bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of a Biocompatible Copolymer to be Used as Cell Culture Support
Authors: Becerra Natalia , Restrepo Luz Marina , López Betty Lucy 
Published: November 2007

AbstractSummary: N‐isopropylacrylamide (NIPAAm)/butylacrylate (BAc) copolymer was synthesized by emulsion polymerization in order to use it as a cell culture surface for corneal epithelium biosubstitutes. Results showed that the obtained polymers were thermosensitive hydrogels. The copolymer was characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and swelling degree. 3T3 Swiss cells were used as feeder layers and they were used to test the cytotoxic effect of the hydrogels. The conditions to isolate, cultivate, expand and cryo‐preserve human oral mucosal cells were established and analysis of several morphological and immuno‐histochemical characteristics of the cultivated oral mucous were made.
Functionalization of Biodegradable Polyester for Tissue Engineering Applications
Authors: Thiré Rossana M. S. M. , Meiga Taíla O. , Dick Sabrina , Andrade Leonardo R. 
Published: November 2007

AbstractSummary: Chemical modification of polymer surface may potentially be used to create smart materials that can guide cellular adhesion, proliferation and maintenance of specific expression of molecules. The microbial polyester poly (3‐hydroxybutyrate) (PHB) has been attracted attention as promising material for applications in tissue engineering. In this work, a wet‐chemical method, base ethylenediamine aminolysis, was performed to improve the adhesion of chondrocytes isolated from human articular cartilage to PHB films. The effects of chemical treatment on PHB films was evaluated by following changes in morphology and surface chemical composition using atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS), respectively. While the effect on cells morphology was studied by scanning electron microscopy (SEM). The treatment with ethylenediamine did not change significantly the morphology of the structures of PHB films surface. However, the roughness of the aminolyzed films was slightly higher. The introduction of nitrogen‐containing groups was confirmed by XPS. In vitro experiments indicated that the surface modification did not have toxic effects in cells, since they could adhere and proliferate on modified PHB films. It was observed that long‐time treatment improved ability of PHB films to support cell growth, which could be accounted to physicochemical and topological effects.
Monitoring the Interaction of Albumin with a Paclitaxel‐Polymer Conjugate: Complex with Warfarin as Local Probe
Authors: Wunderlich Stefan , Zähres Manfred , Jo Byung‐Wook , Hess Michael 
Published: November 2007

AbstractSummary: We have used warfarin as a local probe to investigate the orientation of paclitaxel and water soluble polymer conjugates of paxlitaxel in albumin. The relative orientation of warfarin and paclitaxel in a 1:1 complex in solution was investigated by 1H‐NMR‐spektroskopy (NOESY) and the results are used for the interpretation of the steric situation of paclitaxel respectively the polymer conjugate in albumin.
Mesoporous Silica Applications
Authors: Giraldo L. F. , López B. L. , Pérez L. , Urrego S. , Sierra L. , Mesa M. 
Published: November 2007

AbstractSummary: The mesoporous silica have been considered fascinating materials for many techonological applications due to their porous and morphological characteristics. This review focuses on their use as stationary phases for liquid chromatography, supports for immobilizing biomolecules, catalysts, agent for polymer reinforcement and hard templates for the preparation of mesoporous carbons.
Stress Cracking and Photodegradation: The Combination of Two Major Causes of HIPS Failure
Authors: Timóteo G.A.V. , Fechine G.J.M. , Rabello M.S. 
Published: November 2007

AbstractSummary: This work investigates the effects of photodegradation on the stress cracking resistance of high impact polystyrene (HIPS). Injection moulded samples were exposed to the ultraviolet light for various times in the laboratory prior to solvent contact. The bars were then stressed with several different loads in a tensile testing machine under the presence of several types of alcohols (mostly butanol). During this period, the stress relaxation was monitored and, after unloading, the ultimate properties were evaluated. Complementary tests were done by size exclusion chromatography, and scanning electron microscopy. The results indicated that both photodegradation and butanol causes significant modification in HIPS properties, with reduction in mechanical properties. The previously degraded samples showed a higher level of stress relaxation and a greater loss in tensile strength in comparison to the undegraded ones. The synergistic action of photodegradation and stress cracking in polystyrene may be a consequence of the chemical changes caused by oxidation and the reduction in molecular sizes.
Effect of Hibiscus anthocyanins‐rich extract induces apoptosis of proliferating smooth muscle cell via activation of P38 MAPK and p53 pathway
Authors: Lo Chia‐Wen , Huang Hui‐Pei , Lin Hui‐Mei , Chien Cheng‐Ting , Wang Chau‐Jong 
Published: November 2007

AbstractHibiscus sabdariffa L. (Malvaceae), an attractive plant believed to be native to Africa, is cultivated in Sudan and in eastern Taiwan. It has been reported to contain a number of protocatechuic acid and anthocyanins. In vitro experimental studies have shown that anthocyanins administration of the extract produces anti‐inflammation and chemoprevention effects. In spite of the wide use of Hibiscus sabdariffa L. in folk medicine for treating various diseases, our previous study indicated a potency of Hibiscus sabdariffa extract (HSE) in anti‐atherosclerosis. The mechanisms of anthocyanins administration of the extract produce from Hibiscus sabdariffa L. to attenuate atherosclerosis were not clarified. In this study, we found that Hibiscus anthocyanins (HAs) could inhibit the serum‐stimulated proliferation of smooth muscle cell (SMC) and result in cell apoptosis. The HAs inducing cell apoptosis was dose dependent. We further used SB203580 (p38 inhibitor) to block cellular apoptosis and evaluate its effect on the HAs‐inducing SMC death via some apoptosis criteria including DNA fragmentation and flow cytometry. We suggested that the mechanisms of the inhibitory effect of HAs on atherosclerosis could be via inhibiting the proliferation of SMC. HAs induces apoptosis via (i) activating p38 MAP kinase that subsequently phosphorylates target protein c‐Jun and transduces the signal to further activate the apoptotic protein cascades that contain Fas‐mediated signaling (Fas/caspase‐8 signaling module) and (ii) activating p53 and inducing bax expression. As an outcome of the events, cytochrome c releases from the mitochondria, leading to cell apoptosis. In these experiments, HAs showed strong potential to induce SMC cell apoptosis via p38 and p53 pathway. In consequence, the rate of atherosclerotic formation is slowed down, and the progress is suppressed.
Comparison of ODE methods for laminar reacting gas flow simulations
Authors: van Veldhuizen S. , Vuik C. , Kleijn C.R. 
Published: November 2007

AbstractTwo‐dimensional transient simulations are presented of the transport phenomena and multispecies, multireaction chemistry in chemical vapor deposition (CVD). The transient simulations are run until steady state, such that the steady state can be validated against the steady state solutions from literature. We compare various time integration methods in terms of efficiency and robustness. Besides stability, which is important due to the stiffness of the problem, preservation of non‐negativity is crucial. It appears that this latter condition on a time integration method is much more restrictive toward the time step size than stability. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
Very low surface recombination velocity of crystalline silicon passivated by phosphorus‐doped a‐SicxNy:H(n) alloys
Authors: Ferre R. , Orpella A. , Munoz D. , Martín I. , Recart F. , Voz C. , Puigdollers J. , Cabarrocas P. Roca i , Alcubilla R. 
Published: November 2007

AbstractHydrogenated and phosphorus‐doped amorphous silicon carbonitride films (a‐SiCxNy:H(n)) were deposited by plasma‐enhanced chemical vapor deposition (PECVD) on crystalline silicon surface in order to explore surface passivation properties. Very silicon‐rich films yielded effective surface recombination velocities at 1 sun‐illumination as low as 3 cm s−1 and 2 cm s−1 on 1 Ω cm p‐ and n‐type crystalline silicon substrates, respectively. In order to use them as anti‐reflection coating, we increased alternatively either the carbon or nitrogen content of these films. Also, a combination of passivation and antireflective films was analyzed. Finally, we explored the passivation stability under high‐temperature steps. Copyright © 2007 John Wiley & Sons, Ltd.
The Effect of Grinding on the Ground Material Flowability
Authors: Grant Evgeny , Kalman Haim , Averbuh Moshe 
Published: November 2007

AbstractIn this paper, attempts have been made for the first time, to experimentally evaluate the transformation, decrease and dissipation of the energy consumed during grinding by measuring the physical, chemical and mechanical properties of the ground material. By using a standard shear tester (Jenike shear cell) the unconfined yield strength and major consolidation stress of the ground material were measured immediately and after a period of storage. Also the solubility rate (ground material in water) of the same materials was defined simultaneously by measuring the electrical conductivity. The new experimental results aid the understanding of the behavior of ground material and may help provide better engineering tools for industrial design. A clear correlation has been found between solubility and flowability. Therefore, the flowability variations can be explained in the same way as the solubility.
Dynamics of Multiple Drive Belt Conveyor Systems
Authors: Nuttall Ashley J. G. , Lodewijks Gabriël 
Published: November 2007

AbstractThis paper investigates the dynamic starting behavior of long multiple drive belt conveyors. By simulating a speed controlled start procedure with a dynamic model, a comparison is made between the starting behavior of a single and a multiple drive layout, with no load on the belt. These simulations are also compared with simulations of a multiple drive layout that is configured for a loaded belt. These results show that a link can be established between the dynamic behavior of the belt sections in a multiple drive belt conveyor and a single driven conveyor system.
Analysis of Dry Bulk Terminals: Chances for Exploration
Authors: Schott Dingena L. , Lodewijks Gabriël 
Published: November 2007

AbstractOver the last ten years, global economic developments have had an increasing influence on supply and demand trend in the dry bulk market. This increase has impacted on the shipping, dry cargo handling, bulk terminal operations and transportation industries. As a result the capacity of bulk handling terminals had to be increased, where on the other hand discussions about environmental regulations and pollution increase.The objective of this paper is to point out several issues to be solved in the near future. It results in an overview and analysis of differences and similarities of the facilities for the handling, storage, and processing of the bulk material.The analysis will be used to set up research projects at the department of Marine and Transport Technology of Delft University of Technology to further investigate the chances and challenges on improving equipment for the storage and transportation of particulate solids as well as their logistics.
Effects of Cyclic Loading and Various Test Conditions in an Uniaxial Tester
Authors: Nysaeter Trude O. , Enstad Gisle G. 
Published: November 2007

AbstractThe effect of cyclic loading during consolidation in an uniaxial tester is investigated. The effect seems to be a reduction of the compressive strength of BCR limestone powder, except for consolidation stresses close to the stress level of the cyclic loading. The larger the consolidation stress level is, the more the compressive strength is reduced compared to standard consolidation without cycling. The velocity of the piston under consolidation, as well as the number of cycles and at what stress level the cycling took place, also affect the compressive strength.
Bulk Solid Interactions in Belt Conveying Systems: Transition Zone
Authors: Ilic Dusan D. , Wheeler Craig A. , Roberts Alan W. 
Published: November 2007

AbstractIn belt conveying systems, bulk solid material immediately prior to discharge moves from a troughed profile on the last idler set to a flat profile at the head pulley. How the bulk solid material behaves in this zone is a function of the material properties of the bulk solid and the transition time, which in turn depends on the transition length and belt speed. The accurate determination of the discharge profile is essential for effective transfer chute design.This paper describes an experimental test rig which aims to simulate the motion of the bulk solid material on the conveyor belt during transportation and throughout the transition zone. Results are presented and compared to existing theoretical approximations.
Investigations of Porosity Changes during Granular Silo Flow Using Electrical Capacitance Tomography (ECT) and Particle Image Velocimetry (PIV)
Authors: Niedostatkiewicz Maciej , Tejchman Jacek 
Published: November 2007

AbstractThe paper presents results of measurements of porosity changes in sand during granular flow in model silos using two different non‐invasive methods, i.e., Electrical Capacitance Tomography (ECT) and Particle Image Velocimetry (PIV). The experiments in model silos are carried out with different initial unit weights of sand and silo wall roughness. Advantages and disadvantages of both methods are outlined.
The Pattern of Fine Comminution Products
Authors: Gente Vincenzo , Giancontieri Vincenzo , La Marca Floriana , Massacci Paolo 
Published: November 2007

AbstractA new approach is suggested for the purposes of obtaining a proper character‐distribution pattern of a particle set. Different methods of modeling the series of size characterization data are examined. Fourier analysis is applied to detail new parameters (features) for enhancing the differences between size distributions under different comminution operating conditions. Size distribution relating to a set of comminuted particles is processed as a signal (size vector) to extract the feature set. The results are compared to provide an insight into the effectiveness of each data analysis method. In particular, some of the Fourier series sine‐coefficient values, relating to the size vector of a particle set, can represent the post‐comminution size‐distribution pattern. For example, size distribution following cryogenic comminution under different temperature conditions can be modeled using a second‐order equation function of four selected Fourier analysis sine coefficients.
A Rotational Tester for the Characterization of Aerated Shear Flow of Powders
Authors: Barletta Diego , Donsì Giorgio , Ferrari Giovanna , Poletto Massimo 
Published: November 2007

AbstractA rotational shear tester for aerated shear flow was built on the work bench of a Peschl shear tester. Measurements with a conventional incipient shear test procedure and a purposely developed dynamic shear test procedure were carried out on two different cohesive powders: a magnesium carbonate powder and a silica powder. Permeability measurements were carried out in the dynamic shear test experiments to assess the effect of shearing. The results obtained at low powder consolidation levels confirm literature findings at higher degrees of consolidation. In particular, aeration does not appear to have the ability to change the rheological properties of the powder. Shear test results at different aeration intensities are the same if the stress changes induced by aeration on the shear plane are correctly accounted for. Permeability measurements were compared following uniaxial powder compaction and shearing powder compaction experiments. The internal powder structure of the magnesium carbonate powder appeared to change between experiments. Further investigations are required to determine if this change also occurs with the silica powder.
Investigation of Heat and Moisture Effects in Silos Containing Agricultural Bulk Solids
Authors: Prusiel Jolanta A. , Lapko Andrzej 
Published: November 2007

AbstractThis paper presents the results of experimental and theoretical analyses concerning thermal and moisture effects on a model cylindrical silo. The experimental studies were conducted on a thin‐walled cylindrical silo model bin of diameter 800 mm and total depth 2500 mm, filled with mustard seeds. For the purposes of modeling thermal changes in the particles, the external surface of the model silo bin was exposed to heating by electrical wires and then allowed to cool naturally, before filling the bin. The experimental results were compared with the numerical simulation results performed on the basis of equations of coupled heat and moisture transfer in the particulate solid and concrete wall, with the use of experimentally determined bulk solid properties.
2D‐Fractal Based Algorithms for Fine and Ultrafine Particulate Solids Systems Characterization
Authors: Bonifazi Giuseppe 
Published: November 2007

AbstractFractal geometry concerns the study of non‐Euclidean geometrical figures generated by a recursive sequence of mathematical operations. The proposed 2D‐fractal approach was applied to characterise the image structure and texture generated by fine and ultrafine particles when impacting on a flat surface. The work was developed with reference to particles usually produced in the ornamental stone sector during the different working phases carried out in dry conditions. Specific milling actions have been performed at a laboratoty scale on different ornamental stone products, in order to generate different particle populations to utilize in the study. The aim of the work was to develop a simple, reliable and low cost analytical set of procedures with the ability to establish correlations between particles detected by fractal characteristics and their classical attributes, e.g., i) size class distribution, ii) shape, iii) composition, etc. Such a logic should constitute the core of a control engine with the ability to optimize dust capture abatement strategies, according to produced dusts characteristics.
Effect of the Mineral Filler on the Surface Properties of Co‐Ground Polymeric Composites
Authors: Zapata‐Massot Céline , Le Bolay Nadine 
Published: November 2007

AbstractThis study presents results on the influence of the nature of the filler on the surface properties of polymeric composites produced by co‐grinding in a tumbling ball mill. The polymer used in the study was poly(vinyl acetate) which is a model material, while two mineral fillers were tested, i.e., calcium carbonate and silica. The variations of the surface properties of the separately ground and co‐ground materials were studied for different grinding times, using the sessile drop method, and the properties were compared to those of matrix‐filler blends. The different components of the surface energy were determined by Van Oss decomposition. Grinding generates a large change of the particle surface and especially of the Lewis acid‐base energy. These changes depend on the filler nature. In addition, particle agglomeration may be due to an electronic deficit at the particle surface, which is immediately replaced by another particle also possessing an electronic deficit.
Generalization of cluster treatment of characteristic roots for robust stability of multiple time‐delayed systems
Authors: Sipahi Rifat , Fazelinia Hassan , Olgac Nejat 
Published: November 2007

AbstractA new perspective is presented for studying the stability robustness of nth order systems with p rationally independent delays. It deploys a holographic mapping procedure over the delay space into a new coordinate system in order to achieve the objective. This mapping collapses the entire set of potential stability switching points on a manageably small number of hypersurfaces, which are explicitly defined in the new domain. This property considerably alleviates the problem, which is otherwise infinite dimensional, and therefore notoriously complex to handle. We further declare some unrecognized features of these switching hypersurfaces, that they are (a) encapsulated within a higher‐dimensional cube with edges of length 2π, which we name the ‘building block’, and (b) the ‘offspring’ of this building block, which represent the secondary stability switchings, appear within the adjacent and identical building blocks (cubes) stacked up next to each other. The final outlook is an exclusive representation of stability for this general class of systems at any arbitrary point in the delay space. Two example case studies are also provided, which are not possible to analyze using any other methodology known to the authors. Copyright © 2007 John Wiley & Sons, Ltd.
Stable, High‐Efficiency Ionic‐Liquid‐Based Mesoscopic Dye‐Sensitized Solar Cells
Authors: Kuang Daibin , Klein Cedric , Zhang Zhipan , Ito Seigo , Moser Jacques‐E. , Zakeeruddin Shaik. M. , Grätzel Michael 
Published: November 2007

AbstractEfficient and stable mesoscopic dye‐sensitized solar cells (DSCs) introducing a low‐viscosity binary ionic liquid (1‐propyl‐3‐methyl‐imidazolium iodide (PMII) and 1‐ethyl‐3‐methyl‐imidazolium tetracyanoborate (EMIB(CN)4)) electrolyte in combination with a new high‐molar‐extinction‐coefficient ruthenium complex, Ru(2,2′‐bipyridine‐4,4′‐dicarboxylic acid)(4,4′‐bis(2‐(4‐tert‐butyloxy ‐phenyl)ethenyl) −2,2′‐bipyridine) (NCS)2, are demonstrated. The dependence of photovoltaic performance, charge transport and electron lifetime on the composition of the binary ionic‐liquid electrolyte with different ratios of PMII/EMIB(CN)4 were investigated by electrochemical impedance and photovoltage transient techniques. A photovoltaic conversion efficiency of 7.6 % was obtained under simulated full sunlight illumination, which is a record for solvent‐free DSCs. These devices exhibit excellent stability at 80 °C in the dark or under visible‐light soaking at 60 °C during 1000 h of accelerated tests.
Technology Transfer and IPR Policy for Small and Medium Firms in South‐East Asia
1
Authors: Macdonald Stuart , Turpin Tim 
Published: November 2007

Abstract
In theory, small and medium firms have much to gain from the intellectual property rights system: in practice, SMEs have trouble using the IPR system. Yet the developing world is encouraged by the developed to look to IPR to make its SMEs more innovative and hence competitive. If SMEs are to make effective use of IPR, it must be within their existing business strategy. For them, copying may be a more appropriate and successful form of technology transfer than licensing IPR from developed countries.