bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lateral flux and velocity of FCC particles in a CFB riser
Authors: Malcus Stefan , Pugsley Todd 
Published: March 2009

AbstractThe radial profiles of the lateral solids mass flux and the lateral solids velocity were determined for FCC particles in a 7 m tall circulating fluidtzed bed riser 0.14 m in diameter by applying a lateral flux probe and electrical capacitance tomography. The external solids mass flux was varied between 148 and 302 kg/(m2.s), while the superficial gas velocity was varied between 3.7 and 4.7 m/s. Under these conditions, a dense bottom region and an upper dilute region coexisted in the riser. Lateral fluxes in the dense bottom region reached 100 kg/(m2.s) at the wall, but fell to 14 kg/(m2.s) at the wall in the upper dilute region. At both axial locations, a net deposition of solids from the core to the annulus occurred, indicating that fully developed flow was never established under these conditions. The lateral fluxes in the bottom region were significantly larger than those found in previous studies. It was further concluded that considering the lateral solids flux to be only a function of solids concentration is an over‐simplification.
Effect of packed structure on flow behaviour in a trickle bed biofilter
Authors: Li Meisen , Bando Yoshiyuki , Tanigawara Ryo , Kamiya Toru , Yasuda Keiji , Nakamura Masaaki 
Published: March 2009

AbstractThe effects of operation conditions on the flow behaviour in gas–liquid countercurrent trickle bed biofilter were experimentally examined. In order to prevent gas channelling in the biofilter, packings with a relatively large void fraction, which have a role to maintain a high void fraction in the bed, were added. The gas and liquid velocities of the packed structure and the packings were changed, and the residence time distributions (RTDs) of the gas and liquid were measured. It was found that the addition of void supporters was very effective in the suppression of gas channelling.
Study of arc stability and erosion behaviour of a transferred arc with graphite DC electrodes
Authors: Seon Hongsun , Munz Richard J. 
Published: March 2009

AbstractThe arc stability and erosion behaviour of a hollow graphite DC cathode were studied using a graphite anode in an argon atmosphere. The main factors controlling the arc stability were the geometry of the cathode tip and the argon gas flow rate. It is suggested that high argon gas flow rates might shift the electron emission mechanism of the cathode from the thermionic‐field to the thermionic emission regime. Arcs were generally stable if the cathode is in the thermionic emission regime. The erosion rate of the cathode at 150 A was strongly dependent on the arc stability and higher for the unstable arc operation. Meanwhile, the erosion rates at 300 and 400 A showed the opposite trend because of carbon redeposition.
New pinch technology based hen analysis methodologies for cost‐effective retrofitting
Authors: Nordman Roger , Berntsson Thore 
Published: March 2009

AbstractIn this paper, new pinch technology based curves for retrofitting of heat exchangers are presented. Advantages compared to traditional pinch curves, and the information that can be extracted from these curves, are discussed. The curves have been applied to an example where different energy saving levels has been studied. The results have been verified by detailed calculations using the Matrix method.
Effect of an unsteady agitation method on drop coalescence characteristics in suspension polymerization of styrene
Authors: Yang Bin , Takahashi Koji 
Published: March 2009

AbstractA tracer dye technique was used to investigate the effect of the co‐reverse rotational of impeller method, the agitation speed and periodic time interval on the coalescence rate in the suspension polymerization of styrene. The results showed that the extent of coalescence decreased with the use of the co‐reverse rotational method and with the decrease in the periodic time interval or agitation speed. The results also showed that the final particle sizes became small and the particle size distributions became uniform with the use of the co‐reverse rotational method and with a decrease in the periodic time interval.
On solving optimal control problems with free initial condition using iterative dynamic programming
Authors: Mekarapiruk Wichaya , Luus Rein 
Published: March 2009

AbstractFor solving optimal control problems where the initial conditions of some of the state variables are not specified, a procedure based on iterative dynamic programming (IDP) is presented. In this procedure, the free initial conditions are taken to be additional control variables for the first time stage only; then the search for the optimal initial conditions and also the optimal control policy is carried out simultaneously using IDP. The procedure is straightforward, and as illustrated with two nonlinear optimal control problems, for each case the optimum performance index is readily obtained.
The use of partitioning bioreactors for the treatment of high‐concentration benzene solutions
Authors: Louie Jennifer , Daugulis Andrew J. , Yeom Sung‐Ho 
Published: March 2009

AbstractAqueous solutions containing high concentrations (circa 1000 mg/L) of benzene can be treated biologically through the intervention of organic 'sponges'. In reality these sponges are immiscible and biocompatible organic solvents that can be added in very low volumes, and act to draw benzene out of the aqueous phase, reducing levels appropriate for biological treatment. As the organisms consume benzene, the sponges release additional substrate to maintain an equilibrium relationship between the two phases, and this rate is determined by the metabolic activity of the cells. We have used 1‐actadsene as the organic sponge, and Klebsiella sp. as the degradative organism to consume 1000 mg/L of benzene in 12 h. By draining the aqueous phase to 10% of its original volume (and letting it serve as an inoculum), additional benzene solutions, at 1000 mg/L, can be reintroduced to the system, and the action of the sponge used a second, and subsequent times, to control benzene levels and benzene delivery to the organisms.
Friedel‐crafts alkylation of diphenyl oxide with 1‐decene over sulfated zirconia as catalyst
Authors: Yadav Ganapati D. , Kundu Buddhadeb 
Published: March 2009

AbstractFriedel‐Crafts alkylation and acylation reactions, using highly polluting homogeneous Lewis and Bronsted acids, are ubiquitous in a variety of organic process industries. In many cases very high conversions and selectivities can be achieved with aluminum chloride as catalyst and nitrobenzene as a solvent. However, environmental concerns associated with aluminum chloride‐nitrobenzene or BF3‐HF or mineral acids catalysts have encouraged development of solid acids, which not only intensify the rates of reactions but also offer better product selectivity. Amongst these catalysts, sulfated zirconia has gained a considerable importance due to its super‐acidity under certain conditions. The alkylation of diphenyl oxide with 1‐decene was studied over sulfated zirconia catalyst and it leads to industrially important products. The surface reaction between chemisorbed 1‐decene diphenyl oxide from the liquid phase, in the absence of any mass transfer resistance, was found to be the rate determining step with Eley‐Rideal type of mechanism.
A new approach to evaluate the energetic efficiency of batch‐jacketed reactors
Authors: Martins Fernando G. , Coelho Manuel A. N. 
Published: March 2009

AbstractThis paper presents a new heat transfer configuration for exothermic batch‐jacketed reactors. The proposed design for the heat transfer scheme comprises an additional heat exchanger in the jacket‐cooling loop. A detailed comparison study considering the new concept and the conventional process is presented in terms of energetic efficiency (refrigerated fluid consumption per batch cycle) and process control (control of reaction temperature). The simulation results of the new heat transfer configuration show a substantial decrease in the total volume of refrigerated fluid injected in the cooling loop, whereas the process control performance was practically unaffected.
Étude de l'aspect cornbinatoire de la gestion des conflits dans un atelier discontinu
Authors: Floquet Pascal , Domenech Serge , Azzaro‐Pantel Catherine , Pibouleau Luc 
Published: March 2009

AbstractDans cet article, les auteurs présentent l'aspect combinatoire lié à la gestion des ateliers discontinus de chimie fine de type multi‐objectif ou job‐shop. En effet l'ordre de priorité des recettes des produits, qui permet de déterminer le lot à charger en premier à un instant donné, induit un fort aspect combinatoire. Sa prise en compte par l'utilisation d'algorithmes stochastiques nécessite un dénombrement précis des ordres de priorité non redondants. Une étude mathématique assez complexe fournit une formule non récurrente aisée à mettre en œoeuvre. Celle‐ci est fondée sur l'analyse d'une famille de polynǒmes pseudo‐orthogonaux.
Modulating the relaxivity of hyperpolarized substrates with gadolinium contrast agents
Authors: Gabellieri Cristina , Leach Martin O. , Eykyn Thomas R. 
Published: March 2009

AbstractGadolinium contrast agents are known to affect the outer‐sphere relaxivities of nuclei other than protons. We have investigated the heteronuclear relaxivities of four commercial gadolinium contrast agents (Magnevist, Omniscan, Dotarem and Gadovist) on the relaxation of 13C in glycine, 13C in pyruvate and 15N in choline with long relaxation times. Marked differences in the relaxivities were found between different contrast agents and are attributed to electrostatic effects. This methodology may find applications in the field of hyperpolarized magnetic resonance and by way of example we show that injection of a bolus of contrast agent into an aqueous solution containing hyperpolarized 15N labeled tetramethylammonium or 13C labeled pyruvate leads to a predictable shortening of the lifetime of the hyperpolarized signal. Copyright © 2009 John Wiley & Sons, Ltd.
Revisiting the practices of corporate social and environmental disclosure in Bangladesh
Authors: Sobhani Farid Ahammad , Amran Azlan , Zainuddin Yuserrie 
Published: March 2009

AbstractFew studies are available on Corporate Social and Environmental Disclosure (CSED) in a developing country like Bangladesh. The latest study on the state of CSED was conducted about 10 years ago. During this period, in addition to global diversities, many changes have occurred in the socio‐political scenario in Bangladesh. The Government of Bangladesh (GOB) has recently undertaken pragmatic steps in order to make institutional and organizational changes. Attempts are being made to ensure good governance in all parts of public administration, declaring war against corruption. The Securities and Exchange Commission (SEC), the controlling body for the stock exchanges, has taken necessary action to establish corporate governance of the listed companies in Bangladesh. Stakeholders of the companies are gradually becoming aware of corporate operations. These socio‐political and organizational changes might influence the social responsibilities of the corporate bodies that might ultimately be reflected in the disclosure practices of the listed companies. This study attempts to revisit the state of CSED through content analysis. Annual reports of 100 companies, listed both on the Dhaka Stock Exchange and the Chittagong Stock Exchange, are selected based on a stratified random sampling technique. The study reveals that the level of disclosure has improved over the last 10 years. Based on the proposed research instrument for content analysis, all sample companies (n = 100) in Bangladesh are found to disclose at least one item of disclosure on human resource issues; while community issues (47%), consumer issues (23%) and environmental issues (19%). From a global perspective, however, the level and the extent of disclosure are found to be meagre. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
The small heat shock protein HSP25 protects astrocytes against stress induced by proteasomal inhibition
Authors: Goldbaum Olaf , Riedel Michael , Stahnke Thomas , Richter‐Landsberg Christiane 
Published: March 2009

AbstractProteasomal dysfunction has been implicated in neurodegenerative diseases, and molecular chaperones may provide a first line of defence against protein aggregate formation. We have shown before that oligodendrocytes respond to proteasomal inhibition by the onset of apoptotic cell death, whereas astrocytes have a higher capability to cope with stressful conditions that might be causally related to their high constitutive level of HSP25. This study was undertaken to investigate the effects of the proteasomal inhibitor MG‐132 on aggregate formation in astrocytes, and to test if HSP25 exerts a protective means. Our data show that upon proteasomal inhibition aggresomes are formed in astrocytes that contain the small HSPs, HSP25 and αB‐crystallin, and ubiquitinated proteins. HSP expression is induced and HSP25, αB‐crystallin and ubiquitinated proteins are translocated from the soluble to the detergent‐insoluble fraction. Simultaneously, the cytoskeletal organization is disturbed, microfilaments are fragmented, GFAP intermediate filaments and microtubules surround the aggresome, and mitochondria are assembled in these structures. Mitochondria membrane potential, however, stays intact. Aggresome formation and apoptotic cell death do not correlate. After the removal of MG‐132, the observed effects are reversible. MG‐132 promotes the formation of small oligomers of HSP25, which have been connected to the protection of the microfilament system. Downregulation of HSP25 by siRNA approach causes actin filament breakdown in control cells in the absence of stress stimuli, and sensitizes astrocytes against stress induced by proteasomal inhibition. Hence, HSP25 enables astrocytes to prevent irreversible damage and to recover after removal of the proteasomal inhibitor MG‐132. © 2009 Wiley‐Liss, Inc.
Molecular pathways mediating MDS/AML with focus on AML1/RUNX1 point mutations
Authors: Harada Yuka , Harada Hironori 
Published: March 2009

AbstractAML1/RUNX1 point mutations have been identified in myelodysplastic syndrome (MDS) and MDS‐related acute myeloid leukemia (AML), or MDS/AML, and are distributed throughout the full length of AML1/RUNX1. Gene mutation is proposed to be one of the disease‐defining genetic abnormalities of MDS/AML. Most of the mutants lose trans‐activation potential, which leads to a loss of normal function indicating that AML1/RUNX1 dysfunction is one of the major pathogenic mechanisms of MDS/AML. However, N‐terminal in‐frame mutations (Ni‐type) and C‐terminal truncated mutations (Ct‐type) of AML1/RUNX1 show a dominant‐negative effect on the trans‐activation activity, suggesting that these types of mutants may have some oncogenic potential in addition to the loss of normal function. The patients with Ni‐type mutations have hypoplastic marrows with other genetic abnormalities, whereas the patients with Ct‐type mutations display hyperplastic marrows without other mutations. Although biological analysis using a mouse bone marrow transplantation model transduced with Ni‐type of D171N or Ct‐type of S291fsX300 mutants has partially confirmed the oncogenic ability of AML1 mutants, it could not explain the mutant specific clinical features of MDS/AML. Biological analysis using human CD34+ cells revealed that the two types exhibited distinct molecular mechanisms. Ni‐type shows differentiation block without cell growth, but additional BMI‐1‐expression resulted in increased blastic cells. In contrast, Ct‐type itself has proliferation ability. Thus, AML1/RUNX1 mutants play a central role in the pathogenesis of MDS/AML. Both AML1 mutants are initiating factors for MDS‐genesis by inhibiting differentiation of hematopoietic stem cells, and Ni‐type mutant requires acquisition of proliferation ability. J. Cell. Physiol. 220: 16–20, 2009. © 2009 Wiley‐Liss, Inc.
Enhanced recombinant protein synthesis in batch and fed‐batch Escherichia coli fermentation based on removal of inhibitory acetate by electrodialysis
Authors: Wong Michael , Wright Michael , Woodley John M , Lye Gary J 
Published: March 2009

AbstractBACKGROUND: The formation of acetate as a metabolic by‐product in Escherichia coli fermentation is well known to have detrimental effects on cell growth and productivity. Various bioprocess and genetic approaches have previously been made to limit acetate accumulation, however, they tend to be conservative, limiting overall process productivity, or lead to other problems such as a decrease in maximum specific growth rate and decreased product yield on carbon.RESULTS: In this work, the utility of electrodialysis is examined as a potentially generic approach for in situ acetate removal and its impact on recombinant protein production. Using the induced synthesis of recombinant green fluorescent protein (GFP) in E. coli Tg1 (pGLO) as an example, it is shown that in situ removal of acetate to below inhibitory levels (∼1 g L−1) provides significant improvements in cell growth rate as well as specific biomass and recombinant protein yields. Experiments were performed in a 7.5 L stirred‐tank bioreactor using an external single cell‐pair electrodialysis module with an effective ion exchange membrane area of 0.01 m2. For this system increases in specific recombinant protein yield of up to 4‐fold have been observed dependent upon the time of induction, the mode of operation and the level to which acetate concentration is reduced in the fermentation broth.CONCLUSIONS: The implementation of ED can significantly increase the level of recombinant protein synthesis in batch and fed‐batch fermentation. The approach is considered to be generic, readily implemented and has wide application for the production of recombinant enzymes and proteins. Copyright © 2009 Society of Chemical Industry
Rough road to the market: Constrained biotechnology innovation and entrepreneurship in Nigeria and Ghana
Authors: Sampath Padmashree Gehl , Oyelaran‐Oyeyinka Banji 
Published: March 2009

AbstractThe paper analyses collaborative learning in knowledge generation in biotechnology in two very late follower economies, namely, Nigeria and Ghana in order to compare the innovation and entrepreneurship experiences they present. We suggest that the quality of physical infrastructure, knowledge infrastructure (including appropriate human skills), in addition to institutions and incentives for innovation contribute in large part to observed processes of innovation success. Regardless of whether the initiating step is the incremental design or laboratory‐based R&D stage, these factors are critical determinants of commercialisation. We use empirical data from the public sector institutions collected through field level surveys to substantiate these results. Copyright © 2009 John Wiley & Sons, Ltd.
Nano‐Templates from Thermoresponsive Poly(ethoxytriethyleneglycol acrylate) for Polymeric Nano‐Capsules
Authors: Dimitrov Philip , Toncheva Natalia , Weda Pawel , Rangelov Stanislav , Trzebicka Barbara , Dworak Andrzej , Tsvetanov Christo B. 
Published: March 2009

AbstractTemperature responsive poly(ethoxytriethyleneglycol acrylate) (PETEGA) of Mn = 8000 and Mw/Mn = 2.30 was synthesized by ATRP. Dilute aqueous solutions of PETEGA exhibit lower critical solution temperature (LCST) at around 34 °C. We found that PETEGA can form nano‐sized uniform colloidal aggregates (50‐200 nm) above LCST either with or without an additional surfactant. Therefore PETEGA nano‐aggregates were used as templates for the seeded free radical copolymerization of acrylamides or methacrylates together with a cross‐linker to form acrylamide or methacrylate based core‐shell particles. The formation of the PETEGA templates was investigated by dynamic light scattering (DLS) in order to find optimal conditions for obtaining narrow dispersed aggregates of desired sub‐micron dimensions. Core‐shell particles were characterized by DLS and scanning electron microscopy.
New approach for the selective chemical functionalization of porous silicon films with organic monolayers
Authors: Pace Stéphanie , Gazagnes Laetitia , Gonzalez Philippe , Guimon Claude , Granier Michel , Cot Didier , Devoisselle Jean‐Marie , Cunin Frédérique 
Published: March 2009

AbstractA new approach for the selective chemical modification of porous silicon surfaces with organic monolayers is reported. The organic layers are first covalently grafted onto (100) surface of hydrogen terminated silicon via thermal hydrosilylation of alkene or functionalized alkene molecules yielding stable monolayers on flat Si surfaces. The functionalized silicon surfaces are then electrochemically etched in a hydrofluoric acid solution. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Engineered linearity of GaN‐based HEMTs power devices by tailoring transfer characteristics
Authors: Bahat‐Treidel Eldad , Khalil Ibrahim , Hilt Oliver , Würfl Joachim , Tränkle Günther 
Published: March 2009

AbstractThis paper presents an innovative method of increasing inherent linearity of GaN/AlGaN HEMT by tailoring the effective transconductance. The effective transconductance of the whole device is tailored by optimizing individual transconductance of subunits of the device. In this work GaN HEMT units were individually optimized with different recess depth. The unit cells with different recess dept were optimized such a way so that the resultant transfer characteristic is suitable for high linearity. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investment dynamics and financial constraints in IPO firms
Authors: Chaddad Fernando R. , Reuer Jeffrey J. 
Published: March 2009

AbstractWe join research in entrepreneurship and corporate finance to investigate financial constraints on investments by IPO firms. The evidence indicates that IPO firms generally possess valuable growth opportunities, yet financial constraints also limit their ability to exploit them. Capital expenditures decline significantly post‐IPO, and information asymmetries between IPO firms and external capital providers help explain why some IPO firms are more financially constrained than others. Intangible assets that are often seen at the root of IPO firms' competitive advantages can also exacerbate external financing costs, constraining IPO firms' abilities to make future strategic investments. We also find that financial constraints are persistent, as they do not diminish as younger IPO firms mature. Copyright © 2009 Strategic Management Society.
Evolution of oil and gas generation in the Earth’s history and petroleum prediction in sedimentary basins
Authors: Bazhenova T.K. 
Published: March 2009

Abstract
Oil and gas generation is a basic problem of geology and natural sciences, which is associated with energy resources as well as with the origination of life on the Earth. The evolution of hydrocarbons is controlled by the evolution of the biosphere and is an issue of phylogeny. Organic matter (OM) buried in sediments since the Early Precambrian consists mostly of phytoplankton, the main carrier of lipids producing hydrocarbons. Organic matter accumulates in marine sediments according to the law of periodicity. Middle Paleozoic fossilized OM is largely composed of zooplankton. Zooplanktonic OM, classified as sapropelites, had interfered with the process of oil and gas generation since its origin, e.g., tentaculites of the Domanik formation increased oil content. The inception of low-lipid macrophytes gave rise to introduction of humic OM into water bodies and formation of mixed-type OM. The larger the humic component in OM, the higher its gas potential. However, instead of replacing oil generation, enhanced gas generation had come on the scene since the Mesozoic, and their scales were approximately equal. The actual oil/gas ratio in sedimentary basins depends both on phylogenetic factors and on the evolution of each separate basin.