bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth and Application of Paired Gold Electrode Junctions: Evidence for Nitrosonium Phosphate During Nitric Oxide Oxidation
Authors: French Robert W. , Collins Andrew M. , Marken Frank
Published: October 2008

A bipotentiostatic gold electrodeposition process is developed to grow gold junctions between two adjacent 100 μm diameter platinum disc electrodes. Gold is electrodeposited simultaneously on both electrodes with an automated termination mechanism close to short‐circuit conditions. Gap junctions (average gap width ca. 4 μm) are obtained reproducibly and the behavior of the resulting generator–collector electrode system is investigated for two relevant redox systems. First, the chemically reversible oxidation of 1,1′‐ferrocenedimethanol in aqueous 0.1 M KCl is studied. Well‐defined feedback currents across the electrode junction in generator–collector mode are recorded down to sub‐micromolar analyte concentration. Electrochemically reversible voltammetric responses suggest fast heterogeneous electron transfer and this allows further gap geometry analysis. Second, the (apparently) chemically irreversible oxidation of nitric oxide in 0.1 M phosphate buffer solution (pH 7) at gold electrodes is re‐investigated and, perhaps surprisingly, generator–collector feedback currents are observed for a solution phase intermediate, here tentatively assigned to nitrosonium phosphate, NO+H2PO$\rm{ {_{4}^{-}}}$. The life time of this intermediate, ca. 10 ms, is surprisingly long, given a typical decay time for free NO+ in water of only nanoseconds. The results are consistent with an estimated nitrosonium phosphate association equilibrium constant, K≈107 mol−1 dm3. Without further optimization of the electrode junction gap geometry, the determination of nitric oxide down to ca. 10 μM concentration is achieved. The benefits of smaller junctions and potential analytical applications of paired nanojunction electrodes are discussed.
Separation of dansylated amino acid enantiomers by chiral ligand‐exchange CE with a zinc(II) L‐arginine complex as the selecting system
Authors: Qi Li , Chen Yi , Xie Mingyi , Guo Zhenpeng , Wang Xiaoyu
Published: October 2008

A facile chiral ligand‐exchange capillary electrophoretic method has been explored for the enantioseparation and UV detection of dansyl‐amino acids with Zn(II) L‐arginine complex as a chiral selecting system. Successful enantioseparation of 17 pairs of amino acid enantiomers has been achieved with a buffer of 100 mM boric acid, 5 mM ammonium acetate, 3 mM ZnSO4 and 6 mM L‐Arg at pH 8.0, of which 10 pairs were fully resolved with resolution in between 1.59 and 4.21. This new method was shown to be applicable to the separation of some mixed pairs of amino acids and to the quantitative analysis of some real samples such as rice vinegars, with a linear range between 0.8 and 150 μg/mL, correlation coefficient above 0.99 and recovery in between 90.1 and 112.4%. It was found that amino acids with low resistance side chain(s), low tendency to form intramolecular hydrogen bond or high tendency to form intermolecular hydrogen bonds are more easily enantioseparated than those with extra carboxyl and/or phenyl groups. By the use of the suggested buffer, the running pH should be selected at 7.4–9.0 to compromise the resolution and elution speed.
Experimental investigation on thermo‐driving heat transfer in porous medium in a centrifugal force field
Authors: Xia Jie , Chang Hai‐Ping , Tang Hou‐Xiang
Published: October 2008

Based on the research in turbine blade super cooling techniques, experiments were carried out to investigate the thermo‐driving heat transfer phenomenon in a new cooling configuration filled with porous medium in a centrifugal force field. Moreover, the heat transfer effectiveness of the configuration was compared to one with no porous medium. The results showed that the thermo‐driving heat transfer effectiveness of the configuration filled with porous medium could be enhanced by increasing the rotating speed, heat flux, and cooling air speed. Meanwhile, the heat transfer effectiveness of the configuration was strengthened with the installation of porous medium. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(6): 329– 338, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20219
Hedonic price models and indices based on boosting applied to the Dutch housing market
Authors: Kagie Martijn , Wezel Michiel Van
Published: October 2008

We create a hedonic price model for house prices for six geographical submarkets in the Netherlands. Our model is based on a recent data‐mining technique called boosting. Boosting is an ensemble technique that combines multiple models, in our case decision trees, into a combined prediction. Boosting enables capturing of complex nonlinear relationships and interaction effects between input variables.

We report mean relative errors and mean absolute error for all regions and compare our models with a standard linear regression approach. Our model improves prediction performance by up to 39% compared with linear regression and by up to 20% compared with a log‐linear regression model. Next, we interpret the boosted models: we determine the most influential characteristics and graphically depict the relationship between the most important input variables and the house price. We find the size of the house to be the most important input for all but one region, and find some interesting nonlinear relationships between inputs and price.

Finally, we construct hedonic price indices and compare these with the mean and median index and find that these indices differ notably in the urban regions of Amsterdam and Rotterdam. Copyright © 2008 John Wiley & Sons, Ltd.
Interpretable credit model development via artificial neural networks
Authors: Trinkle Brad S. , Baldwin Amelia A.
Published: October 2008

Poor credit granting decisions are coming back to haunt providers of loan finance. Past poor credit granting decisions are in part due to the Equal Credit Opportunity Act (1975). This act requires lenders to explain the decision to grant or refuse credit. As a result, models such as artificial neural networks, which offer improved ability to identify poor credit risks but which do not offer easy explanations of why a loan applicant has scored badly, remain unused. This paper investigates whether these models can be interpreted so that explanations for credit application rejection can be provided. The results indicate that while the artificial neural networks can be used (with caution) to develop credit scoring models, the limitations imposed by the credit granting process make their use unlikely until interpretation techniques are developed that are more robust and that can interpret multiple hidden‐layer artificial neural networks. Copyright © 2008 John Wiley & Sons, Ltd.
Self‐assembled monolayer for low density lipoprotein detection
Authors: Matharu Zimple , Arya Sunil K. , Sumana G. , Gupta Vinay , Malhotra B. D.
Published: October 2008

Heparin (HEP) has been covalently immobilized onto 4‐aminothiophenol (ATP) self‐assembled monolayer (SAM) deposited onto gold (Au)‐coated glass plate for low density lipoprotein (LDL) detection. The HEP/ATP/Au and LDL/HEP/ATP/Au electrodes have been characterized using cyclic voltammetry (CV) and scanning electron microscopy (SEM). Surface plasmon resonance (SPR) measurements reveal that HEP/ATP/Au electrode is sensitive to detection of the LDL in the range 0.03 µM (10 mg/dl)–0.39 µM (130 mg/dl). The values of association and dissociation rate constants in the association phase calculated by kinetic analysis have been found to be ka = 9.67 × 101 M−1 s−1 and kd = 2.64 × 10−4 s−1. Copyright © 2008 John Wiley & Sons, Ltd.
Consistency of modelled and observed temperature trends in the tropical troposphere
Authors: Santer B. D. , Thorne P. W. , Haimberger L. , Taylor K. E. , Wigley T. M. L. , Lanzante J. R. , Solomon S. , Free M. , Gleckler P. J. , Jones P. D. , Karl T. R. , Klein S. A. , Mears C. , Nychka D. , Schmidt G. A. , Sherwood S. C. , Wentz F. J.
Published: October 2008

A recent report of the U.S. Climate Change Science Program (CCSP) identified a ‘potentially serious inconsistency’ between modelled and observed trends in tropical lapse rates (Karl et al., 2006). Early versions of satellite and radiosonde datasets suggested that the tropical surface had warmed more than the troposphere, while climate models consistently showed tropospheric amplification of surface warming in response to human‐caused increases in well‐mixed greenhouse gases (GHGs). We revisit such comparisons here using new observational estimates of surface and tropospheric temperature changes. We find that there is no longer a serious discrepancy between modelled and observed trends in tropical lapse rates.

This emerging reconciliation of models and observations has two primary explanations. First, because of changes in the treatment of buoy and satellite information, new surface temperature datasets yield slightly reduced tropical warming relative to earlier versions. Second, recently developed satellite and radiosonde datasets show larger warming of the tropical lower troposphere. In the case of a new satellite dataset from Remote Sensing Systems (RSS), enhanced warming is due to an improved procedure of adjusting for inter‐satellite biases. When the RSS‐derived tropospheric temperature trend is compared with four different observed estimates of surface temperature change, the surface warming is invariably amplified in the tropical troposphere, consistent with model results. Even if we use data from a second satellite dataset with smaller tropospheric warming than in RSS, observed tropical lapse rate trends are not significantly different from those in all other model simulations.

Our results contradict a recent claim that all simulated temperature trends in the tropical troposphere and in tropical lapse rates are inconsistent with observations. This claim was based on use of older radiosonde and satellite datasets, and on two methodological errors: the neglect of observational trend uncertainties introduced by interannual climate variability, and application of an inappropriate statistical ‘consistency test’. Copyright © 2008 Royal Meteorological Society
Raman scattering features of lead pyroantimonate compounds. Part I: XRD and Raman characterization of Pb2Sb2O7 doped with tin and zinc
Authors: Rosi F. , Manuali V. , Miliani C. , Brunetti B. G. , Sgamellotti A. , Grygar T. , Hradil D.
Published: October 2008

Yellow pyroantimonates PbSb, PbSbSn and PbSbZn were synthesized by solid‐state reactions at high temperature and characterized by X‐ray diffraction and Raman spectroscopy. The lattice size of cubic pyrochlores increases with Sn and Zn doping and with Pb overstoichiometry, indicating the replacement of Sb5+ by the larger cations. This fact permits the understanding of the corresponding Raman spectral modifications as a consequence of the changes in the local symmetry of the SbO polyhedra, justifying the exploitation of Raman spectroscopy to noninvasively identify structural modifications of pyroantimonate pigments in artworks. Copyright © 2008 John Wiley & Sons, Ltd.
Density functional and experimental studies on the FT‐IR and FT‐Raman spectra and structure of benzoic acid and 3,5‐dichloro salicylic acid
Authors: Krishnakumar V. , Mathammal R.
Published: October 2008

FT‐IR and FT‐Raman spectra of benzoic acid (BA) and 3,5‐dichloro salicylic acid (SA) have been recorded in the regions of 4000–400 and 4000–50 cm−1 respectively. The spectra were interpreted with the aid of normal coordinate analysis following the full structure optimizations and force field calculations based on density functional theory (DFT) using standard B3LYP6‐31G** method and basis set combinations. The DFT force field transformed to natural internal coordinates was corrected by a well‐established set of scale factors that were found to be transferable to the title compounds. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of the simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes. Copyright © 2008 John Wiley & Sons, Ltd.
Enhancing extraction rate in solid‐phase microextraction by using nano‐structured polyaniline coating
Authors: Mehdinia Ali , Fazlollah Mousavi Mir
Published: October 2008

The decrement of equilibrium extraction time without losing extraction efficiency in solid‐phase microextraction (SPME) was achieved using nano‐structured coating. Polyaniline (PANI) was used as an extraction phase for the comparison of extraction capacity and equilibrium extraction time of nano‐ and micro‐structured coatings. Polychlorinated biphenyls (PCBs) were used as model compounds to examine the extraction properties of nano‐ and micro‐structured coatings. The results revealed that nano‐structured PANI coating showed higher extraction rate and shorter desorption time than micro‐structured coating, because of the larger surface area. In order to evaluate the extraction capability of prepared nano‐structured PANI coating, headspace‐SPME method was used for the determination of PCBs in sediment samples by GC‐electron capture detector. The proposed method was validated using the certified reference material.
Influence of tungstate ion dopants in corrosion protection behavior of polyaniline coating on mild steel
Authors: Sabouri M. , Shahrabi T. , Hosseini M. G.
Published: October 2008

Electropolymerization of polyaniline (PANI) and polyaniline‐tungstate (PANIW) coatings on mild steel were successfully performed using cyclic voltammetry technique. Processes were carried out in aqueous electrolyte solutions of 0.3 M oxalic acid + 0.1 M aniline and 0.3 M oxalic acid + 0.1 M aniline + 0.001 M sodium tungstate dehydrate. Corrosion protection of PANI and PANIW coatings was evaluated with the help of open circuit potential (Eocp) monitoring and electrochemical impedance spectroscopy (EIS) methods. All the results reveal the influence of additional doping agent (i.e., tungstate) in corrosion protection behavior of PANI coating.
Fourier algebra of a hypergroup – II. Spherical hypergroups
Authors: Muruganandam Varadharajan
Published: October 2008

We in this article, introduce a class of hypergroups called ultraspherical hypergroups and show that the Fourier space of an ultraspherical hypergroup forms a Banach algebra under pointwise product. These hypergroups need not be commutative and include for example double coset hypergroups. We also show that the structure space of this algebra equals the underlying hypergroup. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hermite–Fejér interpolation operator and characterization of functions
Authors: Xie Tingfan , Zhou Xinlong
Published: October 2008

In this paper we investigate the approximation behaviour of the so‐called Hermite–Fejér interpolation operator based on the zeros of Jacobi polynomials. As a result we obtain the asymptotic formula of approximation rate for these operators. Moreover, such a formula is valid for any individual continuous function. We will also study the K ‐functional deduced by this operator. Consequently the asymptotic term of this K ‐functional is established. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Narrow Energy Gap Polymers with Absorptions up to 1 200 nm and their Photovoltaic Properties
Authors: Yi Hunan , Johnson Richard G. , Iraqi Ahmed , Mohamad David , Royce Richard , Lidzey David G.
Published: October 2008

A series of donor/acceptor carbazole copolymers comprising alternating 6,7‐diphenyl‐4,9‐bis‐(thiophen‐2‐yl)‐[1,2,5]thiadiazolo[3,4‐g]quinoxaline and 3,6‐dimethyl‐9‐alkyl‐9H‐carbazole repeat units (P1), or 3,6‐dimethyl‐9‐triarylamino‐9H‐carbazole repeat units (P2), or 9‐triarylamino‐9H‐carbazole repeat units (P3) has been prepared following Suzuki polymerization procedures. P3 absorbs light up to 1 200 nm and has an energy gap of 1.1 eV, while P1 and P2 have energy gaps of 1.3 and 1.25 eV, respectively. Photovoltaic cells with ITO/PEDOT:PSS/P3:PCBM (1:1 w/w)/Ca showed an open‐circuit voltage of 0.4 V under white light illumination, power conversion efficiency of 0.61%, and short‐circuit current of 5.2 mA · cm−2.

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On a capacity scaling algorithm for the constrained maximum flow problem
Authors: Çalışkan Cenk
Published: October 2008

Ahuja and Orlin (Networks 25 (1995), 89–98) introduced a constrained maximum flow problem and proposed its first polynomial combinatorial algorithm. The problem has important applications and is related to important problems such as the knapsack problem. In this article, we show that the algorithm may not terminate with a feasible solution in certain instances and provide a modified version with the same complexity. © 2008 Wiley Periodicals, Inc. NETWORKS, 2009
Cost minimization in wireless networks with a bounded and unbounded number of interfaces
Authors: Klasing Ralf , Kosowski Adrian , Navarra Alfredo
Published: October 2008

Given a graph G = (V,E) with |V| = n and |E| = m, which models a set of wireless devices (nodes V) connected by multiple radio interfaces (edges E), the aim is to switch on the minimum cost set of interfaces at the nodes to satisfy all the connections. A connection is satisfied when the endpoints of the corresponding edge share at least one active interface. Every node holds a subset of all the possible k interfaces. Depending on whether k is a priori bounded or not, the problem is called Cost Minimization in Multi‐Interface Networks or Cost Minimization in Unbounded Multi‐Interface Networks, respectively. We distinguish two main variations for both problems by treating the cost of maintaining an active interface as uniform (i.e., the same for all interfaces), or nonuniform.

For bounded k, we show that the problem is APX‐hard while we obtain an approximation factor of min ${\{\lceil {k + 1 \over 2} \rceil, {2m \over n}}\}$ for the uniform caseand a (k − 1)‐approximation for the nonuniform case.

For unbounded k, i.e., k is not set a priori but depends on the given instance, we prove that the problem is not approximable within O(log k) while the same approximation factor of the k‐bounded case holds in the uniform case, and a min $\{k-1, \, \sqrt{n} \, {(1 + {\rm In} \, n)} \}$‐approximation factor holds for the nonuniform case. Next, we also provide hardness and approximation results for several classes of networks: with bounded degree, trees, planar, and complete graphs. © 2008 Wiley Periodicals, Inc. NETWORKS, 2009
Mathematical models to reconstruct phylogenetic trees under the minimum evolution criterion
Authors: Catanzaro Daniele , Labbé Martine , Pesenti Raffaele , Salazar‐González Juan‐José
Published: October 2008

A basic problem in molecular biology is to rebuild phylogenetic trees (PT) from a set of DNA or protein sequences. Among different criteria used for this purpose, the minimum evolution criterion is an optimality based criterion aiming to rebuild PT characterized by a minimal length. This problem is known to be 𝒩𝒫‐hard. We introduce in this article some mixed integer programming models, and we also study possible cuts and lower bounds for the optimal value. So far, the number of sequences that can be involved in optimal phylogenetic reconstruction is still limited to 10. © 2008 Wiley Periodicals, Inc. NETWORKS, 2009
Ladder‐like polymer synthesized by template polymerization of poly(2‐ methacryloyloxyethyl methacrylate): architectural effect of ladder‐like polymer on glass transition temperature
Authors: Saito Reiko , Iijima Yuki
Published: October 2008

Ladder‐like polymers with different degrees of ladder were synthesized by copper‐mediated atom transfer radical polymerization (ATRP) of poly(2‐methacryloyloxyethyl methacrylate) with α,α′‐dibromo‐p‐xylene, as a bifunctional initiator. The livingness of ATRP was confirmed by kinetic analysis. The size of ladder‐like sequence in ladder‐like polymer was controlled by the hydrolysis. It was found that the remaining ester group was preferentially hydrolyzed and then the ester group of the ladder unit was hydrolyzed due to the high mobility of the remaining ester groups and high chemical resistance of the ladder‐like unit. The products are block copolymers with different content of ladder‐like sequences in the range of 18.2–73.5 mol%. All products showed two different glass transition temperatures (Tgs) and their high Tg was owing to the ladder‐like sequence. The segregation of cyclic units in the ladder‐like polymers was effective in improving the thermal stability of products. Copyright © 2008 John Wiley & Sons, Ltd.
Proteomic profiling of rice embryos from a hybrid rice cultivar and its parental lines
Authors: Wang Weiwei , Meng Bo , Ge Xiaomeng , Song Shuhui , Yang Yue , Yu Xiaomin , Wang Liguo , Hu Songnian , Liu Siqi , Yu Jun
Published: October 2008

Elite rice hybrids, when compared to their parental lines, exhibit increased yield and other favorable agronomical traits, such as pathogen‐ and water‐stress resistances, which are described as heterosis, and the molecular mechanism of heterosis remains to be elucidated. Since genomic sequences of the paternal (9311) and maternal lines (P64S) of a major rice hybrid variety LYP9 (Liang‐You‐Pei‐Jiu) were acquired recently, we performed a proteomic study on mature embryos of this hybrid triad based on 2‐DE and MALDI‐TOF MS analyses, and identified 54 differentially expressed proteins involved in major biological processes including nutrient reservoir, response to stress, and metabolism. We observed that most of the storage proteins exhibit overdominance and stress‐induced proteins display additivity. We compared proteomic results with transcriptomic data generated from the same embryo samples and found 28 candidate heterosis‐associated genes shared by the two datasets. We further traced back to their genomic structures including protein‐coding and regulatory regions and found that most of these genes have multiple copies in rice genomes as paralogous genes. Based on alignment of coding and regulation regions, we found that most of the differentially expressed genes at both protein and RNA levels are recent gene duplicates (paralogous genes) with relative little difference in protein‐coding regions between orthologous genes (between genes of the two parental genomes) as compared to regulatory regions that harbor numerous indels and base substitutions.
Multiplex analysis of cytokines as biomarkers that differentiate benign and malignant thyroid diseases
Authors: Linkov Faina , Ferris Robert L. , Yurkovetsky Zoya , Marrangoni Adele , Velikokhatnaya Lyudmila , Gooding William , Nolan Brian , Winans Matthew , Siegel Eric R. , Lokshin Anna , Stack Brendan C.
Published: October 2008

Thyroid cancer incidence is increasing, and its diagnosis can be challenging. Fine needle biopsy, the principal clinical tool to make a tissue diagnosis, leads to inconclusive diagnoses in up to 30% of the cases, leading to surgery. Advances in proteomics are improving abilities to diagnose malignant conditions using small samples of tissue or body fluids. We hypothesized that analysis of serum growth factors would uncover diagnostically informative differences between benign and malignant thyroid conditions. Using xMAP profiling, we evaluated concentrations of 19 cytokines, chemokines, and growth factors. We used sera from 23 patients with cancer (Malignant group), 24 patients with benign nodular thyroid disease (Benign group), and 23 healthy subjects (Normal group). In univariate analysis, five factors (epithelial growth factor, hepatocyte growth factor, Interleukins‐5 and ‐8, and regulated upon activation, normally T‐expressed and presumably secreted (RANTES) distinguished subjects with thyroid disease from the Normal group. In multivariate analysis, the set {Interleukin‐8, hepatocyte growth factor, monocyte‐induced γ interferon, interleukin‐12 p40} achieved noteworthy discrimination between Benign and Malignant groups (area under the receiver operating characteristics curve was 0.81 (95% confidence interval: 0.65–0.90)). Multiplex panels of serum biomarkers may be promising tools to diagnose cancer in patients presenting with evidence of nodular thyroid disease.
Simultaneous electro‐thermal experimental analysis of RF‐MEMS switches for high microwave power handling
Authors: Coccetti F. , Plana R.
Published: October 2008

An experimental setup for the characterization of electromagnetically induced heat on MEMS devices operating in high RF power regimes (> 5 W) is here proposed. The technique is based on infrared (IR) imaging of on‐probe DUT, in working conditions. The present work focuses on switches. Undoubtedly the switch represents the most emblematic and strategic component across the RF‐MEMS device portfolio. The capacitive ones can withstand more RF power with respect to DC contact (or ohmic) counterparts. Here, both serial and shunt configurations will be considered in the two working states (ON‐OFF). The approach presented here is based on a non‐intrusive real‐time IR imaging method capable to provide high resolution thermal maps and thermal transients of DUTs undertaking up to 6.3 W of CW incident power at 10 GHz. This technique represents a very powerful approach toward design optimization on the one hand and fast testing and product quality assessment against RF induced failures in production line for integrated RF MEMS and MMIC front‐end. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular nanodevices based on functionalized cyclodextrins
Authors: Velessiotis D. , Maffeo D. , Millios C. , Makarona E. , Viswanathan C. , Yannakopoulou K. , Mavridis I. , Pikramenou Z. , Glezos N.
Published: October 2008

Planar nanodevices, consisted of gold electrodes in the nanometer scale fabricated by a conventional e‐beam lithography and lift‐off process and functionalized by suitably synthesized cyclodextrin‐based self‐assembled monolayers were electrically characterized. The monolayers were supramolecularly connected to gold nanoparticles, so that the electrodes were bridged. Thus, conductive paths through the cyclodextrin molecules (ideally Au contact/molecule/Au bridge/molecule/Au contact) were formed. In order to study the electrical behaviour of the various samples, different arrangements were used, varying in the cyclodextrin derivative exploited, the way the CD molecules were connected the underlying gold surface and the association of the gold nanoparticles with the monolayer. Hysteresis effects that can be exploited in molecular memory devices were studied in terms of the type of the cyclodextrin complex. The transport properties as well as the topography of the cyclodextrin monolayers were also investigated by scanning tunnelling microscopy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
White photoluminescence from Si/SiO2 nanostructured film
Authors: Duong P. H. , Huy P. T. , Ngan N. T. T. , Tuan C. A. , Itoh T.
Published: October 2008

We present in this work the results of PL measurement of Si‐NC embedded in Si/SiO2 multilayer system. A very intense broad luminescence band was observed in the sample under illumination in vacuum by UV laser line. The PL intensity enhancement and quenching effect observed in different ambients can be attributed to the energy exchange from NC to MO. The storage of the annealed sample in vacuum for a long time drastically changed the PL properties of Si–NC. The origin of these phenomena will be discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron and exciton energy spectra in self‐assembled InGaAs/GaAs ring‐like nanostructures
Authors: Fomin V. M. , Gladilin V. N. , Devreese J. T. , Kleemans N. A. J. M. , Bozkurt M. , Koenraad P. M.
Published: October 2008

Theoretical analysis of the electron energy spectrum and the magnetization of an electron in a strained Inx Ga1–x As/GaAs self‐assembled quantum ring (SAQR) is performed with realistic parameters, determined from the cross‐sectional scanning‐tunneling microscopy characterization of that nanostructure. The effects of the Coulomb interaction on the energy spectrum of an exciton in a SAQR as well as on the optical‐transition probabilities are studied within our model of a SAQR. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of phase transition and expansion behaviour of Al2(WO4)3 by temperature‐regulated X‐ray diffraction
Authors: Hashimoto Takuya , Sugimoto Takayuki , Omoto Kazuki , Kineri Nanami , Ogata Yoichiro , Tsuda Kenji
Published: October 2008

X‐ray diffraction measurements of Al2(WO4)3 were carried out under various temperatures from 123 K to 373 K. Diffraction patterns above 273 K and below 253 K could be successfully explained as orthorhombic Pbcn (No. 60) and monoclinic P21/n (No. 14) with superstructure, respectively, which were in agreement with the results of convergent‐beam electron diffraction. Thermal expansion of low‐temperature monoclinic phase and slight shrinkage of high‐temperature orthorhombic phase were observed from the temperature dependence of lattice constants and molar volume, showing agreement with the result of dilatometry. It is revealed that abrupt expansion of Al2(WO4)3 at the structural phase transition is attributed to an abrupt increase of the c‐axis, which is parallel to the 21 screw axis and perpendicular to the n‐glide plane. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Negative thermal expansion in the PbTi1–xFex O3 system
Authors: Sun Ce , Cao Zhanmin , Chen Jun , Yu Ranbo , Sun Xueyi , Hu Penghao , Liu Guirong , Xing Xianran
Published: October 2008

Multiferroic magnetoelectric PbTi1–x Fex O3 compounds were prepared using a solid‐state reaction method in the composition range 0 ≤ x ≤ 0.15. The temperature dependence of lattice parameters of PbTi1–x Fex O3 was determined from high‐temperature X‐ray diffraction. The average volumetric thermal expansion coefficient of the tetragonal phase increases from –1.99 × 10–5 °C–1 for PbTiO3 to –1.13 × 10–5 °C–1 for PbTi0.90Fe0.10O3. The negative thermal expansion and the Curie temperature (TC) of PbTiO3 are reduced by the introduction of Fe. Raman spectral measurements show a softening behaviour for A1(1TO) and A1(2TO) of PbTi1–x Fex O3 with increasing Fe concentration, which means that the decrease in both TC and c /a is due to the reduced spontaneous polarization. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
QD technology and market prospects in the sectors of space exploration, biomedicine, defense, and security
Authors: Charitidis C. A. , Golnas A. , Chouliaras F. , Arpatzanis N. , Dimitriadis C. A. , Lee J. I. , Bakolias C.
Published: October 2008

Quantum dots (QD) are a unique subset of nanomaterials characterized by their extraordinary quantum confinement behaviour. Even though the quantum dot industry is still in its infancy with revenues now reaching $10 million, it is expected to surpass $500 million in 2009. However, in order to leverage the full potential of the QD technology, new fabrication processes must be developed to attain high detectivity and high operating temperature (HOT) photodetector devices. The Quantum Dot Infrared Photodetectors (QDIPs) possess an immense potential for civilian and military applications due to the distinct characteristics stemming from their dimensionality – which provides 3D carrier confinement and the capacity for normal‐incidence detection – and their amenability to bandgap engineering – which allows tailoring the peak and cutoff wavelengths according to custom needs. The QDIPs, especially when optimized to operate at higher temperatures, can become critical components in space exploration, defence and security, optical communication, quantum computing and cryptography, and medical imaging applications. Robust and reliable solutions for these fields will command a premium position in the marketplace as by responding to the societal need for secure electronic transactions, exponentially faster data processing, and higher quality diagnostic tools. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A wireless sensor network for building structural health monitoring and seismic detection
Authors: Katsikogiannis P. , Zervas E. , Kaltsas G.
Published: October 2008

The aim of this work is to develop a wireless sensor network for both structural health monitoring of civil infrastructure and seismic event detection and recording. The network is consisted of a small number of nodes, on which high resolution ADXL accelerometers are connected. The nodes are placed within the building in pre‐determined locations, in order to acquire and record data generated by seismic activity. A massive installation of such networks could monitor the seismic activity of wide areas within a city, allowing civil safeguard to act quickly in case of serious earthquakes events. The nodes are stationary and the network is self‐organized and self‐configured. We mainly focus on the routing protocol of the network and the time synchronization of the data. Since all data are gathered to a master node placed at the base of the building, successful transmission to that node is of great importance. Therefore, the developed routing protocol emphasizes at the delivery robustness of the transmitted data, trading off latency. Data travel through a multi‐hop order and no periodic routing advertisement is required. Regarding the time synchronization, the desired accuracy is on the order of 1ms. In order to achieve such accuracy, a time synchronization protocol has been developed. Clock differences and drifts between the nodes are calculated and taken into account when synchronizing the acquired data, thus accomplishing even better accuracy (tens of μs). Experimental evaluation in laboratory specially designed set‐up, proved that the performance of both protocols meet the needs of the propose application. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of photoluminescence and chemical composition of the nanostructured silicon in water solutions
Authors: Shevchenko V. B. , Makara V. A. , Dacenko O. I. , Veblaya T. S.
Published: October 2008

Modification of the IR absorption spectra and photoluminescent properties of nanoporous silicon as a result of its interaction with water solutions is investigated. The effect of air pre‐oxidation and the solution pH on the interaction is studied. It is found that the reaction of silicon dissolution dominates at the first stage of water treatment, while the formation of the stoichiometric silicon oxide occurs at the second one. Thereafter, the properties of nanoporous silicon are stabilized. The pre‐oxidation extent of the sample is found to determine the stabilization time for its properties and the ultimate photoluminescence (PL) parameters. Variation of the solution pH from 4 to 8.5 affects only the evolution rate of the PL spectra. The modifications of the nanostructured silicon PL spectra are explained within the quantum‐size model of luminescence. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Naringin ameliorates mitochondrial lipid peroxides, antioxidants and lipids in isoproterenol‐induced myocardial infarction in Wistar rats
Authors: Rajadurai M. , Prince P. Stanely Mainzen
Published: October 2008

The present study was undertaken to evaluate the preventive role of naringin on mitochondrial lipid peroxides, antioxidants and lipids in isoproterenol (ISO)‐induced myocardial infarction (MI) in male Wistar rats. Rats subcutaneously injected with ISO (85 mg/kg) at an interval of 24 h for 2 days resulted in a significant increase in the levels of mitochondrial lipid peroxides with a significant decrease in the activities/levels of mitochondrial antioxidants (superoxide dismutase, catalase, glutathione peroxidase, glutathione‐S‐transferase and reduced glutathione). ISO‐induction also showed a significant increase in the levels of mitochondrial cholesterol, triglycerides and free fatty acids with a subsequent decrease in the levels of phospholipids. Oral pretreatment with naringin (10, 20 and 40 mg/kg) to ISO‐induced rats daily for a period of 56 days significantly decreased the levels of mitochondrial lipid peroxides with a significant increase in the activities/levels of mitochondrial antioxidants and significantly minimized the alterations in the mitochondrial lipid levels in ISO‐induced rats. Thus, the findings demonstrate that naringin prevents alterations in mitochondrial lipid peroxides, antioxidants and lipids in ISO‐induced MI in rats. Copyright © 2008 John Wiley & Sons, Ltd.
Accelerator mass spectrometry 14C determination in CO2 produced from laser decomposition of aragonite
Authors: Rosenheim Brad E. , Thorrold Simon R. , Roberts Mark L.
Published: October 2008

The determination of 14C in aragonite (CaCO3) decomposed thermally to CO2 using an yttrium‐aluminum‐garnet doped neodymium laser is reported. Laser decomposition accelerator mass spectrometry (LD‐AMS) measurements reproduce AMS determinations of 14C from the conventional reaction of aragonite with concentrated phosphoric acid. The lack of significant differences between these sets of measurements indicates that LD‐AMS radiocarbon dating can overcome the significant fractionation that has been observed during stable isotope (C and O) laser decomposition analysis of different carbonate minerals. The laser regularly converted nearly 30% of material removed into CO2 despite it being optimized for ablation, where laser energy breaks material apart rather than chemically altering it. These results illustrate promise for using laser decomposition on the front‐end of AMS systems that directly measure CO2 gas. The feasibility of such measurements depends on (1) the improvement of material removal and/or CO2 generation efficiency of the laser decomposition system and (2) the ionization efficiency of AMS systems measuring continuously flowing CO2. Copyright © 2008 John Wiley & Sons, Ltd.
Direct measurement of the nitrogen content by XPS in self‐passivated TaNx thin films
Authors: Lamour Patrice , Fioux Philippe , Ponche Arnaud , Nardin Michel , Vallat Marie‐France , Dugay Pierre , Brun Jean‐Paul , Moreaud Nathanaël , Pinvidic Jean‐Marc
Published: October 2008

The nitrogen content in tantalum nitride (TaNx) thin films, where x indicates that TaNx is not generally stoechiometric, can be measured directly by XPS. This is the purpose of the present study. However, the XPS spectra of TaNx present electron energy loss spectroscopy (EELS) peaks that lead to a complex peak fitting, particularly for self‐passivated thin films. A complete peak fitting procedure based upon Tougaard's background, the Doniach‐Sunjic Function and EELS peaks, is presented. It is applied to two self‐passivated TaNx thin films elaborated by reactive sputtering and presenting a different nitrogen content. The physical properties of these surfaces are interpreted in terms of Ta 4f7/2 chemical states directly dependent on the nitrogen content. The main results are discussed and improvements are proposed to the method. Copyright © 2008 John Wiley & Sons, Ltd.
Behaviors of single CO2molecule on pentagon at carbon nanotube tip observed by field emission microscopy
Authors: Kishimoto Yoshiki , Hata Koichi
Published: October 2008

Behaviors of a single CO2 molecule on a clean pentagon at a tip of multiwall carbon nanotube (MWNT) were investigated by field emission microscopy (FEM). A CO2 admolecule was recognized as a gourd‐shaped bright spot in an FEM image similar to the nitrogen admolecule previously reported. The shape of bright spot reflected an adsorption state that the molecular axis was parallel to substrate pentagon. The CO2 admolecule moved between five steady adsorption sites which were reflected in the geometrical five‐fold symmetry of pentagon. From these experimental results, we propose an adsorption site model for a CO2 admolecule on a clean pentagon. By an Nd:YAG pulse laser irradiation, the CO2 admolecule successfully desorbed without any damage of the substrate pentagon whereas the end‐atoms are oxygen. This suggests that a CO2 molecule on a pentagon is physisorbed and chemically inert for surfaces of MWNT. Copyright © 2008 John Wiley & Sons, Ltd.
Sources of stress and coping strategies of US soccer officials
Authors: Voight Mike
Published: October 2008

Stress from officiating has been found to have a profound impact on official's mental health, attentional focus, performance, satisfaction with their profession and dropout intentions. Although some studies have been conducted regarding the frequency and intensity of the major sources of stress experienced by sport officials, no research has attempted to determine how sport officials cope or attempt to cope with these stressors. Through a national soccer official organization, questionnaire packets were administered to over 200 officials. Questionnaire packets included sources of stress and ways of coping questionnaires. The top sources of stress experienced by the officials included ‘conflict between officiating and family demands,’ ‘making a controversial call’ and ‘conflict between officiating and work demands.’ The top acute coping strategies utilized by the officials included ‘thought hard about steps to manage’ and ‘asked fellow officials what they did’ (problem‐focused strategies). Other results indicated the importance of officials' learning and implementing numerous stress management interventions, including time management, restructuring unproductive thoughts, physiological relaxation techniques, communication training and mental skill training techniques such as imagery, relaxation breathing and self talk. Copyright © 2008 John Wiley & Sons, Ltd.
Rhétorique, dialectique et probabilité au XVIe Siècle
Authors: Spranzi zuber Marta
Published: October 2008

Dans cet article sont examinés les différents sens du mot « probable » tel qu'il apparaît dans certains commentaires des Topiques d'Aristote, notamment ceux d'Alexandre d' Aphrodise, d' Averroès et surtout celui d' Agostino Nifo, ainsi que dans des traités qui s'en inspirent, notamment le De dialogo de Carlo Sigonio et le De inventione dialectica de Rudolph Agricola. On retrouve dans ces écrits les trois sens principaux de ce mot depuis Aristote et Cicéron: celui d'opinion communément admise, celui d'opinion qui correspond à« ce qui se passe la plupart du temps» et celui d'opinion apte à produire la persuasion. À partir de cette polysémie du mot «probable», l'article met en évidence les différentes fonctions attribuées aux opinions probables dans ces divers écrits, plus particulièrement au xvie siècle. L'association du mot «probable» avec la notion de vérité contingente conduit à mettre en valeur le lien entre hypothèse probable et conjecture.
Révolution industrielle logique et signification de l'opératoire
Authors: Durand-Richard Marie-José
Published: October 2008

Dans la première moitié du XIXe siècle en Angleterre, autour de Charles Babbage (1791-1871), John F. W. Herschel (1792-1871), George Peacock (1791- 1858), Duncan F. Gregory (1813-1844), Augustus de Morgan (1806-1871), George Boole (1815-1864), et d'autres auteurs moins connus, un réseau d'algébristes renouvelle singulièrement la conception de l'algèbre, à tel point que leur travail est le plus souvent interprété comme émergence des travaux sur l'algèbre abstraite. Comme ces algébristes sont également des réformateurs impliqués dans la réorganisation de la science, il s'agira de proposer de ces travaux une lecture plus contextuelle, afin d'éclairer leur inscription parmi les effets de la Révolution industrielle (1760-1830), et d'analyser leur rôle de médiation culturelle entre les racines d'un savoir universitaire fondé sur la fidélité aux Anciens, et de nouvelles formes d'élaboration des connaissances. Une médiation marquée par un premier rapprochement entre algèbre et logique.
L'histoire des sciences et l'enseignement scientifique
Authors: HuliN Nicole
Published: October 2008

Dans la deuxième moitié du XIXe siècle, Victor Duruy introduit une innovation remarquable avec l'instauration d'une composition de méthode et d'histoire des sciences dans les trois agrégations scientifiques (mathématiques, sciences physiques, sciences naturelles). Les sujets posés ont été rassemblés et la place réservée à l'histoire, après l'abandon de l'épreuve, est analysée. Au début du xxe siècle, l'histoire des sciences a totalement disparu de l'agrégation; mais le problème de la formation des professeurs en histoire des sciences est encore posé et des demandes sont formulées pour inclure la discipline dans leur cursus. L'introduction de l'histoire des sciences pourrait contribuer à « décloisonner » les disciplines et l'histoire de l'enseignement des sciences permettrait de donner aux professeurs du recul par rapport à la chose enseignée.
L'expérience des nombres de bernard frenicle de bessy
Authors: Goldstein Catherine
Published: October 2008

Focalisé sur un problème posé par Bernard Frenicle de Bessy vers 1639, sa solution et les réponses de ses correspondants, cet article s'attache à décrire plusieurs registres enchevêtrés de l'expérience du mathématicien: expérimentation sur les nombres empruntée en partie aux sciences de la nature, injonctions d'une pratique collective cimentée par les problèmes et leurs constructions explicites, entraînement personnel de l'attention et du savoir-faire s'articulent ainsi dans les efforts de Frenicle pour contester la suprématie de l'analyse algébrique et dans les modes de conviction qui fondent son travail. Ce récit d'expérience permet en retour d'apprécier les problèmes que posèrent à Frenicle la transmission de ses résultats et, à ses historiens, la restitution de son activité.
High Postoperative Interleukin‐8 Levels Related to Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Surgery
Authors: Wu Zhong‐Kai , Laurikka Jari , Vikman Saila , Nieminen Riina , Moilanen Eeva , Tarkka Matti R.
Published: October 2008

Background

Atrial fibrillation (AF) is the most frequently encountered postoperative arrhythmic complication after coronary artery bypass graft (CABG). There is increasing evidence to support the influence of inflammation in the pathogenesis of AF. The aim of the present study was to investigate the relation of postoperative new AF and systemic inflammatory changes after CABG.

Methods

A total of 113 CABG patients were recruited in the present study. Holter data from 24‐hour electrocardiography were collected from 1 day before the operation to postoperative day 2 (POD2). AF was registered as positive if any AF event occurred. Serum cytokine, including interleukin (IL)‐6, IL‐8, and IL‐10 were analyzed before and after surgery.

Results

The overall incidences of postoperative AF and sustained AF were 36.3% and 31.9%, respectively. Patients with postoperative AF had longer respiratory treatment, intensive care unit treatment, and inotropic medication periods. Similar concentrations of serum IL‐6 were found after surgery in patients with and without AF. The concentrations of serum IL‐8 was significantly higher at 2 hours and on POD1 and POD2 in patients with postoperative AF. The concentration of serum IL‐10 was significantly higher on POD1 in patients with postoperative AF.

Conclusions

Postoperative AF in CABG patients is associated with a more complicated postoperative outcome. Higher concentrations of serum IL‐8 in CABG patients with postoperative AF suggested that an influence of inflammation in the pathogenesis postoperative AF after open heart surgery.