bluuebunny/crossref_metadata_2025 huggingface dataset:
Chia (Salvia hispanica) can be used to manufacture sugar-snap cookies with an improved nutritional value
Authors: Barrientos V.A. , Aguirre A. , Borneo Rafael
Published: October 2012

Technologists and nutritionists are always looking for alternative ingredients to use in their formulations to improve functional and nutritional properties. Therefore, cookies using Chia (Salvia hispanica), a grain with high quality nutrients, were prepared. The nutritional value was determined by measuring the chemical composition, mineral content, and the fatty acid composition (saturated, monunsaturated, polyunsaturated, linoleic and linolenic acids). Data obtained from this chemical analysis was used to estimate the nutrients intake and compare them to the dietary reference intakes (DRIs). Cookies supplemented with chia flour contained signicantly more protein, fat, crude fiber, calcium, zinc, and alpha-linolenic (n-3) acid. It was estimated that the supplemented cookies would contribute to the corresponding DRIs in the range of 8.1-13.8% (children) and 6.5-11.0% (males/females) for calcium; and 14.0-18.0% (children) and 6.4-11.3 (males/females) for zinc. The addition of chia flour to the cookies resulted in a product sensorially acceptable with a better fatty acid profile (lower n-6/n-3). Supplemented cookies would contribute to alpha-linolenic DRI in the range of 65.9-134.5% (children), 49.4-100.9% (males), and 53.9-110.0% (females). Dietary intake of protein, fiber, calcium, zinc, and alpha-linolenic (n-3) acid could be increased by the consumption of sugar-snap cookies supplemented with chia flour.
Drying kinetics and quality aspects during heat pump drying of onion (Allium cepa L.)
Authors: Sahoo Nihar Ranjan , Pal Uma Sankar , Dash Sanjaya Kumar , Khan M.D. K.
Published: October 2012

A prototype heat pump dryer has been developed for drying of fruits and vegetables at low temperature and relative humidity to maintain the quality of dried product. Onions, of Nasik red variety were peeled, trimmed and sliced to 2 mm thickness. The onion slices were dried in the heat pump dryer at 35ºC (32 % R.H.), 40ºC (26 % R.H.), 45ºC (19 % R.H.) and 50ºC (15 % R.H.). Samples were also dried in a hot air dryer at 50ºC (52 % R.H.) for comparison. The drying rate increased with increase in drying air temperature, associated with reduced R.H., in the heat pump dryer. Drying took place mainly under the falling rate period. The Page equation, resulting in a higher coefficient of determination and lower root mean square error, better described the thin-layer drying of onion slices than the Henderson and Pabis equation. Heat pump drying took less drying time of 360 min and yielded better quality dried product, with higher retention of ascorbic acid and pyruvic acid and lower colour change, as compared to a hot air dryer at the same drying air temperature of 50ºC.
Bridging academic research and agribusiness in the recovery of byproducts from swine farming
Authors: Nunes Estela De Oliveira , Perazzoli Simone , Pasqual Janaina Camile
Published: October 2012

Nowadays, food production has the challenging mission to encourage the growth of the rural economy assuring long term sustainability of their natural resources. The qualification of human resources and the generation of new knowledge are the main pillars that give sustainability to agribusiness. Animal protein production is one of the branches of the agribusiness sector. Swine production is recognized as an activity of high pollution potential, producing a large quantity of waste. This study aimed to identify the activities developed in partnership among academic, research and extension institutes in a midsize company of the agribusiness sector, more specifically a swine farm (São Roque Farm) in its sustainable restructuring. An exploratory and quantitative research was developed, which comprehended literature reviews, data collection and analysis of documents from the São Roque Farm. It was considered the period that includes the beginning of the sustainable restructuring of the property (2003) until December 2011. During the analysis of the Sustainable Restructuring Project, special attention was given to the readjustment of the wastewater treatment system and to the energy management and carbon credits, being innovative and pilot projects in the state of Santa Catarina. For this purpose, technologies and knowledge are being developed and applied in treatment of three routes: gaseous, liquid and solid. This pilot project allowed the development of applied studies at undergraduate, masters and PhD level and the main results achieved are the improvement of understanding and the achievement of technical and financial benefits by connecting agribusiness, academia and government research institutions.
Nanotechnology: the word is new but the concept is old. An overview of the science and technology in food and food products at the nanoscale level
Authors: Bryksa Brian C. , Yada Rickey Y.
Published: October 2012

Food scientists and technologists are actively engaged in examining and developing nanotechnologies for applications such as novel functional ingredients and nutrient delivery systems, safety testing, packaging, and authenticity/authentication at an ever-increasing pace. However, before these new products/technologies are commercialised, rigorous safety testing and risk/benefit analysis are required to ensure that public and environmental concerns are addressed. This review provides an overview of food nanoscience and technology including a brief history, education, definitions pertaining to policy and regulation, and applications. The most recent findings and advances are emphasised, focussing on bioactives' delivery. In addition, proposed directions in the area of nano-based targeting of pathogens for food safety as well as medical foods are discussed. As food nanoscience and technology has been extensively reviewed in recent years, specific case examples will be limited to those reported within the past year.
Application of Near-Field Emission Processing for Microwave Circuits under Ultra-Short Duration Perturbations
Authors: Liu Y. , Ravelo B.
Published: October 2012

This paper is dealing with a time-frequency modeling method of electromagnetic (EM) near-field (NF) radiated by electronic devices excited by transient pulse signals. The model developed enables to calculate the EM NF maps at different distances from the given device and also the synthesis of radiation sources enabling to reproduce the field maps. The method proposed is based on the ultra wide band (UWB) frequency model of EM NF maps. The number of EM NF maps can be reduced by considering an innovative algorithm in order to establish simply the dipole model. Then, the transient model can be realized by considering the convolution between the transient excitation signals and the dipole-array model. The method proposed was validated by a standard 3D EM tool with a planar microstrip device excited by microwave signal modulating 1.25-GHz-carrier with 0.5-GHz-bandwidth. As expected, good correlation is found between results from simulation and the investigated modelling method.  The method introduced in this paper is particularly useful for the investigation of time-domain emissions for EMC applications by considering transient EM interferences (EMIs).
A Review on Diesel Soot Emission, its Effect and Control
Authors: Prasad Ram , Bella Venkateswara Rao
Published: October 2012

The diesel engines are energy efficient, but their particulate (soot) emissions are responsible of severe environmental and health problems. This review provides a survey on published information regarding diesel soot emission, its adverse effects on the human health, environment, vegetations, climate, etc. The legislations to limit diesel emissions and ways to minimize soot emission are also summarized. Soot particles are suspected to the development of cancer; cardiovascular and respiratory health effects; pollution of air, water, and soil; impact agriculture productivity, soiling of buildings; reductions in visibility; and global climate change. The review covers important recent developments on technologies for control of particulate matter (PM); diesel particulate filters (DPFs), summarizing new filter and catalyst materials and DPM measurement. DPF technology is in a state of optimization and cost reduction. New DPF regeneration strategies (active, passive and plasma-assisted regenerations) as well as the new learning on the fundamentals of soot/catalyst interaction are described. Recent developments in diesel oxidation catalysts (DOC) are also summarized showing potential issues with advanced combustion strategies, important interactions on NO2 formation, and new formulations for durability. Finally, systematic compilation of the concerned newer literature on catalytic oxidation of soot in a well conceivable tabular form is given. A total of 156 references are cited. © 2010 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)
Mesoporous Silica from Rice Husk Ash
Authors: Shelke V. R. , Bhagade S. S. , Mandavgane S. A.
Published: October 2012

Mesoporous silica is used as a raw material in several areas: in preparation of catalysts, in inks, as a concrete hardening accelerator, as a component of detergents and soaps, as a refractory constituent etc. Sodium silicate is produced by reacting rice hull ash (RHA) with aqueous NaOH and silica is precipitated from the sodium silicate by acidification. In the present work, conversion of about 90% of silica contained in RHA into sodium silicate was achieved in an open system at temperatures of about 100 °C. The results showed that silica obtained from RHA is mesoporous, has a large surface area and small particle size. Rice Husk is usually mixed with coal and this mixture is used for firing boilers. The RHA therefore, usually contains carbon particles. Activated carbon embedded on silica has been prepared using the carbon already present in RHA. This carbon shows good adsorption capacity. © 2010 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)
Kinetic Study of Esterification of Acetic Acid with n-butanol and isobutanol Catalyzed by Ion Exchange Resin
Authors: Toor Amrit Pal , Sharma Mamta , Kumar Ghansyam , Wanchoo R. K.
Published: October 2012

Esters are an important pharmaceutical intermediates and very useful perfumery agents. In this study the esterification of acetic acid with n-butanol and iso-butanol over an acidic cation exchange resin, Amberlyst 15 were carried out. The effects of certain parameters such as temperature, catalyst loading, initial molar ratio between reactants on the rate of reaction were studied. The experiments were conducted in a stirred batch reactor in the temperature range of 351.15 K to 366.15K.Variation of parameters on rate of reaction demonstrated that the reaction was intrinsically controlled.The activation energy for the esterification of acetic acid with n-butanol and iso butanol is found to be 28.45 k J/mol and 23.29 kJ/mol respectively. © 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)
In Situ Biodiesel Production from Residual Oil Recovered from Spent Bleaching Earth
Authors: Mat Ramli , Ling Ow Shin , Johari Anwar , Mohamed Mahadhir
Published: October 2012

Currently, semi-refined and refined vegetable oils are used as a feedstock in biodiesel production. However, due to competition with conventional fossil fuel, economic reasons, shortage supply of food and its social impact on the global scale has somewhat slowed the development of biodiesel industry. Studies have been conducted to recover oil from mill palm oil operation especially from the spent bleaching earth. Hence, the study was to investigate the potential recovery of oil from spent bleaching earth to be used as a feedstock for biodiesel production. The effect of different types of catalysts (sodium hydroxide alkali and sulfuric acid catalysts) on biodiesel yield was studied. In addition, the effect of volume addition of methanol to the weight of spent bleaching earth on the product yield was also studied. Furthermore, the effect of ratio of hexane to methanol was also carried out to determine its product yield. The studies were carried out in an in-situ biodiesel reactor system and the biodiesel product was analyzed using gas chromatography mass spectrometry. Result shows that the use of alkali catalyst produced the highest yield of biodiesel and the most optimum biodiesel yield was obtained when the methanol to spent bleaching earth ratio was 3.2:1 (gram of methanol: gram of SBE) and hexane to methanol ratio of 0.6:1 (volume of hexane: volume of methanol). © 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)
Ion-exchange Resin Catalyzed Esterification of Lactic Acid with Isopropanol: a Kinetic Study
Authors: Toor Amrit Pal , Sharma Mamta , Thakur Sakshi , Wanchoo Ravinder K.
Published: October 2012

The kinetic behavior of esterification of lactic acid with isopropanol over an acidic cation exchange resin, Amberlyst 15, was studied under isothermal condition. Isopropyl lactate synthesized in this reaction is an important pharmaceutical intermediate. The experiments were carried out in a stirred batch reactor in the temperature range of 323.15 to 353.15 K. The effect of various parameters such as temperature, molar ratio and catalyst loading was studied. Variation in parameters on rate of reaction demonstrated that the reaction was intrinsically controlled. Kinetic modeling was performed using Eley-Rideal model which acceptably fits the experimental data. The activation energy was found to be 22.007 kJ/mol and frequency factor was 0.036809 l2 g-1 mol-1 min-1 for forward reaction. The value of entropy for the forward reaction was found to be 182.317 J K-1 mol-1. © 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)
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

This 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

Copy‐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

In 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

Titanium 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

Nanoscale 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

Thermochemical 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

Bulk‐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.
A novel type of equipment for reactive distillation: Model development, simulation, sensitivity and error analysis
Authors: von Harbou Erik , Schmitt Markus , Großmann Christoph , Hasse Hans
Published: October 2012

A simulation study of heterogeneously catalyzed reactive distillation experiments carried out with the D + R tray, a novel type of laboratory equipment, is presented. One advantage of the D + R tray is that reaction and distillation are alternating stage‐wise, in a well‐defined way that can be modeled straightforwardly. An equilibrium stage model is used to describe the distillation and a plug flow reactor model to describe the catalyst bed reactors. The model parameters are derived from a systematic experimental characterization of the D + R tray both as a reactor and as a distillation unit. A validated physicochemical fluid property model is used. The primary experimental data are reconciled. Results from the predictive simulations are in good agreement with the experimental results. The influence of errors in the input parameters on the simulation results is investigated by means of a sensitivity and error analysis. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1533–1543, 2013
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

The 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

Die 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

Three 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
Multiplicative and fractional strategies when journals are assigned to several subfields
Authors: Herranz Neus , Ruiz‐Castillo Javier
Published: October 2012

In many data sets, articles are classified into subfields through the journals in which they have been published. The problem is that while many journals are assigned to a single subfield, many others are assigned to several. This article discusses a multiplicative and a fractional strategy to deal with this situation. The empirical part studies different aspects of citation distributions under the two strategies, namely: the number of articles, the mean citation rate, the broad shape of the distribution, their characterization in terms of size‐ and scale‐invariant indicators of high and low impact, and the presence of extreme distributions, that is, distributions that behave very differently from the rest. We found that, despite large differences in the number of articles according to both strategies, the similarity of the citation characteristics of articles published in journals assigned to one or several subfields guarantees that choosing one of the two strategies may not lead to a radically different picture in practical applications. Nevertheless, the characterization of citation excellence through a high‐impact indicator may considerably differ depending on that choice.
Citation patterns of the pre‐web and web‐prevalent environments: The moderating effects of domain knowledge
Authors: Wu Ling‐Ling , Huang Mu‐Hsuan , Chen Ching‐Yi
Published: October 2012

The Internet has substantially increased the online accessibility of scholarly publications and allowed researchers to access relevant information efficiently across different journals and databases (Costa & Meadows, ). Because of online accessibility, academic researchers tend to read more, and reading has become more superficial (Olle & Borrego, ), such that information overload has become an important issue. Given this circumstance, how the Internet affects knowledge transfer, or, more specifically, the citation behavior of researchers, has become a recent focus of interest. This study assesses the effects of the Internet on citation patterns in terms of 4 characteristics of cited documents: topic relevance, author status, journal prestige, and age of references. This work hypothesizes that academic scholars cite more topically relevant articles, more articles written by lower status authors, articles published in less prestigious journals, and older articles with online accessibility. The current study also hypothesizes that researcher knowledge level moderates such Internet effects. We chose the “IT and Group” subject area and collected 241 documents published in the pre‐web period (1991–1995) and 867 documents published in the web‐prevalent period (2006–2010) in the Web of Science database. The references of these documents were analyzed to test the proposed hypotheses, which are significantly supported by the empirical results.
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

An 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

Integrated 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

Cytochrome 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.
Cell behavior observation and gene expression analysis of melanoma associated with stromal fibroblasts in a three‐dimensional magnetic cell culture array
Authors: Okochi Mina , Matsumura Taku , Yamamoto and Shuhei , Nakayama Eiichi , Jimbow Kowichi , Honda Hiroyuki
Published: October 2012

A three‐dimensional (3D) multicellular tumor spheroid culture array has been fabricated using a magnetic force‐based cell patterning method, analyzing the effect of stromal fibroblast on the invasive capacity of melanoma. Formation of spheroids was observed when array‐like multicellular patterns of melanoma were developed using a pin‐holder device made of magnetic soft iron and an external magnet, which enables the assembly of the magnetically labeled cells on the collagen gel‐coated surface as array‐like cell patterns. The interaction of fibroblast on the invasion of melanoma was investigated using three types of cell interaction models: (i) fibroblasts were magnetically labeled and patterned together in array with melanoma spheroids (direct‐interaction model), (ii) fibroblasts coexisting in the upper collagen gel (indirect‐interaction model) of melanoma spheroids, and (iii) fibroblast‐sheets coexisting under melanoma spheroids (fibroblast‐sheet model). The fibroblast‐sheet model has largely increased the invasive capacity of melanoma, and the promotion of adhesion, migration, and invasion were also observed. In the fibroblast‐sheet model, the expression of IL‐8 and MMP‐2 increased by 24‐fold and 2‐fold, respectively, in real time RT‐PCR compared to the absence of fibroblasts. The results presented in this study demonstrate the importance of fibroblast interaction to invasive capacity of melanoma in the 3D in vitro bioengineered tumor microenvironment. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013
Matrix effects during monitoring of antibody and host cell proteins using attenuated total reflection spectroscopy
Authors: Capito Florian , Skudas Romas , Stanislawski Bernd , Kolmar Harald
Published: October 2012

Production of recombinant proteins, e.g. antibodies, requires constant real‐time monitoring to optimize yield and quality attributes and to respond to changing production conditions, such as host cell protein (HCP) titers. To date, this monitoring of mammalian cell culture‐based processes is done using laborious and time consuming enzyme‐linked immunosorbent assays (ELISA), two‐dimensional sodium dodecylsulphate polyacrylamide gel electrophoresis, and chromatography‐based systems. Measurements are usually performed off‐line, requiring regular sample withdrawal associated with increased contamination risk. As information is obtained retrospectively, the reaction time to adapt to process changes is too long, leading to lower yield and higher costs. To address the resulting demand for continuous online‐monitoring systems, we present a feasibility study using attenuated total reflection spectroscopy (ATR) to monitor mAb and HCP levels of NS0 cell culture in situ, taking matrix effects into account. Fifty‐six NS0 cell culture samples were treated with polyelectrolytes for semi‐selective protein precipitation. Additionally, part of the samples was subjected to filtration prior to analysis, to change the background matrix and evaluate effects on chemometric quantification models. General models to quantify HCP and mAb in both filtered and unfiltered matrix showed lower prediction accuracy compared to models designed for a specific matrix. HCP quantification in the range of 2,000–55,000 ng mL−1 using specific models was accurate for most samples, with results within the accepted limit of an ELISA assay. In contrast, mAb prediction was less accurate, predicting mAb in the range of 0.2–1.7 g L−1. As some samples deviated substantially from reference values, further investigations elucidating the suitability of ATR for monitoring are required. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013
Biohydrogen production by dark fermentation of glycerol using Enterobacter and Citrobacter Sp
Authors: Maru Biniam T. , Constanti Magda , Stchigel Alberto M. , Medina Francesc , Sueiras Jesus E.
Published: October 2012

Glycerol is an attractive substrate for biohydrogen production because, in theory, it can produce 3 mol of hydrogen per mol of glycerol. Moreover, glycerol is produced in substantial amounts as a byproduct of producing biodiesel, the demand for which has increased in recent years. Therefore, hydrogen production from glycerol was studied by dark fermentation using three strains of bacteria: namely, Enterobacter spH1, Enterobacter spH2, and Citrobacter freundii H3 and a mixture thereof (1:1:1). It was found that, when an initial concentration of 20 g/L of glycerol was used, all three strains and their mixture produced substantial amounts of hydrogen ranging from 2400 to 3500 mL/L, being highest for C. freundii H3 (3547 mL/L) and Enterobacter spH1 (3506 mL/L). The main nongaseous fermentation products were ethanol and acetate, albeit in different ratios. For Enterobacter spH1, Enterobacter spH2, C. freundii H3, and the mixture (1:1:1), the ethanol yields (in mol EtOH/mol glycerol consumed) were 0.96, 0.67, 0.31, and 0.66, respectively. Compared to the individual strains, the mixture (1:1:1) did not show a significantly higher hydrogen level, indicating that there was no synergistic effect. Enterobacter spH1 was selected for further investigation because of its higher yield of hydrogen and ethanol. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013