bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conspiracy Theories and the Conventional Wisdom
Authors: Pigden Charles 
Published: July 2008

ABSTRACTConspiracy theories should be neither believed nor investigated - that is the conventional wisdom. I argue that it is sometimes permissible both to investigate and to believe. Hence this is a dispute in the ethics of belief. I defend epistemic “oughts” that apply in the first instance to belief-forming strategies that are partly under our control. But the belief-forming strategy of not believing conspiracy theories would be a political disaster and the epistemic equivalent of self-mutilation. I discuss several variations of this strategy, interpreting “conspiracy theory” in different ways but conclude that on all these readings, the conventional wisdom is deeply unwise.
CFD study of mixing characteristics of bubble column and external loop airlift reactor
Authors: Roy S. , Joshi J. B. 
Published: July 2008

AbstractIn the present work, a computational fluid dynamics study has been carried out to bring out the mixing characteristics of bubble column and external loop airlift reactor. A comparison of mixing time for two reactors has been presented on the basis of the same reactor volume as well as the total power input. The CFD model was validated by simulating flow, both in bubble column and external loop airlift reactor. An agreement was observed between the predicted and the experimental data available in the published literature. The validated CFD model has been extended for the simulation of the mixing time for both the reactors. The CFD predictions of mixing time show good agreement with the experimental values published in literature. A systematic numerical study was then carried out to bring out the mixing characteristics of both the reactors. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
CFD modeling of rotary cement kilns
Authors: Mujumdar Kaustubh S. , Ranade Vivek V. 
Published: July 2008

AbstractRotary cement kilns are widely used to convert calcineous raw meal into cement clinker, and are key components in the cement industry. In this article, we report a comprehensive computational fluid dynamics (CFD)‐based model to capture key transport processes in rotary cement kilns. Separate but coupled computational models were developed for the bed and the freeboard regions of the rotary kiln. The complex swirling airflow produced by kiln burners, coal combustion, gas‐phase combustion of volatile matter and radiative heat transfer in the freeboard region were modeled. The clinkerization reactions in the bed region were modeled assuming solids as pseudo fluids. Coating formation in cement kilns (for both bed and freeboard regions) was considered. Appropriate source and sink terms were developed to model transfer of CO2 from the bed to the freeboard region due to calcination reaction in the bed region. The developed bed and freeboard models were coupled by mass and energy communication through common interface. These coupled computational models were able to quite satisfactorily predict the available data from industrial kilns and previously published results. The computational models were also able to capture the intricacies of the burning zones of rotary cement kilns for changing burner‐operational parameters like axial to swirl ratio and oxygen enrichment. The developed approach, computational models and simulation results will not only help in developing better understanding of cement kilns but also provide quantitative information about influence of burner design and other design parameters on kiln performance. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
On the hydrodynamics of liquid–liquid slug flow capillary microreactors
Authors: Kashid M. N. , Rivas D. Fernández , Agar D. W. , Turek S. 
Published: July 2008

AbstractMicroreactor technology is an important method of process intensification. Liquid–liquid slug flow capillary microreactors have been used to intensify the reactions with heat and mass transfer limitations. In this type of reactor, either two liquids flow alternate to each other in a capillary or one liquid flows as a continuous flow while the other flows in the form of enclosed drops (slugs) depending on the interfacial tension between two liquids and liquid adhesion with the solid walls. The enhanced mass transfer is due to the internal circulations within the slugs, which rise due to the shearing action between the slug axis and the capillary wall or continuous phase. The slug size and the intensity of internal circulations depend on the type of mixing element and physical properties of the liquids. The proper understanding of physical behaviour of fluids at the microscale is a challenging issue for the growing microreactor application demands. This article highlights the hydrodynamic characteristics of the liquid–liquid slug flow capillary microreactor. Experimental results on flow regime, slug size and particle image velocimetry along with corresponding complementary state‐of‐the‐art computational fluid dynamics (CFD) simulations are discussed in detail. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
CFD modeling of a fluidized bed sewage sludge gasifier for syngas
Authors: Wang Yiqun , Yan Lifeng 
Published: July 2008

AbstractA three‐dimensional model of a fluidized bed for sewage sludge gasification is presented. The model describes the complex physical and chemical phenomena in the gasifier, including turbulent flow, heat and mass transfer, and chemical reactions. The simulation employs the standard κ− ε turbulence model for the gas phase in an Eulerian framework, and the discrete phase model for the sludge particles in a Lagrangian framework, coupled with the nonpremixed combustion model for chemical reactions. In terms of the Computational Fluid Dynamics (CFD) software Fluent 6.1, the simulations provide detailed information on the gas products' composition and temperature distribution inside the gasifier and at the outlet. The results are compared with the experimental data in literature (Manya et al., 2005). Effects of temperature and equivalence ratio (ER) on the product syngas (H2 + CO) quality are studied. The model shows good agreement with the experimental data. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Simultaneous model of chlorine dosing and decay in drinking water distribution system and model predictive control application
Authors: Muslim Abrar , Li Qin , Tadé Moses O. 
Published: July 2008

AbstractThe most commonly applied active disinfectant in drinking water distribution system (DWDS) is free chlorine residual (FCR) in the form of hypochlorous acid and hypochlorite ion. The concentration of FCR decreases along the transport pipeline. Controlled replenishment of chlorine at various sites in DWDS is critical to maintain the FCR in the safe range of 0.2–0.6 ppm. This study proposed a multiple‐input multiple‐output (MIMO) model (developed in Simulink of Matlab 7.0.1) that simultaneously takes into account chlorine dosing and decay process with the considerations of process disturbances. The model is further implemented into a centralised model predictive control (CMPC) system. The advantages of our CMPC system in controlling multiple outputs are its robustness and short settling time, compared to the conventional process‐data‐based proportional integral (PI) control strategies. Moreover, the simplicity of this reactive‐transport‐model‐based MIMO control system and the use of Matlab promise an easy adaptation to field test and plant implementation. It addresses an important need in water quality management, particularly for developing countries. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Removal of methylene blue from aqueous solution by rubber (Hevea brasiliensis) seed shell in a fixed‐bed column
Authors: Oladoja N. A. , Asia I. O. , Ademoroti C. M. A. , Ogbewe O. A. 
Published: July 2008

AbstractThe present study investigated the dynamic sorption of methylene blue (MB) from solution using rubber seed shell (RSS) in a fixed‐bed column. The process of sorption of MB from solution was analyzed using five different isotherm models (Langmuir, Freundlich, Temkin, Harkins–Jura, and Halsey isotherm equations), and the monolayer sorption capacity (82.64 mg/g) obtained from the Langmuir plot was compared with the bed depth service time (BDST) capacity (703.42 mg/l) obtained from the BDST model plot. The effect of two process variables (RSS bed height and initial MB concentration) on the dynamic sorption of MB on RSS was studied using the breakthrough curve. The total time (tx) for the establishment of primary adsorption zone (PAZ), the time required for the movement of the PAZ down the length of the RSS bed (tδ), the fractional capacity (f), and the length or depth of PAZ (δ) were evaluated. The operating design of the fixed was altered using serial dynamic sorption study, and the sensitivity of the RSS bed to drought was monitored when the Ci/Cf approached 0.5. The operational parameters of these variations were also estimated. The process variables were correlated with the BDST model, and a linear graph with high linear correlation (R2 > 0.9) values was obtained (0.9944 and 1.0000 at Tb10 and Tb50 respectively). The results obtained from the correlation of the process variables with the BDST model were used to predict the effect of changing the process variables on the system by using the BDST approach. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Studies to aid process development for the manufacture of neopentyl glycol from isobutyraldehyde: aldol condensation followed by hydrogenation
Authors: Tike M. A. , Gharde A. M. , Mahajani V. V. 
Published: July 2008

AbstractIn our present research and investigations, attempts were made to study aldol condensation of isobutyraldehyde with formaldehyde, and the subsequent hydrogenation of resultant hydroxypivaldehyde (aldol product) to neopentyl glycol. The kinetics of aldol condensation were studied using a weak basic anion‐exchange resin catalyst, Indion‐860, after screening other heterogeneous catalysts. The initial rate data were analyzed using a power‐law model to aid process design. Further, subsequent hydrogenation of resultant hydroxypivaldehyde was studied using 5% Ru/Al2O3 catalyst. The selectivity towards neopentyl glycol was > 99%. The kinetic data were analyzed using a power‐law model. A dual‐site Langmuir–Hinshelwood‐type model suggesting molecular adsorption (nondissociative) of hydrogen and surface reaction as the rate‐controlling step provided the best fit of the experimental data. The catalyst could be recycled with good selectivity. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Understanding capture of non‐Brownian particles in porous media with network model
Authors: Gao Changhong 
Published: July 2008

AbstractParticles can invade porous media such as reservoir rocks and deep‐bed filters, causing severe damage to their permeabilities. The mechanisms of permeability decline are attributed to surface deposition, bridging and size exclusion of particles in porous media. Traditional models are empirical correlations heavily dependent on filtration data. In this paper, a 2D square network model incorporating the damaging mechanisms is used to study the capture of non‐Brownian particles in porous media and the resultant permeability damage. The model employs certain assumptions to imitate the characteristics of real porous media. The proposed procedure applies force analysis to obtain particle invasion depth, and determines damaging mechanisms by pore size to particle size ratio. The method is validated with test data and reasonably good results are obtained. The new model provides more insights into the capture process and does not rely on core flooding data. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Friction between co‐current upward gas–solid flow and column wall
Authors: Qi Xiaobo , Huang Weixing , Zhu Jesse 
Published: July 2008

AbstractFriction between co‐current upflow gas–solid flow and column wall was investigated by measuring apparent solids concentrations and actual ones in two circulating fluidized bed (CFB) risers with fluid catalytic cracking (FCC) and sand particles, respectively. A new model to predict frictional‐pressure drops between the gas–solid flow in the fully developed zone and the column wall was developed. The results show that the friction between the gas–solid flow and the riser wall causes a significant deviation of the apparent solids concentration from the actual ones, especially under those operating conditions with higher superficial gas velocities and solids‐circulation rates. When superficial gas velocities are greater than 8 m/s, the apparent solids concentrations in the fully developed zone of the risers can be greater than 60% of the actual ones. Particle diameters have different influences on the frictional‐pressure loss under different superficial gas velocities. After the frictional‐pressure drops predicted by the proposed model are deducted from the measured total pressure drops, the predicted actual solids concentrations agree well with the measured actual ones. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Optimized experimental design for the inhibition of calcium oxalate using a turbidimetrical model
Authors: Driouch Aouatef , Djelloul Abdelkader , Kaid‐Omar Zohra , Semmoud Ahmed , Rais Abdelmajid , Addou Ahmed 
Published: July 2008

AbstractIn this work, we studied the individual and combined effect of inhibitors such as citrate ions and magnesium ions on crystallization of calcium oxalate. It is the main constituent of more than 70% of urinary stones. In order to optimize the number of experiments with the help of a suitable mathematical model, an experimental design was developed. The crystallization of CaC2O4 with and without inhibitors, at physiological concentrations, was studied by turbidimetry at 37 °C. The inhibition effect was evaluated through the induction time (nucleation) and the turbidimetrical slope (crystalline growth). The experimental design enabled the investigation of the effect of citrate ions, magnesium ions, and their combination on the inhibition rate. The obtained results showed that the inhibition power increases with inhibitor concentration when it is tested alone. This inhibition also affected the delay on nucleation. Thus, the induction time varied from 0.22 min without inhibitor to 4.73 min with citrate ions and 1.96 min with magnesium ions. The two inhibitors were more effective on nucleation and on crystalline growth when they were used in combination compared to one of them tested alone. The mathematical model fitted the experimental results well with a minimum of trials. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Spina bifida before and after folic acid fortification in Canada
Authors: De Wals Philippe , Tairou Fassiatou , Van Allen Margot I. , Lowry R. Brian , Evans Jane A. , Van den Hof Michiel C. , Crowley Marian , Uh Soo‐Hong , Zimmer Pamela , Sibbald Barbara , Fernandez Bridget , Lee Nora S. , Niyonsenga Theophile 
Published: July 2008

AbstractBACKGROUND:In 1998, fortification of a large variety of cereal products with folic acid became mandatory in Canada. A multicentric study was carried out to assess the impact of this policy on the frequency of NTDs. The present analysis focused on spina bifida.METHODS:The study population included approximately 2 million livebirths, stillbirths, and terminations of pregnancies because of fetal anomalies among women residing in seven Canadian provinces, from 1993 to 2002. Spina bifida cases were divided according to the upper limit of the defect: upper (cranial, cervical, or thoracic) and lower (lumbar or sacral) defects. Based on published results of red blood cell folate tests, the study period was divided into prefortification, partial fortification, and full fortification periods.RESULTS:A total of 1,286 spina bifida cases were identified: 51% livebirths, 3% stillbirths, and 46% terminations. Prevalence decreased from 0.86/1,000 in the prefortification to 0.40 in the full fortification period, while the proportion of upper defects decreased from 32% to 13%. Following fortification, regional variations in the prevalence and distribution of sites almost disappeared.CONCLUSIONS:Results confirmed the etiologic heterogeneity of spina bifida and the more pronounced effect of folic acid in decreasing the risk of the more severe clinical presentations. Birth Defects Research (Part A) 2008. © 2008 Wiley‐Liss, Inc.
Genome‐wide pathway analysis of folate‐responsive genes to unravel the pathogenesis of orofacial clefting in man
Authors: Bliek Bart J. B. , Steegers‐Theunissen Régine P. M. , Blok Leen J. , Santegoets Lindy A. M. , Lindemans Jan , Oostra Ben A. , Steegers Eric A. P. , de Klein Annelies 
Published: July 2008

AbstractBACKGROUND:A cleft of the lip with or without the palate (CLP) is a frequent congenital malformation with a heterogeneous etiology, for which folic acid supplementation has a protective effect. To gain more insight into the molecular pathways affected by natural folate, we examined gene expression profiles of cultured B‐lymphoblasts from CLP patients before and after the addition of 5‐methyltetrahydrofolate (5‐mTHF) to the cultures.METHODS:Immortalized B‐lymphoblasts from five children with CLP were cultured in folate‐deficient medium for 5 days. 5‐mTHF was added to a concentration of 30 nM. Gene expression patterns were then evaluated before and after supplementation using Human Genome U133 Plus 2.0 arrays. Data analysis was performed with Omniviz and the GEPAS analysis suite. Differential genes were categorized into biological pathways with Ingenuity Pathway systems. Differential expression was validated by quantitative RT‐PCR.RESULTS:Using supervised clustering, with a false discovery rate <1%, we identified 144 and 409 significantly up‐regulated and down‐regulated probesets, respectively, after 5‐mTHF addition. The regulated genes were involved in a variety of biological pathways, including one carbon pool and cell cycle regulation, biosynthesis of amino acids and DNA/RNA nucleotides, protein processing, apoptosis, and DNA repair.CONCLUSIONS:The large variety of the identified folate responsive pathways fits with the modifying role of folate via the methylation pathway. From the present data we may conclude that folate deficiency deranges normal cell development, which might contribute to the development of CLP. The role of these folate responsive genes in CLP development is intriguing and needs further investigation. Birth Defects Research (Part A) 2008. © 2008 Wiley‐Liss, Inc.
Development of a chitosan‐based nanoparticle formulation for delivery of a hydrophilic hexapeptide, dalargin
Authors: Chen Yan , Siddalingappa Basavaraj , Chan Phoebe H. H. , Benson Heather A. E. 
Published: July 2008

AbstractNanoparticle based delivery systems can offer opportunities for targeting, controlled release, and enhanced stability of their drug, protein, or gene therapy payload. This study investigated the use of chitosan in combination with the ionic additives sulfobutyl‐ether‐7‐β‐cyclodextrin (SB‐CD) or SB‐CD/dextran sulfate (SB‐CD/DS) mixture in comparison with chitosan: DS in the formulation of nanoparticles incorporating the hexapeptide dalargin. The physical characteristics (particle size, zeta potential), entrapment and loading efficiency, and release of dalargin were quantified. It was demonstrated that anionic cyclodextrin, SB‐CD, can be used in complex coacervation with chitosan, with and without the presence of DS, to form nanoparticles. The presence of SB‐CD or DS in the nanoparticle formulation and the weight ratio of chitosan to anionic additive(s) influenced the physical properties of the nanoparticles and their ability to carry dalargin. In addition, the particle size of nanoparticles was also affected by the molecular weight of chitosan and DS. The use of either DS or SB‐CD/DS mixture produced chitosan nanoparticles with small particle size, high dalargin entrapment efficiency, enhanced peptide stability, and sustained release characteristics. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 663–670, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Conformational studies of the α‐helical 28–43 fragment of the B3 domain of the immunoglobulin binding protein G from Streptococcus
Authors: Skwierawska Agnieszka , Rodziewicz‐Motowidło Sylwia , Ołdziej Stanisław , Liwo Adam , Scheraga Harold A. 
Published: July 2008

AbstractTo determine whether the α‐helix in the B3 immunoglobulin binding domain of protein G from group G Streptococcus has conformational stability as an isolated fragment, we carried out a CD and NMR study of the 16‐residue peptide in solution corresponding to this α‐helix. Based on two‐dimensional H‐NMR spectra recorded at three different temperatures (283, 305, and 313 K), it was found that this peptide is mostly unstructured in water at these temperatures. Weak signals corresponding to i,i+3 or i,i+4 interactions, which are characteristic of formation of turn‐like structures, were observed in the ROE spectra at all temperatures. The absence of a stable three‐dimensional structure of the investigated peptide supports an earlier study (Blanco and Serrano, Eur J Biochem 1995, 230, 634–649) of a possible mechanism for folding of other (B1 and B2) immunoglobulin binding domains of Protein G. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 1032–1044, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com