bluuebunny/crossref_metadata_2025 huggingface dataset:
The influences of ENSO and the subtropical Indian Ocean Dipole on tropical cyclone trajectories in the southwestern Indian Ocean
Authors: Ash Kevin D. , Matyas Corene J.
Published: November 2010

El Niño‐Southern Oscillation (ENSO) is known to associate with variability of tropical cyclone (TC) trajectories in the southwestern Indian Ocean. However, consideration of ENSO phase alone does not account for all variability of TC tracks within this region. This study demonstrates that the subtropical Indian Ocean Dipole (SIOD) sea‐surface temperature anomaly pattern is also significantly associated with variability in southwestern Indian Ocean TC tracks. Hierarchical cluster analysis is employed to group TC trajectories by their initial and final positions. Median monthly values of the Niño‐3.4 index and Subtropical Dipole Index corresponding to the life cycles of TCs in each group are compared using non‐parametric analysis of variance. The results suggest that both ENSO and SIOD are significantly associated with different types of southwestern Indian Ocean TC trajectories. Furthermore, significant interactions of ENSO and SIOD phases are found to influence certain types of TC tracks using contingency table tests. During simultaneous warm ENSO and negative SIOD phases, TCs moving across the southwestern Indian Ocean tend to follow more southward or southeastward tracks. During neutral or cool ENSO and positive SIOD phases, TCs moving through the southwestern Indian Ocean tend toward more westward trajectories. These findings suggest that use of an SIOD index in addition to an ENSO index could improve intraseasonal to seasonal statistical prediction of southwestern Indian basin TC activity. Copyright © 2010 Royal Meteorological Society
Raman identification of H2CO in aqueous solutions
Authors: Hanoune B. , Paccou L. , Delcroix P. , Guinet Y.
Published: November 2010

Aqueous formaldehyde solutions of mole fraction from 0.05 to 0.20 were studied by Raman spectroscopy at temperatures up to 180 °C. The previously unreported Raman spectrum of formaldehyde under its non‐hydrated form H2CO has been identified, in addition to the already known bands from methanediol CH2(OH)2 and poly(oxymethylene)glycols HO(CH2O)nH formed by hydration and subsequent polymerization of the formaldehyde molecules. The experimental spectrum of formaldehyde in solutions agrees perfectly with the theoretical calculations. Copyright © 2010 John Wiley & Sons, Ltd.
High resolution spectroscopic imaging of GABA at 3 Tesla
Authors: Zhu He , Edden Richard A. E. , Ouwerkerk Ronald , Barker Peter B.
Published: November 2010

A spin echo‐based MRSI sequence was developed to acquire edited spectra of γ‐aminobutyric acid in an entire slice. Water and lipid signals were suppressed by a dual‐band presaturation sequence, which included integrated outer volume suppression pulses for additional lipid suppression. Experiments in three normal volunteers were performed at 3 T using a 32‐channel head coil. High signal‐to‐noise ratio spectra and metabolic images of γ‐aminobutyric acid were acquired from nominal 4.5 cm3 voxels (estimated actual voxel size 7.0 cm3) in a scan time of 17 min. The sequence is also expected to co‐edit homocarnosine and macromolecules, giving a composite γ‐aminobutyric acid+ resonance. The γ‐aminobutyric acid+ to water ratio was measured using a companion water MRSI scan and was found to correlate linearly with the % gray matter (GM) of each voxel (γ‐aminobutyric acid+/water = (1.5 × GM + 3.2) × 10−5, R = 0.27), with higher γ‐aminobutyric acid+ levels in gray matter compared with white. In conclusion, high signal‐to‐noise ratio γ‐aminobutyric acid‐MRSI is possible at 3 T within clinically feasible scan times. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Intrascanner and interscanner variability of magnetization transfer‐sensitized balanced steady‐state free precession imaging
Authors: Gloor M. , Scheffler K. , Bieri O.
Published: November 2010

Recently, a new and fast three‐dimensional imaging technique for magnetization transfer ratio (MTR) imaging has been proposed based on a balanced steady‐state free precession protocol with modified radiofrequency pulses. In this study, optimal balanced steady‐state free precession MTR protocol parameters were derived for maximum stability and reproducibility. Variability between scans was assessed within white and gray matter for nine healthy volunteers using two different 1.5 T clinical systems at six different sites. Intrascanner and interscanner MTR measurements were well reproducible (coefficient of variation: cv < 0.012 and cv < 0.015, respectively) and results indicate a high stability across sites (cv < 0.017) for optimal flip angle settings. This study demonstrates that balanced steady‐state free precession MTR not only benefits from short acquisition time and high signal‐to‐noise ratio but also offers excellent reproducibility and low variability, and it is thus proposed for clinical MTR scans at individual sites as well as for multicenter studies. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Soft poly(n‐butyl acrylate) networks with tailored mechanical properties designed as substrates for in vitro models
Authors: Cui J. , Kratz K. , Hiebl B. , Jung F. , Lendlein A.
Published: November 2010

Mechanical conditioning can serve as a potent tool to influence mechano‐responsive cells, which plays a prominent role during formation and regeneration of functional tissue. Recently, the differentiation of mesenchymal stem cells could be influenced by the local stiffness of hydrogels used as 2D substrates. However, the mechanical properties and the swellability of hydrogels in physiological liquids are difficult to control precisely as their properties strongly depend on physical parameters like ionic strength or pH value. Here, we explored amorphous, hydrophobic poly(n‐butyl acrylate) networks (cPnBA) as soft substrates for cell culture system with adjustable mechanical properties. cPnBAs were synthesized via bulk radical polymerization from n‐butyl acrylate (nBA) and poly(propylene glycol) dimethacrylate (PPGDMA) as crosslinker. The Young's modulus for cPnBAs determined by tensile tests could be systematically adjusted from 100 kPa to 10 MPa by increasing the PPGDMA‐content at ambient temperature, while the glass transition temperature (Tg) was found to increase from −46 to −22°C. All cPnBAs exhibited similar surface properties with a surface roughness (Rq) in the range from 1.4 to 0.4 µm and advancing contact angles from 115° to 100°, which remained constant after ethylene oxide sterilization. The extracts of sterilized materials were tested for cytotoxic effects with L929 cells. All tested samples were non‐cytotoxic. The functional integrity of cell membranes and mitochondrial activity stayed unaffected. The investigated polymer networks are promising candidates as soft substrates for passive mechanical stimulation of cells in vitro in cell culture devices or in vivo as implant coatings. Copyright © 2010 John Wiley & Sons, Ltd.
Crystallization of polypropylene near the surface in injection‐molded plaques: A comparison of morphology and a numerical analysis
Authors: Kobayashi Yutaka , Otsuki Yasuhiko , Kanno Hiroaki , Sasakawa Tomoyoshi , Hanamoto Yasuhiro , Kanai Toshitaka
Published: November 2010

Skin morphology formation on injection‐molded isotactic polypropylene (PP) was investigated using micro‐beam synchrotron wide‐angle X‐ray diffraction and numerical simulation. The 1–20 μm depth range was characterized with an X‐ray beam of 0.273 μm χ 0.389 μm in size. From an evaluation of doping nucleating agents (NA) in PP, the NAs did not work at a depth of 1 μm. α‐specified NA affected crystallization within a 5‐μm depth. β‐specified PP showed α‐form crystallinity at the 5–20 μm depth. The mesomorphic crystal near the surface showed extremely high orientation. From viscoelastic flow simulation, PP molecules near the surface were oriented in the flow direction by extensional flow in the flow front, but freezing occurred faster than flow‐induced crystallization. It was estimated that the delay of crystallization occurred during the transient temperature. The deformation rate did not cause a difference in crystal morphology near the surface, but the cooling rate did. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.
Electrical properties of polyaniline‐manganese chloride composites
Authors: Ozkazanc Ersel , Zor Sibel , Ozkazanc Hatice , Abaci Ufuk
Published: November 2010

Electrical and morphological properties of Polyaniline (PANI) filled with various mass fractions of manganese chloride (MnCl2) synthesized in aqueous hydrochloric acid (HCl) medium using ammonium persulphate as an oxidant were investigated. The sample morphology was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Significant changes were observed in the morphology of the samples depending on the filler level. The direct current (dc) and alternating current (ac) electrical properties were investigated as a function of temperature. The dc conductivity decreased 72% with 10% filler level whereas ac conductivity has shown a 120% increase with 6% filler level at room temperature. It is shown that the alternating charge transport mechanism of the unfilled and filled polyaniline samples is consistent with correlated barrier hopping (CBH) model. Imaginary (M″) parts of electric modulus exhibited temperature‐dependent dielectric relaxation behavior for both filled and unfilled PANI samples. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.
Developing image‐contrast theory and analysis methods in high‐resolution electron microscopy
Authors: Li F. H.
Published: November 2010

It is reviewed that the structural information obtained from high‐resolution electron microscope images can be greatly improved by utilizing a group of analysis methods developed based on an image‐contrast theory derived particularly to show the image‐intensity change with the sample thickness. It is introduced that the experimental images that do not represent the structures of examined samples can be transformed into the structure maps by deconvolution processing with the structure resolution enhanced up to the information limit of the microscope, or further, for perfect crystals, to the electron diffraction limit by subsequently combining the corrected electron‐diffraction data and utilizing the structure analysis methods developed in X‐ray crystallography, and it becomes possible to recognize atoms with different atomic weights by analyzing the image‐contrast change with the sample thickness, etc. The derivation of the image‐contrast theory, the principle and functions of the developed image‐analysis methods are demonstrated. Typical examples of applications to the ab initio crystal‐structure determination and studies of crystal defects at atomic level are given.
The relationship between networks, institutional development, and performance in foreign investments
Authors: Shaner Janet , Maznevski Martha
Published: November 2010

This paper empirically examines the relationship between the external business network of a country business unit (CBU) of a multinational firm, its performance, and the unique institutional characteristics of the foreign market in which it operates. We develop hypotheses about the CBU network structure associated with operating margin given different levels of institutional development, and the categories of network contacts associated with CBU operating margin. We test the hypotheses using social network analysis in 54 CBUs in two different business segments within one multinational company. Results show that the CBU network structure associated with higher operating margin depended partially on the level of the country's institutional development, and that network composition related strongly to CBU operating margin. We identify implications for research. Copyright © 2010 John Wiley & Sons, Ltd.
Fluorographene: A Two‐Dimensional Counterpart of Teflon
Authors: Nair Rahul R. , Ren Wencai , Jalil Rashid , Riaz Ibtsam , Kravets Vasyl G. , Britnell Liam , Blake Peter , Schedin Fredrik , Mayorov Alexander S. , Yuan Shengjun , Katsnelson Mikhail I. , Cheng Hui‐Ming , Strupinski Wlodek , Bulusheva Lyubov G. , Okotrub Alexander V. , Grigorieva Irina V. , Grigorenko Alexander N. , Novoselov Kostya S. , Geim Andre K.
Published: November 2010

A stoichiometric derivative of graphene with a fluorine atom attached to each carbon is reported. Raman, optical, structural, micromechanical, and transport studies show that the material is qualitatively different from the known graphene‐based nonstoichiometric derivatives. Fluorographene is a high‐quality insulator (resistivity >1012 Ω) with an optical gap of 3 eV. It inherits the mechanical strength of graphene, exhibiting a Young’s modulus of 100 N m−1 and sustaining strains of 15%. Fluorographene is inert and stable up to 400 °C even in air, similar to Teflon.
Climate catastrophes and fear
Authors: Dörries Matthias
Published: November 2010

Describing a topic of recent significance, the terms ‘climate catastrophe’ and ‘fear’ have made their way into common speech. ‘Climate catastrophe’ (Klimakatastrophe) was chosen by the German Language Society as word of the year in 2007, while ‘fear’ has gained new presence since 9/11, associated with terrorism, on‐going human destruction of the environment, and more generally with rather vague fears of the future: a state of heightened anxiety. I look at this issue from a historical perspective, asking how our current society has come to conceive of climate change in terms of catastrophe and fear, in line with historians' demands for a more subtle cultural and historical understanding of climate and fear in human society. The current discourses of fear over climate change reflect the attempts to come to grips with the long‐term issue of anthropogenic climate change; they are appeals for action (or calls to inaction) and imply claims to power, while stressing that the issue is political and cultural, not merely a matter of science and reason alone. WIREs Clim Change 2010 1 885–890 DOI: 10.1002/wcc.79

This article is categorized under:

Climate, History, Society, Culture > Ideas and Knowledge
Climate change knowledge and social movement theory
Authors: Jamison Andrew
Published: November 2010

This article discusses climate change knowledge from the perspective of social movement theory, a relatively neglected topic in the literature on climate change knowledge. This article reviews relevant studies and theories of social movements with special attention to the role of knowledge‐making in social movements, before tracing the relations between social movements and climate change knowledge from the 1970s to the present. Climate change first emerged as an issue of public concern within the context of the environmental movements of the 1970s and 1980s, while skepticism was shaped, in significant ways, by the neo‐conservative and neo‐nationalist movements that grew to political significance in the 1980s and 1990s. The neo‐liberal movements of the 1990s and 2000s have helped shape the recent rise to public attention of climate change as an overarching political problem. Finally, this article discusses how concerns with ‘climate justice’ have emerged as part of a social movement for global justice, and concludes by contrasting the different social movements that have affected and influenced the making of climate change knowledge.WIREs Clim Change2010 1 811–823 DOI: 10.1002/wcc.88

This article is categorized under:

Social Status of Climate Change Knowledge > Climate Science and Social Movements
Physical aging of molecular glasses studied by a device allowing for rapid thermal equilibration
Authors: Hecksher Tina , Olsen Niels Boye , Niss Kristine , Dyre Jeppe C.
Published: November 2010

Aging to the equilibrium liquid state of organic glasses is studied. The glasses were prepared by cooling the liquid to temperatures just below the glass transition. Aging following a temperature jump was studied by measuring the dielectric loss at a fixed frequency using a microregulator in which temperature is controlled by means of a Peltier element. Compared to conventional equipment, the new device adds almost two orders of magnitude to the span of observable aging times. Data for the following five glass-forming liquids are presented: dibutyl phthalate, diethyl phthalate, 2,3-epoxy propyl-phenyl-ether, 5-polyphenyl-ether, and triphenyl phosphite. The aging data were analyzed using the Tool–Narayanaswamy formalism. The following features are found for all five liquids: (1) The liquid has an “internal clock,” a fact that is established by showing that aging is controlled by the same material time that controls the dielectric properties. (2) There are no so-called expansion gaps between the long-time limits of the relaxation rates following up and down jumps to the same temperature. (3) At long times, the structural relaxation appears to follow a simple exponential decay. (4) For small temperature steps, the rate of the long-time exponential structural relaxation is identical to that of the long-time decay of the dipole autocorrelation function.
Investigation of possible half-metallic antiferromagnets on double perovskites LaABB′O6 (A=Ca,Sr,Ba; B,B′=transition elements)
Authors: Chen S. H. , Xiao Z. R. , Liu Y. P. , Wang Y. K.
Published: November 2010

We thoroughly investigated all the possible (C229=406) candidates of half-metallic (HM) antiferromagnet (AFM) with the structure LaSrBB′O6, where BB′ pairs are any combination of two 3d, 4d, and 5d transition elements. Sr was also replaced by Ca or Ba whenever HM-AFM was found and similar calculation was performed in order to probe more possibilities. We have found that LaAWXO6, where A=Ca,Sr,Ba and X=Tc,Re are potential candidates of HM-AFM. Among those HM-AFM candidates, LaAWReO6 (A=Sr,Ba) are rather robust than others for the structural optimization. Including previous Wang and Guo’s work in 2006 and this work, we believe that we have found all possible HM-AFM candidates for double perovskites structure LaABB′O6 (A=Ca,Sr,Ba and B,B′=transition elements).
Experimental characterization of aviation-fuel cavitation
Authors: Dunn Patrick F. , Thomas Flint O. , Davis Michael P. , Dorofeeva Irina E.
Published: November 2010

The results of an experimental investigation of the gaseous cavitation of JP-8 aviation fuel in a converging-diverging nozzle are presented. Fuel cavitation is experimentally characterized by high-speed digital imaging, static pressure distributions, and nonintrusive void fraction and bubble velocity measurements. For comparative purposes, experiments were performed using distilled water and dodecane for the same nozzle and nozzle pressure ratios. Dodecane, the largest component of JP-8 by weight, served as its single-component surrogate. For each working fluid, the experiments examined two different flow regimes: an initially single-phase liquid flow in which no cavitation occurred and another that evolved into two-phase cavitating flow. Additional experiments were performed to study the effect of air bubbles injected into either water or JP-8 at the nozzle inlet. For a sufficiently low range of imposed back pressures, gaseous cavitation led to choked flow for each working fluid. The character of the cavitation in the three fluids was different. These differences are highlighted and plausible mechanisms responsible for the observed behavior are discussed.
Superperiodic conductance in a molecularly wired double-dot system self-assembled in a nanogap electrode
Authors: Noguchi Yutaka , Terui Toshifumi , Katayama Takuya , Matsushita Michio M. , Sugawara Tadashi
Published: November 2010

We examined charge transport properties of two gold nanoparticles (GNPs) in a nanogap transistor with a gap width of ∼10 nm. The GNPs connected to each other and to outer electrodes through a small number of dithiolated terthiophene wire molecules as a tunneling barrier. The transport property measured at 11 K was analyzed based on the theory of double-dot single-electron transistors and inelastic cotunneling. The results clearly show mutual Coulomb interactions between the two GNPs. Moreover, we found the appearance of superperiodic conductance, because of differences in the charging energy of the two GNPs.
A Foucault’s pendulum design
Authors: Salva Horacio R. , Benavides Rubén E. , Perez Julio C. , Cuscueta Diego J.
Published: November 2010

In this article we explain our design and their performance, of a Foucault pendulum capable of continuous operation with a following system of the oscillation plane. We have built two pendulums, one of 2.835 m length and other of 4.975 m length. The oscillation amplitudes in either case were 1.8 and 1 deg, respectively. In our latitude the precession speed (9.89 deg/h counterclockwise) can be measured within 0.5 and 0.2 deg/h. The arrangement detected some earthquakes of medium intensity that took place as far as 765 km.
A simple method to deposit palladium doped SnO2 thin films using plasma enhanced chemical vapor deposition technique
Authors: Kim Young Soon , Ansari S. G. , Ansari Z. A. , Wahab Rizwan , Shin Hyung-Shik
Published: November 2010

This work presents a simple method to deposit palladium doped tin oxide (SnO2) thin films using modified plasma enhanced chemical vapor deposition as a function of deposition temperature at a radio frequency plasma power of 150 W. Stannic chloride (SnCl4) was used as precursor and oxygen (O2, 100 SCCM) (SCCM denotes cubic centimeter per minute at STP) as reactant gas. Palladium hexafluroacetyleacetonate (Pd(C5HF6O2)2) was used as a precursor for palladium. Fine granular morphology was observed with tetragonal rutile structure. A peak related to Pd2Sn is observed, whose intensity increases slightly with deposition temperature. Electrical resistivity value decreased from 8.6 to 0.9 mΩ cm as a function of deposition temperature from 400 to 600 °C. Photoelectron peaks related to Sn 3d, Sn 3p3, Sn 4d, O 1s, and C 1s were detected with varying intensities as a function of deposition temperature.
Structural and optical properties of zirconium doped lithium niobate crystals
Authors: Argiolas N. , Bazzan M. , Ciampolillo M. V. , Pozzobon P. , Sada C. , Saoner L. , Zaltron A. M. , Bacci L. , Minzioni P. , Nava G. , Parravicini J. , Yan W. , Cristiani I. , Degiorgio V.
Published: November 2010

Zirconium doped lithium niobate is a promising candidate as a substrate for nonlinear optical applications, since it does not suffer from the so-called “optical damage.” In order to optimize this aspect, the proper Zr concentration has be used, hence the precise determination of the so-called “threshold concentration,” i.e., the concentration above which the photorefractive effect is markedly reduced, is of great importance. In this work, we prepared by Czochralski growth a series of Zr-doped lithium niobate crystals with various Zr content and studied them using structural (high-resolution x-ray diffraction) and optical (birefringence) measurements as a function of the dopant content in the melt. Both the approaches pointed out a marked change in the crystal characteristics for a Zr concentration between 1.5 and 2 mol %, a value which is identified as the threshold concentration.
Static and dynamic magnetic behavior of nanocrystalline and nanocomposites of (Mn0.6Zn0.4Fe2O4)(1−z)(SiO2)z (z=0.0,0.10,0.15,0.25)
Authors: Modak S. , Karan S. , Roy S. K. , Chakrabarti P. K.
Published: November 2010

Nanocrystalline and nanocomposites of (Mn0.6Zn0.4Fe2O4)(1−z)(SiO2)z (z=0.0,0.10,0.15,0.25) were prepared by sol-gel method. The as-prepared samples were annealed at 200, 400, and 600 °C. The crystallographic phases, particle sizes and their distributions, etc. of the annealed samples were determined by x-ray diffraction and high-resolution transmission electron microscopy (TEM). Zero field cooled (ZFC) and field cooled (FC) magnetizations of some selected samples measured in the temperature range of 300–5 K suggest the presence of superparamagnetic (SPM) relaxation in the samples. For a few selected samples particle sizes were also estimated from the TEM micrographs and dc magnetizations. The particle sizes, magnetic anisotropies and blocking temperatures of some samples have also been computed from the difference of FC and ZFC magnetizations data. The particle sizes of the samples were also worked out from the Langevin fitting of the anhysteretic magnetization curve above the blocking temperature. The SPM relaxations of all the samples have also been confirmed by ac magnetic measurements. The SPM relaxations in the nanocomposite samples annealed at higher temperature (600 °C) is stronger than the bare sample which is attributed to the controlled rate of growth of particle sizes by SiO2 coating. In case of sample annealed at 400 °C, the value of magnetic anisotropy constant determined from the ZFC and FC magnetizations is in agreement with that obtained from the Neel’s equation. However it is a bit smaller for the sample annealed at 600 °C.
Improvement of electromechanical properties of an ITER internal tin Nb3Sn wire
Authors: Mondonico G. , Seeber B. , Senatore C. , Flükiger R. , Corato V. , De Marzi G. , Muzzi L.
Published: November 2010

The critical current of an internal tin Nb3Sn wire developed by Oxford Instruments, Superconducting Technology for International Thermonuclear Experimental Reactor (ITER) (OST type-I, billet No. 7567) has been studied under axial strain at fields between 12 and 19 T at 4.2 K. Simulating the situation in a cable in conduit, where thermally induced compressive strain is important, a single wire (strand) was jacketed with AISI 316L stainless steel. The reinforced wire shows an important increase in εm, the applied strain where Ic reaches its maximum, from 0.25% to 0.57%. In addition the irreversibility limit, εirr, is improved from 0.50% applied strain to >1.10%. It could also be shown that the Ic at zero intrinsic strain is almost identical. This demonstrates that jacketing does not influence the physical parameters of the original wire. Experimental data of the bare wire has been well fitted by different strain functions. However, it was not possible to model the data of the jacketed wire. There are indications that only models which take into account the multidimensional character of strain are able to describe the behavior but further development is required.
Correlation of electronic structures of three cyclic dipeptides with their photoemission spectra
Authors: Arachchilage Anoja P. Wickrama , Wang Feng , Feyer Vitaliy , Plekan Oksana , Prince Kevin C.
Published: November 2010

We have investigated the electronic structure of three cyclic dipeptides: cyclo(Glycyl-Glycyl) (cGG), cyclo(Leucyl-Prolyl) (cLP), and cyclo(Phenylalanyl-Prolyl) (cPP). These compounds are biologically active and cLP and cPP are derived from cGG (also known as diketopiperazine), by the addition of the respective functional groups of the amino acids, namely, phenyl, alkyl or a fused pyrrolidine ring (proline). Experimental valence and core level spectra have been interpreted in the light of theoretical calculations to identify the basic chemical properties associated with the central ring, and with the additional functional groups in cLP and cPP. The theoretically simulated spectra of all three cyclic dipeptides in both valence and core spaces agreed reasonably well with the experimental spectra. The three molecules displayed similarities in their core spectra, suggesting that the diketopiperazine structure plays an important role in determining the inner shell spectrum. The experimental C 1s spectra of cLP and cPP are analogous but differ from cGG due to the side chains attached to the diketopiperazine structure. Single spectral peaks in the N 1s (and O 1s) spectra of the dipeptides indicate that the chemical environment of the nitrogen atoms (and oxygen atoms) are very similar, although they show a small splitting in the simulated spectra of cPL and cPP, due to the reduction of their point group symmetry. Valence band spectra of the three dipeptides in the frontier orbital region of 9–11 eV exhibit similarities; however theoretical analysis shows that significant changes occur due to the involvement of the side chain in the frontier orbitals of cPP, while lesser changes are found for cLP.
Influence of superthermal and trapped electrons on oblique propagation of ion-acoustic waves in magnetized plasma
Authors: Ahmadihojatabad N. , Abbasi H. , Pajouh H. Hakimi
Published: November 2010

Effects of superthermal and trapped electrons on the oblique propagation of linear and nonlinear ion-acoustic waves in an electron-ion plasma in the presence of a uniform external magnetic field are investigated. In order to model the superthermal electrons, a Lorentzian (kappa) velocity distribution function has been employed. The ions are cold and their dynamics are studied by hydrodynamic equations. First, the linear dispersion relation of the fast and slow modes are obtained. It is shown that the superthermal electrons cause the both modes to propagate with smaller phase velocities. Then, modified Korteweg–de Vries equations describing the propagation of nonlinear slow and fast ion-acoustic waves are derived. It is shown that the presence of superthermal and trapped electrons has great influence on the nature of magnetized ion-acoustic solitons. The dependency of soliton attributes to the parameters associated with the superthermality and trapping mechanism will be shown.
Connections between numerical behavior and physical parameters in the micromagnetic computation of static hysteresis loops
Authors: Manzin Alessandra , Bottauscio Oriano
Published: November 2010

This work deals with the computation of equilibrium states for the determination of static hysteresis loops of submicrometer magnetic samples. The succession of equilibrium states is here estimated by space-time integrating the Landau–Lifshitz–Gilbert equation. The magnetization time-update is performed by using a norm-conservative algorithm based on the Cayley transform. The analysis puts in evidence the strong connection between damping phenomena and convergence behavior toward equilibrium states, investigating the criticalities that occur during “stiff” transitions. The aim is to give guidelines for the choice of a correct convergence criterion in the hysteresis loop calculation. The influence of viscous effects, introduced via physical or numerical way, is also explored in order to improve the computational efficiency in terms of simulation duration.
Relation between physical parameters and thermal stability of liquid-crystal blue phase
Authors: Chen Hui-Yu , Liu Hsin-Hung , Lai Jia-Liang , Chiu Chih-Hao , Chou Ji-Yi
Published: November 2010

Correlations between the stability of blue phases and the physical parameters of liquid-crystal hosts are reported in this study. Experimental results show that liquid-crystal blue phases are more thermostabilized when the dielectric anisotropy is reduced or the elastic constants increased. These correlations can be explained by Defect theory and Landau theory for blue phases. Moreover, the results give us the clues to develop more suitable blue-phase materials for fundamental researches or fast photonic devices.
Reversible ultraviolet light-manipulated superhydrophobic-to-superhydrophilic transition on a tubular SiC nanostructure film
Authors: Cui H. , Yang G. Z. , Sun Y. , Wang C. X.
Published: November 2010

We demonstrate the ultraviolet (UV) light-induced, reversible wettability behavior for tubular SiC nanostructure film. The as-synthesized tubular SiC nanostructure film shows the superhydrophilic nature with the water contact angle 152.4° and low sliding angle. Moreover, the surface transition between superhydrophobicity and superhydrophilicity can be easily achieved by the alternation of UV irradiation and closed thermal heating. A possible mechanism is also proposed to explain the reversible wettability behavior.
Power law behavior of the zigzag transition in Yukawa clusters
Authors: Sheridan T. E. , Magyar Andrew L.
Published: November 2010

We provide direct experimental evidence that the width of a Yukawa cluster exhibits power law behavior during the one-dimensional (1D) to two-dimensional (2D) zigzag transition. Configurations of small dusty (complex) plasma clusters confined in a biharmonic potential well are characterized as the well anisotropy is varied. When the anisotropy is large the particles are in a 1D straight-line configuration. As the anisotropy is decreased the cluster undergoes a zigzag transition to a 2D configuration. The measured dependence of cluster width on anisotropy follows a power law. A second transition from the zigzag to an elliptical configuration is also observed. The results are in very good agreement with a model of identical particles interacting through a Yukawa potential.
Formation of In2O3 nanorings on Si substrates
Authors: Hsin C. L. , Yu S. Y. , Huang C. W. , Wu W. W.
Published: November 2010

A new approach to form the In2O3 nanorings (NRs) has been proven by tailoring the difference between property of metal and metal oxide. The formation process of the In2O3 NRs is proposed to be resulted form a subtle competition between the oxidation and evaporation of indium at the rim and center, respectively. Patterned In2O3 NRs have been grown on (001) Si substrates in combination with nanosphere lithography. The size and morphology of the NRs can be controlled by the size of polystyrene nanospheres and the thickness of indium layer. The optical property measurements showed that the In2O3 NRs are sensitive in absorption and emission of light between 600 and 622 nm in wavelength. The patterned In2O3 NRs on silicon are advantageous for fabricating optical-response photonic devices at the desired locations and direct integration to the silicon-based photonic devices with current processing technology.
Bubble core field modification by residual electrons inside the bubble
Authors: Wu Hai-Cheng , Xie Bai-Song , Zhang Shan , Hong Xue-Ren , Zhao Xue-Yan , Liu Ming-Ping
Published: November 2010

Bubble core field modification due to the nondepleted electrons present inside the bubble is investigated theoretically. These residual electrons induce charge and current densities that can induce the bubble core field modification as well as the bubble shape change. It is found that the electrons entering into the bubble move backward at almost light speed and would weaken the transverse bubble fields. This reduces the ratio of longitudinal to transverse radius of the bubble. For the longitudinal bubble field, two effects compensate with each other because of their competition between the enhancement by the shortening of bubble shape and the reduction by the residual electrons. Therefore the longitudinal field is hardly changeable. As a comparison we perform particle-in-cell simulations and it is found that the results from theoretical consideration are consistent with simulation results. Implication of the modification of fields on bubble electron acceleration is also discussed briefly.
Exchange-coupling of c-axis oriented L1–FePd and Fe in FePd/Fe thin films
Authors: Ichitsubo T. , Takashima S. , Matsubara E. , Tamada Y. , Ono T.
Published: November 2010

This letter reports the control of the c-axis orientation and the magnetic properties of L10 FePd in the well-annealed FePd/Fe thin films Fe(20 nm)/FePd(10 nm)/Fe(5 nm)/SiO2-substrate and Fe(20 nm)/FePd(5 nm)/Fe(5 nm)/SiO2-substrate, with the compositions of dual phase region in phase equilibrium. After annealing at 550 °C for 24 h, the c-axis of L10 FePd is controlled to be oriented in the normal direction in the soft Fe matrix. These thin films exhibit the exchange-coupling of hard FePd with soft Fe, and a characteristic spring-magnet behavior showed up reversibly as a significant jump from positive to negative in the magnetization reversal.
RNA polymerase mutants found through adaptive evolution reprogram
Escherichia coli
for optimal growth in minimal media
Authors: Conrad Tom M. , Frazier Michael , Joyce Andrew R. , Cho Byung-Kwan , Knight Eric M. , Lewis Nathan E. , Landick Robert , Palsson Bernhard Ø.
Published: November 2010

Specific small deletions within the
rpoC
gene encoding the β′-subunit of RNA polymerase (RNAP) are found repeatedly after adaptation of
Escherichia coli
K-12 MG1655 to growth in minimal media. Here we present a multiscale analysis of these mutations. At the physiological level, the mutants grow 60% faster than the parent strain and convert the carbon source 15–35% more efficiently to biomass, but grow about 30% slower than the parent strain in rich medium. At the molecular level, the kinetic parameters of the mutated RNAP were found to be altered, resulting in a 4- to 30-fold decrease in open complex longevity at an rRNA promoter and a ∼10-fold decrease in transcriptional pausing, with consequent increase in transcript elongation rate. At a genome-scale, systems biology level, gene expression changes between the parent strain and adapted RNAP mutants reveal large-scale systematic transcriptional changes that influence specific cellular processes, including strong down-regulation of motility, acid resistance, fimbria, and curlin genes. RNAP genome-binding maps reveal redistribution of RNAP that may facilitate relief of a metabolic bottleneck to growth. These findings suggest that reprogramming the kinetic parameters of RNAP through specific mutations allows regulatory adaptation for optimal growth in new environments.
SHIFTING INEQUALITIES
Authors: Stolle Dietlind , Hooghe Marc
Published: November 2010

Participation patterns in industrialized democracies have changed considerably in the last couple of decades. While institutionalized forms of participation (e.g., party membership) are declining, we can observe a rise in the occurrence of non-institutionalized forms of political participation. In this article we pose the question of what the effect of this trend has been for patterns of political stratification during the period 1974–2002 using the Political Action Survey as well as the European Social Survey. It can be observed that gender differences have been substantially reduced and in some cases even reversed for non-institutionalized participation and women tend to be more active in these forms than men. Younger age groups also clearly have a preference for non-institutionalized forms. Stratification based on education, however, remains the same compared to the 1970s. These findings are confirmed by a longitudinal analysis of Dutch Election Studies data for the period 1971–1998. We conclude that the emergence of new forms of political participation might have reduced age and gender based inequalities; however, it does not offer a solution for inequalities based on education.
Initial evidence for the criterion‐related and structural validity of the long versions of the Coach–Athlete Relationship Questionnaire
Authors: Rhind Daniel J. A. , Jowett Sophia
Published: November 2010

The aim of the present study was to develop and initially validate a longer version of the direct (Jowett & Ntoumanis, 2004) and meta‐perspectives (Jowett, 2009a, 2009b) of the Coach–Athlete Relationship Questionnaire (CART‐Q). In Study 1, instruments (e.g. questionnaires, scales, and inventories) that have been used to assess relationship quality in the broader psychological literature were examined and items potentially relevant to the coach–athlete relationship were identified. The content validity of the identified items was then assessed using expert panels. A final questionnaire was subsequently prepared and administered to 693 participants (310 coaches and 383 athletes). Confirmatory factor analysis was employed to assess the multidimensional nature of the questionnaire based on the 3Cs (i.e. closeness, commitment, and complementarity) model of the coach–athlete relationship. The findings indicated that the direct and meta‐perspective items of the long versions of the CART‐Q approached an adequate data fit. Moreover, evidence for the internal consistency and criterion validity of the new instruments was also obtained. In Study 2, the newly developed measure was administered to an independent sample of 251 individuals (145 athletes and 106 coaches). Further statistical support was gained for the factorial validity and reliability of the longer version of the CART‐Q.
Opinion
Authors: Visser Reidar
Published: November 2010

This article criticizes the way in which the concept of ‘tribalism’ has been used by Western policy-makers and media in post-2003 Iraq. It has been commonplace to see tribalism as yet another symptom of the supposed ‘fragmentation’ of Iraqi society, and there has been a debate about ways in which a tribe-oriented policy might bring about national reintegration and political progress. Using the case of Banū Mālik – the ‘tribe of Prime Minister Nūrī al-Mālikī’ – it is demonstrated that tribalism is a poor predictor of political behaviour in Iraq and that basic ‘bread-and-butter’ issues are of far greater importance to the population of the country, just like in most other countries in the world.
Marginalization and ethnicization in the Sudan: how the elite failed to stabilize a diverse country
Authors: Musa Abdu Mukhtar
Published: November 2010

This paper is based on the hypothesis that the crisis of the Sudan has resulted from the failure of the elite to establish just and rational governance in this multicultural, multi-ethnic, Afro-Arab state, as well as their failure to harmonize a heterogeneous entity which embraces approximately 572 tribes. The country’s crisis of identity is a product not only of colonial policies, but also of the partisan/sectarian and ethnic-oriented behaviour of the ruling elite that have governed the country since its independence in 1956.
Urban poverty and its connection to internal migration: a sociological study of some of the inner-city neighbourhoods of Riyadh
Authors: Alnuaim Aziza A.
Published: November 2010

This study deals with an important sociological aspect of the city of Riyadh in Saudi Arabia. It analyses urban poverty in the old, slum (shaꜤbī) neighbourhoods in the centre of the city, such as those affiliated to the municipality of ‘al-Baṭḥāʾ’ where families in these areas have witnessed an increase in numbers along with a decrease in income and an increased rate of illiteracy. The residents of these neighbourhoods generally live in small houses – on average, measuring 10 m deep by 5 m wide (50 m2). Riyadh, like other Saudi cities, is characterized by a capacity to attract; however, it is at the forefront of Saudi cities with regard to the size of its population which reached approximately 4.4 million inhabitants in 1422 AH/2002 CE. The number of families is expected to grow by an average rate of 7% over the next ten years to reach 941,000. Similarly, the average rate of population growth reached 8.1% for the five-year period beginning in 1417 AH/1999 CE; and Saudis exhibit a high rate of annual growth reaching 9.6% and representing 69% of the total urban population. This urban growth, in the main, is attributable to internal migration that ranks as one of the chief factors in the size of the population. A demographic survey in 1999 clarified through the use of the variable of ‘place of birth’ that the region of Riyadh was ranked the foremost in the region for attracting Saudis. Similarly, it was obvious from results of the pilot study (Alnuaim 1999) of ‘social adjustment to immigrants from rural areas’ carried out in the neighbourhood of ‘al-Ūd’ and that of ‘Manfūḥah’ that there were Saudi families which had immigrated from the south-west region of the country, six years previously or less, to the impoverished inner city neighbourhoods of Riyadh, and that these families suffered a reduced or lack of income in conjunction with their large family size. Similarly, they also suffered from increased rates of illiteracy among men, women and children altogether. This study, which is a completion of some previous sociological and exploratory studies, attempts to answer the following question. To what extent is recent internal migration to the city of Riyadh and residency in its slum neighbourhoods connected to the phenomenon of urban poverty in them?
Shutting down Dimona: Israel’s nuclear programme, arsenal and environmental threat
Authors: Sleiman Mounzer
Published: November 2010

Israel is considering constructing its ‘first’ officially declared nuclear power plant, raising fears over the potential development of its nuclear arsenal. While international efforts are increasingly focusing on nuclear non-proliferation, one of the world’s oldest nuclear reactors—Dimona—which by all indications is not only obsolete, but also structurally compromised—is still operating in Israel, posing enormous environmental and security threats to the entire Middle East. On the grounds that whatever reasons Israel may have had for acquiring a nuclear arsenal, implicit or explicit, these no longer hold, and given the environmental danger posed, this article argues that Israel should shut down Dimona as a first step toward establishing a nuclear-free region. The article highlights the different types of weapons in Israel’s current nuclear arsenal as well as the attendant hazards of pollution, radiation and wastes, in addition to serious questions about adequate failsafe measures. The case presented is informed by hitherto unpublished material from a series of telephone interviews and consultations with Dr Samuel Cohen, ‘father of the neutron bomb’, and Dr Frank Barnaby, nuclear physicist and weapons expert who debriefed Mordechai Vanunu. Finally, the article suggests certain measures Israel could take to gradually eliminate its arsenal and avoid a cataclysmic scenario evocative of Chernobyl, without detracting from its overall ‘security’ claim. This article reflects the views of the author and does not necessarily reflect the views of Drs Cohen or Barnaby, who were both consulted strictly in a technical capacity, nor does it necessarily reflect the views of either the Centre for Arab Unity Studies (CAUS) or the publisher Routledge (Taylor & Francis, UK).
Sphingomonas oryziterrae sp. nov. and Sphingomonas jinjuensis sp. nov. isolated from rhizosphere soil of rice (Oryza sativa L.)
Authors: Chung Eu Jin , Jo Eun Ju , Yoon Hwan Sik , Song Geun Cheol , Jeon Che Ok , Chung Young Ryun
Published: November 2010

Two Gram-reaction-negative, yellow–orange-pigmented, rod-shaped bacterial strains, designated YC6722Tand YC6723T, were isolated from rhizosphere soil samples collected from rice fields in Jinju, Korea. Strains YC6722Tand YC6723Tgrew optimally at 25–30 °C and at pH 7.0–8.5. Phylogenetic analyses of 16S rRNA gene sequences showed that strain YC6722Twas most closely related toSphingomonas jaspsiTDMA-16T(96.6 % sequence similarity) and strain YC6723Twas related most closely toSphingomonas aquatilisJSS7T(96.9 %). The two strains contained ubiquinone-10 (Q-10) as the major respiratory quinone system andsym-homospermidine as the major polyamine. The G+C contents of the genomic DNA of strains YC6722Tand YC6723Twere 63.3 and 61.0 mol%, respectively. The major fatty acid was C18 : 1ω7c. The polar lipids detected in the two strains were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, sphingoglycolipid, phosphatidyldimethylethanolamine and other unknown lipids. On the basis of their phylogenetic positions, and their biochemical and phenotypic characteristics, strains YC6722Tand YC6723Trepresent two novel species of the genusSphingomonas, for which the namesSphingomonas oryziterraesp. nov. ( = KCTC 22476T = DSM 21455T) andSphingomonas jinjuensissp. nov. (KCTC 22477T = DSM 21457T) are proposed.