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Showing papers by "University of Patras published in 2005"


Journal ArticleDOI
TL;DR: In the ICCP System 1994, the maceral group huminite has been revised from the previous classification (ICCP, 1971) to accommodate the nomenclature to changes in the other maceral groups.

688 citations


Journal ArticleDOI
TL;DR: In this paper, the influence of the preparation method on the physicochemical and catalytic properties of CuO-CeO2 catalysts for the selective CO oxidation in simulated reformate gas was reported.
Abstract: In this work we report on the influence of the preparation method on the physicochemical and catalytic properties of CuO–CeO2 catalysts for the selective CO oxidation in simulated reformate gas. Four CuO–CeO2 samples were prepared using the co-precipitation, the citrate-hydrothermal, the urea-nitrates combustion, and the impregnation methods, and characterized by N2 adsorption–desorption, X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction by H2 (TPR-H2). The combustion-prepared sample exhibited the best catalytic performance, closely followed by that prepared with the citrate-hydrothermal method. The co-precipitated sample was less active followed by the impregnated one. The activity of all samples decreases in the presence of CO2 and, to a higher degree, in the simultaneous presence of both CO2 and H2O in the feed. The resistance to this deactivation was higher in the case of the sample prepared by the urea-nitrates combustion method, which remained the most active and selective, closely followed by the specimen prepared by the citrate-hydrothermal method. The superior catalytic performance of the samples prepared by the urea-nitrates combustion and the citrate-hydrothermal methods is attributed to the existence of well dispersed, strongly interacting with the ceria surface, copper oxide species.

386 citations


Journal ArticleDOI
TL;DR: The application of textile reinforced mortar (TRM) as a means of increasing the shear resistance of reinforced concrete members is investigated in this article, where it is concluded that textile-mortar jacketing provides substantial gain in shear resilience; this gain is higher as the number of layers increases and is sufficient to transform shear type failure to flexural failure.
Abstract: The application of textile reinforced mortar (TRM) as a means of increasing the shear resistance of reinforced concrete members is investigated in this study. TRM may be considered as an alternative to fiber reinforced polymers (FRP), providing solutions to many of the problems associated with application of the latter without compromising much the performance of strengthened members. Based on the experimental response of reinforced concrete members strengthened in shear it is concluded that textile-mortar jacketing provides substantial gain in shear resistance; this gain is higher as the number of layers increases and, depending on the number of layers, is sufficient to transform shear-type failure to flexural failure. TRM jackets were provided in this study either by conventional wrapping of fabrics or by helically applied strips. Both systems resulted in excellent results in terms of increasing the shear resistance. However, compared with their resin-impregnated counterparts, mortar-impregnated textiles may result in reduced effectiveness. Modelling of reinforced concrete members strengthened in shear with TRM jackets instead of FRP ones is presented by the authors as a rather straightforward procedure by the proper introduction of experimentally derived jacket effectiveness coefficients. From the limited results obtained in this study it is believed that TRM jacketing is an extremely promising solution for increasing the shear resistance of reinforced concrete members.

322 citations


Journal ArticleDOI
TL;DR: Major differences in the mobility of the six pharmaceuticals were observed and correlated with the adsorption/desorption properties of the compounds, including Ofloxacin, which was particularly strongly adsorbed while clofibric acid was found to be weakly Adsorbed.

288 citations


Journal ArticleDOI
07 Jan 2005-Science
TL;DR: This study revealed that deep hypersaline anoxic basins in the Mediterranean Sea are not biogeochemical dead ends, but support in situ sulfate reduction, methanogenesis, and heterotrophic activity, and demonstrated the presence of a unique, metabolically active microbial community in the Discovery basin.
Abstract: Deep hypersaline anoxic basins in the Mediterranean Sea are a legacy of dissolution of ancient subterranean salt deposits from the Miocene period. Our study revealed that these hypersaline basins are not biogeochemical dead ends, but support in situ sulfate reduction, methanogenesis, and heterotrophic activity. A wide diversity of prokaryotes was observed, including a new, abundant, deeply branching order within the Euryarchaeota. Furthermore, we demonstrated the presence of a unique, metabolically active microbial community in the Discovery basin, which is one of the most extreme terrestrial saline environments known, as it is almost saturated with MgCl2 (5 M).

285 citations


Proceedings Article
30 Aug 2005
TL;DR: KLEE makes a strong case for approximate top-k algorithms over widely distributed data sources and can achieve major performance gains in terms of network bandwidth, query response times, and much lighter peer loads, all with small errors in result precision and other result-quality measures.
Abstract: This paper addresses the efficient processing of top-k queries in wide-area distributed data repositories where the index lists for the attribute values (or text terms) of a query are distributed across a number of data peers and the computational costs include network latency, bandwidth consumption, and local peer work. We present KLEE, a novel algorithmic framework for distributed top-k queries, designed for high performance and flexibility. KLEE makes a strong case for approximate top-k algorithms over widely distributed data sources. It shows how great gains in efficiency can be enjoyed at low result-quality penalties. Further, KLEE affords the query-initiating peer the flexibility to trade-off result quality and expected performance and to trade-off the number of communication phases engaged during query execution versus network bandwidth performance. We have implemented KLEE and related algorithms and conducted a comprehensive performance evaluation. Our evaluation employed real-world and synthetic large, web-data collections, and query benchmarks. Our experimental results show that KLEE can achieve major performance gains in terms of network bandwidth, query response times, and much lighter peer loads, all with small errors in result precision and other result-quality measures.

250 citations


Book ChapterDOI
27 Aug 2005
TL;DR: A penalty function approach is employed and the algorithm is modified to preserve feasibility of the encountered solutions to investigate the performance of the recently proposed Unified Particle Swarm Optimization method on constrained engineering optimization problems.
Abstract: We investigate the performance of the recently proposed Unified Particle Swarm Optimization method on constrained engineering optimization problems. For this purpose, a penalty function approach is employed and the algorithm is modified to preserve feasibility of the encountered solutions. The algorithm is illustrated on four well–known engineering problems with promising results. Comparisons with the standard local and global variant of Particle Swarm Optimization are reported and discussed.

237 citations


Journal ArticleDOI
TL;DR: It is concluded that Ang-2 by itself stimulates the extravasation of cell-poor fluid, but in the presence of ongoing inflammation it reduces cellular infiltration in tissues.
Abstract: Angiopoietins (Angs) are endothelium-selective ligands that exert most of their actions through the Tie-2 receptor. It is widely accepted that Ang-1 promotes the structural integrity of blood vessels and exhibits anti-inflammatory properties. In contrast, the role of Ang-2 remains less clear because it has been shown to behave as a Tie-2 agonist or antagonist under different experimental conditions. To define the role of Ang-2 in acute inflammation, we studied the effects of recombinant Ang-2 administration in vivo. We show herein that Ang-2, but not Ang-1, induces edema formation in the mouse paw in a dose-dependent manner; the edema seems to be fast-peaking (maximum at 30 min) and resolves within 4 h. The effect of Ang-2 is blocked by the coadministration with a soluble form of the Tie-2 receptor or Ang-1. NO and prostaglandin E 2 levels in mouse paw following the injection of Ang-2 remained unaltered, suggesting that the action of Ang-2 does not involve these mediators. In addition, Ang-2 exerted a weak stimulatory effect on leukocyte migration in the mouse paw. Similarly, Ang-2 injected into the mouse air pouch produced only a modest effect on cell extravasation that peaked at 30 min. However, when cell migration was elicited using zymosan, Ang-2 significantly inhibited leukocyte migration. We conclude that Ang-2 by itself stimulates the extravasation of cell-poor fluid, but in the presence of ongoing inflammation it reduces cellular infiltration in tissues.

231 citations


Journal ArticleDOI
TL;DR: This paper proposes an architecture that promotes model integration not only for implementation space artifacts but also in artifacts of the early analysis and design phases of the development process, which promotes reuse and significantly decreases development and validation time.
Abstract: The traditional approach for the development of manufacturing systems considers the constituent parts of the system, i.e., mechanical, electronic, and software, to be developed independently and then integrated to form the final system. This approach is being criticized as inappropriate for the complexity and the dynamics of today's systems. This paper proposes an architecture that promotes model integration not only for implementation space artifacts but also in artifacts of the early analysis and design phases of the development process. The proposed architecture, which promotes reuse and significantly decreases development and validation time, is at the heart of a new paradigm called model-integrated mechatronics (MIM). MIM applies domain-specific modeling languages for the concurrent engineering of mechanical, electronic and software components of mechatronic systems. It simplifies the integrated development process of manufacturing systems by using as basic construct the mechatronic component. The MIM paradigm was utilized to define "Archimedes," a system platform that supports the engineer through a methodology, a framework, and a set of tools to automate the development process of agile mechatronic manufacturing systems.

215 citations


Journal ArticleDOI
TL;DR: Results from an experimental study concerning wave propagation in cementitious materials show that aggregate content play an important role in wave propagation increasing considerably the wave velocity, while the aggregate size seems to control the attenuation observed.

212 citations


Journal ArticleDOI
TL;DR: Patients with mEOC have significantly lower response to first-line platinum-based chemotherapy compared to patients with sEOC, indicating that a new strategy for chemotherapy in mE OC should be adopted, one that focuses on new agents without cross-resistance to platinum agents.

Journal ArticleDOI
TL;DR: It was found that sulfamethoxazole serves both as carbon and nitrogen source for the enriched consortium and was degraded whenever there was a depletion of carbon or nitrogen or both in the feeding medium, while in the presence of acetate and ammonium nitrogen, it remained intact.

Journal ArticleDOI
TL;DR: A new set of artificial structures which can exhibit a negative refractive index band in excess of 6% in a broad frequency range from the deep infrared to the terahertz region are presented.
Abstract: We present a new set of artificial structures which can exhibit a negative refractive index band in excess of 6% in a broad frequency range from the deep infrared to the terahertz region. The structures are composites of two different kinds of non-overlapping spheres, one made from inherently non-magnetic polaritonic and the other from a Drude-like material. The polaritonic spheres are responsible for the existence of negative effective magnetic permeability whils tt he Drude-like spheres are responsible for negative effective electric permittivity. The resulting negative refractive index structures are truly subwavelength structures with wavelength-to-structure ratio 14:1, which is almost 50% higher than has been previously achieved. Our results are explained in the context of the extended Maxwell–Garnett theory and are reproduced by calculations based on the layer Korringa–Kohn–Rostoker method, an ab initio multiple scattering theory. The role of absorption in the constituent materials is discussed. Effective medium computer F77 code is freely available at http://www.wave-scattering.com

Journal ArticleDOI
TL;DR: In this paper, an atomistic modeling approach is presented for simulating the interface between a polymer melt and a crystalline solid substrate, where a thin film of polyethylene (PE) melt confined between a semi-infinite graphite phase on the one side and vacuum on the other is considered.
Abstract: An atomistic modeling approach is presented for simulating the interface between a polymer melt and a crystalline solid substrate. As a test case, a thin film of polyethylene (PE) melt confined between a semiinfinite graphite phase on the one side and vacuum on the other is considered. The simulation is carried out in the NPT statistical ensemble with an efficient Monte Carlo (MC) algorithm based on state-of-the-art variable connectivity moves. The atomistic simulations are conducted by describing the PE chains with a united atom model, which considers each methylene (CH2) and methyl (CH3) group along the chain backbone as single interaction sites. To calculate the potential energy of interaction between polymer atoms and the semiinfinite graphite substrate, the method designed by Steele was implemented, capable of incorporating the exact crystallographic structure of graphite. The new approach has allowed us to analyze structural and conformational properties on the length scale of just a few angstroms f...

Journal ArticleDOI
TL;DR: In this paper, an extensive study on water-cooled photovoltaic/thermal (PV/T) solar systems has been conducted at the University of Patras, where hybrid prototypes have been experimentally studied.
Abstract: Hybrid photovoltaic/thermal (PV/T) solar systems provide a simultaneous conversion of solar radiation into electricity and heat. In these devices, the PV modules are mounted together with heat recovery units, by which a circulating fluid allows one to cool them down during their operation. An extensive study on water-cooled PV/T solar systems has been conducted at the University of Patras, where hybrid prototypes have been experimentally studied. In this paper the electrical and thermal efficiencies are given and the annual energy output under the weather conditions of Patras is calculated for horizontal and tilted building roof installation. In addition, the costs of all system parts are included and the cost payback time is estimated. Finally, the methodology of life cycle assessment (LCA) has been applied to perform an energy and environmental assessment of the analysed system. The goal of this study, carried out at the University of Rome ‘La Sapienza’ by means of SimaPro 5·1 software, was to verify the benefits of heat recovery. The concepts and results of this work on energy performance, economic aspects and LCA results of modified PV and water-cooled PV/T solar systems, give a clear idea of their application advantages. From the results, the most important conclusion is that PV/T systems are cost effective and of better environmental impact compared with standard PV modules. Copyright © 2005 John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: Vitamin E supplementation in cancer patients may have an important neuroprotective effect, according to a pilot, randomized, open label with blind assessment, controlled trial to determine whether vitamin E supplementation has a neuroprot protective effect in chemotherapy-induced peripheral nerve damage.
Abstract: Background: The authors conducted a pilot, randomized, open label with blind assessment, controlled trial to determine whether vitamin E supplementation has a neuroprotective effect in chemotherapy-induced peripheral nerve damage. Methods: Thirty-one patients with cancer treated with six courses of cumulative cisplatin, paclitaxel, or their combination regimens were randomly assigned in two groups and followed by neurologic examination and electrophysiologic study. Patients assigned in Group I (n = 16) received oral vitamin E at a daily dose of 600 mg/day during chemotherapy and 3 months after its cessation were compared to patients of Group II (n = 15), who received no supplementation and served as controls. The severity of neurotoxicity was summarized by means of a modified peripheral neuropathy score. Results: The incidence of neurotoxicity differed between the two groups, occurring in 4/16 (25%) patients assigned in the vitamin E supplementation group and in 11/15 (73.3%) patients assigned in the control group ( p = 0.019). Mean peripheral neuropathy scores were 3.4 ± 6.3 for patients of Group I and 11.5 ± 10.6 for patients of Group II ( p = 0.026). The relative risk (RR) of developing neurotoxicity was significantly higher in case of control patients, RR = 0.34, 95% CI = 0.14 to 0.84. Conclusion: Vitamin E supplementation in cancer patients may have an important neuroprotective effect.

Proceedings ArticleDOI
19 Sep 2005
TL;DR: A review of mobile applications used in museum environments, focusing on the notion of context and its constituent dimensions, and argues that these results can be useful in other kinds of applications, in which the impact of context is not taken for granted.
Abstract: This paper includes a review of mobile applications used in museum environments, focusing on the notion of context and its constituent dimensions Museums are a representative example in which the context influences interaction During a museum visit, the visitors interact with the exhibits through mobile devices We argue that, effective interaction design needs to take into consideration multiple dimensions of the context Since context is often misinterpreted, superficially used or poorly defined, we attempt to analyze a number of existing mobile applications used in museum environments, through this perspective The point of analysis is to evaluate those applications against various context dimensions We argue that these results can be useful in other kinds of applications, in which the impact of context is not taken for granted

Journal ArticleDOI
TL;DR: In this article, an analytical calculation method is presented, which can be used to determine the multipath components of any point-to-point channel in the indoor power-line environment.
Abstract: The time- and frequency-varying behavior of an indoor power-line network is the result of variable impedance loads connected to its termination points In fact, any signal transmitted through such a communications network is subject to time-varying multipath fading In this paper, an analytical calculation method is presented, which can be used to determine the multipath components of any point-to-point channel in the indoor power-line environment The method calculates all transmission characteristics of the network and, therefore, it can be exploited in the process of designing proper transmission algorithms for optimizing system performance The proposed method is applied to an example network to demonstrate its usefulness in explaining the network's time-dependent behavior and in estimating channel parameters, such as subchannel bandwidth, multipath delay spread, fading conditions, etc

Journal ArticleDOI
TL;DR: In this article, molecular dynamics simulations have been performed on a dense polymer melt adsorbed on a solid substrate on the one side and exposed to vacuum on the other, and the MD simulation data have been analyzed to provide information about the spatial dependence of the short-time dynamical properties (conformational relaxation) o...
Abstract: Molecular dynamics (MD) simulations have been performed on a dense polymer melt adsorbed on a solid substrate on the one side and exposed to vacuum on the other. As a model system, a thin film of polyethylene (PE) melt supported by a crystalline graphite phase on its one side (the other surface of the film is free) has been examined. Most simulations have been carried out with unentangled PE melt systems, such as C78 and C156, in the NPT statistical ensemble at T = 450 K and P = 0 atm for times up to 100 ns, using a multiple-time step MD algorithm and by incorporating the correct dependence of the long-range contribution to the energy and stress tensor on the density profile. To increase the statistical accuracy of the results, large systems have been employed in the MD simulations, such as a 200-chain C78 melt consisting of 15 600 carbon atoms. The MD simulation data have been analyzed to provide information about the spatial dependence of the short-time dynamical properties (conformational relaxation) o...

Journal ArticleDOI
01 Jul 2005
TL;DR: A new learning algorithm for Fuzzy Cognitive Maps, which is based on the application of a swarm intelligence algorithm, namely Particle Swarm Optimization, is introduced, which overcomes some deficiencies of other learning algorithms and improves the efficiency and robustness of FuzzY Cognitive Maps.
Abstract: This paper introduces a new learning algorithm for Fuzzy Cognitive Maps, which is based on the application of a swarm intelligence algorithm, namely Particle Swarm Optimization. The proposed approach is applied to detect weight matrices that lead the Fuzzy Cognitive Map to desired steady states, thereby refining the initial weight approximation provided by the experts. This is performed through the minimization of a properly defined objective function. This novel method overcomes some deficiencies of other learning algorithms and, thus, improves the efficiency and robustness of Fuzzy Cognitive Maps. The operation of the new method is illustrated on an industrial process control problem, and the obtained simulation results support the claim that it is robust and efficient.

Journal ArticleDOI
TL;DR: In this article, the authors examine the range of information consumers seek on labels of quality products and construct an indicative check-list of various types of informational labeling as well as examine whether quality of information demanded segregates the market creating segments to be targeted by firms.
Abstract: Purpose – The purpose of this work is to examine the range of information consumers seek on labels of quality products and construct an indicative check‐list of various types of informational labeling as well as to examine whether quality of information demanded segregates the market‐creating segments to be targeted by firms.Design/methodology/approach – An extensive interdisciplinary literature review based on findings in marketing, economics, geography and sociology reveals the often neglected range of factors forcing consumers to place importance on regionally denominated food and drink. The European Union (EU) has responded to growing consumer trends towards regional and traditional food and established special schemes regulating the production of such food and drink. A survey of 640 consumers of quality wine carried out within the framework of an EU‐funded program provides the empirical material of this work.Findings – The study records the range of informational labeling sought by consumers as well ...

Journal ArticleDOI
TL;DR: In this paper, the authors present a numerical investigation on the seismic response of multidrum classical columns and conclude that typical multi-rum columns can survive the ground shaking from strong ground motions recorded near the causative faults of earthquakes with magnitudes M w = 6.0-7.4.
Abstract: This paper presents a numerical investigation on the seismic response of multidrum classical columns. The motivation for this study originates from the need to understand: (a) the level of ground shaking that classical multidrum columns can survive, and (b) the possible advantages or disadvantages of retrofitting multidrum columns with metallic shear links that replace the wooden poles that were installed in ancient times. The numerical study presented in this paper is conducted with the commercially available software Working Model 2D, which can capture with fidelity the sliding, rocking, and slide-rocking response of rigid-body assemblies. This paper validates the software Working Model by comparing selected computed responses with scarce analytical solutions and the results from in-house numerical codes initially developed at the University of California, Berkeley, to study the seismic response of electrical transformers and heavy laboratory equipment. The study reveals that relative sliding between drums happens even when the g-value of the ground acceleration is less than the coefficient of friction, μ, of the sliding interfaces and concludes that: (a) typical multidrum classical columns can survive the ground shaking from strong ground motions recorded near the causative faults of earthquakes with magnitudes M w =6.0-7.4; (b) in most cases multidrum classical columns free to dislocate at the drum interfaces exhibit more controlled seismic response than the monolithic columns with same size and slenderness; (c) the shear strength of the wooden poles has a marginal effect on the sliding response of the drums; and (d) stiff metallic shear links in-between column drums may have an undesirable role on the seismic stability of classical columns and should be avoided.

Journal ArticleDOI
TL;DR: The results revealed: higher Pb concentration in the samples from urban areas; effect of smoking on Cu level; dietary habits seem to play a role in metal levels in human milk as the logistic regression models revealed.

Journal ArticleDOI
TL;DR: Simulation results in six problems of the PROBEN1 benchmark collection show that the globally convergent modification of the Rprop algorithm exhibits improved learning speed, and compares favorably against the original Rprop and the Improved Rprop, a recently proposed Rrpop modification.

Journal ArticleDOI
TL;DR: The AMBI remains the gold standard for the fractures of trochanteric region, TGN has an easier and faster procedure, facilitates early weight bearing and had minor late complications, while PFN is also an accepted minimally invasive implant for unstable proximal femoral fractures but future modification of the implant should reduce its high complication rate.
Abstract: Introduction: In this study, we initiated a prospective, randomised, clinical trial comparing the AMBI, TGN and PFN operations used for treatment of unstable fractures, for differences in intra-operative use, consolidation, complications and functional outcome. Materials and methods: We have compared the pre-, intra- and post-operating variables of AMBI, TGN and PFN operations that were used for treatment of unstable trochanteric fractures, of 120 patients all above 60 years old diagnosed with extracapsular hip fractures classified as AO Type 31-A2 or Type 31-A3. Results: According to our results the three methods are comparable in the treatment of unstable trochanteric fractures of patients above 60 years old. Conclusion: The AMBI remains the gold standard for the fractures of trochanteric region. TGN has an easier and faster procedure, facilitates early weight bearing and had minor late complications. An improper use of the PFN system was the reason for the most complications and the longer operation time of the device. PFN is also an accepted minimally invasive implant for unstable proximal femoral fractures but future modification of the implant to avoid Z-effect phenomenon, careful surgical technique and selection of the patients should reduce its high complication rate.

Journal ArticleDOI
TL;DR: This paper addresses issues that arise in copyright protection systems of digital images, which employ blind watermark verification structures in the discrete cosine transform (DCT) domain, by designing a new processor for blind watermarks detection using the Cauchy member of the alpha-stable family.
Abstract: This paper addresses issues that arise in copyright protection systems of digital images, which employ blind watermark verification structures in the discrete cosine transform (DCT) domain. First, we observe that statistical distributions with heavy algebraic tails, such as the alpha-stable family, are in many cases more accurate modeling tools for the DCT coefficients of JPEG-analyzed images than families with exponential tails such as the generalized Gaussian. Motivated by our modeling results, we then design a new processor for blind watermark detection using the Cauchy member of the alpha-stable family. The Cauchy distribution is chosen because it is the only non-Gaussian symmetric alpha-stable distribution that exists in closed form and also because it leads to the design of a nearly optimum detector with robust detection performance. We analyze the performance of the new detector in terms of the associated probabilities of detection and false alarm and we compare it to the performance of the generalized Gaussian detector by performing experiments with various test images.

Journal ArticleDOI
01 Jul 2005
TL;DR: A novel hybrid method based on evolutionary computation techniques is presented in this paper for training Fuzzy Cognitive Maps, and results suggest that the hybrid strategy is capable to train FCM effectively leading the system to desired states and determining an appropriate weight matrix for each specific problem.
Abstract: A novel hybrid method based on evolutionary computation techniques is presented in this paper for training Fuzzy Cognitive Maps. Fuzzy Cognitive Maps is a soft computing technique for modeling complex systems, which combines the synergistic theories of neural networks and fuzzy logic. The methodology of developing Fuzzy Cognitive Maps relies on human expert experience and knowledge, but still exhibits weaknesses in utilization of learning methods and algorithmic background. For this purpose, we investigate a coupling of differential evolution algorithm and unsupervised Hebbian learning algorithm, using both the global search capabilities of Evolutionary strategies and the effectiveness of the nonlinear Hebbian learning rule. The use of differential evolution algorithm is related to the concept of evolution of a number of individuals from generation to generation and that of nonlinear Hebbian rule to the concept of adaptation to the environment by learning. The hybrid algorithm is introduced, presented and applied successfully in real-world problems, from chemical industry and medicine. Experimental results suggest that the hybrid strategy is capable to train FCM effectively leading the system to desired states and determining an appropriate weight matrix for each specific problem.

Journal ArticleDOI
30 Aug 2005-Langmuir
TL;DR: It has been found that adsorption of AO7 on the TiO(2) surface occurs to a significant extent only at pH values lower than 7, via the sulfonic group of the azo-dye, through the formation of a bidentate innersphere surface complex.
Abstract: The adsorption of a model textile azo-dye, Acid Orange 7 (AO7), on the surface of titanium dioxide was extensively investigated in aqueous TiO(2) suspensions over wide ranges of AO7 concentrations (1 x 10(-4)-3 x 10(-3) M) and pH values (2-10). Results obtained with the use of a variety of techniques, including potentiometric titrations, adsorption isotherms, adsorption edges, and microelectrophoresis, were used for the description of the "AO7 solution/TiO(2) surface" interface. This has been achieved by taking into account the effects of pH on the speciation of the dye in solution and on the nature and population of the surface groups of TiO(2). Results could be modeled very well with the use of the recently introduced CD-MUSIC approach. According to the model employed, the TiO(2) surface is not considered homogeneous but is characterized by the presence of different types of surface groups, namely singly (TiOH(-1/3)), doubly (Ti(2)O(-2/3)), and triply (Ti(3)O(0)) coordinated. Surface complexes are not treated as point charges, but their charge is spatially distributed in the interfacial region. It has been found that adsorption of AO7 on the TiO(2) surface occurs to a significant extent only at pH values lower than 7, via the sulfonic group of the azo-dye, through the formation of a bidentate innersphere surface complex. The determination of the adsorption mode of TiO(2), which is supported by ex situ FTIR results, as well as of the adsorption constant, K(ads), allowed the description of the pH dependency of the AO7 adsorption over large pH and AO7 concentration ranges.

Journal ArticleDOI
TL;DR: In this paper, the specific barrier model has been implemented in the stochastic method and calibrated with extended databases of response spectral amplitudes from earthquakes of intraplate regions (mainly east-ern North America events), interplate regions, and regions of tectonic extension.
Abstract: The specific barrier model, proposed and developed by Papageorgiou and Aki (1983a,b; 1985) provides the most complete, yet parsimonious, self-consis- tent description of the faulting process. It applies both in the "near-fault" and in the "far-field" region, thus allowing for consistent ground-motion simulations over the entire frequency range and for all distances of engineering interest. The model has been implemented in the stochastic method and calibrated with extended databases of response spectral amplitudes from earthquakes of intraplate regions (mainly east- ern North America events), interplate regions, and regions of tectonic extension (Spu- dich et al., 1999, database). The ensemble average value of a key parameter of the specific barrier model, the local stress drop Dr L ,i s� 161 bars for interplate earth- quakes, � 114 bars for extensional regime earthquakes, and � 180 bars for intraplate earthquakes. The high-frequency source spectral levels of interplate and extensional regime earthquakes deviate significantly from self-similar scaling. The deviation is most likely caused by the "effective" source area and/or irregularities in the rupture kinematics. We account for their overall effects through a high-frequency source complexity factor, f, in the source spectrum of the specific barrier model. As a result, inter- and intraplate source spectra show similar high-frequency levels at moderate magnitudes but intraplate earthquakes have higher spectral levels at the larger mag- nitudes. The interplate soil residuals show clear signs of nonlinear site response, whereas only slight signs of such nonlinearity are observed for the extensional data- set. The regional models calibrated in this study are in reasonably good agreement with other regional attenuation relationships and provide a reliable and physically realistic, yet computationally efficient, way to model strong ground motions with implications for seismic hazard and risk analysis. Online material: Strong-motion station and event-station pair information.

Journal ArticleDOI
TL;DR: In this article, Lactobacillus casei cells were immobilized on fruit (apple and quince) pieces separately and the immobilized biocatalysts were used for 15 successive fermentation batches of whey immediately after their preparation and for fermentations of milk after a long storage period at low temperature.