bluuebunny/crossref_metadata_2025 huggingface dataset:
Truth-Conditions and Necessary Existence
Authors: Nielsen Kai
Published: February 2009

My objectives are twofold. I want first to show (mainly following John Hick) that there is a conception of necessary existence or aseity, distinct from a conception of ‘logically necessary being’, which is at least prima facie plausible and second to show, with respect to this specific conception, that there are relevant questions about stating truth-conditions which are unsatisfied and perhaps even in principle unsatisfiable, and that these are questions which must be met before such a prima facie plausible conception can be taken to give us the basis of a satisfactory theological elucidation of what it is to speak of God. I shall argue that it is doubtful whether these questions about truth-conditions can be met.
The Mission Charge to the Twelve and Modern Medical Missions
Authors: Wilkinson John
Published: February 2009

The group of imperatives usually known as the Mission Charge to the Twelve Disciples deserves consideration for its own sake since it marks an important climax in our Lord's life and ministry, as well as in the experience of those whom he called to be his disciples. It deserves consideration also because in the process of time it became the justification for the medical missionary movement which arose within the Protestant Church in the eighteenth and nineteenth centuries. Today this movement as part of the great worldwide expansion of the Christian Church appears to be coming to an end. It is appropriate, therefore, to look again at what was claimed to be its biblical basis. This article proposes to do this, and to consider medical missions in relation to the Mission Charge to the Twelve Disciples, and in relation to the modern healing ministry of the Church.
An Interpretation of the Babylonian Exile: A Study of 2 Kings 20, Isaiah 38–39
Authors: Ackroyd P. R.
Published: February 2009

There is a certain ‘Looking glass’ quality to the title of this study—by which I mean that Lewis Carroll's White Knight, whose analysis of the relationship between names and titles is the classic one, might well have insisted that this is only what it is called, whereas in fact it is about an interpretation (namely my own) of an interpretation (namely that of the writer of 2 Kings 20 and that of the writer of the parallel but not quite identical material of Isa. 38-39), which is there offered not apparently of the Babylonian Exile but of certain incidents of importance in the reign of king Hezekiah of Judah around the end of the eighth century b.c. The introduction of the Babylonian Exile into this is not my own, since it is already inherent in one moment in the two narratives; but the understanding of the section in terms of interpretation of the Exile is something which needs to be discussed. It is here that I believe we may see the distinctive character of the narratives in their present forms.
Our Knowledge of the Trinity
Authors: Hill Edmund
Published: February 2009

There has been a lesiurely, or perhaps we should say a spasmodic, debate on this topic, going on for the last thirty years, to which I would like to invite St. Augustine to make a contribution. I think he can provide resources which the other participants have rather neglected.
Man's Eschatological Condition
Authors: Dockx Père S.
Published: February 2009

After having listened to the scientists telling us about the phenomenon of biological evolution, the philosophers shared with us their views on evolution on the human level. Then the theologians have given their interpretation of the canonical scriptures of the Old and New Testaments on the basis of exegetical knowledge. Now, by way of conclusion, I have to attempt to give you a synthetic view of man's eschatological condition on the basis of the facts of science and Christian revelation.
Calvin and Christ's Presence in the Supper—True or Real
Authors: Tylenda Joseph N.
Published: February 2009

Calvin is one with the other Christian communities in teaching a presence of Christ's body and blood in the Lord's Supper. To arrive at a conclusion other than this is to misread him, to misunderstand and misinterpret him. Certainly, the reformer cannot be numbered among the sacramentarians, as if he had taught that the partaking of Christ's flesh and the drinking of his blood were nothing more than merely believing in Christ. The sacraments are signs, it is true, but they are not merely signs, they are signs of a present reality.
The Contribution of the Book of Revelation to the Christian Belief in Immortality
Authors: Beasley-Murray G. R.
Published: February 2009

Before we embark on this subject it will be well to review some preliminary considerations relating to the nature of the Book of Revelation.
Long time management of fossil fuel resources to limit global warming and avoid ice age onsets
Authors: Shaffer Gary
Published: February 2009

There are about 5000 billion tons of fossil fuel carbon in accessible reserves. Combustion of all this carbon within the next few centuries would force high atmospheric CO2 content and extreme global warming. On the other hand, low atmospheric CO2 content favors the onset of an ice age when changes in the Earth's orbit lead to low summer insolation at high northern latitudes. Here I present Earth System Model projections showing that typical reduction targets for fossil fuel use in the present century could limit ongoing global warming to less than one degree Celcius above present. Furthermore, the projections show that combustion pulses of remaining fossil fuel reserves could then be tailored to raise atmospheric CO2 content high and long enough to parry forcing of ice age onsets by summer insolation minima far into the future. Our present interglacial period could be extended by about 500,000 years in this way.
Seismic evidence for thermally‐controlled dehydration reaction in subducting oceanic crust
Authors: Nakajima Junichi , Tsuji Yusuke , Hasegawa Akira
Published: February 2009

We perform travel‐time tomography to estimate detailed seismic velocity structures in the crust of the Pacific slab from northeastern (NE) Japan to the Kanto district, Japan, and reveal that the depth extent of the low‐velocity (hydrated) oceanic crust varies along the arc. The low‐velocity oceanic crust is subducting to depths of 120–150 km beneath Kanto, which is 40–70 km deeper compared to NE Japan. Such deeper preservation of the low‐velocity oceanic crust beneath Kanto can be explained by lower‐temperature conditions in the Pacific slab as a result of the subduction of the Philippine Sea slab immediately above it. These observations suggest that dehydration reactions accompanied by large velocity changes are controlled principally by temperatures, not by pressures. We also find spatial correspondence between intensive seismicity in the oceanic crust and the disappearance depth of the low‐velocity oceanic crust, suggesting that breakdown of hydrous minerals triggers earthquakes in the oceanic crust.
Gupta Receives 2008 Robert E. Horton Medal
Authors: O'Connell Enda , Gupta Vijay K.
Published: February 2009

Vijay K. Gupta was awarded the 2008 Robert E. Horton Medal at the AGU Fall Meeting Honors Ceremony, held 17 December 2008 in San Francisco, Calif. The medal is for ”outstanding contributions to hydrology.“
Lithospermic acid B is more responsive to silver ions (Ag+) than rosmarinic acid in Salvia miltiorrhiza hairy root cultures
Authors: Xiao Ying , Gao Shouhong , Di Peng , Chen Junfeng , Chen Wansheng , Zhang Lei
Published: February 2009

LAB (lithospermic acid B) is a dimer of RA (rosmarinic acid) and has been suggested to be derived from RA, but the detailed biosynthesis process has not yet been identified. The accumulation of RA has been intensively investigated in the plant species of Boraginaceae and Lamiaceae. In the present study, we report that silver ions (Ag+; 15 μM), an abiotic elicitor, did not stimulate RA accumulation but dramatically enhanced LAB from approx. 5.4% to 18.8% of dry weight in Salvia miltiorrhiza hairy root cultures, and the rise in LAB was found to be coincident with the decline of RA content at each time point after treatment. Meanwhile, a profiling analysis of genes and metabolites (intermediates) involved in the RA synthesis pathway was performed; the result indicated that several gene transcripts and metabolite accumulations show temporal changes in abundance consistent with LAB production. Thus a potential (putative) biosynthetic route from RA to LAB was presumed, which was suggested to be significantly activated by Ag+ in S. miltiorrhiza hairy root cultures. Further intermediate monitoring and compound feeding experiments were performed to rank the strength of this hypothesis. Our study, for the first time, provides evidence that RA is a precursor leading to LAB synthesis.
Electrons near a graphene edge
Authors: Volkov V. A. , Zagorodnev I. V.
Published: February 2009

To describe the behavior of a 2D electron near a graphene edge, one needs to know the boundary conditions for the effective (envelope) wave function, which obeys an equation of the Weyl–Dirac type. These conditions, which are deduced from general arguments, amount to a linear relation on the components of the spinor comprised of the envelope functions. In neglect of the intervalley interaction, the boundary conditions depend only on one real parameter, which contains a boundary of the general type. The spectrum of electronic edge states for the linear boundary is obtained.
Resonance variation of the kinetic coefficients in a two-dimensional electron system with spin-orbit interaction
Authors: Lyapilin I. I.
Published: February 2009

A study is made of the resonance variation of the kinetic coefficients in two-dimensional systems with spin-orbit interaction upon saturation of the combined resonance transitions.
Spin effects and quantum corrections to the conductivity of two-dimensional systems
Authors: Germanenko A. V.
Published: February 2009

A summary of a lecture delivered at the XVII Ural International Winter School on Physics of Semiconductors (Ekaterinburg, 2008) is presented. The basic concepts of quantum corrections to the conductivity of two-dimensional systems are briefly laid out. The interference quantum correction and the Altshuler-Aronov correction due to the electron-electron interaction are examined. Particular attention is devoted to systems with spin-orbit interaction. The main ideas are illustrated with experimental results.
Quantum Hall effect in an InAs∕AlSb double quantum well
Authors: Yakunin M. V. , Podgornykh S. M. , Sadofyev Yu. G.
Published: February 2009

Double quantum wells (DQWs) were first implemented in the InAs∕AlSb heterosystem, which is characterized by a large Landé g factor ∣g∣=15 of the InAs layers forming the well, much larger than the bulk g factor ∣g∣=0.4 of the GaAs in conventional GaAs∕AlGaAs DQWs. The quality of the samples is good enough to permit observation of a clear picture of the quantum Hall effect (QHE). Despite the small tunneling gap, which is due to the large barrier height (1.4eV), features with odd filling factors ν=3,5,7,… are present in the QHE, due to collectivized interlayer states of the DQW. When the field is rotated relative to the normal to the layers, the ν=3 state is suppressed, confirming the collectivized nature of that state and denying that it could owe its existence to a strong asymmetry of the DQW. Previously the destruction of the collectivized QHE states by a parallel field had been observed only for the ν=1 state. The observation of a similar effect for ν=3 in an InAs∕AlSb DQW may be due to the large bulk g factor of InAs.
On the origin of room-temperature ferromagnetism in wide-gap semiconductors
Authors: Korbecka A. , Majewski J. A.
Published: February 2009

The emerging field of semiconductor spintronics would be dramatically boosted if a semiconductor exhibiting room-temperature ferromagnetism could be found. Here, we discuss the recent stage of research, paying particular attention to the understanding of the observed room-temperature ferromagnetism in the wide-gap semiconductors GaMnN and ZnMnO. Since spinodal decomposition has been observed in these structures, we consider the possibilities of influencing density fluctuations of the alloys to obtain ferromagnetic semiconductors with required functionalities. We contrast these compounds with (In,Mn)As and (Ga,Mn)As, where the ferromagnetism is well understood, albeit well below room temperature.
Diluted magnetic semiconductors based on II–VI, III–VI, and IV–VI compounds
Authors: Lashkarev G. V. , Sichkovskiyi V. I. , Radchenko M. V. , Karpina V. A. , Butorin P. E. , Dmitriev O. I. , Lazorenko V. I. , Slyn’ko E. I. , Lytvyn P. M. , Jakiela R. , Knoff W. , Story T. , Aleshkevych P.
Published: February 2009

Chemical and phase composition, magnetic susceptibility, SIMS, magnetic force microscopy, and neutron diffraction data for Ge1−x−ySnxMnyTe, InSe⟨Mn⟩, and ZnO⟨Co, Mn⟩ single crystals are investigated over a wide range of temperatures and magnetic fields. For Ge1−x−ySnxMnyTe the existence of ferromagnetic (FM) ordering with a Curie temperature TC∼50K, due to an indirect exchange interaction between Mn ions via the degenerate hole gas, is established. It is shown that at T<50K the ferromagnetic regions of the crystal form a spin-glass phase. In InSe⟨Mn⟩ it is found that hysteresis loops of the magnetic moment M(H) are observed up to 350K. They attest to the existence of ferromagnetic ordering, which is apparently due to ferromagnetic clusters in which a superexchange of the Mn ions via the Se anions is proposed, and to an indirect interaction via the 2D electron gas. At T<70K a period doubling of the magnetic sublattice of α-MnSe second-phase inclusions is observed, and their distribution in the layered structure of the InSe⟨Mn⟩ host matrix has a regular character, forming a self-organized FM∕AFM superlattice. In ZnO⟨Co, Mn⟩ the temperature dependence of M obeys a Curie law. When the solubility limit of Co in ZnO is exceeded, hysteresis loops are observed as a consequence of the appearance of a ferromagnetic second phase. In ZnO⟨Mn⟩ samples and also in some ZnO⟨Co⟩ samples with Co content below the solubility limit an antiferromagnetic (AFM) interaction takes place.
Soft x-ray emission spectra and ferromagnetism in wide-gap doped semiconductors
Authors: Surkova T. P. , Galakhov V. R. , Kurmaev É. Z.
Published: February 2009

A study is made of the resonant and nonresonant L x-ray emission spectra of impurities in the semiconducting compounds ZnS:Mn, ZnO:Mn, ZnO:Co, and Co2O:Mn. An analysis of the Mn L2,3 x-ray emission spectra of Zn1−xMnxS (x=0.1–0.3) reveals that the Mn impurities do not form clusters in the ZnS lattice. Studies of the Mn L2,3 spectra and electronic structure of epitaxial films of Zn0.8Mn0.2O annealed at different temperatures show that the cause of the observed suppression of ferromagnetism at T>600°C is segregation of Mn atoms. In this case the Mn atoms occupy both Zn sites and interstitial positions. For Zn1−xCoxO (x=0.02, 0.06, and 0.10) the absence of free carriers that could mediate an exchange interaction between Co ions is established. Mn L2,3 x-ray emission measurements show that in Mn-doped oxides Cu2O synthesized at 650 and 800°C the Mn atoms are found both in interstitial positions and occupy Cu sites, but the configurations of these defects depend on the synthesis temperature. A decrease of the Curie temperature with increasing synthesis temperature may be explained as a manifestation of antiferromagnetic superexchange between substituent Mn atoms via oxygen.
Donor exciton of cobalt and its interaction with lattice vibrations in the semiconductor crystal ZnO:Co
Authors: Gruzdev N. B. , Sokolov V. I. , Yemelchenko G. A.
Published: February 2009

Vibrational states interacting with a donor exciton in the compound ZnO:Co are revealed by the sensitive method of field exciton-vibrational spectroscopy. The vibrational modes of the electroabsorption spectrum of the compound ZnO:Co in the region of the donor exciton are given an interpretation based on the existing data on the symmetrized local density of states of the compounds ZnO and ZnO:Ni3+. The results are compared with the known data for II–VI:Ni compounds in the case of an acceptor exciton. The position of the donor level of the Co2+ ion relative to the bottom of the conduction band in the given compound is determined and found to conform well to the universal trend for donor levels of 3d ions in II–VI compounds.
Electron transport and band structure in phosphorus-doped polycrystalline silicon films
Authors: Young David L. , Branz Howard M. , Liu Fude , Reedy Robert , To Bobby , Wang Qi
Published: February 2009

We study transport mechanisms, effective mass, and band structure by measuring the resistivity, Hall, and Seebeck and Nernst coefficients in heavily phosphorus-doped polycrystalline silicon films made by thermal crystallization of amorphous silicon. We observe a change in transport mechanism which results in an increase in electron mobility from 10% to 80% of the single-crystal silicon mobility as the carrier concentration increases from 1019 to 1020 cm−3. Our measurements of effective mass at the Fermi level indicate that as the carrier concentration increases, there is a shift from impurity-band transport to conduction-band transport, and that the electron effective mass is lower in the impurity band than in the conduction band of Si. The shift to conduction-band transport improves electron mobility with carrier density by improving intragrain carrier mean free path lengths and relaxation times.
Chimera states in heterogeneous networks
Authors: Laing Carlo R.
Published: February 2009

Chimera states in networks of coupled oscillators occur when some fraction of the oscillators synchronize with one another, while the remaining oscillators are incoherent. Several groups have studied chimerae in networks of identical oscillators, but here we study these states in heterogeneous models for which the natural frequencies of the oscillators are chosen from a distribution. For a model consisting of two subnetworks, we obtain exact results by reduction to a finite set of differential equations, and for a network of oscillators in a ring, we generalize known results. We find that heterogeneity can destroy chimerae, destroy all states except chimerae, or destabilize chimerae in Hopf bifurcations, depending on the form of the heterogeneity.
Ultraviolet laser ablation of polycarbonate and glass in air
Authors: Bormotova T. A. , Blumenthal R.
Published: February 2009

The fundamental physical processes that follow ultraviolet laser ablation of polycarbonate and borosilicate glass in air have been investigated using photodeflection as a function of the distance from the surface to probe laser. Four features were observed in the data sets for each material. Two of these features correlate well with gas dynamical predictions for the expansion of the shock wave and gas plume. The third feature is consistent with the propagation of the popping sound of the laser ablation event. The final feature, which occurs at very early times and does not shift significantly in time as the surface to probe distance is increased from 0 to greater than 6 mm, has been tentatively ascribed to the ejection of fast electrons. The final significant observation is complete blocking of the probe laser, only observed during borosilicate ablation, which is attributed to scattering of the probe laser light by macroscopic SiOx particles that grow in the final stages of plume expansion and cooling.
Success and pitfalls of the Sin−2C2H2–C2Bn−2Hn isolobal analogy: Depth and breadth of the boron connection
Authors: Zdetsis Aristides D.
Published: February 2009

The extent and depth of the so-called boron connection suggested recently by the present author [J. Chem. Phys. 128, 184305 (2008)] for the Sin−2C2H2–C2Bn−2Hn isovalent species [following similar connection of (Sin)2−–(BnHn)2− dianions] are further investigated by considering larger species up to n=12 and additional isovalent moieties. Here we consider, using density functional and coupled clusters theory, isovalent Sin−2C2H2 and Gen−2C2H2 clusters, in comparison to the corresponding C2Bn−2Hn carboranes and to each other for n=3–8, 12. Special attention is given to the n=8 species, where the corresponding carborane is highly fluxional, and to n=12, where the “parent structures” of the corresponding (Si12)2− and (B12H12)2− dianions have drastically different symmetries. The structures generated by substitutions on (Si12)2−, as well as (B12H12)2−, are compared and interrelated for both C2B10H12 and Si10C2H12. The carborane generated from the Cs (Si12)2− dianion provides an illustrative example of carborane rearrangements, reverting after geometry optimization to the second lowest C2B10H12 meta isomer of C2v symmetry, 0.12 eV above the lowest energy para isomer. This demonstrates the amphidirectional character of the boron connection. It is found that n=8 is the upper limit of the n range in which the isolobal Sin−2C2H2–C2Bn−2Hn analogy is fully operative not only for the lowest but also for the second and third lowest energy states. For n≤8 all three pairs of structures are isovalent, isostructural, and isolobal. For large values of n (n>8) the boron connection, although not fully isolobal, is still valid in a broader and more general sense, still providing deeper and broader fundamental understanding and insight for both species. It was also found that the Gen−2C2H2 clusters are not fully homologous (isolobal) neither to the isovalent Sin−2C2H2 clusters nor to the corresponding C2Bn−2Hn carboranes, preferring structures in which the two carbon atoms are always in adjacent positions. This is attributed to the relative weakness of the Ge–Ge and Ge–C bonds relative to Si–Si and Si–C bonds and the “inert pair effect.”
Plykin-type attractor in nonautonomous coupled oscillators
Authors: Kuznetsov Sergey P.
Published: February 2009

A system of two coupled nonautonomous oscillators is considered. Dynamics of complex amplitudes is governed by differential equations with periodic piecewise continuous dependence of the coefficients on time. The Poincaré map is derived explicitly. With the exclusion of the overall phase, on which the evolution of other variables does not depend, the Poincaré map is reduced to three–dimensional (3D) mapping. It possesses an attractor of Plykin-type located on an invariant sphere. Computer verification of the cone criterion confirms the hyperbolic nature of the attractor in the 3D map. Some results of numerical studies of the dynamics for the coupled oscillators are presented, including the attractor portraits, Lyapunov exponents, and the power spectral density.
Molecular photoionization cross sections by Stieltjes–Chebyshev moment theory applied to Lanczos pseudospectra
Authors: Gokhberg K. , Vysotskiy V. , Cederbaum L. S. , Storchi L. , Tarantelli F. , Averbukh V.
Published: February 2009

Stieltjes imaging technique is widely used for the ab initio computation of photoionization cross sections and decay widths. The main problem hampering the application of the standard Stieltjes imaging algorithms in conjunction with high-level ab initio methods to polyatomic molecules is the requirement of full diagonalization of excessively large Hamiltonian matrices. Here we show that the full diagonalization bottleneck can be overcome by applying the Stieltjes imaging procedure to Lanczos pseudospectrum of the atomic or molecular Hamiltonian. Using the helium and neon atoms as examples, we demonstrate that the Lanczos pseudospectrum obtained after only a relatively small number of iterations can be used for Stieltjes-type calculations of photoionization cross sections essentially without loss of accuracy. The new technique is applied to the calculation of the total photoionization cross section of benzene within an ab initio approach explicitly taking into account single and double electronic excitations. Good agreement with experimental results is obtained.
Effective coarse-grained simulations of super-thick multi-walled carbon nanotubes under torsion
Authors: Zou Jian , Huang Xu , Arroyo Marino , Zhang Sulin
Published: February 2009

Under torsion and beyond the buckling point, multi-walled carbon nanotubes (MWCNTs) develop a periodic wave-like rippling morphology. Here, we show that torsional rippling deformations can be accurately described by a simple sinusoidal shape function. Combining this observation with the geometry optimization, we develop an effective coarse-grained model that reproduces the complex nonlinear mechanical responses of thick MWCNTs under torsion predicted by large-scale atomistic simulations. Furthermore, the model allows us to simulate super-thick tubes, inaccessible by other coarse-grained methods. With this effective coarse-grained model, we show from an energetic analysis that the rippling deformation is a result of in-plane strain energy relaxation, penalized by the increase in the interlayer van der Waals interaction energy. Our simulations reveal that the torsional response of MWCNTs with up to 100 layers approximately follows a simple bilinear law, and the ratio of the torsional rigidities in the pre- and post-buckling regimes is nearly a constant, independent of the tube radius. In contrast, the bifurcation torsional strain powerly scales with the tube radius. We also find that the wave number in the circumferential direction linearly increases with tube radius, while the wavelength monotonically increases with tube radius, and approaches a constant in the limit of bulk graphite. The bilinear constitutive relation, together with the scaling law of the bifurcation torsional strain, furnishes a simple nonlinear beam theory, which facilitates the analysis of MWCNT bundles and networks.
Influence of microstructure on room temperature ferromagnetism in Ni implanted nanodimensional ZnO films
Authors: Pandey B. , Ghosh S. , Srivastava P. , Kumar P. , Kanjilal D.
Published: February 2009

Room temperature ferromagnetism (RT-FM) is observed in ZnO/Si thin films on implantation of 200 keV Ni2+ ions at fluences of 6×1015, 8×1015, and 2×1016 ions/cm2. RT-FM observed without any preheat or postheat treatment is studied by alternating gradient magnetometry. The average grain size, oxygen vacancies, and charge carrier concentration are found to be maximum in the film implanted at fluence of 8×1015 ions/cm2, which also shows maximum saturation magnetization (Ms). In all implanted films no extra crystalline phase (apart from ZnO) is observed. Exchange interaction between the charge carriers generated due to thermal effects of ion implantation and the localized spins of Ni is considered as main reason behind RT-FM. The effect of microstructure of the films on exchange interaction and hence on RT-FM properties is also discussed.
Giant birefringence and tunable differential group delay in Bragg reflector based on tapered three-dimensional hollow waveguide
Authors: Kumar Mukesh , Sakagichi Takahiro , Koyama Fumio
Published: February 2009

A tunable Bragg reflector based on a tapered three-dimensional (3D) hollow waveguide (HWG) with variable taper angle has been proposed and demonstrated. A large grating coupling coefficient for a large reflection band and a giant birefringence of 0.01 have been achieved by optimizing the structure of the 3D HWG. The large birefringence causes a delay difference between the orthogonal polarizations and the variable taper angle provides tuning in the delay difference. A 13 ps tuning in differential group delay has been reported with a 3 mm long compact device, which can be used for adjustable compensation of polarization mode dispersion in optical fiber links.
Pentacene thin film transistors with a poly(methyl methacrylate) gate dielectric: Optimization of device performance
Authors: Yun Youngjun , Pearson Christopher , Petty Michael C.
Published: February 2009

The electrical characteristics of pentacene-based organic thin film transistors (OTFTs) using poly(methyl methacrylate) (PMMA) as the gate dielectric are reported. Uniform pinhole-free and crack-free films of PMMA could be obtained by spin coating, with a lower limit of thickness of about 150 nm. The effects of the insulator thickness and channel dimensions on the performance of the devices have been investigated. Leakage currents, which are present in many polymeric gate dielectrics, were reduced by patterning the pentacene active layer. The resulting devices exhibited minimal hysteresis in their output and transfer characteristics. Optimized OTFT structures possessed a field-effect mobility of 0.33 cm2 V−1 s−1, a threshold voltage of −4 V, a subthreshold slope of 1.5 V/decade, and an on/off current ratio of 1.2×106.
Enhanced photon tunneling for light enhancements from nanopatterned surfaces with subwavelength nanoholes
Authors: Kim Keunjoo , Choi Jaeho
Published: February 2009

Nanoporous alumina thin films were fabricated via an electrochemical anodization process and utilized as patterning masks for a plasma etching process to convert nanohole patterns as photonic crystal slabs to the surfaces of GaAs and GaN semiconducting materials. The nanostructural GaAs and GaN surfaces enhance the light extraction of the photoluminescence spectra at wavelengths of 857 and 456 nm, respectively. The enhancement mechanism has been analyzed in terms of a photon tunneling process of surface evanescent waves. The enhanced transmissions at the surface regions are related to the removal of absorption modes at 640 and 440 nm for GaAs and GaN materials, respectively.
Determination of third- and fifth-order nonlinear coefficients by using quasi-one-dimensional slit beam Z-scan technique
Authors: Lu Shi-Zhuan , Wang Hui-Tian
Published: February 2009

We report a theoretical study on the Z-scan technique by using quasi-one-dimensional slit beam, when a nonlinear medium possesses third- and fifth-order nonlinearities simultaneously. For the case when the third- and fifth-order nonlinear refraction coefficients γ and γ′ have the same sign, we can extract both γ and γ′ from the empirical formula we found. When γ and γ′ have the opposite sign, a high-accuracy method was proposed to allow the determination of the nonlinear refraction coefficients related to the third- and fifth-order effects. We also find the empirical formulae, which can easily estimate the pure two-photon absorption coefficient and the pure three-photon absorption coefficient, respectively.
Magnetoimpedance behavior and its equivalent circuit analysis of Co/Cu/Co/Py pseudo-spin-valve with a nano-oxide layer
Authors: Chien Wei-Chih , Yao Yeong-Der , Wu Jiann-Kuo , Lo Chi-Kuen , Hung Ruei-Feng , Lan M. D. , Lin Pang
Published: February 2009

Magnetoimpedance behaviors and thermal effects of a Co/Cu/Co/Py pseudo-spin-valve (PSV) with a nano-oxide layer (NOL) were studied. The PSV can be regarded as a combination of resistances, inductances, and capacitances. In addition, equivalent circuit theory can be used to analyze the ac behavior of this system. The imaginary part of the magnetoimpedance (magnetoreactance) ratio is more than 1700% at the resonance frequency (fr)=476 kHz at room temperature (RT). The dc magnetoresistance (MR) ratio decreases as the annealing temperature increases because the NOL is formed at the interface between the spacer and the magnetic layer. The NOL deteriorates the differential spin scattering and reduces the dc MR ratio. Impedance spectroscopy was utilized to analyze the capacitance effect from NOL after annealing. The effective capacitance of the PSV was 21.8 nF at RT and changed to 11.8 nF after annealing at 200 °C. The useful equivalent capacitor circuit not only is a nondestructive measurement technology but can also explain the experimental results and prove the formation of the NOL.
Effect of wind speed and load power factor variation on optimal sizing of the machine and converters for double output induction generator based stand-alone wind energy conversion systems
Authors: Saha T. K. , Bagarty D. P. , Kastha D.
Published: February 2009

In this paper, an algorithm for finding out the optimal ratings of the machine and power electronic converters of a wind turbine driven stand-alone double output induction generator based variable speed constant frequency generation system is reported, which seeks to minimize the cost of energy generation. The nonlinear constrained optimization technique employed includes, among others, the reactive power balance constraints, which are not often considered for stand-alone systems. For this purpose, the load power factor is modeled as a random variable with known probability density function. The total energy captured is calculated for a given wind velocity density function and load power factor density function. The proposed method finally finds the optimum combination of machine and converter ratings, which results in minimum cost of energy. The effects of changes in load power factor and wind velocity distribution are also discussed in detail.
Parametric simulations of the metallic double-ring metamaterials: Geometric optimization and terahertz response
Authors: Dong Zheng-Gao , Xu Ming-Xiang , Liu Hui , Li Tao , Zhu Shi-Ning
Published: February 2009

Metallic double-ring metamaterial without splits in both of the rings was recently studied to show its negative refraction with magnetic resonance [Z.-G. Dong et al., Appl. Phys. Lett. 92, 064101 (2008)]. As a consequent work, systematic numerical results are presented in this paper to investigate the dependence of the magnetically resonant transmission on the structural parameters. The origin of the transmission band with magnetic resonance is shown rather explicitly with these numerical results. In addition, the optimized structure of the double-ring metamaterial is used to explore its terahertz response with all the sizes scaled down simultaneously.
Liquid crystal dynamic flow control by bidirectional alignment surface
Authors: Li Y. W. , Lee C. Y. , Kwok H. S.
Published: February 2009

We investigate the behavior of liquid crystal dynamic flow in a cell with a bidirectional alignment (BDA) surface. Numerical simulations show that with a BDA surface having a pitch comparable to the cell gap d, the liquid crystal dynamic flow direction can be controlled by the driving voltage. Such an effect can be applied to bistable twisted nematic displays without the need for anchoring breaking.
Dynamics of repulsive dual-frequency atomic force microscopy
Authors: Stark Robert W.
Published: February 2009

In bimodal atomic force microscopy, two flexural modes are driven at their resonances. The oscillation of the second eigenmode, which is usually an incommensurate multiple of the fundamental frequency, perturbs the dynamic system. Numerical simulations show that the tip motion is almost periodic at typical set points and that harmonics and intermodulation frequencies prevail in the spectrum. The simulations also predict a very small increase in the noise of the first mode amplitude and phase due to the second mode oscillation. At small average tip sample separations, however, phases with repulsive and purely attractive forces can occur intermittently.
Near-IR subwavelength microdisk lasers
Authors: Song Q. , Cao H. , Ho S. T. , Solomon G. S.
Published: February 2009

We report single-mode lasing in subwavelength GaAs disks under optical pumping. The disks are fabricated by standard photolithography and two steps of wet chemical etching. The simple fabrication method can produce submicron disks with good circularity, smooth boundary, and vertical sidewalls. The smallest lasing disks have a diameter of 627 nm and thickness of 265 nm. The ratio of the disk diameter to the vacuum lasing wavelength is about 0.7. Our numerical simulations confirm that the lasing modes are whispering-gallery modes with the azimuthal number as small as 4 and a modal volume of 0.97(λ/n)3.
Terminal velocity and drag reduction measurements on superhydrophobic spheres
Authors: McHale G. , Shirtcliffe N. J. , Evans C. R. , Newton M. I.
Published: February 2009

Super water-repellent surfaces occur naturally on plants and aquatic insects and are created in the laboratory by combining micro- or nanoscale surface topographic features with hydrophobic surface chemistry. When such types of water-repellent surfaces are submerged they can retain a film of air (a plastron). In this work, we report measurements of the terminal velocity of solid acrylic spheres with various surface treatments settling under the action of gravity in water. We observed increases in terminal velocity corresponding to drag reduction of between 5% and 15% for superhydrophobic surfaces that carry plastrons.
AMPA receptor and GEF-H1/Lfc complex regulates dendritic spine development through RhoA signaling cascade
Authors: Kang Myoung-Goo , Guo Yurong , Huganir Richard L.
Published: February 2009

AMPA receptors (AMPA-R) are major mediators of synaptic transmission and plasticity in the developing and adult central nervous system. Activity-dependent structural plasticity mediated by dynamic changes in the morphology of spines and dendrites is also essential for the formation and tuning of neuronal circuits. RhoA and Rac1 are known to play important roles in the regulation of spine and dendrite development in response to neuronal activity. These Rho GTPases are activated by guanine nucleotide exchange factors (GEFs). In this study, we identified GEF-H1/Lfc as a component of the AMPA-R complex in the brain. GEF-H1 is enriched in the postsynaptic density and is colocalized with GluR1 at spines. GEF-H1 activity negatively regulates spine density and length through a RhoA signaling cascade. In addition, AMPA-R-dependent changes in spine development are eliminated by down-regulation of GEF-H1. Altogether, these results strongly suggest that GEF-H1 is an important mediator of AMPA-R activity-dependent structural plasticity in neurons.
Claudin-3 gene silencing with siRNA suppresses ovarian tumor growth and metastasis
Authors: Huang Yu-Hung , Bao Yunhua , Peng Weidan , Goldberg Michael , Love Kevin , Bumcrot David A. , Cole Geoffrey , Langer Robert , Anderson Daniel G. , Sawicki Janet A.
Published: February 2009

Claudin-3 (CLDN3) is a tight junction protein that is overexpressed in 90% of ovarian tumors. Previous in vitro studies have indicated that CLDN3 overexpression promotes the migration, invasion, and survival of ovarian cancer cells. Here, we investigated the efficacy of lipidoid-formulated CLDN3 siRNA in 3 different ovarian cancer models. Intratumoral injection of lipidoid/CLDN3 siRNA into OVCAR-3 xenografts resulted in dramatic silencing of CLDN3, significant reduction in cell proliferation, reduction in tumor growth, and a significant increase in the number of apoptotic cells. Intraperitoneal injection of lipidoid-formulated CLDN3 siRNA resulted in a substantial reduction in tumor burden in MISIIR/TAg transgenic mice and mice bearing tumors derived from mouse ovarian surface epithelial cells. Ascites development was reduced in CLDN3 siRNA-treated mice, suggesting the treatment effectively suppressed metastasis. Toxicity was not observed after multiple i.p. injections. Importantly, treatment of mice with nonimmunostimulatory 2′-OMe modified CLDN3 siRNA was as effective in suppressing tumor growth as unmodifed siRNA. These results suggest that lipidoid-formulated CLDN3 siRNA has potential as a therapeutic for ovarian cancer.
Variability in Sublingual Microvessel Density and Flow Measurements in Healthy Volunteers
Authors: HUBBLE SHEENA M. A. , KYTE HAYLEY L. , GOODING KIM , SHORE ANGELA C.
Published: February 2009

Objectives: As sublingual microvascular indices are increasingly heralded as new resuscitation end‐points, better population data are required to power clinical studies. This paper describes improved methods to quantify sublingual microvessel flow and density in images obtained by sidestream dark field (SDF) technology in healthy volunteers, including vessels under 10 μm in diameter.

Materials and Methods: Measurements of sublingual capillary density and flow were obtained by recording three 15‐second images in 20 healthy volunteeers over three days. Two independent observers quantified capillary density by using two methods: total vessel length (mm/mm2) and counting (number/mm). Both intraoral and temporal variabilities within subject and observer reproducibilities were determined by using coefficients of variability and reproducibility indices.

Results: For small (1–10 μm), medium (11–20 μm), and large (21–50 μm) diameter, mean vessel density with standard deviations (SDs) in volunteers was 21.3(±4.9), 5.2 (±1.2), and 2.7 (±0.9) mm/mm2, respectively. Also, 94.0±1.4% of small vessels, 94.5±1.4% of medium vessels, and 94.5±4.0% of large vessels had continuous perfusion. Within subjects, the means of all measurements over three days varied less than 13, 22, and 35% in small, medium, and large vessels, respectively. Interobserver reproducibility was good, especially for capillary (1–10 μm) density and flow measurements.

Conclusions: Our methods of microvessel flow and density quantification have low observer variability and confirm the stability of microcirculatory measurements over time. These results facilitate the development of SDF‐acquired sublingual microvascular indices as feasible microperfusion markers in shock resuscitation.
Age and growth of bluemouth, Helicolenus dactylopterus, from the Portuguese continental slope
Authors: Sequeira Vera , Neves Ana , Vieira Ana Rita , Figueiredo Ivone , Gordo Leonel S.
Published: February 2009

Sequeira, V., Neves, A., Vieira, A. R., Figueiredo, I., and Gordo, L. S. 2009. Age and growth of bluemouth, Helicolenus dactylopterus, from the Portuguese continental slope. – ICES Journal of Marine Science, 66: 524–531. In all, 933 bluemouth (Helicolenus dactylopterus) were obtained from bottom-trawl research surveys along the Portuguese continental slope between October 2005 and February 2007 and from commercial landings. Age was determined by reading whole sagittal otoliths, and age estimates were validated by daily growth increment (DGI) analysis. Fish ranged from 5.2 to 44.9 cm, which corresponded to fish between 0 and 30 years old. The mean total length obtained from DGI analysis for age class 1 fish was 8.6 cm, corresponding to otoliths with a mean radius of 1.8 mm. As no statistical differences between sex were observed, the von Bertalanffy growth equation fitted was Lt = 45.50[1 − e−0.05(t+4.01)]. Comparisons with other studies using Hotelling's T2 test and the growth perform index (Ф) are drawn. The growth rates estimated in this study using whole otolith readings were the lowest of all the studies available, and the estimated L∞ is lower then those obtained for Azorean waters and higher than those published for the Mediterranean.
Towards a standard operating procedure for fishery acoustic surveys in the Laurentian Great Lakes, North America
Authors: Rudstam Lars G. , Parker-Stetter Sandra L. , Sullivan Patrick J. , Warner David M.
Published: February 2009

Rudstam, L. G., Parker-Stetter, S. L., Sullivan, P. J., and Warner, D. M. 2009. Towards a standard operating procedure for fishery acoustic surveys in the Laurentian Great Lakes, North America. – ICES Journal of Marine Science, 66: 1391–1397. Acoustic surveys are conducted annually in all five of the Laurentian Great Lakes and Lake Champlain to assess forage-fish abundance. The main target species are rainbow smelt (Osmerus mordax), alewife (Alosa pseudoharengus), and several coregonine species (Coregonus spp.). The Great Lakes Fishery Commission sponsored an Acoustic Study Group from 2002 to 2006 to discuss common problems and suggest standardized methods across these lakes. The study group produced a set of recommendations, available as a Great Lakes Fishery Commission Special Publication and on the web, that use in situ target strength (TS) to scale volume backscattering. Here, we review these recommendations with special attention to four often-overlooked topics of interest to all acoustic users, namely issues associated with first, the choice of thresholds for both TS and volume-backscattering strength, second, different settings for single-echo detection algorithms for measures of in situ TS, third, those taking account of measuring in situ TS in dense fish concentrations, and finally, detection limits.
The Rab GTPase RabA4d Regulates Pollen Tube Tip Growth inArabidopsis thaliana
Authors: Szumlanski Amy L. , Nielsen Erik
Published: February 2009

During reproduction in flowering plants, pollen grains form a tube that grows in a polarized fashion through the female tissues to eventually fertilize the egg cell. These highly polarized pollen tubes have a rapid rate of growth that is supported by a tip-focused delivery of membrane and cell wall components. To gain a better understanding of how this growth is regulated, we investigated the function RABA4D, a member of the Arabidopsis thaliana RabA4 subfamily of Rab GTPase proteins. Here, we show that RABA4D was expressed in a pollen-specific manner and that enhanced yellow fluorescent protein (EYFP)-RabA4d-labeled membrane compartments localized to the tips of growing pollen tubes. Mutant pollen in which the RABA4D gene was disrupted displayed bulged pollen tubes with a reduced rate of growth in vitro and displayed altered deposition of some cell wall components. Expression of EYFP-RabA4d restored wild-type phenotypes to the raba4d mutant pollen tubes, while expression of EYFP-RabA4b did not rescue the raba4d phenotype. In vivo, disruption of RABA4D resulted in a male-specific transmission defect with mutant raba4d pollen tubes displaying aberrant growth in the ovary and reduced guidance at the micropyle. We propose that RabA4d plays an important role in the regulation of pollen tube tip growth.
‘They’ve Always Been There for Me’: Grandparental Involvement and Child Well‐Being
Authors: Griggs Julia , Tan Jo‐Pei , Buchanan Ann , Attar‐Schwartz Shalhevet , Flouri Eirini
Published: February 2009

With diversifying families, increased life expectancy, growing numbers of dual‐worker households and higher rates of family breakdown, grandparents are now playing an increasing role in their grandchildren’s lives. Despite growing importance there has been little empirical research exploring how grandparental involvement impacts on young people’s well‐being. This national study, which includes a survey of 1596 children (aged 11–16) and in‐depth interviews with 40 young people, aimed to address this deficit. Multivariate analyses demonstrate that grandparental involvement is significantly associated with child well‐being – results that are reinforced by qualitative evidence. Findings suggest grandparents may be under‐recognised in the policy agenda.