The thermodynamic properties of liquid binary mixtures of <Emphasis Type=Italic>n</Emphasis>-alkanes: <Emphasis Type=Italic>n</Emphasis>-decane + <Emphasis Type=Italic>n</Emphasis>-hexadecane

Data on sound velocity are used for determining the density, the isobaric expansion coefficient, the isobaric and isochoric heat capacity, and the isothermal compressibility of liquid binary mixture of n-decane + n-hexadecane of three compositions in the temperature range of 298–433 K and pressure range of 0.1–100 MPa. The coefficients of Tait equation are calculated in the above-identified range of parameters. The calculation results are compared with experimental data on density. The divergence does not exceed 0.2% for the most reliable data.     

<Emphasis Type=Italic>hg</Emphasis>-index: a new index to characterize the scientific output of researchers based on the <Emphasis Type=Italic>h</Emphasis>- and <Emphasis Type=Italic>g</Emphasis>-indices

To be able to measure the scientific output of researchers is an increasingly important task to support research assessment decisions. To do so, we can find several different measures and indices in the literature. Recently, the h-index, introduced by Hirsch in 2005, has got a lot of attention from the scientific community for its good properties to measure the scientific production of researchers. Additionally, several different indicators, for example, the g-index, have been developed to try to improve the possible drawbacks of the h-index. In this paper we present a new index, called hg-index, to characterize the scientific output of researchers which is based on both h-index and g-index to try to keep the advantages of both measures as well as to minimize their disadvantages.     

Generalization of <Emphasis Type=Italic>T</Emphasis> and <Emphasis Type=Italic>A</Emphasis> integrals to time-dependent materials: analytical formulations

This paper deals with the generalization of T-integral to crack growth process in viscoelastic materials. In order to implement this expression in a finite element software, a modelling form of this integral, called Aθ, is developed. The analytical formulation is based on conservative law, independent path integral, and a combination of real, virtual displacement fields, and real, virtual thermal fields introducing, in the same time, a bilinear form of free energy density F. According to the generalization of Noether’s method, the application of Gauss Ostrogradski’s theorem combined with curvilinear cracked contour, T _v is obtained. By introducing a volume domain around crack tip, the modelling expression Aθ is also defined.. Finally, the viscoelastic generalization through a thermodynamic approach, called A _v , is introduced by using a discretisation of the creep tensor according to a generalized Kelvin Voigt representation.     

A precision <Emphasis Type=Italic>RLC</Emphasis>-meter

The MNS1100 precision RLC-meter, which operates over a wide range of frequencies and measurable impedance parameters, is described. The instrument is based on new impedance measuring principles with a reduced set of measures and methods of calibrating the measuring circuits, which enable the measurement accuracy to be increased considerably, extend the functional capabilities and automate the apparatus adjustment.     

Symmetry of Superconductivity in YBa<Subscript>2</Subscript>Cu<Subscript>3</Subscript>O<Subscript>7</Subscript>: <Emphasis Type=Italic>s</Emphasis> or <Emphasis Type=Italic>d</Emphasis>

The superconducting hole condensate of YBa₂Cu₃O₇ resides in its BaO layers, and involves s-wave paired holes. This picture differs from the currently widespread opinion that the superconductivity at the surface and in the bulk is d-like, and resides in the CuO₂ planes: it is the main reason why high-temperature superconductivity has been unsolved.     

Combination of <Emphasis Type=Italic>Eigenfactor</Emphasis><Superscript>TM</Superscript> and <Emphasis Type=Italic>h-</Emphasis>index to evaluate scientific journals

The h-index and Eigenfactor ^TM values of top and specialized scientific/engineering journals are tabulated and combined to provide a simple graphical representation of the journals. The information may be tailored to specific uses by respective stakeholders to aid decision making processes with regards to scholarly research and scientific journal publications.     

Gravireception in <Emphasis Type=Italic>Phycomyces Blakesleeanus</Emphasis> and <Emphasis Type=Italic>Arabidopsis Thaliana</Emphasis>: Hysteretic Behavior of Primary Reactions

The gravireception of the fungus Phycomyces blakesleeanus and seedlings of Arabidopsis thaliana is accompanied by gravity-induced absorption changes (GIACs) that occur very fast and most likely represent primary responses of gravireception. GIACs that were analyzed during parabolic flights in micro- and hypergravity invariably display hysteretic behavior. Even though the identity of the pigments generating the GIACs remain presently unknown, it is nevertheless clear that they are specific for gravireception. This is strongly suggested by the fact that hystereses loops of wild-type specimen are significant larger than of gravitropic mutants. Hystereses are largely kinetically determined, are specific for the different organisms and stimulus programs, and thus aid in characterizing the requisite transduction chains of gravireception. The fact that monocot as well as dicot plants display GIACs just in the area of highest gravitropic sensitivity at the tip supports the conclusion that gravireception is generally associated with primary reactions.     

Polaronic Effect and Its Impact on <Emphasis Type=Italic>T</Emphasis><Subscript><Emphasis Type=Italic>c</Emphasis></Subscript> for Novel Layered Superconducting Systems

The crystal lattice of a complex compound may contain a subsystem of ions with each one possessing two close equilibrium positions (double-well structure). For example, the oxygen ions in the cuprates form such a subsystem. In such a situation it is impossible to separate electronic and local vibrational motions. This leads to a large increase in the effective strength of the electron–lattice interaction, which is beneficial for pairing.     

Electron field emission from <Emphasis Type=Italic>sp</Emphasis><Superscript>2</Superscript>-induced insulating to metallic behaviour of amorphous carbon (<Emphasis Type=Italic>a</Emphasis>-C) films

The influence of concentration and size of sp ² cluster on the transport properties and electron field emissions of amorphous carbon films have been investigated. The observed insulating to metallic behaviour from reduced activation energy derived from transport measurement and threshold field for electron emission of a-C films can be explained in terms of improvements in the connectivity between sp ² clusters. The connectivity is resulted by the cluster concentration and size. The concentration and size of sp ² content cluster is regulated by the coalescence of carbon globules into clusters, which evolves with deposition conditions.     

Thermal decomposition of trimethylamine borane as a precursor to nanocrystalline CVD BC<Subscript><Emphasis Type=Italic>x</Emphasis></Subscript>N<Subscript><Emphasis Type=Italic>y</Emphasis></Subscript> films

We have studied the kinetics of BC _x N _y chemical vapor deposition through trimethylamine borane decomposition at atmospheric pressure. The rate constant of the heterogeneous interaction between trimethylamine borane and an adsorption center has been determined to be k _s ⁰ = 2.7 × 10⁷exp(−10560/T) cm/s. The obtained kinetic parameters of the reaction fully determine the growth rate of nanocrystalline carbonitride films under kinetic control. The film thickness has been determined as a function of time, temperature, reactant concentration, and reactor dimensions.     

The speed of sound of <Emphasis Type=Italic>n</Emphasis>-heptane, <Emphasis Type=Italic>n</Emphasis>-octane and their binary mixtures at temperatures <Emphasis Type=Italic>T</Emphasis> = 293.15 to 523.15 K and pressures up to 60 MPa

Speeds of sound in liquid n-heptane, n-octane and their binary mixtures were measured at the temperatures T = 293.15 to 523.15 K and pressures up to 60 MPa. The pulse-echo method with a frequency of 8MHz and uncertainty of ±0.08% was used. The measured values were fitted by polinomials, as functions of temperature and pressure, and the reliability of the present results was proved by comparison with the literature data.     

Electrical impedance of ethylene-carbon monoxide/propylene-carbon monoxide (<Emphasis Type=Italic>EPEC</Emphasis>-<Emphasis Type=Italic>69</Emphasis>) thermoplastic polyketone

Electrical impedance technique was employed to investigate the electrical properties of ethylene-carbon monoxide/propylene-carbon monoxide terpolymer (EPEC-69). The measurements were performed in the frequency range 0.1–10⁵ Hz and in the temperature range 30–110 °C. The results reveal that the dielectric constant, loss factor, modulus, and ac conductivity are dependent of frequency and temperature. A Debye relaxation peak was detected in the plot of Z″ versus frequency where the activation energy was determined and found to be 1.26 eV. When the surface phenomenon effects were separated using the imaginary part of the complex admittance a second dielectric dispersion was observed in the low frequency region. Two models were proposed from the impedance measurements depending on temperature range.     

A methodology for Institution-Field ranking based on a bidimensional analysis: the <Emphasis Type=Italic>IFQ</Emphasis><Superscript>2</Superscript><Emphasis Type=Italic>A</Emphasis> index

The problem of comparing academic institutions in terms of their research production is nowadays a priority issue. This paper proposes a relative bidimensional index that takes into account both the net production and the quality of it, as an attempt to provide a comprehensive and objective way to compare the research output of different institutions in a specific field, using journal contributions and citations. The proposed index is then applied, as a case study, to rank the top Spanish universities in the fields of Chemistry and Computer Science in the period ranging from 2000 until 2009. A comparison with the top 50 universities in the ARWU rankings is also made, showing the proposed ranking is better suited to distinguish among non-elite universities.     

Marginal integration <Emphasis Type=Italic>M</Emphasis>-estimators for additive models

Additive regression models have a long history in multivariate non-parametric regression. They provide a model in which the regression function is decomposed as a sum of functions, each of them depending only on a single explanatory variable. The advantage of additive models over general non-parametric regression models is that they allow to obtain estimators converging at the optimal univariate rate avoiding the so-called curse of dimensionality. Beyond backfitting, marginal integration is a common procedure to estimate each component in additive models. In this paper, we propose a robust estimator of the additive components which combines local polynomials on the component to be estimated with the marginal integration procedure. The proposed estimators are consistent and asymptotically normally distributed. A simulation study allows to show the advantage of the proposal over the classical one when outliers are present in the responses, leading to estimators with good robustness and efficiency properties.     

Kink State in a Stack of Intrinsic Josephson Junctions in Layered High-<Emphasis Type=Italic>T</Emphasis><Subscript><Emphasis Type=Italic>c</Emphasis></Subscript> Superconductors and Terahertz Radiation

A new family of dynamic states are found in a stack of inductively coupled intrinsic Josephson junctions in the absence of an external magnetic field. In this state, (2m _l +1)π phase kinks with integers m _l ’s stack along the c axis and lock neighboring junctions together. A significant part of the dc power is pumped into plasma oscillations via kinks at the cavity resonances. The plasma oscillation is uniform along the c axis with the frequency satisfying the ac Josephson relation. Thus this state supports strong terahertz radiation and seems to be compatible with the recent experimental observations.     

Skew <Emphasis Type=Italic>t</Emphasis> distributions via the sinh-arcsinh transformation

A version of the sinh-arcsinh transformation is used to generate a skew extension of Student’s t distribution which provides an alternative to previously proposed skew t distributions. The basic properties of the resulting sinh-arcsinhed t family of distributions are presented, many of them effectively having the same level of complexity as their Student t counterparts. Quantile-based measures, which come to the fore due to the non-existence of moments, are readily available. The parameters of the distribution have clear interpretations. Limiting distributions as shape parameters tend to their extreme values are especially appealing. The family’s simplest sub-class is closely related to a sub-class of the L _U family. Likelihood based inference is considered and applied in the analysis of heavy-tailed and skew data on fibre glass strengths. Comparisons are made throughout with two of the most popular existing competitors to this distribution: it scores very well relative to them on a number of tractability grounds.     

RF plasma chemical vapor deposition of SiN<Subscript><Emphasis Type=Italic>x</Emphasis></Subscript>:H films

This paper reports on the growth of hydrogenated silicon nitride films by plasma enhanced chemical vapor deposition in the temperature range 100–200°C. We examine the effect of deposition parameters on the growth kinetics, composition, and properties of the films and describe examples of the use of such films in the fabrication of uncooled IR photodetectors, antireflection coatings of solar cells, and three-dimensional microsystems.