bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of Plasma Properties of the Atmospheric Oxy‐Combustion Flame by Using Double Probe Method
Authors: Osaka Y. , Kobayashi N. , Ohno N. , Takamura S. , Tanaka Y. , Uesugi Y. 
Published: June 2008

AbstractOxy‐combustion generates a high‐temperature field of more than 3000 K and represents a nitrogen‐free process. In order to apply oxy‐combustion to next‐generation power plants and high‐temperature industrial technology this process has been enhanced by a new method, referred to as ‘plasma‐assisted combustion’. This method uses to control the oxy‐combustion flame with the radio‐frequency electromagnetic force acting on the hightemperature field of the oxy‐combustion flame. In order to establish the plasma‐assisted combustion technique it is necessary to assess the influence of the electromagnetic field on the flame parameters, i.e. to compare the main plasma properties (conductivity, electron density and temperature) of the oxy‐combustion flame with and without the assistance of the electromagnetic field. For that purpose we have developed a reciprocating double probe method to measure the plasma properties of the oxy‐combustion flame. In this paper we present (i) the experimental part (ii) the model that enables to estimate the electron temperature and density from the conductivity derived from the double probe measurements and (iii) measurements without the applied electromagnetic force. At the centre of the flame, the measured electrical conductivity is (1.3 ± 0.7) × 10–4 S/m which gives an electron temperature of 2800 ± 100 K and an electron density of (1.2 ± 0.5) × 1015 m–3. The electron temperature in oxy‐combustion is equivalent to the adiabatic flame temperature. The equilibrium adiabatic flame temperature in the oxy‐combustion of methane is estimated to be approximately 3100 K, which is in good agreement with the electron temperature measured in this study. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of a Fast Electron Component on the Plasma Sheath Structure at the Inside of the Tunnel Probe
Authors: Rompuy T. Van , Gunn J. P. , Oost G. Van 
Published: June 2008

AbstractThe possible influence of a small population of suprathermal electrons on the tunnel probe, a new kind of Langmuir probe for fast DC measurements of ion flux and electron temperature in the tokamak scrape‐off layer, has been investigated by numerical simulations. It was found that suprathermal electrons can influence the ion current distribution over the inner plasma collecting surfaces of the tunnel probe, and thus influence tunnel probe Te measurements. The ion current distribution depends on the structure of the Debye and the magnetic sheath inside the tunnel probe. Therefore, we make here a first attempt at investigating the influence of suprathermal electrons on the scaling of those sheaths. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ion‐Neutral Collision Effects in Langmuir Probe Theory
Authors: Taccogna F. , Longo S. , Capitelli M. 
Published: June 2008

AbstractIn weakly collisional sheaths, potential wells and barriers could appear. These can cause the presence of repulsed and trapped ions in the region surrounding a negatively biased Langmuir probe, invalidating the orbital motion limited (OML) theory. In this work, a Particle‐In‐Cell/Test‐Particle Monte Carlo (PIC/TPMC) model of Ar plasma at medium gas pressure has been developed in order to show the effect of ion‐neutral collisions. In fact, the results of the present simulation for different discharge pressures demonstrate the complex structure of electric potential around the probe and the failure of analytical theories. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deposition of BaxSr1–xTiO3 thin Films by Double RF Hollow Cathode Plasma Jet System
Authors: Hubička Z. , Virostko P. , Tichý M. , Čada M. , Adámek P. , Olejníček J. , Deyneka A. , Churpita O. , Valvoda V. , Jastrabík L. 
Published: June 2008

AbstractLow‐pressure plasma jet system with two hollow cathodes was used for deposition of Bax Sr1–x TiO3 (BSTO) ferroelectric thin films. Two RF hollow cathode plasma jet guns were pointed to the substrate where BSTO thin films were deposited. High density RF hollow cathode discharge was generated in ceramic nozzles made of SrTiO3 (STO) and BaTiO3 (BTO). Pulse modulated RF power was applied on water‐cooled copper block insulated from the plasma by ceramic and grounded stainless steel shield. In the experiment, the composition of BSTO films was controlled by magnitude of average RF power applied on particular plasma jet guns with STO and BTO nozzles. By this method, BSTO films were deposited on single crystal silicon substrate and on Pt top of Pt/TiO2/SiO2/Si multi‐layer system. X‐ray diffraction proved that BSTO thin films were polycrystalline with perovskite structure and measurement of dielectric properties showed ferroelectric hysteresis loop at room temperature. Time resolved Langmuir probe system and plasma impedance monitor were used for in situ plasma diagnostics and control of deposition conditions. Furthermore, plasma jets were analyzed during the deposition process by spatially resolved optical emission spectroscopy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the Langmuir Probe Shaft on Measuring Plasma Parameters
Authors: Waldmann O. , Fussmann G. 
Published: June 2008

AbstractBecause of their good spatial and temporal resolution Langmuir probes are often used for plasma diagnostics. One has to keep in mind, however, that the presence of the probe can substantially perturb the neighboring plasma.Apart from the probe tip, in particular the probe shaft may affect the measured values of temperature and density. We have studied this latter effect at the linear plasma generator PSI‐2 which provides a stationary plasma column of 2.6 m in length and 8 cm in diameter.Two single probes differently arranged were used in these experiments. In the first case the probes were in the same plane but tilted to each other in azimuthal direction. In the second arrangement the probes were separated by a distance along the magnetic field lines at the same azimuthal angle. One probe was kept at a fixed (but variable) position while the other was scanning the plasma radially.It is found that the electron temperature is hardly influenced by the presence of the second probe, but the electron density is decreased up to 30%. The results can approximately be described in the frame of a global particle model treating the probe shafts as additional plasma sinks. Most striking is the observation that large global reductions of the density are accompanied by only moderate local changes. This means that the perturbations caused by the probe are characterized by a large scale effect, possibly indicating anomalous diffusion. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kalman filter‐based channel estimation and ICI suppression for high‐mobility OFDM systems
Authors: Gupta Prerana , Mehra D. K. 
Published: June 2008

AbstractThe use of orthogonal frequency division multiplexing (OFDM) in frequency‐selective fading environments has been well explored. However, OFDM is more prone to time‐selective fading compared with single‐carrier systems. Rapid time variations destroy the subcarrier orthogonality and introduce inter‐carrier interference (ICI). Besides this, obtaining reliable channel estimates for receiver equalization is a non‐trivial task in rapidly fading systems. Our work addresses the problem of channel estimation and ICI suppression by viewing the system as a state‐space model. The Kalman filter is employed to estimate the channel; this is followed by a time‐domain ICI mitigation filter that maximizes the signal‐to‐interference plus noise ratio (SINR) at the receiver. This method is seen to provide good estimation performance apart from significant SINR gain with low training overhead. Suitable bounds on the performance of the system are described; bit error rate (BER) performance over a time‐invariant Rayleigh fading channel serves as the lower bound, whereas BER performance over a doubly selective system with ICI as the dominant impairment provides the upper bound. Copyright © 2008 John Wiley & Sons, Ltd.
Chaotic communication systems in the presence of parametric uncertainty and mismatch
Authors: Ji Yuan , Wen Changyun , Li Zheng Guo 
Published: June 2008

AbstractA recently developed synchronization scheme in (Phys. Lett. A 2007; 361:108–114) is applied to design a secure communication system with parametric uncertainties and mismatches in this paper. Based on the bounds of the uncertainties and mismatches and a pre‐specified bound of the synchronization error, a scheme is given to determine an upper bound of impulsive intervals. With the scheme, the synchronization error is ensured to approach to and stay within the given pre‐specified bound and this in turn guarantees that signals can be decoded accurately. To further enhance system security, it is also proposed to transmit functions of the chaotic states at impulsive instants, instead of the states directly. The designed system is tested and verified with text, audio and image encryption and transmission with comparisons to some existing schemes. Copyright © 2008 John Wiley & Sons, Ltd.
Stereoselective Synthesis of the Naturally Occurring 2‐Pyranone Dodoneine
Authors: Álvarez‐Bercedo Paula , Falomir Eva , Murga Juan , Carda Miguel , Marco J. Alberto 
Published: June 2008

AbstractThe first total synthesis of the naturally occurring dihydropyranone dodoneine is reported. Asymmetric allylation reactions were used for the stereoselective generation of the two stereogenic centers. The pyranone ring was created by ring‐closing metathesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Room‐Temperature Electrophilic 5‐endo‐dig Chlorocyclization of Alk‐3‐yn‐1‐ones with the Use of Pool Sanitizer: Synthesis of 3‐Chlorofurans and 5‐Chlorofuropyrimidine Nucleosides (Eur. J. Org. Chem. 20/2008)
Authors: Sniady Adam , Morreale Marco S. , Wheeler Kraig A. , Dembinski Roman 
Published: June 2008

AbstractThe cover picture shows an artistic image related to the chlorocyclization reaction with the use of trichloro‐s‐triazinetrione, which is sold as a chemical for pools. This reagent is a source of electrophilic chlorine that triggers a tandem chlorination/cylization reaction that yields 3‐chlorofurans or 5‐chlorofuropyrimidine nucleosides. Details are discussed in the Short Communication by R. Dembinski et al. on p. 3449 ff. Cover art by Tomasz Sniady.
Highly sensitive double‐fluorescent dye staining on microchip electrophoresis for analysis of milk proteins
Authors: Okada Hiroki , Kaji Noritada , Tokeshi Manabu , Baba Yoshinobu 
Published: June 2008

AbstractWe demonstrated a highly sensitive double‐fluorescent dye staining in microchip electrophoresis (ME) for analysis of milk proteins. The detection sensitivity of ME was very limited so far and needed improvement. Our staining method consisted of two steps. First, in sample preparation before electrophoresis, protein was covalently bound to an amine‐reactive fluorescent dye, Cy5. Then, the Cy5‐attached protein was denatured with SDS and was further stained, during electrophoresis, with Agilent fluorescent dye, which was noncovalently attached to hydrophobic regions of the SDS‐protein complexes. This double‐fluorescent staining enhanced fluorescent intensity and lowered the detection limit to 200 pg of protein. This provided higher sensitivity than silver‐ or SYPRO Ruby‐staining methods, which have previously given the highest sensitivity in protein staining. In addition, we applied our staining method to analysis of milk proteins and achieved their successful detection, whereas it was difficult to analyze them by the unimproved method.
The synthesis and structures of deuterium‐labeled 5‐substituted 1H‐tetrazoles
Authors: Zhao Hong 
Published: June 2008

AbstractThe synthesis and crystal structures of deuterium‐labeled 5‐substituted 1H‐tetrazoles, 5‐[2H5]phenyl‐1H‐tetrazole (I), 5‐[2H7]tolyl‐1H‐tetrazole (II), and 5‐[2H7]benzyl‐1H‐tetrazole (III) are reported. All syntheses were carried out using simple, facile steps and the products were obtained in high yields. Copyright © 2008 John Wiley & Sons, Ltd.
Mechanical Reinforcement of a Supramolecular Hydrogel Comprising an Artificial Glyco‐Lipid through Supramolecular Copolymerization
Authors: Ikeda Masato , Shimizu Yusuke , Matsumoto Shinji , Komatsu Harunobu , Tamaru Shun‐ichi , Takigawa Toshikazu , Hamachi Itaru 
Published: June 2008

AbstractSupramolecular copolymer hydrogels were prepared by mixing 1 and the additives 2–8, and their rheological properties were evaluated. It was found that additive 3 reinforced the mechanical strength of the resultant hydrogel most efficiently, increasing the yield stress of SCH 1+3 about fourfold. The optimal mixing between the glyco‐lipid hydrogelator 1 and the additive 3 sufficiently enhanced the mechanical strength of the resultant SCH, which improved the handling of the SH on the large scale. These results indicate that supramolecular copolymerization can provide the supramolecular hydrogel with desired properties and/or functions.magnified image
A Combined Analysis of PVT and Rheological Measurements: Novel Results for Three Amorphous Polymers
Authors: Fernández Mercedes , Muñoz María Eugenia , Santamaría Anton 
Published: June 2008

AbstractThe fractional free volume f of polycarbonate (PC), polystyrene (PS) and poly(methyl methacrylate) (PMMA) is determined by pressure–volume–temperature (PVT) measurements using the Simha–Somcynsky equation of state. Results are compared with the free volume obtained by viscoelastic measurements. Temperature and pressure dependent viscosity and free volume results are correlated using the characteristic ratio C∞ and the parameter B of the monomeric friction factor ζ = ζexp B/f. This leads to obtain new results on the temperature and pressure dependence of C∞, as well as on the pressure dependence of B parameter.magnified image
Facile Synthesis and Characterization of Novel Capsicum‐Like Polyphosphazene Nanotubes via an in situ Template Route
Authors: Fu Jianwei , Huang Xiaobin , Zhu Yan , Zhu Lu , Tang Xiaozhen 
Published: June 2008

AbstractNovel polyphosphazene nanotubes with closed ends were prepared by polycondensation of HCCP and BPS via an in situ template approach at room temperature. The nanotubes were characterized by FT‐IR and NMR spectroscopy and elemental analysis. Their cross‐linked structures were confirmed. SEM and TEM indicated that they resemble capsicum, with a length of 2–6 µm, and the outer diameters of the two ends were about 200–500 and 100 nm. The majority of nanotubes had inner diameters of about 30–50 nm. The tube ends were closed. TGA analysis showed that their decomposition started at 468 °C. A formation mechanism of the capsicum‐like nanotubes is proposed.magnified image
Construction of Linear Polymers, Dendrimers, Networks, and Other Polymeric Architectures by Copper‐Catalyzed Azide‐Alkyne Cycloaddition “Click” Chemistry
Authors: Johnson Jeremiah A. , Finn M. G. , Koberstein Jeffrey T. , Turro Nicholas J. 
Published: June 2008

AbstractThe enrichment of materials synthesis with the diverse chemical building blocks and functional groups of small molecule organic chemistry has been greatly accelerated in recent years by the introduction of the copper‐catalyzed azide‐alkyne cycloaddition (CuAAC). The efficiency and modular nature of this unique reaction enables materials chemists to prepare novel functional materials of unprecedented complexity. This review summarizes the application of CuAAC to the field of materials construction, defined here as the preparation of materials with architectural integrity dependent upon the triazole linkage. Recent examples, including linear polymers, dendrimers, polymer networks, polymeric nanoparticles, and other polymeric architectures, are described.magnified image
Cationic and Anionic Conjugated Polyelectrolytes: Aggregation‐Mediated Fluorescence Energy Transfer to Dye‐Labeled DNA
Authors: Jin Youngeup , Yang Renquiang , Suh Hongsuk , Woo Han Young 
Published: June 2008

AbstractAn electrostatic complex of water‐soluble conjugated polyelectrolytes (CPs) between anionic poly(9,9‐bis(4′‐sulfonatobutyl)fluorene‐co‐alt‐1,4‐phenylene) disodium salt (a‐PFP) and cationic poly(9,9‐bis((6′‐N,N,N,‐trimethylammonium)hexyl)fluorene‐co‐2,1,3‐bezothiadiazole) dibromide (85:15) (c‐PFB15) was tested as a fluorescence resonance energy transfer (FRET) donor to Texas Red (TR)‐labeled single‐stranded DNA (ssDNA‐TR) via two‐step FRET processes. Electrostatic complexation of a‐PFP and c‐PFB15 in water leads to aggregation of polymer chains, a concomitant reduction of intersegment distances, and energy transfer to the benzothiadiazole (BT) segments. The following complexation with ssDNA‐TR leads to energy transfer from BT to TR via two‐step FRET processes. This detection schematic shows an FRET‐induced signal amplification, which can be achieved by adjusting the charge ratio in the cationic/anionic CP complex and controlling the number density of the binding CPs around the acceptor, resulting in enhanced antenna effects and sensitivity in CP‐based FRET DNA detection assays.magnified image
Synthesis of a Multi Alternating‐Arm‐Containing Dendritic Star Copolymer by RAFT and Cationic Ring‐Opening Polymerization
Authors: Zhong Ling , Zhou Yongfeng , Yan Deyue , Pan Caiyuan 
Published: June 2008

AbstractA new dendritic heteroarm star copolymer that contains multi‐alternating arms of poly(ethylene oxide‐tetrahydrofuran) (P(EO‐THF)) and poly(methyl methacrylate) (PMMA) on a dendritic polyester core has been synthesized by a ‘core‐first’ approach by combination of sequential cationic ring‐opening polymerization (CROP) and reversible addition–fragmentation transfer (RAFT) polymerization initiated by a dendritic macroinitiator (3) capped with multi‐alternating terminal carboxylic acid groups (used directly to initiate the ROP of THF in the presence of EO as a polymerization promoter to attain P(EO‐THF) arms) and dithiobenzoate groups (used to initiate RAFT polymerization of MMA to attain PMMA arms). The structures of the products were confirmed by NMR spectroscopy, GPC‐MALLS, and DSC measurements.magnified image
On the stabilization of the Timoshenko system by a weak nonlinear dissipation
Authors: Messaoudi Salim A. , Mustafa Muhammad I. 
Published: June 2008

AbstractIn this paper we consider the following Timoshenko‐type system:

Without imposing any restrictive growth assumption on g at the origin, we establish a general decay result depending on g and α. Copyright © 2008 John Wiley & Sons, Ltd.
Penalty finite element approximations for the Stokes equations by L2 projection
Authors: Li Jian 
Published: June 2008

AbstractThis paper considers the penalty finite element method for the Stokes equations, based on some stable finite elements space pair (Xh, Mh) that do satisfy the discrete inf–sup condition. Theoretical results show that the penalty error converges as fast as one should expect from the order of the elements. Moreover, the penalty finite element method by L2 projection can improve the penalty error estimates. Finally, we confirm these results by a series of numerical experiments. Copyright © 2008 John Wiley & Sons, Ltd.
Charged relativistic spheres with generalized potentials
Authors: Thirukkanesh S. , Maharaj S. D. 
Published: June 2008

AbstractA new class of exact solutions of the Einstein–Maxwell system is found in closed form. This is achieved by choosing a generalized form for one of the gravitational potentials and a particular form for the electric field intensity. For specific values of the parameters it is possible to write the new series solutions in terms of elementary functions. We regain well‐known physically reasonable models. A physical analysis indicates that the model may be used to describe a charged sphere. The influence of the electromagnetic field on the gravitational interaction is highlighted. Copyright © 2008 John Wiley & Sons, Ltd.
Complete NMR data assignments for novel pterocarpans from Harpalyce brasiliana
Authors: Araújo Renata Mendonça , Pinheiro Sávio Moita , Lima Mary Anne Sousa , Silveira Edilberto Rocha 
Published: June 2008

AbstractA NMR study of two new pterocarpans isolated from the roots of Harpalyce brasiliana is described. In addition to 1D NMR, 2D shift‐correlated NMR pulse sequences (1H1H‐COSY, HSQC and HMBC) were used to establish the structures, and unambiguously perform the 1H and 13C chemical shift assignments. Copyright © 2008 John Wiley & Sons, Ltd.
Continuous Miniemulsion Polymerization
Authors: Schork F. Joseph , Guo Juchen 
Published: June 2008

AbstractMost miniemulsion polymerizations are carried out in batch reactors. However, continuous reactors or continuous reactor trains can provide a high level of consistency when operated at steady state. In this feature article, progress in continuous miniemulsion polymerization will be reviewed. Special attention will be given to issues of monomer diffusion and secondary nucleation. A large portion of the paper will be devoted to controlled radical polymerization for two reasons. First, this is a relatively new field, particularly when continuous reactors are considered, and second, for controlled radical polymerization in continuous reactors, the molecular weight distribution of the product is a direct function of the reactor residence time distribution.magnified image
Short‐scan‐time multi‐slice diffusion MRI of the mouse cervical spinal cord using echo planar imaging
Authors: Callot Virginie , Duhamel Guillaume , Cozzone Patrick J. , Kober Frank 
Published: June 2008

AbstractMouse spinal cord (SC) diffusion‐weighted imaging (DWI) provides important information on tissue morphology and structural changes that may occur during pathologies such as multiple sclerosis or SC injury. The acquisition scheme of the commonly used DWI techniques is based on conventional spin‐echo encoding, which is time‐consuming. The purpose of this work was to investigate whether the use of echo planar imaging (EPI) would provide good‐quality diffusion MR images of mouse SC, as well as accurate measurements of diffusion‐derived metrics, and thus enable diffusion tensor imaging (DTI) and highly resolved DWI within reasonable scan times. A four‐shot diffusion‐weighted spin‐echo EPI (SE‐EPI) sequence was evaluated at 11.75 T on a group of healthy mice (n = 10). SE‐EPI‐derived apparent diffusion coefficients of gray and white matter were compared with those obtained using a conventional spin‐echo sequence (c‐SE) to validate the accuracy of the method. To take advantage of the reduction in acquisition time offered by the EPI sequence, multi‐slice DTI acquisitions were performed covering the cervical segments (six slices, six diffusion‐encoding directions, three b values) within 30 min (vs 2 h for c‐SE). From these measurements, fractional anisotropy and mean diffusivities were calculated, and fiber tracking along the C1 to C6 cervical segments was performed. In addition, high‐resolution images (74 × 94 µm2) were acquired within 5 min per direction. Clear delineation of gray and white matter and identical apparent diffusion coefficient values were obtained, with a threefold reduction in acquisition time compared with c‐SE. While overcoming the difficulties associated with high spatially and temporally resolved DTI measurements, the present SE‐EPI approach permitted identification of reliable quantitative parameters with a reproducibility compatible with the detection of pathologies. The SE‐EPI method may be particularly valuable when multiple sets of images from the SC are needed, in cases of rapidly evolving conditions, to decrease the duration of anesthesia or to improve MR exploration by including additional MR measurements. Copyright © 2008 John Wiley & Sons, Ltd.