Terms Of Redistribution Research Articles

Chronological Reorganization of Microtubules, Actin Microfilaments, and Chromatin during the First Cell Cycle in Swamp Buffalo (Bubalus bubalis) Embryos

This paper aimed to study the dynamics of early embryonic development, in terms of redistribution of cytoskeleton (microtubules, actin microfilaments) and chromatin configurations during the first cell cycle in swamp buffalo embryos. Oocytes were matured and fertilized in vitro, and they were fixed at various time points after IVF. At 6 h after IVF, 44.4% matured oocytes were penetrated by spermatozoa. Partial ZP digestion, however, did not improve fertilization rate compared to control (P > .05). At 12 h after IVF, the fertilized oocytes progressed to the second meiotic division and formed the female pronucleus simultaneously with the paternal chromatin continued to decondense. A sperm aster was observed radiating from the base of the decondensing sperm head. At 18 h after IVF, most presumptive zygotes had reached the pronuclear stage. The sperm aster was concurrently enlarged to assist the migration and apposition of pronuclei. Cell cleavage was facilitated by microfilaments and firstly observed by 30 h after IVF. In conclusion, the cytoskeleton actively involves with the process of fertilization and cleavage in swamp buffalo oocytes. The centrosomal material is paternally inherited. Fertilization failure is predominantly caused by poor sperm penetration. However, partial digestion of ZP did not improve fertilization rate.

A first principles study of the properties of Al:ZnO and its adhesion to Ag in an optical coating

A first principles density functional study of the atomistic properties of Al:ZnO and its adhesion to Ag is presented. Optical coatings often contain interfaces between ZnO (0001) and Ag (111) layers whose bonding can be improved by incorporating small amounts of Al into the ZnO but the underlying strengthening mechanism remains unclear. It is assumed that Al relaxes the internal compressive stress in the film but the situation is complicated by the presence of hydrogen and/or water which can adsorb on the ZnO surface during fabrication of the coating. Hydrogen and/or water are known to weaken the Ag/ZnO interface particularly when it is O terminated. In this paper it is shown that aluminum substitutes on Zn sites in ZnO and this does indeed reduce the internal stress in the layer under compression. However, it is also shown that Al segregates to the ZnO surface when it is O terminated (but not Zn terminated) and this reduces the propensity for hydrogen adsorption. Thus by eliminating some of the hydrogen from the ZnO surface which is more likely to be O terminated than Zn terminated under ambient conditions, the strength of the Ag/ZnO interface can be increased. The effect of aluminum incorporation into the ZnO layer is therefore twofold: it relaxes the residual stresses in the coating and also improves the chemical bonding at the metal/oxide interface by removing the weakening effects of gaseous adsorption. The changes in interfacial bonding are explained in terms of an electron redistribution and compensation model.

Modification of surface electronic properties on alloy surfaces: Standing waves on aCu-9 at. % Al(111)surface observed by STM

A direct and real-space study of the surface electronic structure on $\text{Cu-}9\text{ }\text{at}\text{.}\text{ }%\text{ }\text{Al}(111)$ alloy surfaces was performed using low-temperature scanning tunneling microscopy. The standing waves on $\text{Cu-}9\text{ }\text{at}\text{.}\text{ }%\text{ }\text{Al}(111)\text{\ensuremath{-}}(1\ifmmode\times\else\texttimes\fi{}1)$ and $(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})R30\ifmmode^\circ\else\textdegree\fi{}$ surfaces, which were obtained by controlling annealing temperature, were observed by differential-conductance mapping. Surface imperfection caused by segregation of aluminum atoms acted as static scattering centers in order to sustain the standing-wave formation. An analysis of the standing waves revealed a significant downward energy shift of the Shockley surface states on both surfaces. This shift is explained in terms of the strong redistribution of the surface electrons.

In situ x-ray studies of native and Mo-seeded surface nanostructuring during ionbombardment of Si(100)

Native and Mo-seeded nanostructuring of the Si(100) surface duringAr+ ion bombardment is investigated by means of real-time grazing-incidence small-angle x-rayscattering and atomic force microscopy. During off-axis bombardment at roomtemperature, the native early-stage growth kinetics of nanoripples on the surface is foundto be in reasonable overall agreement with theoretical predictions, particularlywhen an ion impact induced lateral mass redistribution term is included. Fornormal-incidence bombardment at room temperature, a native short wavelengthsmoothing of the amorphized Si surface is observed, suggesting that ion impactinduced lateral mass redistribution dominates the Bradley–Harper instability.During 5% Mo-seeded normal-incidence bombardment at temperatures up to450 °C, nanodots form with heights decreasing as the substrate temperature increases.This trend is counter to that typically observed for the growth of largecone structures on metals and suggests that the primary effect of thermalenergy here is in promoting surface smoothing, rather than increasing diffusionof seed atoms to form protective clusters. During seeded bombardment at650 °C the surface remains crystalline and surface corrugations exhibit dynamic scalingcharacteristic of surface diffusion-driven instabilities. This is the same behavior as is foundin the absence of seeding and its presence suggests that at this concentration seeding doesnot play a large role during normal-incidence bombardment of the Si surface at hightemperatures.

Finite element method for modeling radiative transfer in semitransparent graded index cylindrical medium

Both Galerkin finite element method (GFEM) and least squares finite element method (LSFEM) are developed and their performances are compared for solving the radiative transfer equation of graded index medium in cylindrical coordinate system (RTEGC). The angular redistribution term of the RTEGC is discretized by finite difference approach and after angular discretization the RTEGC is formulated into a discrete-ordinates form, which is then discretized based on Galerkin or least squares finite element approach. To overcome the RTEGC-led numerical singularity at the origin of cylindrical coordinate system, a pole condition is proposed as a special mathematical boundary condition. Compared with the GFEM, the LSFEM has very good numerical properties and can effectively mitigate the nonphysical oscillation appeared in the GFEM solutions. Various problems of both axisymmetry and nonaxisymmetry, and with medium of uniform refractive index distribution or graded refractive index distribution are tested. The results show that both the finite element approaches have good accuracy to predict the radiative heat transfer in semitransparent graded index cylindrical medium, while the LSFEM has better numerical stability.

New agendas? Culture and citizenship in EU policy

If the liberal tradition considered citizenship mostly as a legal status entailing both rights and duties, opposing views from communitarian or republican theorists privilege its substantive dimensions. Social equality is no longer configured exclusively in terms of material redistribution, they argue, but also through the recognition of cultural difference. Whether related to cultural identity or the empowerment of public agency, citizenship is increasingly couched in cultural terms. Taking recourse to political theory, this paper analyses the connections between culture and citizenship in policy documents by the European Union (EU). It identifies three ‘semantic clusters’, which it discusses in more detail: the ontological, the intercultural and the participatory. If the first harnesses culture to address the EU’s ‘legitimacy deficit’ by promoting a European demos, the second shows how these are complemented with new policy concerns emerging in the context of transnational migration. The third in turn focuses on culture as a platform for citizens’ agency through participation in political and deliberative processes.

Structure and physical properties of isopropyl TTF semisquarates

The synthesis, characterization and physical properties of two isopropyl TTF semisquarates, TTFsqiPr and EDT-TTFsqiPr, are reported. These molecules show a solvatochromism effect in solution and electrical conductivity in the solid state in their neutral form. These behaviors can be explained in terms of a small electrical charge redistribution from the TTF-centered HOMO to the semisquarate-centered LUMO of the molecules.

Temperature Insensitivity of Optical Properties of InAs/GaAs Quantum Dots due to a Pregrown InGaAs Quantum Well

Both the peak position and linewidth in the photoluminescence spectrum of the InAs/GaAs quantum dots usually vary in an anomalous way with increasing temperature. Such anomalous optical behaviour is eliminated by inserting an In0.2Ga0.8As quantum well below the quantum dot layer in molecular beam epitaxy. The insensitivity of the photoluminescence spectra to temperature is explained in terms of the effective carrier redistribution between quantum dots through the In0.2Ga0.8As quantum well.

Assessment of the Cathode Contribution to the Degradation of Anode-Supported Solid Oxide Fuel Cells

The degradation of anode-supported cells was studied over as a function of cell polarization either in air or oxygen on the cathode side. Based on impedance analysis, contributions of the anode and cathode to the increase of total resistance were assigned. Accordingly, the degradation rates of the cathode were strongly dependent on the . Microstructural analysis of the cathode/electrolyte interface carried out after removal of the cathode showed craters on the electrolyte surface where the lanthanum strontium manganite (LSM) particles had been located. The changes of shape and size of these craters observed after testing correlated with the cell voltage degradation rates. The results can be interpreted in terms of element redistribution at the cathode/electrolyte interface and formation of foreign phases giving rise to a weakening of local contact points of the LSM cathode and yttria-stabilized zirconia electrolyte and consequently a reduced three-phase boundary length.

Transferencias fiscales y políticas públicas

En un sistema descentralizado, las transferencias fiscales intergubernamentales constituyen un importante instrumento de gestión pública, pues contribuyen al logro de objetivos redistributivos o compensatorios, y por tanto, a la disminución de problemas de ineficiencia asignativa y/o de equidad social y territorial. En el proceso de descentralización boliviano se han establecido varios sistemas de transferencias fiscales a partir de diferentes políticas públicas, y al presente constituyen la principal fuente de financiamiento de las administraciones subnacionales. Si bien estos sistemas han logrado un importante avance en términos de redistribución territorial de recursos fiscales, con posibles efectos significativos desde un punto de vista social, en la práctica pueden estar generando problemas de ineficiencia y pereza fiscal, poniendo en peligro los avances en el logro de mayor equidad. El documento describe este proceso y resalta, como uno de los grandes desafíos en la profundización del proceso de descentralización, el rediseño de los sistemas de transferencias con una orientación al logro de mayor eficiencia y equidad, y principalmente hacia su propia sostenibilidad.

Switching between generation of two quantum states in quantum-well laser diodes

The dynamics of emission spectra in semiconductor quantum-well lasers generating from two quantum states have been experimentally studied. In the case of electric pumping with 100-ns pulses, the lasing via transitions from the ground state is switched off and the emission from an excited state is switched on within 10–50 ns after laser turn-on. The switching is accompanied by a dip in the intensity of lasing, the duration of which depends on the pumping pulse amplitude. The observed phenomenon is explained in terms of gain clamping and redistribution of the carrier concentration between the ground and excited states.

Densification, magnetic and dielectric behaviour of Cu-substituted Mg–Zn ferrites

The physical, magnetic and dielectric properties of Cu-substituted Mg–Zn ferrites having the general formula of Mg 0.55− x Cu x Zn 0.45O(Fe 2O 3) 0.97 prepared by standard double sintering ceramic technique have been studied. X-ray diffraction (XRD) patterns of the samples indicate the formation of single-phase cubic spinel structure. The lattice parameter ‘ a’ is increased with increasing Cu 2+ ion substitution. A significant increase in density is observed with increasing Cu content. The beneficial effect of copper ions on the densification of Mg–Zn ferrite can be reasonably explained by possible bimodal diffusion mechanism. The initial permeability μ′ shows a good stability with frequency for x = 0.0–0.25 while μ′ shows the constant value up to 200 kHz for x = 0.30 and 0.35 beyond which it falls rapidly. The permeability is found to increase as copper content increases which is consistent with the variation of density with copper ions. Saturation magnetization ( M s) increases with copper content up to x = 0.30 and then it decreases. The observed variation in M s can be explained in terms of the cation redistribution between A and B sublattices. Dielectric constant ( ɛ′) decreases with increase in frequency which is rapid at lower frequencies and slower at higher frequencies which may be due to the Maxwell-Wagner interfacial polarization. Dielectric relaxation peaks were observed for the frequency dependence of dielectric loss tangent curves. ɛ′ increases as the temperature increases which is attributed to the fact that the hoping of electrons between Fe 2+ and Fe 3+ ions is thermally activated on increasing the temperature.

Transported PDF Modelling of a High Velocity Bluff-Body Stabilised Flame (HM2) Using Detailed Chemistry

A transported probability density function (PDF) approach closed at the joint scalar level was used to model a bluff body stabilised turbulent diffusion flame (HM2) investigated experimentally by Masri and co-workers. The current effort extends a previous study of HM1 (Re = 15,800) to a flame with a higher degree of local extinction (Re = 23,900). The impact of an algebraic model that accounts for local Damkohler number effects on the time-scale ratio of scalar to mechanical turbulence is also evaluated along with the impact of improved thermochemistry. The computations have been performed using a hybrid Monte Carlo/finite volume algorithm and a systematically reduced H/C/N/O mechanism featuring 300 reactions, 20 solved and 28 steady-state species. The joint scalar PDF equations were solved using moving particles in a Lagrangian framework and the velocity field was closed at the second moment level. The redistribution terms were modelled using the Generalized Langevin model of Haworth and Pope. Results show that scalar fields are reproduced with encouraging accuracy and that the revised time scale model improves agreement with experimental data. A high sensitivity to the NO chemistry was observed and encouraging agreement was obtained for the first two moments following adoption of updated reaction rates proposed in an earlier study.

Assessment of the axisymmetric radiative heat transfer in a cylindrical enclosure with the finite volume method

The radiative heat transfer in an axisymmetric enclosure containing an absorbing, emitting, and scattering gray medium is investigated by using the finite volume method (FVM). Especially, formulations with the cylindrical base vectors are introduced and its characteristics is discussed by comparing with other solution methods in the finite volume category. By considering the three-dimensional procedure, the angular redistribution term, which appears in such curvilinear coordinates as axisymmetric and spherically symmetric ones, can be treated efficiently without any artifice usually introduced in the conventional discrete ordinates method (DOM). After a mathematical formulation and corresponding discretization equation for the radiative transfer equation (RTE) are derived, final discretization equation is introduced by using the directional weight, which is the key parameter in the FVM since it represents the inflow or outflow of radiant energy across the control volume faces depending on its sign. The present approach is then validated by comparing the present results with those of previous works. All the results presented in this work show that the present method is accurate and valuable for the analysis of cylindrically axisymmetric radiative heat transfer problems.

Effects of low levels of tungsten doping in bismuth niobates

Tungsten doping into Bi 7Nb 2O 15.5 was investigated using a combination of X-ray and neutron diffraction and ac impedance spectroscopy. Only limited solid solution formation is observed in the system Bi 7Nb 2 − 2 x W 2 x O 15.5 + x , with a defect fluorite type phase observed up to around x = 0.2. The defect structure of this phase shows, that Nb 5+ and W 6+ ions are likely to adopt a distorted octahedral coordination geometry, with Bi 3+ ions in predominantly four-pyramidal geometry. Non-linearity in the Arrhenius plot of conductivity as well as the thermal variation of the cubic lattice parameter are interpreted in terms of a subtle redistribution of oxide ions in the structure at elevated temperatures.

An implicit finite volume scheme for a scalar hyperbolic problem with measure data related to piecewise deterministic Markov processes

We are interested here in the numerical approximation of a family of probability measures, solution of the Chapman–Kolmogorov equation associated to some non-diffusion Markov process with uncountable state space. Such an equation contains a transport term and another term, which implies redistribution of the probability mass on the whole space. An implicit finite volume scheme is proposed, which is intermediate between an upstream weighting scheme and a modified Lax–Friedrichs one. Due to the seemingly unusual probability framework, a new weak bounded variation inequality had to be developed, in order to prove the convergence of the discretised transport term. Such an inequality may be used in other contexts, such as for the study of finite volume approximations of scalar linear or nonlinear hyperbolic equations with initial data in L 1 . Also, due to the redistribution term, the tightness of the family of approximate probability measures had to be proven. Numerical examples are provided, showing the efficiency of the implicit finite volume scheme and its potentiality to be helpful in an industrial reliability context.

AgI Nanoplates in Unusual 7H/9R Structures: Highly Ionically Conducting Polytype Heterostructures

Homogeneous AgI nanoplates in diameter and in thickness can be prepared by a solution-based route using poly(diallyldimethylammonium chloride) as capping agent. The formation of unusual 7H/9R polytype modifications is the origin of the huge room temperature superionic conductivity and the large hysteresis in the phase transition with respect to the superionic high-temperature phase . All these properties indicate a substantial Ag disorder in the 7H/9R polytype AgI unlike the normal in wurtzite structure. The Ag disorder in 7H/9R polytype structure can be formally understood in terms of an equilibrium redistribution of charge carriers at heterojunctions in ionically conducting zinc blende heterostructures in the subnano regime. Upon martensitic transformation of with its body-centered-cubic iodine lattice, the 7H/9R stacking sequence rather than the 2H sequence of occurs in the presence of attracting surface adsorbents of . The usability of these materials as electrolytes in rechargeable all-solid-state Ag batteries working at was demonstrated by using Ag as anode and as cathode.

Plasma-assisted self-organized growth of uniform carbon nanocone arrays

The self-organized growth of uniform carbon nanocone arrays using low-temperature non-equilibrium Ar + H 2 + CH 4 plasma-enhanced chemical vapor deposition (PECVD) is studied. The experiment shows that size-, shape-, and position-uniform carbon nanocone arrays can develop even from non-uniformly fragmented discontinuous nickel catalyst films. A three-stage scenario is proposed where the primary nanocones grow on large catalyst particles during the first stage, and the secondary nanocones are formed between the primary ones at the second stage. Finally, plasma-related effects lead to preferential growth of the secondary nanocones and eventually a uniform nanopattern is formed. This does not happen in a CVD process with the same gas feedstock and surface temperature. The proposed three-stage growth scenario is supported by the numerical experiment which generates nanocone arrays very similar to the experimentally synthesized nanopatterns. The self-organization process is explained in terms of re-distribution of surface and volumetric fluxes of plasma-generated species in a developing nanocone array. Our results suggest that plasma-related self-organization effects can significantly reduce the non-uniformity of carbon nanostructure arrays which commonly arises from imperfections in fragmented Ni-based catalyst films.

Field effect of carbon nanotubes with an ionomeric polymer

AbstractFlexible field effect transistors based on a single walled carbon nanotube (SWNT) network and an ionomeric polymer (nafion) were obtained by spraying nanotubes onto the polymer film. The threshold gate voltage was extremely low, ∼1 V, which was surprising since the nafion layer was so thick, ∼180 μm. This was attributed to the electrolytic nature of nafion, which results in the existence of a screening layer at the polymer‐nanotube interface. FET hysteresis can be rationalized in terms of charge redistribution induced by mobile protons inside nafion clusters in proximity to the nanotube surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

DFT study of hydrogen bond bridging mode of pyridine and diazenes in water environment

Optimized geometries and vibrational spectra of pyridine (Py), pyridazine (Py 1,2), pyrimidine (Py 1,3), pyrazine (Py 1,4) and their complexes with water molecules have been calculated with a view to look into the strength of hydrogen bonds, binding energies and vibrational wavenumbers of hydrogen bond bridging modes. The counterpoise corrected binding energies for different complexes are also calculated. The results of DFT calculations have been used to draw the potential energy curve and to calculate the amplitude of stretching vibration of hydrogen bond bridging modes. The three types of hydrogen bonds: N…H O, O…H O, and O…H C have been studied. The relative hydrogen bond strengths and vibrational wavenumbers of these bridging modes have been explained in terms of redistribution of electronic charges on individual atoms.