes, and for spectral reflectance with a high‐resolution spectroradiometer (GER 3700) in the visible and near‐infrared regions (400‐2500 nm). The study documented chemical and environmental implications of the spectral properties of salt formed from the studied saline‐systems. The reported results can be used to understand remotely sensed signatures of salt crusts and their implications.
Three‐Stage Sequential Extraction Procedure for Metal Partitioning in Polluted Soils and Sediments
Authors: Elass Khalid , Laachach Abderrahmane , Azzi Mohamed 
Published: April 2004

AbstractThe sequential extraction procedure proposed by the Standard, Measurements and Testing program “SM&T” of the European Union has been applied to evaluate the amounts of Cr, Cu, Mn, Ni, Pb and Zn, extracted at each stage and indirectly their mobility and bioavailability in soil and sediment samples from a polluted area. Analysis of the extracts was carried out by flame atomic absorption spectrometry (FAAS). No significant matrix interferences were found except for Cr in the acetic acid and hydroxylammonium chloride extracts, which required determination by the standard additions method. Both of soils and sediments studied show similar partitioning of Mn, Ni, Cu and Cr. Mn and Ni can be considered to have significant component bound to the acido‐soluble fraction, whereas, Cr and Cu occur largely in the organic and residual phases. The partitioning of Pb and Zn was different between soil and sediment. In terms of mobility and bioavailability, in soils, Ni and Mn can be regarded as moderately available followed by a lower availability of Pb while Cu, Zn and Cr have a very limited availability. In sediments, a higher availability (short‐medium term) of Mn and Zn was presumed followed by a lower availability of Ni and Pb, whereas, Cu and Cr, occurring largely in the organic and residual phases, were of very limited availability.
Extractive Spectrophotometric Determination of Tungsten(VI) Using 3‐Hydroxy‐2‐(2'‐Thienyl)‐4‐OXO‐4H‐1‐ Benzopyran
Authors: Agnihotri Nivedita , Mehta Jaswant R. 
Published: April 2004

AbstractA simple, rapid, highly sensitive and selective spectrophotometric method for the determination of tungsten(VI) in trace amounts is developed using 3‐ hydroxy‐2‐(2'‐thienyl)‐4‐oxo‐4H‐1‐benzopyran (HTB) as a reagent for the complexation of metal ion and extracting the 1:2 (metal:ligand) complex into dichloromethane from 0.2 M HCl solution. It obeys Beer's law in the range 0‐2.8 μg Wml‐1 with molar absorptivity and Sandell's sensitivity at 415 nm as 6.45 x 104 L mol‐1cm‐1 and 0.0029 μg W(VI) cm‐2, respectively. The method is free from the interference of a large number (39) of elements and handles satisfactorily the analysis of various samples of varying complexity.
The economic efficiency of Irish dairy marketing co‐operatives
Authors: Boyle G.E. 
Published: April 2004

AbstractThis paper is concerned with an empirical test for the economic efficiency of Irish dairy marketing co‐operatives. The paper develops a test for the pricing behavior of dairy marketing co‐operatives based on previous work by R.J. Sexton, B.M. Wilson, and J.J. Wann (1989) and K. Conrad and R. Unger (1987). The proposed test is implemented with data for the Irish dairy‐processing sector. The findings suggest that Irish co‐operatives behaved “as if” they were profit maximizers, and we could find no evidence that this behavior coincided with postulated co‐operative pricing rules. We conclude the paper with a discussion of the economic impact of the EU dairy quota on the Irish dairy‐processing sector. We also discuss the emergence of Public Limited Companies (PLCs) as the dominant organizational structure in the Irish dairy sector. [JEL citations: D21; Q13.] © 2004 Wiley Periodicals, Inc. Agribusiness 20: 143–153, 2004.
The forecasting performance of implied volatility from live cattle options contracts: Implications for agribusiness risk management
Authors: Manfredo Mark R. , Sanders Dwight R. 
Published: April 2004

AbstractThis research examines the forecasting performance of implied volatility derived from nearby live cattle options contracts in predicting 1‐week volatility of nearby live cattle futures prices. Forecast evaluation is conducted from the perspective of an agribusiness risk manager. The methodology employed avoids overlapping forecast horizons and focuses on forecast errors, minimizing interpretive issues. Results suggest that implied volatility is a biased and inefficient forecast of 1‐week nearby live cattle futures price volatility. However, implied volatility encompasses all information provided by a time series alternative, and it has improved as a forecast over time. These findings provide insight to agribusiness risk managers on how to adjust for bias and inefficiency of implied volatility, and provide insight into their information content. [JEL/EconLit citations: Q130, Q140, G130.] © 2004 Wiley Periodicals, Inc. Agribusiness 20: 217–230, 2004.
Consumer response to functional foods produced by conventional, organic, or genetic manipulation
Authors: Larue Bruno , West Gale E. , Gendron Carole , Lambert Rémy 
Published: April 2004

AbstractThe agro‐food industry is developing a “second generation” of genetically modified (GM) foods that can offer functional health benefits to consumers. Many consumers, however, are turning to organic foods in order to avoid GM foods. This report attempts to differentiate consumer valuation of functional health properties in conventional, organic, and GM foods. A representative sample of 1,008 Canadian household food shoppers responded to twelve stated‐choice experiments during a telephone survey. Because opinions about organic and GM foods varied greatly, random parameters logit models were used to analyze their choices. Results indicate that many Canadian consumers will avoid GM foods, regardless of the presence of functional health properties. For others, the introduction of GM functional plant foods should increase acceptance of GM production methods, but many consumers will likely avoid functional foods derived from GM animals. The organic food industry could also profit from the introduction of organic functional foods. [EconLit citations: I120; D120.] © 2004 Wiley Periodicals, Inc. Agribusiness 20: 155–166, 2004.
The determinants of direct mail coupon usage revisited: Evidence from count panel data models
Authors: Chiou‐Wei Song Zan 
Published: April 2004

AbstractThis report employs count panel (as opposed to cross‐sectional) data to empirically investigate the determinants of direct‐mail coupon use. We focus on comparing the coupon use discrepancies between national and store dairy brands. The results do not support the main hypothesis that participants use more coupons the longer they stay in the coupon program. Evidence also shows that prior use significantly explains the coupon‐redemption behavior, while it is found that there are significant expiration date and face value effects. The distance of the consumers from the redemption location is found to be significant. [EconLit citations: C25, J10, and M37.] © 2004 Wiley Periodicals, Inc. Agribusiness 20: 189–200, 2004.
Biochemical diagnosis of Antley–Bixler syndrome by steroid analysis
Authors: Shackleton Cedric , Marcos Josep , Malunowicz Ewa M. , Szarras‐Czapnik Maria , Jira Petr , Taylor Norman F. , Murphy Nuala , Crushell Ellen , Gottschalk Michael , Hauffa Berthold , Cragun Deborah L. , Hopkin Robert J. , Adachi Masanori , Arlt Wiebke 
Published: April 2004

AbstractAntley–Bixler syndrome (ABS, MIM 207410) is a skeletal abnormality syndrome primarily affecting head and limbs. Little is known of the origin of the condition but inactivating mutations in the fibroblast growth factor receptor (FGFR2) has been found in some patients. Genital ambiguity is seen occasionally in this condition, suggesting possible disordered steroidogenesis in early pregnancy. We report the steroid excretion of eight patients diagnosed with the syndrome and one with a related condition, a mild phenotype of the disorder since skeletal and genital abnormalities were not evident. The steroid excretion pattern was consistent and very distinctive in all nine patients. Metabolites of the two primary precursors of steroid hormones, pregnenolone and progesterone, were elevated as were the classical diagnostic metabolites for 17‐ and 21‐hydroxylase deficiencies. Cortisol production was typically within the normal range but generally had blunted response to ACTH. Androgen metabolite excretion tends to be low in patients over 2 months of age, but may be elevated in the newborn period. The metabolome suggested attenuated steroid hydroxylation (including 17,20‐lyase activity) although underlying cause is yet to be established. Mutations in CYP17 and CYP21 have not been found and currently the prime suspect is an abnormality in an essential redox partner (P450 oxidoreductase). This paper proposes use of the distinctive steroid metabolome as the primary biochemical parameter for diagnosis of ABS, at least the form not associated with FGFR2 mutations. © 2004 Wiley‐Liss, Inc.
Prediction of kinetic curves of oxygen consumption on a thermooxidative degradation process for polymer melts
Authors: Kozlov G. V. , Zaikov G. E. 
Published: April 2004

AbstractThe possibility of theoretical prediction of oxygen consumption kinetic curves in a thermooxidative degradation process for polymer melts under conditions that allow for both chemical constitution of polymer and physical structure of melt is shown, the last of which can be quantitatively identified within the framework of fractal analysis. Although obtained for the purposes of predicting kinetic curves, the equation does not contain empirical‐fitting parameters. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3601–3604, 2004
Crystallization and melt behavior of Mg(OH)2/PP composites modified by functionalized polypropylene
Authors: Lin Zhidan , Qiu Yixin , Mai Kanchen 
Published: April 2004

AbstractThe crystallization and melting behavior of Mg(OH)2/PP composites modified by the addition of functionalized polypropylene (FPP) or acrylic acid (AA) and the formation of in situ FPP were investigated by DSC. The results indicated that addition of FPP increased the crystallization temperatures of PP because of the nucleation effect of FPP. The formation of in situ FPP resulted in a reduced crystallization rate, melting point, and degree of crystallization attributed to the decreased regularity of the PP chain. For Mg(OH)2/PP composites, the addition of Mg(OH)2 increased the crystallization temperatures of PP resulting from a heterogeneous nucleation effect of Mg(OH)2. The addition of FPP into Mg(OH)2/PP composites further enhanced the crystallization temperatures of PP. It is suggested that there is an activation of FPP to the heterogeneous nucleation effect on the Mg(OH)2 surface. The addition of AA also increased the crystallization temperatures of PP in Mg(OH)2/PP composites, although the crystallization temperature of PP was not influenced by the AA content, which is explained by the heterogeneous nucleation effect of the Mg(OH)2 surface activated by FPP and AA. A synergistic effect on the crystallization of PP in Mg(OH)2/PP composites further increased the crystallization temperatures of PP. However, The crystallization temperatures of Mg(OH)2/PP composites modified by in situ FPP were lower than those of Mg(OH)2/PP composites modified by addition of either FPP or AA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3610–3621, 2004
Graft copolymerization of nitrile monomers onto bleached jute fiber using potassium persulfate system and their textile characteristics
Authors: Mondal Md. Ibrahim H. , Alam Rashidul , Sayeed Md. Abu 
Published: April 2004

AbstractGraft copolymerization of nitrile monomers, such as acrylonitrile and methacrylonitrile, onto bleached jute fiber was carried out by using K2S2O8/FeSO4 redox system in nitrogen atmosphere and their effect on the textile characteristics was also investigated. Percent graft yield increased with the increase of concentrations of monomer, initiator, and catalyst, reaction time, and reaction temperature up to a certain value, and, thereafter, it decreased. The effect of percent grafting efficiency was similar to that of percent graft yield, except for the monomer concentration. The increase of percent graft yield was dependent on the availability of jute‐macroradicals as well as monomer radicals. Sometimes the predominancy of homopolymerization over grafting and the premature termination of growing grafted chains occurred because of the higher monomer radicals and excess primary radicals, SO4−• and •OH, from K2S2O8 initiator. The percent graft yield of acrylonitrile and methacrylonitrile was 20.5 and 29.1%, respectively. Higher graft yield for methacrylonitrile might be due to the methyl group present in it. Infrared spectra at 2229–2235 cm−1 of acrylonitrile‐ and methacrylonitrile‐grafted jute strongly supported the graft formation. Grafting of jute fiber improved the thermal stability, protected from photooxidative degradation, and decreased swellability as well as dyeability, etc. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3622–3629, 2004
Bending‐electrostrictive response of polyurethane films subjected to a reversed electric field
Authors: Watanabe Masashi , Hirai Toshihiro 
Published: April 2004

AbstractThis study dealt with the bending‐electrostrictive response of a polyurethane film, which was a promising candidate for a material to be used in polymer actuators. The film bent under an electric field (2.5 MV/m). However, when the field polarity was reversed, the bending direction curiously did not change. To clarify the mechanism of this behavior, we measured the space charge distribution in the film. The measurement showed a pair of charges (induced charge on an electrode and space charge in the film) on one side of the film during the application of the field. However, when the field polarity was reversed, the location of the charges did not change. The charges were assumed to be the cause of the bending. Therefore, we concluded that the bending direction did not change despite the reversed field because the location of the charges did not change. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3644–3650, 2004
Preparation and swelling characterization of poly (n‐isopropylacrylamide)‐based porous hydrogels
Authors: Chern Jia‐Ming , Lee Wen‐Fu , Hsieh Meng‐Yow 
Published: April 2004

AbstractNine different poly(n‐isopropylacrylamide)‐based hydrogels, including nonionic, cationic, and anionic hydrogels, were synthesized in with and without the addition of pore‐forming agents. The synthesized hydrogels were characterized with dry gel density measurements, scanning electron microscopy observations, and the determination of the swelling ratio swelling kinetics. All the results showed that the cationic hydrogels had faster swelling kinetics than the anionic and nonionic hydrogels. The addition of pore‐forming agents (NaHCO3 and carboxymethylcellulose) during the synthesis process led to porous hydrogels with lower dry densities, swelling ratios, and swelling kinetic parameter values. An empirical equation was developed to successfully correlate the swelling kinetic parameter with the hydrogel swelling ratio. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3651–3658, 2004
Comparison of maleic anhydride grafting onto powder and granular polypropylene in the melt by reactive extrusion
Authors: Güldoğan Yılser , Eğri Sinan , Rzaev Zakir M. O. , Pişkin Erhan 
Published: April 2004

AbstractThe grafting of powder and granular polypropylene (PP) with maleic anhydride (MA) was investigated in a reactive extrusion process with dicumyl peroxide (DCP) as an initiator. The effects of the MA and DCP contents in the feed on grafting were investigated. Under the experimental conditions applied in this study, the grafted monomer unit content was varied from 0.023 to 0.5%. The MA grafting efficiency of powder PP was higher than that obtained for the granular form of PP. In general, the grafting degree first increased with the MA or DCP content in the feed, then reached a maximum value, and finally decreased because of several possible alternative reactions during the grafting. The grafting of powder PP was more successful because of better initial mixing and less diffusional resistance during the grafting. An increase in the MA content in the feed caused significant reductions in the melt‐flow index of the graft copolymers. The results obtained with Fourier transform infrared, differential scanning calorimetry, and X‐ray powder diffraction analyses indicated that the structure, macrotacticity, crystallinity, crystallization, and thermal behavior of PP changed with grafting and depended on the grafting degree. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3675–3684, 2004
Thermal stability of polycaprolactone/Nafion blends prepared in the presence of 3‐aminopropyltriethoxysilane
Authors: Cassu Silvana Navarro , Zoppi Rita Aparecida , Felisberti Maria Isabel 
Published: April 2004

AbstractPolycaprolactone (PCL) and Nafion blends were prepared in the presence of 3‐aminopropyltriethoxysilane (3‐APTEOS) by a sol–gel reaction. The presence of 3‐APTEOS allowed the preparation of macroscopically homogeneous self‐supported films of PCL/Nafion blends in a wider composition range. The thermal properties of the blends were evaluated by thermogravimetric analysis and differential scanning calorimetry. The thermal stability of the blends decreased as the Nafion content increased. The reduction of the thermal stability of PCL in the presence of Nafion was confirmed with Fourier transform infrared/photoacoustic spectroscopy, and it was attributed to the possible hydrolysis of PCL caused by the reaction with the SO3H acid groups of Nafion. An opposite effect on the thermal stability of the blends was caused by the addition of 3‐APTEOS. The increase in the thermal stability of the blends with the increase in the 3‐APTEOS content was assigned to the neutralization of the acid groups of Nafion by the formation of an ionic complex. The differential scanning calorimetry results showed that PCL and Nafion were immiscible. The degree of crystallinity of PCL slightly increased with an increase in the Nafion content, whereas the melting temperature remained basically unchanged. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3701–3709, 2004
Effect of radiation dose on the thermal degradation of poly(ethylene terephthalate) fabric
Authors: El‐Gendy E. H. , El‐Shanshoury I. A. 
Published: April 2004

AbstractThe effect of radiation dose (10–30 kGy) on the thermal decomposition of poly(ethylene terephthalate) was studied using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD) analysis. The TGA and DSC were carried out in a flowing nitrogen atmosphere at heating rates of 5 and 30°C/min for TGA and 10°C/min for DSC. The degradation process was composed of three overlapping stages. The second stage, at which a rapid degradation occurs, was studied in detail. The process was found to follow a second‐order kinetics and was independent of radiation dose or heating rate. The reaction rate constant (k) was found to depend on the heating rate and iradiation dose. The apparent activation energy (Q) and the logarithm of the preexponential rate constant (log A) were found to decrease linearly with the increase in dose at rates of 3.32 kJ mol−1 kGy−1 and 0.177 s−1 kGy−1 with intercepts of 249 kJ/mol and 12.26 s−1 for Q and log A of unirradiated fabric, respectively. A direct relationship was found between the percentage decrease in Q and log A and the percentage decrease in the temperature corresponding to 50% conversion (T50%) for samples irradiated at different doses. It was found that a decrease in T50% by 1% resulted in a decrease in Q and log A by 1.855 and 2.1%, respectively. Changes in Q and log A resulting from radiation, mechanical and thermal treatments, or their combinations can be predicted from the shift in T50%. The history of the fibers substantially affected the thermal properties. DSC and XRD studies revealed changes in the fabric crystallinity. DSC measurements indicated a linear increase in heat of fusion with dose increase at a rate of 0.855 kJ kg−1 kGy−1. XRD analysis confirmed structural changes, rearrangement by plane rotations, and formation of compact crystalline lattice with patterns characterizing irradiated samples. An attempt to explain the dependency of the apparent activation energy on dose was given. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3710–3720, 2004