bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sol‐Gel/Polyelectrolyte Active Corrosion Protection System
Authors: Lamaka Svetlana V. , Shchukin Dmitry G. , Andreeva Daria V. , Zheludkevich Mikhail L. , Möhwald Helmuth , Ferreira Mario G. S. 
Published: October 2008

AbstractThis work presents a new type of feed‐back active coating with inhibitor‐containing reservoirs for corrosion protection of metallic substrates. The reservoirs are composed of stratified layers of oppositely charged polyelectrolytes deposited on AA2024 aluminum alloy coated with hybrid sol‐gel film. The layer‐by‐layer assembled polyelectrolyte film with the entrapped corrosion inhibitor is constructed by sequential spray‐coating deposition of water solutions of poly(ethyleneimine), poly(sodium styrenesulfonate) and 8‐hydroxyquiniline on the top of the sol‐gel coating. The active corrosion protection of AA2024 alloy coated with SiO2/ZrO2 sol‐gel film and modified by polyelectrolytes is demonstrated by electrochemical impedance spectroscopy and scanning vibrating electrode technique. The results obtained here show that polyelectrolyte films deposited atop of the hybrid sol‐gel coating on AA2024 alloy remarkably improve the long‐term protection performance providing additional “intelligent” anticorrosion effect that results from delivery of inhibiting species “on demand”. This becomes possible since the configuration of the polyelectrolyte molecules depends on the presence of H+ ions making the polyelectrolyte film sensitive to the pH of the surrounding solution. The source of local pH changes is the corrosion process starting in the micro‐ and nano‐defects leading to increased permeability of the polyelectrolyte reservoir and, consequently, to controllable release of entrapped inhibitor.
Optimal tuning of thermodynamic‐based decentralized PI control loops: Application to the Tennessee Eastman Process
Authors: Antelo Luis T. , Exler Oliver , Banga Julio R. , Alonso Antonio A. 
Published: October 2008

AbstractThe need of designing decentralized control loops emerges to ensure the global stability of a given process plant. To that purpose, it has been proposed in recent works a systematic approach to derive robust decentralized controllers, which is based on the link between thermodynamics and passivity theory, as well as on the fundamentals of process networks. This thermodynamic‐based control (TBC) methodology has several steps: (1) Decomposition of the considered process system into abstract mass and energy inventory networks; (2) design of conceptual mass and energy inventory control loops to guarantee the convergence of the states of the plant to a compact convex region defined by constant inventories, where input‐output stability follows; (3) definition of intensive variable control loops (if needed) to achieve global stability, and (4) realization of the conceptual inventory and intensive variable control loops over the available degrees of freedom in the system by using, for instance, PI controllers. A tool to tune these PI control loops is developed, based on the solution of a nonlinear programming optimization problem (NLP), in order to complete the proposed hierarchical and systematic TBC design. The aim is to minimize a given cost function, subject to both the system dynamics, as well as the linear and nonlinear constraints (no disturbances affecting the system are considered), where the vector of decision variables will be formed by the parameters of the PI controllers used in the defined decentralized control loops. We will test this tuning procedure in several control designs developed for the challenging benchmark of the Tennessee Eastman Process (TEP) by Ricker and Larsson et al., as well as in two TBC candidates, concluding that the best candidate among the proposed ones (in terms of final cost function) will be one of these TBC designs. For solving the NLP problem, two local (FMINCON and NOMADm) solvers, and a new global (MITS) one are used, comparing their performances. Finally, the dynamic analysis of the optimal tuned closed loop systems is carried out, finding that the presented TBC control candidates will be stable, while the other control structures considered exhibit complex dynamic behaviors or even instability when disturbances affecting the process are considered. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Two fluid model using kinetic theory for modeling of one‐step hydrogen production gasifier
Authors: Yu Liang , Lu Jing , Zhang Xiangping , Zhang Suojiang , Wang Xiaoling 
Published: October 2008

AbstractA Two Fluid Model (TFM) using kinetic theory of granular flow has been developed to describe an innovative process of hydrogen production in a single step. An extended Multi‐species of Solid Phase (MSP) method is proposed to simulate the gas‐solid heterogeneous reactions in an entrained flow gasifier, as opposed to Single‐species of Solid Phase (SSP) in previous studies. The intrinsic equations of methane steam reforming and water‐gas shift reactions are used for a good understanding of the reaction mechanism for high concentration of hydrogen production under higher pressure. On the basis of the results of computing, the main feature of core‐annular reaction zone is predicted in the fully developed flow region. And the similar flame‐like structure for velocity and temperature is observed to emerge from the feed injection zone at the bottom of gasifier. The model well illustrates the effects of CaO on enhancing the concentration of hydrogen and sequestering CO2 in the process of coal gasification. The advantages of pressure gasification are also shown that coal conversion increases with increasing pressure while H2S concentration and tar content decreases. Moreover, there is a steep increase in H2S and tar species initiated from the entrance of gasifier and then a decrease at the next section. The model shows good agreement with the measurements of flow field and gas products concentration in laboratory‐scale plants. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Design and optimization of a hybrid distillation/melt crystallization process
Authors: Franke Meik Bernhard , Nowotny Norman , Ndocko Eugene Ndocko , Górak Andrzej , Strube Jochen 
Published: October 2008

AbstractHybrid distillation/melt crystallization processes are widely used for the separation of isomer mixtures. The design of a hybrid separation processes is not a trivial task because of several structural and operational degrees of freedom. In this article, a new three‐step design approach is proposed to address the above mentioned challenges. In the first step, process alternatives are generated by heuristic rules. In the second step, the generated process alternatives are optimized with respect to their energy consumption by using shortcut methods. In the third step, the most promising alternatives are rigorously optimized with respect to their total annualized costs, whereas the resulting mixed‐integer nonlinear programming (MINLP) problem is solved using a modified generalized benders decomposition (GBD) algorithm to take the nonconvexities into account. The feasibility of this design approach is demonstrated by design of a hybrid distillation/melt crystallization process for separation of a ternary isomer mixture. © 2008 American Institute of Chemical Engineers AIChE J, 2008
A two‐level distillation design method
Authors: Amale Amit , Lucia Angelo 
Published: October 2008

AbstractRecently, Lucia et al. have used a distillation line method to develop the concept of shortest stripping line distance approach to minimum energy designs of distillation columns and multiunit processes. It is well known that distillation line methods can be very sensitive to specified product compositions. A two‐level distillation design procedure is proposed for finding portfolios of minimum energy designs when specifications are given in terms of key component recoveries. Thus, product compositions are not specified but calculated. It is shown that the proposed two‐level design procedure is flexible and can find minimum energy designs for both zeotropic and azeotropic distillations. It is also shown that the two‐level design method encompasses Underwood's solution but can find minimum energy designs when Underwood's method fails. Numerical results for several distillation examples involving ternary and quaternary mixtures are presented to support these claims, and geometric illustrations are used to elucidate key points. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Cloning and characterization of the secreted hemocytic prophenoloxidases of Heliothis virescens
Authors: Shelby Kent S. , Popham Holly J. R. 
Published: October 2008

AbstractThe plasma enzyme phenoloxidase plays an important role in host resistance against viral, bacterial, fungal, filarial, and parasitoid challenge. Two Heliothis virescens prophenoloxidase transcripts, HvPPO‐1 and HvPPO‐2, were assembled from ESTs derived from a hemocyte cDNA library. The 2,363‐bp HvPPO‐1 contig encoded a 696–amino acid protein. The 3,255‐bp HvPPO‐2 contig encoded a 684–amino acid protein. Hemocyte and fat body transcript levels of HvPPO‐1 were slightly elevated by bacterial infection in 5th instar larvae; however, HvPPO‐2 expression was not significantly elevated above controls by bacterial infection. Per os infection of 4th instar larvae with the baculovirus Helicoverpa zea SNPV (HzSNPV) had a mild but significant suppressive effect upon fat body and hemocytic HvPPO‐1 expression when compared to expression in same‐aged controls. HvPPO‐2 expression levels in fat bodies and hemocytes from 4th instar larvae was not significantly altered by HzSNPV infection. HzSNPV infection of 5th instar larvae caused no significant alteration of HvPPO‐1 or of HvPPO‐2 expression in either fat bodies or hemocytes. Thus, even though prophenoloxidase subunits are constitutively expressed at high levels in larval H. virescens hemocytes and fat bodies, the subunit HvPPO‐1 is differentially regulated by bacterial and baculoviral infection. Arch. Insect Biochem. Physiol. 69:127‐142, 2008. © 2008 Wiley‐Liss, Inc.
Microwaves from UMTS/GSM mobile phones induce long‐lasting inhibition of 53BP1/γ‐H2AX DNA repair foci in human lymphocytes
Authors: Belyaev Igor Y. , Markovà Eva , Hillert Lena , Malmgren Lars O.G. , Persson Bertil R.R. 
Published: October 2008

AbstractWe have recently described frequency‐dependent effects of mobile phone microwaves (MWs) of global system for mobile communication (GSM) on human lymphocytes from persons reporting hypersensitivity to electromagnetic fields and healthy persons. Contrary to GSM, universal global telecommunications system (UMTS) mobile phones emit wide‐band MW signals. Hypothetically, UMTS MWs may result in higher biological effects compared to GSM signal because of eventual “effective” frequencies within the wideband. Here, we report for the first time that UMTS MWs affect chromatin and inhibit formation of DNA double‐strand breaks co‐localizing 53BP1/γ‐H2AX DNA repair foci in human lymphocytes from hypersensitive and healthy persons and confirm that effects of GSM MWs depend on carrier frequency. Remarkably, the effects of MWs on 53BP1/γ‐H2AX foci persisted up to 72 h following exposure of cells, even longer than the stress response following heat shock. The data are in line with the hypothesis that the type of signal, UMTS MWs, may have higher biological efficiency and possibly larger health risk effects compared to GSM radiation emissions. No significant differences in effects between groups of healthy and hypersensitive subjects were observed, except for the effects of UMTS MWs and GSM‐915 MHz MWs on the formation of the DNA repair foci, which were different for hypersensitive (P < 0.02[53BP1]//0.01[γ‐H2AX]) but not for control subjects (P > 0.05). The non‐parametric statistics used here did not indicate specificity of the differences revealed between the effects of GSM and UMTS MWs on cells from hypersensitive subjects and more data are needed to study the nature of these differences. Bioelectromagnetics 30:129–141, 2009. © 2008 Wiley‐Liss, Inc.
Effects of 60 Hz 14 µT magnetic field on the apoptosis of testicular germ cell in mice
Authors: Kim Yoon‐Won , Kim Hee‐Sung , Lee Jin‐Sang , Kim Young‐Jin , Lee Sang‐Kon , Seo Jae‐Nam , Jung Kyeong‐Cheon , Kim Nam , Gimm Youn‐Myoung 
Published: October 2008

AbstractWe recently reported that continuous exposure, for 8 weeks, of extremely low frequency (ELF) magnetic field (MF) of 0.1 or 0.5 mT might induce testicular germ cell apoptosis in BALB/c mice. In that report, the ELF MF exposure did not significantly affect the body weight or testicular weight, but significantly increased the incidence of testicular germ cell death. In the present study, we aimed to further characterize the effect of a 16‐week continuous exposure to ELF MF of 14 or 200 µT on testicular germ cell apoptosis in mice. There were no significant effects of MF on body weight and testosterone levels in mice. In TUNEL staining (In situ terminal deoxynucleotidyl transferase‐mediated deoxy‐UTP nick end labeling), germ cells showed a significantly higher apoptotic rate in exposed mice than in sham controls (P < 0.001). TUNEL‐positive cells were mainly spermatogonia. In an electron microscopic study, degenerating spermatogonia showed condensation of nuclear chromatin similar to apoptosis. These results indicate that apoptosis may be induced in spermatogenic cells in mice by continuous exposure to 60 Hz MF of 14 µT. Bioelectromagnetics 30:66–72, 2009. © 2008 Wiley‐Liss, Inc.
Effect of long term exposure to 0.5 T static magnetic fields on growth and size of GH3 cells
Authors: Rosen Arthur D. , Chastney Erin E. 
Published: October 2008

AbstractBrief exposure to moderate intensity static magnetic fields has been shown to produce a transient alteration in physiological function in a variety of biological systems, primarily those related to changes in intracellular Ca2+. In the present study GH3 cells were cultured during continuous exposure to a 0.5 T field, for periods of up to 5 weeks. Following a 1‐week exposure, cell growth declined by 22% and returned to control levels in 1 week. This was not statistically significant but, with a 4‐week exposure, a statistically significant decline in growth of 51% was observed and return to control levels did not occur for 4 weeks. Cell diameter, on the other hand, significantly increased following 3 weeks of exposure and did not return to control levels for 3 weeks after termination of exposure. Ca2+‐dependent changes in the dynamic reorganization of the actin cytoskeleton are suggested as the probable explanation for these observations. Bioelectromagnetics 30:114–119, 2009. © 2008 Wiley‐Liss, Inc.
Die Unterinntaltrasse in der Bauausführung
Authors: Herdina Johann 
Published: October 2008

AbstractDer 2,3 Mrd. Euro teure Abschnitt der zweigleisigen Zulaufstrecke zum Brennerbasistunnel im Unterinntal wird fast zur Gänze unterirdisch errichtet. Die seichte Lage der Tunnel in einem inneralpinen Tal führt dazu, dass bei der Bauausführung fast alle im Spezialtiefbau bekannten Verfahren zur Anwendung kommen. Diese werden sogar in Kombinationen verwendet, die weltweit noch nie zusammen eingesetzt wurden. Der Bericht gibt einen Einblick in die einzelnen Baulose dieses schwierigen 41 km langen Abschnitts der europäischen TEN Achse Nr.1 zwischen Berlin und Palermo.
Hinweise zum neuen DIN‐Fachbericht 102 – Betonbrücken, Ausgabe 2008 Teil 2
Authors: Haveresch Karlheinz , Maurer Reinhard 
Published: October 2008

AbstractIn Heft 8 von Beton‐ und Stahlbetonbau wurden wichtige neue Regelungen der bevorstehenden Neuausgabe von DIN‐Fachbericht 102 vorgestellt und erläutert. Dort wurden die Themenschwerpunkte:– Schnittstelle Bauwerk und Baugrund– Einwirkungen während der Bauzeit– Schnittgrößen aus Zwang im Grenzzustand der Tragfähigkeit– Besonderheiten von Brücken mit Kastenquerschnitten– Bestimmung der Spaltzugbewehrung an Spanngliedverankerungen– Behandlung von Spannverfahren– Robustheitsbewehrung und– Querkraftbemessungbehandelt.Im vorliegenden Beitrag wird die Erläuterung des neuen DIN‐Fachberichts 102 zu weiteren Themenschwerpunkten fortgesetzt.
Language learning with interactive virtual agent scenarios and speech recognition: Lessons learned
Authors: Anderson James N. , Davidson Nancie , Morton Hazel , Jack Mervyn A. 
Published: October 2008

AbstractThe SPELL (Spoken Electronic Language Learning) system is a self‐access computer‐assisted language learning (CALL) package that integrates speaker‐independent continuous speech recognition technology with virtual worlds and embodied virtual agents to create an environment in which learners can converse in the target language within meaningful contextualized scenarios. In this paper we provide an overview of the functionality, architecture, and implementation of the SPELL system. We also describe four phases of usability evaluation conducted with the system and summarize the main results of these user assessments. Finally, we discuss the most significant lessons learned in the development and evaluation of the system. The paper focuses on the technological aspects of the system and its evaluation for usability and robustness, rather than its pedagogical methodology. Copyright © 2008 John Wiley & Sons, Ltd.
A Mitochondriotropic Derivative of Quercetin: A Strategy to Increase the Effectiveness of Polyphenols
Authors: Mattarei Andrea , Biasutto Lucia , Marotta Ester , De Marchi Umberto , Sassi Nicola , Garbisa Spiridione , Zoratti Mario , Paradisi Cristina 
Published: October 2008

AbstractMitochondria‐targeted compounds are needed to act on a variety of processes that take place in these subcellular organelles and that have great pathophysiological relevance. In particular, redox‐active molecules that are capable of homing in on mitochondria provide a tool to intervene on a major cellular source of reactive oxygen species and on the processes they induce, notably the mitochondrial permeability transition and cell death. We have linked the 3‐OH of quercetin (3,3′,4′,5,7‐pentahydroxy flavone), a model polyphenol, and the triphenylphosphonium moiety, a membrane‐permeant cationic group, to produce proof‐of‐principle mitochondriotropic quercetin derivatives. The remaining hydroxyls were sometimes acetylated to hinder metabolism and improve solubility. The new compounds accumulate in mitochondria in a transmembrane potential‐driven process and are only slowly metabolised by cultured human colon cells. They inhibit mitochondrial ATPase activity much as quercetin does, and are toxic for fast‐growing cells.
Direct Epoxidation in Candida antarctica Lipase B Studied by Experiment and Theory
Authors: Svedendahl Maria , Carlqvist Peter , Branneby Cecilia , Allnér Olof , Frise Anton , Hult Karl , Berglund Per , Brinck Tore 
Published: October 2008

AbstractCandida antarctica lipase B (CALB) is a promiscuous serine hydrolase that, besides its native function, catalyzes different side reactions, such as direct epoxidation. A single‐point mutant of CALB demonstrated a direct epoxidation reaction mechanism for the epoxidation of α,β‐unsaturated aldehydes by hydrogen peroxide in aqueous and organic solution. Mutation of the catalytically active Ser105 to alanine made the previously assumed indirect epoxidation reaction mechanism impossible. Gibbs free energies, activation parameters, and substrate selectivities were determined both computationally and experimentally. The energetics and mechanism for the direct epoxidation in CALB Ser105Ala were investigated by density functional theory calculations, and it was demonstrated that the reaction proceeds through a two step‐mechanism with formation of an oxyanionic intermediate. The active‐site residue His224 functions as a general acid‐base catalyst with support from Asp187. Oxyanion stabilization is facilitated by two hydrogen bonds from Thr40.
Statistical methods for evaluating the linearity in assay validation
Authors: Hsieh Eric , Hsiao Chin‐fu , Liu Jen‐pei 
Published: October 2008

AbstractOne of the most important characteristics for evaluation of the accuracy in assay validation is the linearity. Kroll, et al. 1 proposed a method based on the average deviation from linearity (ADL) to evaluate the linearity. Hsieh and Liu 2 suggested that hypothesis for proving the linearity be formulated as the alternative hypothesis and proposed the corrected Kroll's method. However, the issue concerning the variability in estimation of the non‐centrality parameter is still unresolved. Consequently, the type I error rates may still be inflated for the corrected Kroll's method. To overcome this issue, we propose the sum of squares of deviations from linearity (SSDL) as an alternative metric for evaluation of linearity. Based on SSDL, we applied the method of generalized pivotal quantities (GPQ) for the inference of evaluation of linearity. The simulation studies were conducted to empirically investigate the size and power between current and proposed methods. The simulation results show that the proposed GPQ method not only adequately control size but also provide sufficient power than other methods. A numeric example illustrates the proposed methods. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of benzylamine on the resolution of ibuprofen with (+)‐(R)‐phenylethylamine via supercritical fluid extraction
Authors: Molnár Péter , Bombicz Petra , Varga Csaba , Bereczki Laura , Székely Edit , Pokol György , Fogassy Elemér , Simándi Béla 
Published: October 2008

AbstractThe resolution of racemic ibuprofen was studied by partial diastereomer salt formation. The resolution was performed via two methods: resolution with (+)‐(R)‐phenylethylamine as chiral agent and resolution with a mixture of (+)‐(R)‐phenylethylamine and benzylamine. The diastereomers and unreacted enantiomers were separated by supercritical fluid extraction with carbon dioxide at 15 MPa and 33°C. The influence of the achiral benzylamine on the resolution efficiency was studied by varying the concentrations of the structurally related amines in their mixtures, keeping the sum molar ratio of the amines to racemic ibuprofen constant at 0.55 ± 0.02. The presence of benzylamine positively influenced the resolution efficiency at certain concentrations. The crystal structure of the salts of (+)‐(R)‐phenylethylamine with (−)‐(R)‐ibuprofen and (+)‐(S)‐ibuprofen, respectively, as well as the cocrystal of the benzylamine—ibuprofen salt with neutral ibuprofen molecules are presented. These structures were determined by single crystal X‐ray diffraction, proving the significantly different stoichiometry of the related amines with the chiral acid, in accordance with mass balance calculations. Chirality, 2008. © 2009 Wiley‐Liss, Inc.