bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Preparation Methods of Copper Based PGMFree Diesel-Soot Oxidation Catalysts
Authors: Prasad Ram , Bella V. R. 
Published: October 2012

CuO-CeO2 systems have been proposed as a promising catalyst for low temperature diesel-soot oxidation. CuO-CeO2 catalysts prepared by various methods were examined for air oxidation of the soot in a semi batch tubular flow reactor. The air oxidation of soot was carried out under tight contact with soot/catalyst ratio of 1/10. Air flow rate was 150 ml/min, soot-catalyst mixture was 110 mg, heating rate was 5 0C/min. Prepared catalysts were calcined at 500 0C and their stability was examined by further heating to 800 0C for 4 hours. It was found that the selectivity of all the catalysts was nearly 100% to CO2 production. It was observed that the activity and stability of the catalysts greatly influenced by the preparation methods. The strong interaction between CuO and CeO2 is closely related to the preparation route that plays a crucial role in the soot oxidation over the CuO-CeO2 catalysts. The ranking order of the preparation methods of the catalysts in the soot oxidation performance is as follows: sol-gel > urea nitrate combustion > Urea gelation method > thermal decomposition > co-precipitation. © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Catalyst Deactivation Simulation Through Carbon Deposition in Carbon Dioxide Reforming over Ni/CaO-Al2O3 Catalyst
Authors: Istadi Istadi , Anggoro Didi D. , Saidina Amin Nor Aishah , Wei Ling Dorothy Hoo 
Published: October 2012

Major problem in CO2 reforming of methane (CORM) process is coke formation which is a carbonaceous residue that can physically cover active sites of a catalyst surface and leads to catalyst deactivation. A key to develop a more coke-resistant catalyst lies in a better understanding of the methane reforming mechanism at a molecular level. Therefore, this paper is aimed to simulate a micro-kinetic approach in order to calculate coking rate in CORM reaction. Rates of encapsulating and filamentous carbon formation are also included. The simulation results show that the studied catalyst has a high activity, and the rate of carbon formation is relatively low. This micro-kinetic modeling approach can be used as a tool to better understand the catalyst deactivation phenomena in reaction via carbon deposition. © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Impeller Submergence Depth for Stirred Tanks
Authors: Devi Thiyam Thamphasana , Sinha Annu Priya , Thakre Meena , Kumar Bimlesh 
Published: October 2012

Impeller submergence governs the performance of mixing tanks employed in oxygen transfer operation. Present work experimentally investigates the effect of impeller submergence depths on oxygen transfer and corresponding power consumption. It has been found that at higher range of impeller submergence, mixing tanks consume less power and gives higher values of oxygen transfer coefficient. Optimal range of submergence depth is 0.7 to 0.9 times the impeller diameter. © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Pressure Drop Hysteresis of Hydrodynamic States in Packed Tower for Foaming Systems
Authors: Sodhi Vijay , Gupta Renu 
Published: October 2012

An experimental investigation was carried out to determine the effects of gas and liquid flow velocities and surface tension on the two-phase phase pressure drop a in a downflow trickle bed reactor. Water and non- Newtonian foaming solutions were employed as liquid phase. More than 240 experimental points for the trickle flow (GCF) and foaming pulsing flow (PF/FPF) regime were obtained for present study. Hydrodynamic characteristics involving two-phase pressure drop significantly influenced by gas and liquid flow rates. For 15 and 30 ppm air-aqueous surfactant solutions, two-phase pressure drop increases with higher liquid and gas flow velocities in trickle flow and foaming/pulsing flow regimes. With decrease in surface tension i.e. for 45 and 60 ppm air-aqueous surfactant systems, two-phase pressure drop increases very sharply during change in regime transition at significantly low liquid and gas velocities. © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Applications and Preparation Methods of Copper Chromite Catalysts: A Review
Authors: Prasad Ram , Singh Pratichi 
Published: October 2012

In this review article various applications and preparation methods of copper chromite catalysts have been discussed. While discussing it is concluded that copper chromite is a versatile catalyst which not only catalyses numerous processes of commercial importance and national program related to defence and space research but also finds applications in the most concerned problem worldwide i.e. environmental pollution control. Several other very useful applications of copper chromite catalysts are in production of clean energy, drugs and agro chemicals, etc. Various preparation methods about 15 have been discussed which depicts clear idea about the dependence of catalytic activity and selectivity on way of preparation of catalyst. In view of the globally increasing interest towards copper chromite catalysis, reexamination on the important applications of such catalysts and their useful preparation methods is thus the need of the time. This review paper encloses 369 references including a well-conceivable tabulation of the newer state of the art. © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Model‐Free Tests for Genetic Linkage
Authors: Amos Christopher I. , Schnell Audrey , Chen Wei V. , Elston Robert C. 
Published: October 2012

AbstractThis unit covers statistical methods of linkage analysis that do not require the assumption of a detailed genetic model, as is required for standard lod score analysis. The unit has been updated to include the latest methods in sib‐pair analysis, including updates to using the software program SIBPAL as well as the relative‐pair analysis software applications GENEHUNTER, GENEHUNTER PLUS, and Merlin. Curr. Protoc. Hum. Genet. 75:1.8.1‐1.8.32. © 2012 by John Wiley & Sons, Inc.
A Survey of Copy‐Number Variation Detection Tools Based on High‐Throughput Sequencing Data
Authors: Xi Ruibin , Lee Semin , Park Peter J. 
Published: October 2012

AbstractCopy‐number variation (CNV) is a major class of genomic variation with potentially important functional consequences in both normal and diseased populations. Remarkable advances in development of next‐generation sequencing (NGS) platforms provide an unprecedented opportunity for accurate, high‐resolution characterization of CNVs. In this unit, we give an overview of available computational tools for detection of CNVs and discuss comparative advantages and disadvantages of different approaches. Curr. Protoc. Hum. Genet. 75:7.19.1‐7.19.15. © 2012 by John Wiley & Sons, Inc.
Multiperson zero‐sum differential games for a class of uncertain nonlinear systems
Authors: Liu Derong , Wei Qinglai 
Published: October 2012

SUMMARYIn this paper, multiperson zero‐sum differential games for a class of continuous‐time uncertain nonlinear systems are solved using a new iterative adaptive dynamic programming (ADP) algorithm. The idea is to use ADP technique to obtain the optimal control pair iteratively that makes the performance index function reach the optimal solution of the zero‐sum differential games without the system model. It proves that the iterative performance index functions are convergent to the optimal solution of the game. Stability properties of the system under the iterative control pairs are also presented. Neural networks are used to build the system model, approximate the performance index function, and compute the optimal control policy, respectively, for facilitating the implementation of the iterative ADP method. Finally, two simulation examples are given to demonstrate the performance of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.
Properties of Titanium Foams for Biomedical Applications
Authors: Lefebvre Louis‐Philippe , Baril Eric 
Published: October 2012

AbstractTitanium foams are presently used in various load bearing orthopedic applications. Such foams are characterized by an open network of porosity with high surface area. This paper presents the structure, microstructure, and properties of titanium foams produced with a powder metallurgy process. Fully porous CpTi and Ti6Al4V cylinders and CpTi foam coating on CpTi and Ti6Al4V substrates were produced and characterized. The microstructure of the foam cell walls is representative of annealed CpTi and Ti6Al4V. Alloying elements and oxygen in solution increase the mechanical strength of the foams but lower their ductility. Ductility affects the fatigue life of the material. When CpTi foam is bonded to Ti6Al4V substrates, migration of alloying elements in the foam cell walls is observed. Good metallurgical bonding is created between the coatings and the dense substrate and shear strength above the requirements of the FDA guidelines are obtained.
Hierarchical Intrafibrillar Nanocarbonated Apatite Assembly Improves the Nanomechanics and Cytocompatibility of Mineralized Collagen
Authors: Liu Yan , Luo Dan , Kou Xiao‐Xing , Wang Xue‐Dong , Tay Franklin R. , Sha Yin‐Lin , Gan Ye‐Hua , Zhou Yan‐Heng 
Published: October 2012

AbstractNanoscale replication of the hierarchical organization of minerals in biogenic mineralized tissues is believed to contribute to the better mechanical properties of biomimetic collagen scaffolds. Here, an intrafibrillar nanocarbonated apatite assembly is reported, which has a bone‐like hierarchy, and which improves the mechanical and biological properties of the collagen matrix derived from fibril‐apatite aggregates. A modified biomimetic approach is used, which based on the combination of poly(acrylic acid) as sequestration and sodium tripolyphosphate as templating matrix‐protein analogs. With this modified dual‐analog‐based biomimetic approach, the hierarchical association between collagen and the mineral phase is discerned at the molecular and nanoscale levels during the process of intrafibrillar collagen mineralization. It is demonstrated by nanomechanical testing, that intrafibrillarly mineralized collagen features a significantly increased Young's modulus of 13.7 ± 2.6 GPa, compared with pure collagen (2.2 ± 1.7 GPa) and extrafibrillarly‐mineralized collagen (7.1 ± 1.9 GPa). Furthermore, the hierarchy of the nanocarbonated apatite assembly within the collagen fibril is critical to the collagen matrix's ability to confer key biological properties, specifically cell proliferation, differentiation, focal adhesion, and cytoskeletal arrangement. The availability of the mineralized collagen matrix with improved nanomechanics and cytocompatibility may eventually result in novel biomaterials for bone grafting and tissue‐engineering applications.
Facile Aerosol Route to Hollow CuO Spheres and its Superior Performance as an Oxidizer in Nanoenergetic Gas Generators
Authors: Jian Guoqiang , Liu Lu , Zachariah Michael R. 
Published: October 2012

AbstractThermochemical metal/metal oxide redox reactions have twice the energy density of 2,4,6‐trinitrotoluene (TNT). They suffer, however, from low pressure‐volume work due to low gas expansion from the reaction. This study focuses on the development of a nanocomposite that delivers a high energy density and the potential of rapid gas release. Hollow CuO spheres with nanosized building blocks are fabricated using a “droplet‐to‐particle” aerosol spray pyrolysis method with the introduction of gas‐blowing agents in the synthesis procedure. Nanoaluminum with hollow CuO as an oxidizer ignites in a very violent manner and exhibits excellent gas‐generation behavior, demonstrating a high pressurization rate of 0.745 MPa μs−1 and a transient peak pressure of 0.896 MPa with a charge density of 1 mg cm−3, as well as a rapid oxygen release. Compared with wet‐chemistry methods, gas‐phase processes are relatively low cost, nominally offer a higher purity product, and are usually configured as continuous production processes, with a limited number of steps. The synthesis strategy demonstrated is simple and should be extendable to the preparation of other hollow metal oxide structures.
Additive‐Free Bulk‐Heterojuction Solar Cells with Enhanced Power Conversion Efficiency, Comprising a Newly Designed Selenophene‐Thienopyrrolodione Copolymer
Authors: Wang Dong Hwan , Pron Agnieszka , Leclerc Mario , Heeger Alan J. 
Published: October 2012

AbstractBulk‐heterojunction solar cells are reported with an enhanced power conversion efficiency (PCE) based on a newly designed semiconducting selenophene‐thienopyrrolodione (TPD) copolymer blended with [6,6]‐phenyl C71 butyric acid methyl‐ester. The solar cells are fabricated using simple solution processing (implying low‐cost fabrication). The relatively deep highest occupied molecular orbital (HOMO) level leads to a correspondingly high open‐circuit voltage of 0.88 V. The PCE approaches 5.8% when Clevious P VP AI4083 is used as the hole‐transport interlayer, with an optimized active layer thickness of approximately 95 nm, and a donor‐acceptor blend ratio of 1:1. A fill factor (FF) of 0.62 is achieved. The use of additives does not seem to be beneficial in this blended system, due to the achievement of proper phase separation in the as‐cast films. Also, the BHJ devices with a 3% ratio of a 1‐chloronaphthalene (CN) additive exhibit much more severe oxidative degradation from the decreased FF with a high series resistance than BHJ devices without additive. The selenophene‐TPD based BHJ solar cell is a promising candidate for high‐performance single cells with a low‐cost additive‐free fabrication and a long‐term stable operation.
An investigation of age‐related changes at the acetabulum in 18th–19th century ad adult skeletons from Christ Church Spitalfields, London
Authors: Mays S. 
Published: October 2012

AbstractThe age‐markers described at the adult acetabulum by Rissech et al. (J Forensic Sci 51 (2006) 213–229) were scored in the Spitalfields collection of skeletons of documented age and sex (N = 161). The purpose of the work was as a contribution to the evaluation of the general utility of these markers for estimating age at death. To this end, their relationship both with age, and with some other factors, was investigated. The latter comprised sex, general tendency toward bone formation in periarticular soft tissue (as measured by the occurrence of diffuse idiopathic skeletal hyperostosis), and occupation (as documented for some of the males). Of the seven Rissech et al. variables, only four were found to show a statistically significant relationship with age. The correlation between a composite score derived from a linear combination of these four variables, and age was similar to or greater than correlations between age and composite scores based on other age indicators reported in the literature for Spitalfields. Male acetabula aged at a greater rate than those of females. There was no relationship with the occurrence of DISH, but for occupation, those in nonmanual professions showed greater acetabular scores‐for‐age than those in manual trades. Am J Phys Anthropol 2012. © 2012 Wiley Periodicals, Inc.
Nachweis kleiner anorganischer Moleküle durch oberflächenverstärkte Raman‐Streuung (SERS)
Authors: Alvarez‐Puebla Ramón A. , Liz‐Marzán Luis M. 
Published: October 2012

AbstractDie oberflächenverstärkte Raman‐Streuung (SERS) ist ein leistungsfähiges und relativ direktes molekülspektroskopisches Verfahren aus dem Bereich der Nanoplasmonik. Das Prinzip von SERS ist die Verstärkung der unelastischen Streuung von Molekülen, die sich nahe einer nanostrukturierten Metalloberfläche mit durch Bestrahlung angeregten Oberflächenplasmonen befinden. Die SERS‐Analytik ist dann weniger geeignet, wenn die Moleküle (wie oft bei anorganischen Molekülen der Fall) zu kleine Raman‐Querschnitte haben. Noch schwieriger ist die Identifizierung von atomaren Spezies, da diese noch nicht einmal ein Schwingungssignal aufweisen. Hier erörtern wir die jüngsten Fortschritte beim SERS‐Nachweis kleiner anorganischer Spezies, darunter Moleküle und Atome.
Structures and properties of easily dyeable copolyesters and their fibers respectively modified by three kinds of diols
Authors: Fu Changfei , Gu Lixia 
Published: October 2012

AbstractThree kinds of modified poly(ethylene terephthalate) copolyesters were synthesized, using sodium‐5‐sulfo‐bis‐(hydroxyethyl)‐isophthalate as the third monomer, 1,3‐propanediol (PDO), 2‐methyl‐1,3‐propanediol (MPD), and 2,2‐dimethyl‐1,3‐propanediol (neopentyl glycol or NPG) as the fourth monomer, respectively. The copolyester fibers were also prepared by melt spinning and drawing processes. The effect of PDO, MPD, and NPG on the synthesis and spinning process was investigated, and the structures and properties of both copolyesters and the produced fibers were characterized. The results exhibited that the structural difference of PDO, MPD, and NPG played an important role in the synthesis and spinning process, and significantly affected the structures and properties of both copolyesters and the produced fibers, which thereby resulted in the difference in terms of dyeability improvement of copolyester fibers. The dyeing at boiling temperature under normal pressure experiments of copolyester fibers in both disperse dyebath and cationic dyebath revealed that incorporation of the fourth monomer could improve the dyeability of copolyester fiber, and copolyester fiber containing MPD unit had better dyeability due to a looser, more accessible structure when compared with the fiber containing PDO or NPG unit. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Acoustic detection of cell adhesion on a quartz crystal microbalance
Authors: Da‐Silva Ana‐Carina , Rodrigues Rogério , Rosa Luís F. M. , de‐Carvalho Jorge , Tomé Brigitte , Ferreira Guilherme N. M. 
Published: October 2012

AbstractAn acoustic quartz crystal microbalance (QCM) was used to signal and follow the cell‑adhesion process of epithelial cells [human embryonic kidney(HEK) 293T and cervical cancer (HeLa) and fibroblasts [African Green Monkey kidney cells (COS–7)] onto gold surfaces. Cells were applied on the sensor and grown under serum‐free and serum‐supplemented culture media. The sensor resonance frequency (Δf) and motional resistance (ΔR) variations were measured during cell growth to monitor cell adhesion processes. Fingerprints of the adhesion processes, generated using the QCM signal, were found to be specific for each cell type while enabling the identification of the phases of the adhesion process. Under serum‐free conditions, the deposition of HEK 293T and HeLa cells was characterized by a decrease of Δf with constant ΔR, whereas for COS‑7 cells, this initial deposition was signaled by variations of ΔR at constant Δf. Toward the end of the adhesion process, fingerprints were characterized by a continuous increase of ΔR consistent with the increase in viscoelasticity. The morphology of adherent cells was visualized by fluorescent microscopy, enabling the association of the cell morphology with QCM signals.
Periodic counter‐current chromatography – design and operational considerations for integrated and continuous purification of proteins
Authors: Godawat Rahul , Brower Kevin , Jain Sujit , Konstantinov Konstantin , Riske Frank , Warikoo Veena 
Published: October 2012

AbstractIntegrated and continuous processing of recombinant proteins offers several advantages over batch or semi‐batch processing used traditionally in the biotechnology industry. This paper presents a theoretical and practical approach for designing a periodic counter‐current chromatography (PCC) operation as a continuous capture purification step that is integrated with a perfusion cell culture process. The constraints for continuous and optimal PCC operation govern the selection of residence time and number of columns. The flexibility available in PCC design for selection of these parameters is dictated by the binding characteristics of the target protein on the capture resin. Using an empirical model for the protein breakthrough curve, analytical solutions to determine these conditions were derived and verified with experimental results for three different proteins: two relatively unstable proteins (recombinant enzymes) and a relatively stable protein (monoclonal antibody). The advantages of a continuous downstream capture step are highlighted for the three case studies in comparison with the existing batch chromatography processes. The use of PCC leads to improvements in process economics due to higher resin capacity utilization and correspondingly lower buffer consumption. Furthermore, integrated and continuous bioprocessing results in a smaller facility footprint by elimination of harvest hold vessels and clarification, as well as by reducing the capture column size by one to two orders of magnitude.
Screening for cytochrome P450 expression in Pichia pastoris whole cells by P450‐carbon monoxide complex determination
Authors: Gudiminchi Rama Krishna , Geier Martina , Glieder Anton , Camattari Andrea 
Published: October 2012

AbstractCytochrome P450 (CYP) enzymes are useful biocatalysts for the pharmaceutical and biotechnological industries. A high‐throughput method for quantification of CYP expression in yeast is needed in order to fully exploit the yeast expression system. Carbon monoxide (CO) difference spectra of whole cells have been successfully used for the quantification of heterologous CYP expressed in Escherichia coli in the 96‐well format; however, very few researchers have shown whole‐cell CO difference spectra with yeast cells using 1‐cm path length. Spectral interference from the native hemoproteins often obscures the P450 peak, challenging functional CYP quantification in whole yeast cells. For the first time, we describe the high‐throughput determination of CO difference spectra using whole cells in the 96‐well format for the quantification of CYP genes expressed in Pichia pastoris. Very little interference from the hemoproteins of P. pastoris enabled CYP quantification even at relatively low expression levels. P. pastoris strains carrying a single copy or three copies of both hCPR and CYP2D6 integrated into the chromosomal DNA were used to establish the method in 96‐well format, allowing to detect quantities of CYP2D6 as low as 6 nmol gCDW–1 and 12 pmol per well. Finally, the established method was successfully demonstrated and used to screen P. pastoris clones expressing Candida CYP52A13.