bluuebunny/crossref_metadata_2025_split huggingface dataset:
Active sensing using impedance‐based ARX models and extreme value statistics for damage detection
Authors: Fasel Timothy R. , Sohn Hoon , Park Gyuhae , Farrar Charles R. 
Published: January 2005

AbstractIn this paper, the applicability of an auto‐regressive model with exogenous inputs (ARX) in the frequency domain to structural health monitoring (SHM) is established. Damage sensitive features that explicitly consider non‐linear system input/output relationships are extracted from the ARX model. Furthermore, because of the non‐Gaussian nature of the extracted features, Extreme Value Statistics (EVS) is employed to develop a robust damage classifier. EVS provides superior performance to standard statistical methods because the data of interest are in the tails (extremes) of the damage sensitive feature distribution. The suitability of the ARX model, combined with EVS, to non‐linear damage detection is demonstrated using vibration data obtained from a laboratory experiment of a three‐story building model. It is found that the vibration‐based method, while able to discern when damage is present in the structure, is unable to localize the damage to a particular joint. An impedance‐based active sensing method using piezoelectric (PZT) material as both an actuator and a sensor is then investigated as an alternative solution to the problem of damage localization. Copyright © 2005 John Wiley & Sons, Ltd.
Challenge of CIP as a universal solver for solid, liquid and gas
Authors: Yabe T. , Takizawa K. , Chino M. , Imai M. , Chu C. C. 
Published: January 2005

AbstractWe review some recent progress of the CIP method that is known as a general numerical solver for solid, liquid, gas and plasmas. This method is a kind of semi‐Lagrangian scheme and has been extended to treat incompressible flow in the framework of compressible fluid. Since it uses primitive Euler representation, it is suitable for multi‐phase analysis. Some applications to skimmer, swimming fish and laser cutting are presented. This method is recently extended to almost mesh‐free system that is called ‘soroban grid’ that ensures the third‐order accuracy both in time and space with the help of the CIP method. Copyright © 2005 John Wiley & Sons, Ltd.
Multidimensional positive definite advection transport algorithm (MPDATA): an edge‐based unstructured‐data formulation
Authors: Smolarkiewicz Piotr K. , Szmelter Joanna 
Published: January 2005

AbstractWe report a new development in the area of non‐oscillatory transport methods. We derive, discuss, and test the iterative upwind scheme MPDATA in the Finite Volume framework with the edge‐based data structure and arbitrary hybrid mesh. MPDATA has proven successful in simulations of geophysical flows using single block, structured cuboidal meshes, while employing continuous invertible mappings to accommodate time‐dependent curvilinear domains. Our motivation for the finite‐volume formulation and the choice of unstructured meshes is to facilitate the use of MPDATA schemes for a wider range of applications involving complex geometries and/or inhomogeneous anisotropic flows, where mesh adaptivity is advantageous. Our development preserves the signature benefits of the standard Cartesian‐mesh MPDATA scheme, i.e. the second‐order accuracy, sign‐preservation, and a full multidimensionality free of directional‐splitting errors. Copyright © 2005 John Wiley & Sons, Ltd.
A moving mesh finite element algorithm for fluid flow problems with moving boundaries
Authors: Baines M. J. , Hubbard M. E. , Jimack P. K. 
Published: January 2005

AbstractA moving mesh finite element method is proposed for the adaptive solution of second‐ and fourth‐order moving boundary problems which exhibit scale invariance. The equations for the mesh movement are based upon the local application of a scale‐invariant conservation principle incorporating a monitor function and have been successfully applied to problems in both one and two space dimensions. Examples are provided to show the performance of the proposed algorithm using a monitor function based upon arc‐length. Copyright © 2005 John Wiley & Sons, Ltd.
Multiscale modelling and computation of fluid flow
Authors: Hou Thomas Y. 
Published: January 2005

AbstractMany problems of fundamental and practical importance have multiscale solutions. Direct numerical simulation of these multiscale problems is difficult due to the range of length scales in the underlying physical problems. Here, we describe two multiscale methods for computing nonlinear partial differential equations with multiscale solutions. The first method relies on constructing local multiscale bases for diffusion‐dominated problems. We demonstrate that such an approach can be used to upscale two‐phase flow in heterogeneous porous media. The second method is to construct semi‐analytic multiscale solutions local in space and time. We use these solutions to approximate the large‐scale solution for convection‐dominated transport. This approach overcomes the common difficulty due to the memory effect in deriving the averaged equations for convection‐dominated transport. Our multiscale analysis provides a useful guideline for designing effective numerical methods for incompressible flow. Copyright © 2005 John Wiley & Sons, Ltd.
On using discontinuous finite element methods to simulate inertial confinement fusion
Authors: Burbeau‐Augoula Anne 
Published: January 2005

AbstractThis paper is devoted to the simulation of inertial confinement fusion for target design. An arbitrary Lagrangian Eulerian formulation based on discontinuous Galerkin finite element methods is proposed. It is totally different from Wilkins' scheme used in traditional ICF codes. The objective here is to test the robustness of the method on non‐uniform moving grids. The emphasis is put on the preservation of the spherical symmetry. Copyright © 2005 John Wiley & Sons, Ltd.
A pressure‐correction algorithm with Mach‐uniform efficiency and accuracy
Authors: Nerinckx Krista , Vierendeels J. , Dick E. 
Published: January 2005

AbstractWe present a collocated Mach‐uniform pressure‐correction method. By using a low Mach adapted AUSM+ flux for the spatial discretization, we reach Mach‐uniform accuracy. Mach‐uniform efficiency is obtained by a pressure‐correction equation based on the energy equation. Furthermore, we take heat conduction into account, which as far as we know, has never been done before in the context of Mach‐uniform pressure‐correction methods. An explicit treatment of the conduction terms results in a diffusive limit on the time step. To avoid this, a coupled solution of the energy equation and the continuity equation is needed. The results for both the adiabatic and the non‐adiabatic algorithms are in full accordance with the developed theory. Copyright © 2005 John Wiley & Sons, Ltd.
Long‐term survival and concomitant gene expression of ribozyme‐transduced CD4+ T‐lymphocytes in HIV‐infected patients
Authors: Macpherson Janet L. , Boyd Maureen P. , Arndt Allison J. , Todd Alison V. , Fanning Gregory C. , Ely Julie A. , Elliott Fiona , Knop Alison , Raponi Mitch , Murray John , Gerlach Wayne , Sun Lun‐Quan , Penny Ronald , Symonds Geoff P. , Carr Andrew , Cooper David A. 
Published: January 2005

AbstractBackgroundAn anti‐HIV‐1 tat ribozyme, termed Rz2, has been shown to inhibit HIV‐1 infection/replication and to decrease HIV‐1‐induced pathogenicity in T‐lymphocyte cell lines and normal peripheral blood T‐lymphocytes. We report here the results of a phase I gene transfer clinical trial using Rz2.MethodsApheresis was used to obtain a peripheral blood cell population from each of four HIV‐negative donors. After enrichment for CD4+ T‐lymphocytes, ex vivo expansion and genetic manipulation (approximately equal aliquots of the cells were transduced with the ribozyme‐containing (RRz2) and the control (LNL6) retroviral vector), these cells were infused into the corresponding HIV‐1‐positive twin recipient. Marking was assessed over an initial 24‐week period and in total over an approximate 4‐year period.ResultsThe gene transfer procedure was shown to be safe, and technically feasible. Both RRz2‐ and LNL6‐gene‐containing peripheral blood mononuclear cells (PBMC) were detected at all time points examined to 4 years. There was concomitant gene construct expression in the absence of the need for ex vivo peripheral blood cell stimulation and there was no evidence of immune elimination of the neoR T‐lymphocytes nor of silencing of the Moloney murine leukemia virus long terminal repeat.ConclusionsThe proof of principle results reported here demonstrate safety and feasibility of this type of gene transfer approach. While not specifically tested, T‐lymphocytes containing an anti‐HIV gene construct may impact on HIV‐1 viral load and CD4+ T‐lymphocyte count, potentially representing a new therapeutic modality for HIV‐1 infection. Copyright © 2005 John Wiley & Sons, Ltd.
Direct injection of plasmid DNA into the skin induces dermatitis by activation of monocytes through toll‐like receptor 9
Authors: Sawamura D. , Abe R. , Goto M. , Akiyama M. , Hemmi H. , Akira S. , Shimizu H. 
Published: January 2005

AbstractBackgroundDirect injection of naked DNA into skin can be efficiently used to transfer genes into keratinocytes in vivo. However, bacterial DNA is known to be a potent stimulus for vertebrate immune cells and immune systems. Towards the clinical use of this method, this study examined whether the application of plasmid DNA by direct injection induces any adverse skin effects.MethodsSeveral plasmid preparations were prepared and directly injected into rat and human skin. Migration, IL‐6 production, and reactive oxygen production assays were performed to determine the type of the primary cells responsible for the reaction. Involvement of toll‐like receptor (TLR) 9 was examined by experiments using TLR9‐knockout mice.ResultsInjection of several plasmid preparations into rat and human skin resulted in an inflammatory reaction at the treated site. Contamination by endotoxin in the plasmid preparation was shown to worsen this skin inflammation reaction. Immunohistochemical analysis showed that the infiltrating cells in the skin lesions were predominantly monocytes and neutrophils. Further experiments examining migration, IL‐6 production, and reactive oxygen production indicated that the primary responsible cells were monocytes rather than neutrophils. Since it was recently shown that cytosine‐guanosine dinucleotide (CpG) motif is critical for immune reaction induction in bacterial DNA and cellular responses were mediated by TLR9, we injected plasmids into the ear skin of TLR9‐knockout mice. A decrease in ear swelling was noted in the knockout mice, compared to controls, suggesting that plasmid‐DNA‐induced dermatitis was mediated mostly by TLR9.ConclusionsThis study demonstrates that injection of plasmid DNA induces skin inflammation initiated by monocyte activation via TRL9. We should therefore attempt to counteract this dermatitis during the clinical use of the naked DNA injection method in skin. Copyright © 2005 John Wiley & Sons, Ltd.
Tight control of transgene expression by lentivirus vectors containing second‐generation tetracycline‐responsive promoters
Authors: Pluta Krzysztof , Luce Milson J. , Bao Lili , Agha‐Mohammadi Siamak , Reiser Jakob 
Published: January 2005

AbstractBackgroundThe goal of this study was to design improved regulatable lentivirus vector systems. The aim was to design tetracycline (tet)‐regulatable lentivirus vectors based on the Tet‐on system displaying low background expression in the absence of the doxycycline (DOX) inducer and high transgene expression levels in the presence of DOX.MethodsWe constructed a binary lentivirus vector system that is composed of a self‐inactivating (SIN) lentivirus vector bearing inducible first‐ or second‐generation tet‐responsive promoter elements (TREs) driving expression of a transgene and a second lentivirus vector encoding a reverse tetracycline‐controlled transactivator (rtTA) that activates transgene expression from the TRE in the presence of DOX.ResultsWe evaluated a number of different rtTAs and found rtTA2S‐M2 to induce the highest levels of transgene expression. Regulated transgene expression was stable in human breast carcinoma cells implanted into nude mice for up to 11 weeks. In an attempt to minimize background expression levels, the chicken β‐globin cHS4 insulator element was cloned into the 3′ long terminal repeat (LTR) of the transgene transfer vector. The cHS4 insulator element reduced background expression but expression levels following DOX addition were lower than those observed with vectors lacking an insulator sequence. In a second strategy, vectors bearing second‐generation TREs harboring repositioned tetracycline operator elements were used. Such vectors displayed greatly reduced leakiness in the absence of DOX and induced transgene expression levels were up to 522‐fold above those seen in the absence of DOX.ConclusionsInducible lentivirus vectors bearing insulators or second‐generation TREs will likely prove useful for applications demanding the lowest levels of background expression. Copyright © 2005 John Wiley & Sons, Ltd.
Dispersion Behavior of TiO2 Nanoparticles in LLDPE/LDPE/TiO2 Nanocomposites
Authors: Wang Zhaobo , Li Guicun , Xie Guangwen , Zhang Zhikun 
Published: January 2005

AbstractSummary: TiO2 nanoparticles were introduced into linear low‐density polyethylene (LLDPE)/low‐density polyethylene (LDPE) composite films in the form of master batch where TiO2 was pre‐dispersed in LDPE by melt compounding. The dispersion behavior of TiO2 nanoparticles was investigated by field‐emission scanning electron microscopy (FE‐SEM). The rheology results show that the viscosity of LDPE/TiO2 master batch is lower than that of LLDPE/LDPE composites. Energy dispersive X‐ray spectrometer (EDS) composition distribution map indicates that TiO2 nanoparticles were dispersed randomly in the master batch. Scanning electron microscopy (SEM) images show that LDPE/TiO2 master batch is crushed into micron scale dispersed phases due to the shear stress during the blow‐forming process. Subsequently, TiO2 nanoparticles in the dispersed phases are released into the ambient matrix and form a wide ring composed of monodispersed particles. The sizes of spherical crystals decrease due to the presence of TiO2 nanoparticles in LLDPE/LDPE/TiO2 nanocomposites. The transparency of LLDPE/LDPE/TiO2 composite films decreases little compared to that of LLDPE/LDPE composite films.SEM image of TiO2 nanoparticles dispersed randomly in LLDPE/LDPE/TiO2 composite films.magnified imageSEM image of TiO2 nanoparticles dispersed randomly in LLDPE/LDPE/TiO2 composite films.
Photochemical Surface Modification of Polytetrafluoroethylene with Hydrazine: Characterization of the Surface with Zeta‐Potential Measurements and Spectroscopic Techniques
Authors: Meyer Ursula , Köstler Stefan , Ribitsch Volker , Kern Wolfgang 
Published: January 2005

AbstractSummary: Surfaces of PTFE were modified by polychromatic UV irradiation in the presence of hydrazine vapors. The surfaces were characterized by FTIR and XP spectroscopy as well as by zeta‐potential and contact angle measurements. FTIR spectroscopy revealed that – in addition to the introduction of amino and hydrazinyl groups onto the PTFE surface – a partial hydrogenation of the CF units proceeds (generation of hydrocarbon units CH). This finding is backed by XPS results. A fraction of the photochemically modified PTFE layers is soluble in aqueous media, while hydrogenated units appear to be more stable. The determination of the zeta potential (ζ) of the PTFE surface showed a shift of the isoelectric point towards higher pH values as a result of the surface modification. The zeta potential vs. pH curves are shifting steadily towards more positive values at increasing duration of the N2H4/UV treatment. The analysis of the surface tension components of hydrazine‐modified PTFE indicates a strong increase of the Lifshitz‐Van der Waals components (γLW) and electron‐donor components (γ−) compared to untreated PTFE. These components change in different fashion after extraction of the PTFE surface with aqueous media. Finally it is shown that amino and hydrazinyl groups at the PTFE surface can be derivatized by polymer‐analogous reactions with isothiocyanates and anhydrides.Zeta‐potential versus pH plots of modified PTFE samples. Dependence on the UV irradiation time in the presence of hydrazine vapor. (○) 0 min; (▴) 30 min; (▾) 45 min; (♦) 70 min; (▪) 90 min; (•) 120 min.magnified imageZeta‐potential versus pH plots of modified PTFE samples. Dependence on the UV irradiation time in the presence of hydrazine vapor. (○) 0 min; (▴) 30 min; (▾) 45 min; (♦) 70 min; (▪) 90 min; (•) 120 min.
Effect of the Polyimide Structure and ZnO Concentration on the Morphology and Characteristics of Polyimide/ZnO Nanohybrid Films
Authors: Hsu Shou‐Chian , Whang Wha‐Tzong , Hung Chin‐Hsien , Chiang Pei‐Chun , Hsiao Yi‐Nan 
Published: January 2005

AbstractSummary: A series of polyimide/ZnO nanohybrid films with different ZnO content were prepared from a rigid pyromellitic dianhydride‐4,4′‐diaminodiphenyl ether (PMDA‐ODA) polyimide (PI) and a flexible 3,3′,4,4′‐benzophenonetetracarboxylic acid dianhydride‐4,4′‐diaminodiphenyl ether (BTDA‐ODA) PI with ZnO nanoparticles (3–4 nm). Fourier‐transform infrared (FT‐IR) and X‐ray photoelectron spectroscopy (XPS) depict that the ZnO nanoparticles function as a physical cross‐linking agent with PI through hydrogen bonding between the OH on the ZnO nanoparticles and the CO of the imide groups. ZnO nanoparticles in the rigid PMDA‐ODA matrix cause a larger percentage decrease in the coefficient of linear thermal expansion (CTE) than in the flexible BTDA‐ODA matrix. The BTDA‐ODA/ZnO hybrid films have two transition peaks in dynamic mechanical tan δ curves, but PMDA‐ODA/ZnO hybrid films only have one transition peak. Thermogravimetric analysis reveals that ZnO decreases the thermal degradation temperature (Td) in both hybrid films, but less so in PMDA‐ODA/ZnO films. Transmission electron microscopy (TEM) images reveal that the rigid matrix induces larger particle size (30–40 nm) compared to the flexible matrix (10–15 nm).Illustration of the interaction between ZnO nanoparticles and PI.magnified imageIllustration of the interaction between ZnO nanoparticles and PI.
Proton Conductivity of Acid Doped Styrene‐Maleic Imide Copolymer With Benzimidazole Side Group
Authors: Pu Hongting , Qiao Lei 
Published: January 2005

AbstractSummary: Styrene‐maleic imide copolymer with benzimidazole side group was prepared from 2‐amino‐benzimidazole and styrene‐maleic anhydride copolymer. The structures of the new styrene‐maleic imide copolymers from both random and alternating styrene‐maleic anhydride copolymer were characterized by FTIR, DSC, and gel permeation chromatography (GPC). Styrene‐maleic imide copolymer has good solubility, excellent film forming ability, and is easy to prepare, though the solubility of styrene‐maleic imide copolymer decreases a little with increasing maleic imide. The proton conductivity of phosphoric acid doped styrene‐maleic imide copolymer was studied. The temperature dependence of proton conductivity in H3PO4 doped a‐styrene‐maleic imide copolymer can be fitted by a simple Arrhenius equation very well, while H3PO4 doped r‐styrene‐maleic imide copolymer has somewhat deviation from Arrhenius equation. The structure of alternating copolymer is more favorable for proton transport contributed by hopping mechanism. The proton conductivity of phosphoric acid doped styrene‐maleic imide copolymer can be improved by increasing the acid doping level or the imidazole content.
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Photoreactive Functionalization of Poly(ethylene terephthalate) Track‐Etched Pore Surfaces with “Smart” Polymer Systems
Authors: Geismann Christian , Ulbricht Mathias 
Published: January 2005

AbstractSummary: Poly(ethylene terephthalate) (PET) track‐etched membranes with a pore diameter of ca. 700 nm, optionally surface‐functionalized to create a “carboxyl” or “amino” surface, were used for heterogeneous graft copolymerizations. Grafted poly(acrylic acid) acted as a pH responsive, “smart” polymer. To evaluate the surface‐specific initiation of graft copolymerizations unmodified and primary functionalized membranes were systematically combined with three differently charged benzophenone derivatives as photoinitiators, which were adsorbed on the PET surface prior to the reaction. The functionalized membranes thus obtained were characterized for chemical structure and permeability as a function of pH. The pore structure with a narrow size distribution and the resulting high sensitivity of the membrane permeability to the grafting functionalizations made the track‐etched PET membranes a very useful tool for analyzing structure and function of responsive grafted polymer layers. The primary functionalization of the base polymer with a molecular layer of a multifunctional alkylamine (“amino” surface) enhanced the efficiency of the subsequent graft copolymerization via photoinitiated hydrogen abstraction considerably because a high density of well accessible reactive groups had been introduced. The preadsorption of the photoinitiator on the base polymer surface was significantly improved by ionic interactions between the respective functional groups of the surface and the photoinitiator. Such a photoinitiator preadsorption, especially when combined with a reactive layer from the primary functionalization, enabled a very efficient and surface selective functionalization because a better control of grafting density and a reduction of photoinitiated side reactions along with a more efficient use of the photoinitiator were possible.Water permeabilities (pH 2 and pH 7) of unmodified and functionalized PET membranes for identification of optimal synthesis and evaluation conditions.magnified imageWater permeabilities (pH 2 and pH 7) of unmodified and functionalized PET membranes for identification of optimal synthesis and evaluation conditions.
Synthesis of Novel Polycations Using the Chemistry of Ionic Liquids
Authors: Marcilla Rebeca , Blazquez J. Alberto , Fernandez Raquel , Grande Hans , Pomposo Jose A. , Mecerreyes David 
Published: January 2005

AbstractSummary:In this work, we report the synthesis of a great variety of polycations with varying counter‐anions. These new polymers were obtained by a simple anion exchange reaction facilitated by the phase separation of the resulting products. This strategy has been successfully applied to three different polycations, poly(1‐vinyl‐3‐ethylimidazolium bromide) poly(ViEtIm+Br−), poly(1‐ethyl‐4‐vinylpyridinium bromide) poly(ViEtPy+Br−), and poly(methacryloyloxyethyltrimethylammonium chloride) poly(EMTMA+Cl−), with seven counter‐anions such as PF, CF3SO, (CF3SO2)2N−, (CF3CF2SO2)2N−, dodecylbenzenesulfonate, toluene‐4‐sulfonate, and bis(2‐ethylhexyl) hydrogen phosphate. The solubility range of the new polymeric ionic liquids becomes very broad, including apolar organic solvents and ionic liquids, depending on the nature of the counter‐anion. Thermogravimmetric experiments showed that the thermal stability of the PILs also depends on the nature of the counter‐anion improving in the order CF3SO > (CF3CF2SO2)2N− > C12H25C6H4SO > PF > Br− > C16H34PO.A simple anion exchange procedure similar to the reaction used in ionic liquids chemistry is used to the synthesis of new polymeric ionic liquids (PILs).magnified imageA simple anion exchange procedure similar to the reaction used in ionic liquids chemistry is used to the synthesis of new polymeric ionic liquids (PILs).