bluuebunny/crossref_metadata_2025_split huggingface dataset:
Life cycle assessment of ISPRA Mark 9 thermochemical cycle for nuclear hydrogen production
Authors: Utgikar Vivek , Ward Bradley 
Published: October 2006

AbstractThe nuclear energy driven thermochemical cycle is one of the potential water‐splitting processes for producing hydrogen, presumed to be the transportation fuel of the future. A life cycle assessment (LCA) of one such system, which utilizes nuclear energy to drive the ISPRA Mark 9 thermochemical cycle, is presented in this paper. The results of the LCA are presented in terms of the emissions of greenhouse gases (CO2‐equivalent) and acid gases (SO2‐equivalent). The contributions of the thermochemical plant to the emissions were determined through the estimation of material and energy requirements for chemical inventory, raw materials consumption and plant fabrication/installation. The greenhouse gas emissions from the system are 2515 g CO2‐equivalent kg−1 H2 produced and acid gas emissions 11.252 g SO2‐equivalent kg−1 H2 produced. A comparison of this hydrogen production route with other routes, including steam reforming of methane and high‐temperature electrolysis, is also presented in the paper. Copyright © 2006 Society of Chemical Industry
A continuous process for the recovery of lactic acid by reactive distillation
Authors: Kumar Rakesh , Nanavati Hemant , Noronha Santosh B , Mahajani Sanjay M 
Published: October 2006

AbstractSeparation and purification of lactic acid from the fermentation broth are difficult because of its non‐volatile nature and the presence of other organic acids. Esterification of lactic acid with methanol followed by hydrolysis of the separated methyl lactate is an effective technique for this purpose. A continuous process for recovery is proposed and various aspects are evaluated through simulation and experiments. In the proposed route, a vapor stream containing methyl lactate is removed from a two‐phase CSTR, used for esterification, operated under boiling conditions. The ester thus separated from the aqueous solution is further hydrolyzed in a reactive distillation column. Continuous removal of the volatile component (i.e. methanol) from the reaction zone increases conversion, thus pure lactic acid is obtained from the bottom of reactive distillation column. The results obtained in the experiments are compared with the simulation results. Further simulation studies were performed to obtain the suitable operating conditions for higher conversion and concentration of lactic acid. Copyright © 2006 Society of Chemical Industry
A modified cellulose adsorbent for the removal of nickel(II) from aqueous solutions
Authors: O'Connell David W , Birkinshaw Colin , O'Dwyer Thomas F 
Published: October 2006

AbstractA series of adsorption studies was carried out on a glycidyl methacrylate‐ modified cellulose material functionalised with imidazole (Cellulose‐g‐GMA‐Imidazole) to assess its capacity in the removal of Ni(II) ions from aqueous solution. The study sought to establish the effect of a number of parameters on the removal of Ni(II) from solution by the Cellulose‐g‐GMA‐Imidazole. In particular, the influence of initial metal concentration, contact time, solution temperature and pH were assessed. The studies indicated a Ni(II) uptake on the Cellulose‐g‐GMA‐Imidazole sorbent of approximately 48 mg g−1 of nickel from aqueous solution. The adsorption process fitted the Langmuir model of adsorption and the binding process was mildly endothermic. The kinetics of the adsorption process indicated that nickel uptake occurred within 400 min and that pseudo‐second order kinetics best describe the overall adsorption process. Nickel(II) adsorption, recovery and re‐adsorption studies indicated that at highly acidic pH values the adsorbent material becomes unstable, but in the range pH 3–6, the adsorbent is stable and shows limited but significant Ni(II) recovery and re‐adsorption capability. Copyright © 2006 Society of Chemical Industry
Removal of anionic pollutants from groundwaters using Alamine 336: chemical equilibrium modelling
Authors: Bringas Eugenio , San Román M Fresnedo , Ortiz Inmaculada 
Published: October 2006

AbstractThis work reports the study of the chemical equilibrium of the extraction of chromium(VI) anions from groundwaters where other anionic species are present, mainly sulfate and chloride anions, using Alamine 336 as extractant. The analysis was performed working with two different systems: (i) a binary system (sulfate and chloride anions) and, (ii) a tertiary system (chromium, sulfate and chloride anions) with a composition of 9.6–15.4 mol Cr6+ m−3, 5.2–16.7 mol SO42− m−3 and 4.2–13.5 mol Cl− m−3 respectively. A careful experimental design was performed and the data were correlated to the mathematical models obtaining the equilibrium parameters of the extraction reactions in both systems. Copyright © 2006 Society of Chemical Industry
Continuous biotransformation of pyrogallol to purpurogallin using cross‐linked enzyme crystals of laccase as catalyst in a packed‐bed reactor
Authors: Roy J Jegan , Abraham T Emilia 
Published: October 2006

AbstractCross‐linked enzyme crystals (CLEC) of laccase were prepared by crystallizing laccase with 75% (NH4)2SO4 and cross‐linking using 1.5% glutaraldehyde. The cross‐linked enzyme crystals were further coated with 1 mmol L−1 β‐cyclodextrin by lyophilization. The lyophilized enzyme crystals were used as such for the biotransformation of pyrogallol to purpurogallin in a packed‐bed reactor. The maximum conversion (76.28%) was obtained with 3 mmol L−1 pyrogallol at a residence time of 7.1 s. The maximum productivity (269.03 g L−1 h−1) of purpurogallin was obtained with 5 mmol L−1 pyrogallol at a residence time of 3.5 s. The productivity was found to be 261.14 g L−1 h−1 and 251.1 g L−1 h−1 when concentrations of 3 mmol L−1 and 7 mmol L−1 respectively were used. The reaction rate of purpurogallin synthesis was maximum (2241.94 mg purpurogallin mg−1 CLEC h−1) at a residence time of 3.5 s, when 5 mmol L−1 pyrogallol was used as the substrate. The catalyst to product ratio calculated for the present biotransformation was 1:2241. The CLEC laccase had very high stability in reuse and even after 650 h of continuous use, the enzyme did not lose its activity. Copyright © 2006 Society of Chemical Industry
Chlorogenic acid is poorly absorbed, independently of the food matrix: A Caco‐2 cells and rat chronic absorption study
Authors: Dupas Coralie , Marsset Baglieri Agnès , Ordonaud Claire , Tomé Daniel , Maillard Marie‐Noëlle 
Published: October 2006

AbstractAccording to epidemiologic studies, dietary phenolic antioxidants, such as chlorogenic acid (CQA), could prevent coronary heart diseases and some cancers. Coffee is the main source of CQA in the human diet. The aim of this study was to assess the effect of usual coffee consumption conditions, such as the addition of milk, on CQA bioavailability. Interactions between CQA and milk proteins were shown, using an ultrafiltration technique. These interactions proved to be slightly disrupted during an in vitro digestion process. CQA absorption and bioavailability were then studied in vitro using a Caco‐2 cell model coupled with an in vitro digestion process, and in vivo, in a chronic supplementation study in which rats were fed daily coffee or coffee and milk for 3 weeks. Both experiments showed that CQA absorption under its native form is weak, but unmodified by the addition of milk proteins, and slightly reduced by the addition of Maillard reaction products. These data show that there are some interactions between coffee phenolics and milk proteins, but these have no significant effect on CQA bioavailability from coffee in the rat. CQA is poorly absorbed under its native form in the body, when ingested in a realistic food matrix.
Studies on acrylamide levels in roasting, storage and brewing of coffee
Authors: Lantz Ingo , Ternité Ruediger , Wilkens Jochen , Hoenicke Katrin , Guenther Helmut , van der Stegen Gerrit H. D. 
Published: October 2006

AbstractThe content of acrylamide in coffee reaches a peak early in the roasting process, reflecting occurrence of both formation and destruction of acrylamide during roasting. Levels of acrylamide in the fully roasted product are a small fraction of the peak reached earlier. Glucose and moisture in green coffee do not show a significant correlation with acrylamide in roasted coffee. Pre‐roasting levels of asparagine show a correlation only in Arabica coffee. The main factors affecting the level of acrylamide in roasted coffee appear to be the Arabica/Robusta ratio, with Robusta giving higher levels; time and degree of roast, with both shorter and lighter roasting at the edges of the normal roasting range giving higher levels; storage condition and time, with clear reduction at ambient storage. This storage reduction of acrylamide followed second order reaction kinetics with an activation energy of 73 KJ/mole. The acrylamide in roasted coffee is largely extracted into the brew and stable within usual time of consumption. As these four main factors also substantially affect the sensorial characteristics of the brew, and as modifications of the process have to comply with the consumer‐accepted boundaries of taste profiles, only small effects on the acrylamide level are expected to be achievable.
Determination of bioaccessibility of β‐carotene in vegetables by in vitro methods
Authors: Veda Supriya , Kamath Akshaya , Platel Kalpana , Begum Khyrunnisa , Srinivasan Krishnapura 
Published: October 2006

AbstractThe in vitro method in use for the determination of β‐carotene bioaccessibility involves simulated gastrointestinal digestion followed by ultracentrifugation to separate the micellar fraction containing bioaccessible β‐carotene and its quantitation. In this study, the suitability of two alternatives viz., membrane filtration and equilibrium dialysis were examined to separate the micellar fraction. Values of β‐carotene bioaccessibility obtained with the membrane filtration method were similar to those obtained by the ultracentrifugation method. Equilibrium dialysis was found not suitable for this purpose. Among the vegetables analyzed, fenugreek leaves had the highest content of β‐carotene (9.15 mg/100 g), followed by amaranth (8.17 mg/100 g), carrot (8.14 mg/100 g) and pumpkin (1.90 mg/100 g). Percent bioaccessibility of β‐carotene ranged from 6.7 in fenugreek leaves to 20.3 in carrot. Heat treatment of these vegetables by pressure cooking and stir‐frying had a beneficial influence on the bioaccessibility of β‐carotene from these vegetables. The increase in the percent bioaccessibility of β‐carotene as a result of pressure‐cooking was 100, 48 and 19% for fenugreek leaves, amaranth and carrot, respectively. Stir‐frying in presence of a small quantity of oil led to an enormous increase in the bioaccessibility of β‐carotene from these vegetables, the increase being 263% (fenugreek leaves), 192% (amaranth leaves), 63% (carrot) and 53% (pumpkin).
A regularized force‐based beam element with a damage–plastic section constitutive law
Authors: Addessi Daniela , Ciampi Vincenzo 
Published: October 2006

AbstractA new beam finite element is presented, with a generalized section constitutive law based on damage mechanics and plasticity, to analyse the cyclic structural response of plane frames. Both displacement‐based and force‐based (FB) approaches are used and compared, to demonstrate the significant advantages of the FB formulation in the presence of material non‐linearity. In order to overcome the analytical problems and the pathological mesh dependency of the numerical response in the presence of strain‐softening post‐peak behaviour, a classical non‐local regularization procedure is adopted first, based on the integral definition of the associated variable governing the damaging evolution process. Subsequently, for the FB element a new simple regularization technique is proposed based on a selected integration procedure along the element length, which predefines the location of the Gauss points in the beam region, where the localization phenomena take place. As for the other computational aspects, an iterative element state determination is adopted for the FB formulation and a local predictor–corrector algorithm is used to solve the incremental evolution problems of the damage and plastic internal variables. Finally, some examples are shown on simple beams and frames, subjected to monotonically increasing and cyclic loading conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and properties of fluorinated polyimides from a new unsymmetrical diamine: 1,4‐(2′‐Trifluoromethyl‐4′,4′‐diaminodiphenoxy)benzene
Authors: Shao Yu , Li Yan‐Feng , Zhao Xin , Wang Xiao‐Long , Ma Tao , Yang Feng‐Chun 
Published: October 2006

AbstractA new aromatic, unsymmetrical ether diamine with a trifluoromethyl pendent group, 1,4‐(2′‐trifluoromethyl‐4′,4″‐diaminodiphenoxy)benzene, was successfully synthesized in three steps with hydroquinone as a starting material and polymerized with various aromatic tetracarboxylic acid dianhydrides, including 4,4′‐oxydiphthalic anhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, 2,2′‐bis(3,4‐dicarboxyphenyl)‐hexafluoropropane dianhydride, and pyromellitic dianhydride, via a conventional two‐step thermal or chemical imidization method to produce a series of fluorinated polyimides. The polyimides were characterized with solubility tests, viscosity measurements, IR, 1H NMR, and 13C NMR spectroscopy, X‐ray diffraction studies, and thermogravimetric analysis. The polyimides had inherent viscosities of 0.56–0.77 dL/g and were easily dissolved in both polar, aprotic solvents and common, low‐boiling‐point solvents. The resulting strong and flexible polyimide films exhibited excellent thermal stability, with decomposition temperatures (at 5% weight loss) above 522 °C and glass‐transition temperatures in the range of 232–272 °C. Moreover, the polymer films showed outstanding mechanical properties, with tensile strengths of 74.5–121.7 MPa, elongations at break of 6–13%, and initial moduli of 1.46–1.95 GPa, and good dielectric properties, with low dielectric constants of 1.82–2.53 at 10 MHz. Wide‐angle X‐ray diffraction measurements revealed that these polyimides were predominantly amorphous. These outstanding combined features ensure that the polymers are desirable candidate materials for advanced microelectronic applications. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6836–6846, 2006
Melt compounding of polylactide/organoclay: Structure and properties of nanocomposites
Authors: Pluta Miroslaw 
Published: October 2006

AbstractA Brabender mixer was used to deagglomerate and disperse organomodified montmorillonite Cloisite® 30B (3 wt %) in polylactide (PLA) matrix to obtain nanocomposite systems. The influence of compounding conditions such as blending time (6.5, 10, 20, and 30 min) and compression molding on the nanostructure of nanocomposites was investigated. Molecular weight changes of the PLA matrices induced by melt compounding were determined. Good rheological behavior of the PLA during melt blending with Cloisite® 30B was observed. Prolongation of the blending process improved homogenization of the nanocomposites with the formation of more intercalated and exfoliated structures as revealed by transmission electron microscopy (TEM) and X‐ray analysis. Some orientation of the silicate nanoplatelets induced by compression molding of the nanocomposites was revealed by TEM. It was found that an increase of dispersion degree of the silicate layers modified pronouncedly the physical properties of nanocomposites through an increase of thermal stability as revealed by the thermogravimetric analysis, a decrease of crystallizability of the PLA matrix during melt‐crystallization and upon heating from the glassy, amorphous state. Rheological properties of the nanocomposites determined during dynamic frequency sweep appeared to be very sensitive to the nanostructure evolution. Moreover, the scanning electron microscopy and light microscopy investigations showed the presence of the micron‐size inorganic contaminations in the nanocomposites originating from organoclay Cloisite® 30B. These inclusions were resistive to deagglomeration during melt processing. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3392–3405, 2006
Superdrawing of polytetrafluoroethylene nascent powder by solid‐state coextrusion
Authors: Sawai Daisuke , Watanabe Daisuke , Morooka Naoyuki , Kuroki Haruka , Kanamoto Tetsuo 
Published: October 2006

AbstractA film of nascent powder of polytetrafluoroethylene (PTFE), compacted below the ambient melting temperature (Tm, 335 °C), was drawn by two‐stage draw techniques consisting of a first‐stage solid‐state coextrusion followed by a second‐stage solid‐state coextrusion or tensile draw. Although the ductility of extrudates was lost for the second‐stage tensile draw at temperatures above 150 °C due to the rapid decrease in strength, as previously reported, the ductility of extrudates increased with temperature even above 150 °C when the second‐stage draw was made by solid‐state coextrusion, reflecting the different deformation flow fields in a free space for the former and in an extrusion die for the latter. Thus, a powder film initially coextruded to a low extrusion draw ratio (EDR) of 6–20 at 325 °C was further drawn by coextrusion to EDRs up to ∼︁400 at 325–340 °C, near the Tm. Extremely high chain orientation (fc = 0.998 ± 0.001), crystallinity (96.5 ± 0.5)%, and tensile modulus (115 ± 5 GPa at 24 °C, corresponding to 73% of the X‐ray crystal modulus) were achieved at high EDRs. Despite such a morphological perfection and a high modulus, the tensile strength of a superdrawn tape, 0.48 ± 0.03 GPa, was significantly low when compared with those (1.4–2.3 GPa) previously reported by tensile drawing above the Tm. Such a low strength of a superdrawn, high‐modulus PTFE tape was ascribed to the low intermolecular interaction of PTFE and the lack of intercrystalline links along the fiber axis, reflecting the initial chain‐extended morphology of the nascent powder combined with the fairly high chain mobility associated with the crystal/crystal transitions at around room temperature. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3369–3377, 2006
Common and distinct gene expression patterns induced by the herbicides 2,4‐dichlorophenoxyacetic acid, cinidon‐ethyl and tribenuron‐methyl in wheat
Authors: Pasquer Frédérique , Ochsner Urs , Zarn Jürg , Keller Beat 
Published: October 2006

AbstractIn wheat, herbicides are used to control weeds. Little is known about the changes induced in the metabolism of tolerant plants after herbicide treatment. The impact of three herbicides [2,4‐dichlorophenoxyacetic acid (2,4‐D), cinidon‐ethyl and tribenuron‐methyl] on the wheat transcriptome was studied using cDNA microarrays. Gene expression of plants grown in a controlled environment or in the field was studied between 24 h and 2 weeks after treatment. Under controlled conditions, 2,4‐D induced genes of the phenylpropanoid pathway soon after treatment. Cinidon‐ethyl triggered peroxidase and defence‐related gene expression under controlled conditions, probably because reactive oxygen species are released by photo‐oxidation of protoporphyrin‐IX. The same genes were upregulated in the field as under controlled conditions, albeit at a weaker level. These results show that cinidon‐ethyl specifically induces genes involved in plant defence. Under controlled conditions, tribenuron‐methyl did not change the expression profile immediately after treatment, but defence‐related genes were upregulated after 1 week. Sulfonylurea compounds such as tribenuron‐methyl specifically inhibit acetolactate synthase and are rapidly detoxified, but the activity of some of the resulting metabolites could explain later changes in gene expression. Finally, overexpression of the isopropylmalate synthase gene, involved in branched‐chain amino acid synthesis, and of defence‐related genes was observed in the field after sulfonylurea treatment. Copyright © 2006 Society of Chemical Industry
A novel synthesis route for a gold–polymer soft composite material
Authors: Mallick Kaushik , Witcomb Mike , Scurrell Mike 
Published: October 2006

AbstractWe report on the synthesis of a metal–polymer composite material using an interfacial polymerization approach. The advantage of this approach is to form an intimate contact be‐tween the metal and polymer, which is an important param‐ eter for the synthesis of a nanocomposite material. It was found that polymerization of o‐phenylenediamine (PDA) us‐ing HAuCl4 as an oxidizing agent leads to the formation of poly‐PDA with a fiber‐like morphology, while the reduction of HAuCl4 results in the formation of well dispersed and sta‐bilized gold nanoparticles within the polymer matrix. The synthesis was carried out at the organic–aqueous interface. The resultant composite material was purely hydrophilic in nature and deposited at the aqueous fraction of the reaction medium. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Method development and validation for zotarolimus concentration determination in stented swine arteries by liquid chromatography/tandem mass spectrometry detection
Authors: Zhang Jun , Todd Reimer M. , Alexander Nicholas E. , Ji Qin. C. , El‐Shourbagy Tawakol A. 
Published: October 2006

AbstractDrug‐eluting stents have attracted significant attention in the medical community and pharmaceutical industry due to their proven success in significantly reducing restenosis. Abbott Laboratories is developing a drug‐eluting stent coated with zotarolimus and swine was recently used as an animal model for the pre‐clinical study of stent implantation. In this article, we present a detailed experimental design and results for the validation and sample analysis of zotarolimus drug concentration in stented swine artery samples. Introduction of tissue quality control (QC) samples allows evaluation of the entire analytical process as well as the stability of the drug in both original tissue and homogenized tissue samples. In addition, a novel approach using 100% swine blood as the homogenization solution was developed for the consistency of the liquid–liquid extraction recovery and stability of the zotarolimus in tissue homogenates. Standards were prepared by spiking zotarolimus working solution in swine blood and tissue QC samples were used along with the artery samples during the sample analysis. The linear dynamic range of blood standard samples is from 0.61 to 333.20 ng/mL to accommodate the predicted artery homogenate concentrations. Overall tissue QC %CV during the method validation was from 4.4% to 8.6%. The overall %bias of tissue QC samples during the method validation was from −7.3% to 16.6%. The method was successfully applied for the analysis of swine artery samples. A similar approach for method validation and sample analysis has been successfully applied for the analysis of swine myocardium, kidney and liver tissue samples. Copyright © 2006 John Wiley & Sons, Ltd.