Prediction of asphaltene deposition during turbulent flow using heat transfer approach

In this study, asphaltene deposition from crude oil has been studied experimentally using a test loop and prediction using theoretical study under turbulent flow (Reynolds numbers below 5000). The effects of many parameters such as oil velocity, surface temperature and concentration of flocculated asphaltene on the asphaltene deposition were investigated. The results showed that asphaltene deposition thickness increases with increasing both surface temperature and concentration of flocculated asphaltene and decreasing oil velocity. Thermal approach was used to describe the mechanisms involved in this process and the results of data fitting showed that there are good agreements between the results of the proposed model and the measured asphaltene deposition rates.     

The analyses of dynamic response and reliability of fuzzy-random truss under stationary stochastic excitation

A new two-factor method based on the probability and the fuzzy sets theory is used for the analyses of the dynamic response and reliability of fuzzy-random truss systems under the stationary stochastic excitation. Considering the fuzzy-randomness of the structural physical parameters and geometric dimensions simultaneously, the fuzzy-random correlation function matrix of structural displacement response in time domain and the fuzzy-random mean square values of structural dynamic response in frequency domain are developed by using the two-factor method, and the fuzzy numerical characteristics of dynamic responses are then derived. Based on numerical characteristics of structural fuzzy-random dynamic responses, the structural fuzzy-random dynamic reliability and its fuzzy numerical characteristic are obtained from the Poisson equation. The effects of the uncertainty of the structural parameters on structural dynamic response and reliability are illustrated via two engineering examples and some important conclusions are obtained.     

Texture/phase evolution during microwave fabrication of nanocrystalline multicomponent (Cu/Zn/Al)O metal oxides with varying diethylene glycol content applied in hydrogen production

A series of Cu/Zn/Al mixed oxides, as steam methanol reforming catalysts, were synthesized via the microwave assisted combustion synthesis method using diethylene glycol as the organic fuel. The nanocatalysts were analyzed by XRD, FESEM, EDX, BET, H₂-TPR and FTIR techniques to ensure authenticity of the synthesis steps and pursuing the effect of the fuel/nitrate ratio on their physicochemical properties. The results proved the necessity of defining an optimum fuel/nitrate ratio for the combustion synthesis method. Fuel/nitrate ratio affects significantly on crystal growth and crystalline facets size. Proper crystallography of CuO/ZnO/Al₂O₃ (DEG/Nitrate = 3) nanocatalyst along with higher specific surface area and distributed particle size, made it predictable that it could result in higher methanol conversion in the steam methanol reforming process. The catalytic performance studies justified assumptions, since the CZA (DEG/N = 3) presented higher methanol conversion and selectivity toward desired products as well as its high stability.     

Modeling and analysis of thermal damping in heat exchanger tube bundles

Most structures and equipment used in nuclear power plant and process plant, such as reactor internals, fuel rods, steam generator tubes bundles, and process heat exchanger tube bundles, are subjected to flow-induced vibrations (FIV). Costly plant shutdowns have been the source of motivation for continuing studies on cross-flow-induced vibration in these structures. Damping has been the target of various research attempts related to FIV in tube bundles. A recent research attempt has shown the usefulness of a phenomenon termed as ‘thermal damping’. The current paper focuses on the modeling and analysis of thermal damping in tube bundles subjected to cross-flow. It is expected that the present attempt will help in establishing improved design guidelines with respect to damping in tube bundles.     

The synthesis of carbon-sulfur bulk compounds

Carbon-sulfur compounds were synthesized by reacting sulfur with bitumen at 400°C. The ratio of the two elements in the compounds could be varied by changing the ratio sulfur/bitumen in the reaction mixture. Heat treatment of the products in the absence of O₂ (500–1000°C) results in loss of weight, and products with different empirical formulae are obtained.     

The encyclopedia of life project: Grid software and deployment

The ongoing global effort of genome sequencing is making large scale comparative proteomic analysis an intriguing task. The Encyclopedia of Life (EOL; http://eol.sdsc.edu) project aims to provide current functional and structural annotations for all available proteomes, a computational challenge never seen before in biology. Using an integrative genome annotation pipeline (iGAP), we have produced 3D models and functional annotations for more than 100 proteomes thus far. This process is greatly facilitated by grid compute resources, and especially by the development of grid application execution environment. AppLeS (Application-Level Scheduling) Parameter Sweep Template (APST) has been adopted by the EOL project as a mediator to grid middleware. APST has made the annotation process much more efficient, highly automated and scalable. Currently we are building a domain-specific bioinformatics workflow management system (BWMS) on top of APST, which further streamlines grid deployment of life science applications. With these developments in mind, we discuss some common problems and expectations of grid computing for high throughput proteomics. Henri Casanova, Ph.D.: He is an adjunct Professor of Computer Science and Engineering at the University of California, San Diego (UCSD), a Research Scientist at the San Diego Supercomputer Center, and the founder and director of the Grid Research and Development Laboratory (GRAIL) at UCSD. His research interests are in the area of parallel, distributed, Grid and Internet computing. He obtained his B.S. from the Ecole Nationale Supérieure d’Electronique, d’Electrotechnique, d’Informatique et d’Hydraulique de Toulouse, France in 1993, his M.S. from the Université Paul Sabatier, Toulouse, France in 1994, and his Ph.D. from the University of Tennessee, Knoxville in 1998. Francine Berman, Ph.D.: She is a Professor and High Performance Computing Endowed Chair at U.C. San Diego, Director of the San Diego Supercomputer Center and a Fellow of the ACM. Her research over two decades has focused on High Performance and Grid Computing, in particular in the areas of programming environments, adaptive middleware, scheduling and performance prediction. She has served on numerous editorial boards, steering committees, and program and conference committees in the areas of Parallel and Grid computing. She is one of the Principal Investigators of the NSF-supported TeraGrid, and directs NSF’s National Partnership for Advanced Computing Infrastructure (NPACI). Peter Arzberger, Ph.D.: He is the Director of Life Sciences Initiatives, University of California San Diego, Director of the National Biomedical Computation Resource (http://nbcr.ucsd.edu), funded by the National Center of Research Resource of NIH and the Chair of the Pacific Rim Application and Grid Middleware Assembly (http://www.pragma-grid.edu), an organization of 20 institutions around the pacific rim whose mission is to establish sustained collaborations and to advance the use of grid technologies in applications. He serves on the US National CODATA Committee and the National Advisory Board of the US Long Term Ecological Research. His hobby is working on Lloyds. Mark A. Miller, Ph.D.: He is Program Coordinator for the Integrative BioSciences Program at San Diego Supercomputer Center. He received his Ph.D. in Biochemistry from Purdue University in 1984. His research interests have slowly moved towards computer driven analyses and quantitative biology, and culminated in managing the BioInformatics Core of the Joint Center for Structural Biology where he helped to plan and implement the informatics solutions for high throughput crystallography. He is currently working on the specification, design and deployment of tools to enable biology research. Philip Bourne, Ph.D.: He is a Professor of Pharmacology at the University of California, San Diego and co-director of the Protein Data Bank (PDB). He is immediate past President of the International Society for Computational Biology, an Associate Editor of Bioinformatics and on the Editorial Board of several other journals. He received his B.Sc. and Ph.D. in chemistry at the Flinders University, South Australia. His research interests include bioinformatics, particularly structural bioinformatics. This implies algorithms, metalanguages, biological databases, biological query languages and visualization with special interest in cell signaling and apoptosis. Major projects ongoing in the Bourne Lab include the PDB, Encyclopedia of Life (EOL), Systematic Protein Annotation and Modeling (SPAM), and the Tree of Life. Bourne’s personal interests include fishing, tennis, squash, walking, skiing, sports cars, motor bikes and writing.     

Numerical analysis of intermodal delay in few-mode fibers for mode division multiplexing in optical fiber communication systems

In order to achieve higher spectral efficiency, mode division multiplexing (MDM) in few-mode fibers is a new research area. The idea faces lots of technical issues including intermodal delay and mode coupling which limit the achievable length of the system. This paper is designated to complete the analysis of intermodal delay in step-index few-mode fibers. We analyze numerically all the parameters of fiber, which could impact intermodal delay in few-mode fibers and identify the conditions which can increase the number of multiplex modes without significant increase in maximum intermodal delay.     

The role of CO2 and ion type in the dynamic interfacial tension of acidic crude oil/carbonated brine

The e ects of CO_2 and salt type on the interfacial tension(IFT) between crude oil and carbonated brine(CB) have not been fully understood. This study focuses on measuring the dynamic IFT between acidic crude oil with a total acid number of 1.5 mg KOH/g and fully CO_2-saturated aqueous solutions consisting of 15,000 ppm of KCl, NaCl, CaCl_2 and MgCl_2 at 30 °C and a wide range of pressures(500–4000 psi). The results of IFT measurements showed that solvation of CO_2 into all the studied aqueous solutions led to an increase in IFT of acidic crude oil(i.e., comparison of IFT of crude oil/CB and crude oil/brine), while no significant e ect was observed for pressure. In contrast, the obtained results of studied salts indicated a positive e ect on the IFT reduction of acidic crude oil/carbonated water(CW)(i.e., comparison of IFT of crude oil/CB and crude oil/CW).     

Synthesis, characterization, and application of chiral ionic liquids and their polymers in micellar electrokinetic chromatography

Two amino acid-derived (leucinol and N-methylpyrrolidinol) chiral ionic liquids are synthesized and characterized in both monomeric and polymeric forms. Leucinol-based chiral cationic surfactant is a room-temperature ionic liquid, and pyrrolidinol-based chiral cationic surfactant melts at 30-35 degrees C to form an ionic liquid (IL). The monomeric and polymeric ILs are thoroughly characterized to determine critical micelle concentration, aggregation number, polarity, optical rotation, and partial specific volume. Herein, we present the first enantioseparation using chiral IL as a pseudostationary phase in capillary electrophoresis. Chiral separation of two acidic analytes, (+/-)-alpha-bromophenylacetic acid and (+/-)-2-(2-chlorophenoxy)propanoic acid (+/-)-(2-PPA) can be achieved with both monomers and polymers of undecenoxycarbonyl-L-pryrrolidinol bromide (L-UCPB) and undecenoxycarbonyl-L-leucinol bromide (L-UCLB) at 25 mM surfactant concentration using phosphate buffer at pH 7.50. The chiral recognition seems to be facilitated by the extent of interaction of the acidic analytes with the cationic headgroup of chiral selectors. Polysodium N-undecenoxycarbonyl-L-leucine sulfate (poly-L-SUCLS) and polysodium N-undecenoxycarbonyl-L-leucinate (poly-L-SUCL) were compared at high and low pH for the enantioseparation of (+/-)-(2-PPA). At pH 7.5, poly-L-SUCLS, poly-L-SUCL, and (+/-)-(2-PPA) are negatively charged resulting in no enantioseparation. However, chiral separation was observed for (+/-)-(2-PPA) using poly-L-SUCLS at low pH (pH 2.00) at which the analyte is neutral. The comparison of chiral separation of anionic and cationic surfactants demonstrates that the electrostatic interaction between the acidic analyte and cationic micelle plays a profound role in enantioseparation.