Ring Distribution Research Articles

Penetration of magnetosonic waves into the plasmasphere observed by the Van Allen Probes

AbstractDuring the small storm on 14–15 April 2014, Van Allen Probe A measured a continuously distinct proton ring distribution and enhanced magnetosonic (MS) waves along its orbit outside the plasmapause. Inside the plasmasphere, strong MS waves were still present but the distinct proton ring distribution was falling steeply with distance. We adopt a sum of subtracted bi‐Maxwellian components to model the observed proton ring distribution and simulate the wave trajectory and growth. MS waves at first propagate toward lower L shells outside the plasmasphere, with rapidly increasing path gains related to the continuous proton ring distribution. The waves then gradually cross the plasmapause into the deep plasmasphere, with almost unchanged path gains due to the falling proton ring distribution and higher ambient density. These results present the first report on how MS waves penetrate into the plasmasphere with the aid of the continuous proton ring distributions during weak geomagnetic activities.

Formulation and Evaluation of Coating Content and Their Distribution on Chips Products by Automated Inspection Using Fuzzy-Based Image Processing

This study proposed a method to develop an intelligent system using an adaptive neuro-fuzzy inference system (ANFIS)-based image processing which predicts the flavor distribution of the chips ring. This study was divided into three stages and different variables in each stage to obtain the best combination. These variables were the number of nozzles employed (one, two and three nozzles), flavor solution temperature (4, 50 and 60C) and the flavor spraying air flow rate (2.5, 3.0 and 3.5 psi). The results showed that the chips rings produced by the combinations of the three nozzles, 50C and with different air flowing rates exhibited significantly higher color distribution, flavor and overall acceptance compared with all other treatments (P < 0.05). These results were supported by the flavor distribution images that were taken for each combination. The ANFIS predicted the experimental results with 100% accuracy. ANFIS processing indicated that the best treatment was the one that was produced by using three nozzles for spraying the flavor under 50C with 2.5 psi air flow rate. Practical Applications This system was developed by using an adaptive neuro-fuzzy inference system (ANFIS)- based image processing to rapidly predict the flavor distribution of the chips ring for accepting or rejecting defects.

The complex phylogeography of the Indo-Malayan Alophoixus bulbuls with the description of a putative new ring species complex.

The Indo-Malayan bioregion has provided some of the most spectacular discoveries of new vertebrate species (e.g. saola, khanyou, bare-faced bulbul) over the last 25years. Yet, very little is known about the processes that led to the current biodiversity in this region. We reconstructed the phylogeographic history of a group of closely related passerines, the Alophoixus bulbuls. These birds are continuously distributed in Indo-Malaya around the Thailand lowlands such that their distribution resembles a ring. Our analyses revealed a single colonization event of the mainland from Sundaland with sequential divergence of taxa from southwest to northeast characterized by significant gene flow between parapatric taxa, and reduced or ancient gene flow involving the two taxa at the extremities of the ring. We detected evidence of population expansion in two subspecies, including one that was involved in the closing of the ring. Hence, our analyses indicate that the diversification pattern of Alophoixus bulbuls fits a ring species model driven by geographic isolation. To our knowledge, the Alophoixus bulbuls represent the first case of a putative broken ring species complex in Indo-Malaya. We also discuss the implications of our results on our understanding of the biogeography in Indo-Malaya.

Wave propagation in piezoelectric rings with rectangular cross-sections

The ring ultrasonic transducers are widely used in the ocean engineering and medical fields. This paper employs an extended orthogonal polynomial approach to solve the guided wave propagation in two-dimensional structures, i.e. piezoelectric rings with rectangular cross-sections. The extended polynomial approach can overcome the drawbacks of the conventional orthogonal polynomial approach which can be used to solve wave propagation in one-dimensional structures. Through numerical comparison with the available results for a rectangular aluminum bar, the validity of the present approach is illustrated. The dispersion curves and displacement and electric potential distributions of various rectangular piezoelectric rings are calculated, and the effects of different radius to thickness ratios, width to height ratios and polarizing directions on the dispersion curves are illustrated.

Molecular dynamics of vitreous silica — Variations in potentials and simulation regimes

Two potential sets, and three thermodynamic regimes were utilised in MD simulations to prepare the corresponding structures of vitreous silica. Standard structure descriptors as RDF's, angle distributions, and primitive ring distributions showed subtle differences among glasses. Structural defects as overcoordinations and dangling bonds revealed higher sensitivity to both used potential sets and TD conditions. Overcoordination is largely driven by the density while the amount of dangling bonds is given by the type of the potential. Connectivity that balances under- and over-coordination is determined rather by TD conditions than type of potential used. Ring distribution as well as radial distribution function of rings shows robustness to alternating conditions of simulation.

Wave normal angle and frequency characteristics of magnetosonic wave linear instability

AbstractMagnetosonic waves, also known as equatorial noise emission, can be unstable in the presence of ion ring velocity distribution of ring current population. Earlier studies have demonstrated that such instability can occur near proton harmonic frequencies and near perpendicular propagation with a narrow range of wave normal angle about 90° and that the waves may contribute significantly to electron acceleration in the radiation belt. However, this effect is sensitive to the values of wave normal angles. Instability characteristics in the regime of weak instability, in particular the dependence on the wave frequency and wave normal angle, is investigated for an ion ring distribution modeled by subtraction of two anisotropic Maxwellian distributions. It is found that two types of instabilities, resonant and nonresonant, occur near 90° wave normal angles. Physics of the two instabilities is explained and discussed. The resonant instability, occurring at a finite parallel wave number k∥, is caused by resonant protons near 90° pitch angle, while the nonresonant instability, occurring for a vanishing k∥, is driven by all thermal protons. A formula for the linear nonresonant instability is derived and generalized for an arbitrary ion distribution.

Linear dispersion properties of ring velocity distribution functions

Linear properties of ring velocity distribution functions are investigated. The dispersion tensor in a form similar to the case of a Maxwellian distribution function, but for a general distribution function separable in velocities, is presented. Analytical forms of the dispersion tensor are derived for two cases of ring velocity distribution functions: one obtained from physical arguments and one for the usual, ad hoc ring distribution. The analytical expressions involve generalized hypergeometric, Kampé de Fériet functions of two arguments. For a set of plasma parameters, the two ring distribution functions are compared. At the parallel propagation with respect to the ambient magnetic field, the two ring distributions give the same results identical to the corresponding bi-Maxwellian distribution. At oblique propagation, the two ring distributions give similar results only for strong instabilities, whereas for weak growth rates their predictions are significantly different; the two ring distributions have different marginal stability conditions.

Capped carbon nanotube photovoltaic cells: Influence of distribution of the five-membered rings on the efficiency

Electronic structure and energy conversion efficiency η for a photovoltaic organic solar cell of single-walled carbon nanotubes (CNTs) with various end-cap geometries facing Zn-phtalocyanine are studied based on density functional theory. Accumulation of the 5566 clusters, composed of two five-membered rings and two six-membered rings, at the cap raises the energy of the localized state, which plays a key role in improving the magnitude of η, whereas both the rotational symmetry around the axis and the chirality of the tube seem to be less important in determining the magnitude of η. These properties are explained by a charge transfer from the CNT to the cap.

Effects of forest type and urbanization on species composition and diversity of urban forest in Changchun, Northeast China

Urban forest is considered as the most important component of urban green infrastructure and can make vital contributions to urban biodiversity. Understanding the species composition and diversity of urban forest is important for urban biodiversity enrichment. In this study, we evaluated the urban forest woody plant diversity and spatial pattern in Changchun, northeast China. The differentiations in species composition and diversity among types of urban forests and gradients of urbanization were then explored. Principal Component Analysis (PCA) was performed to characterize the species distribution. Similarity Percentage (SIMPER) analysis was adopted to determine the species differentiation and the main contributed species among different urban forest types and different urbanization gradients. The results showed that urban forest species in Changchun were abundant with 88 species that belonged to 50 genera and 24 families. The three major species were Salix matsudana, Populus davidiana, and Pinus sylvestris var. mongolica. Native species were preferred in urban forest of Changchun. Significant differentiations in species composition were observed among different types of urban forests. Attached forest (AF) had the highest species richness and biodiversity, whereas production and management forest (PF) had the lowest ones. SIMPER results showed the highest species dissimilarity between AF and PF and lowest species dissimilarity between AF and landscape and relaxation forest (LF). For different urbanization gradients, species richness and diversity in the third ring were the highest and in the first ring were the lowest. SIMPER results showed the lowest species dissimilarity between the third ring and the fourth ring and highest species dissimilarity between the first ring and the fourth ring. Based on the 10/20/30 “rule of thumb”, the diversity must be urgently increased at the species, genus, and family levels for EF and PF. For different urbanization gradients, diversity should be increased at the species level in the first ring and the fifth ring, and should be increased at the family level in the second ring and the fifth ring.

An investigation into the crystallization of low-silica X zeolite

The crystallization of low-silica X (LSX) zeolite with FAU topology was examined under hydrothermal synthesis conditions. PXRD was employed to follow the evolution of the long-range ordering of the gel. Raman spectra provided information on various ring and cage species existing in the gel. 27Al and 29Si solid-state NMR spectroscopy was utilized to monitor the change in local environment of tetrahedral sites. The results indicate that an amorphous aluminosilicate phase was formed immediately upon mixing different reactive species. Hydrothermal treatment led to the formation of sodalite-cage like species and the species with larger cavities, joint four-member rings (4Rs) and branched 4Rs, which are the structural building units of the FAU framework. These units were assembled into the crystalline structure of LSX zeolite. 23Na and 39K solid-state NMR results show that the transformation process was accompanied by the changes of the local structure of hydrated Na+ and K+ ions. The two types of cations may work synergistically to template the crystallization of LSX zeolite.

Stability of the kinetic Alfven wave in a current-less plasma

The two potential theory of Hasegawa has been used to derive the dispersion relation for the kinetic Alfven wave (KAW) in a plasma composed of hydrogen, oxygen and electrons. All three components have been modeled by ring distributions (obtained by subtracting two Maxwellian distributions with different temperatures) with the hydrogen and electrons drifting, respectively, with velocities VdH and Vde. For the most general case, the dispersion relation is a polynomial equation of order five; it reduces to a relation which supports only one mode when VdH=0. For typical parameters at comet Halley, we find that both VdH and Vde can drive the wave unstable; the KAW is thus driven unstable in a current-less plasma. Such an instability was found for the ion acoustic wave by Vranjes et al. (2009).

WHY ARE DENSE PLANETARY RINGS ONLY FOUND BETWEEN 8 AND 20 AU?

The recent discovery of dense rings around the Centaur Chariklo (and possibly Chiron) reveals that complete dense planetary rings are not only found around Saturn and Uranus, but also around small bodies orbiting in the vicinity of those giant planets. This report examines whether there could be a physical process that would make rings more likely to form or persist in this particular part of the outer Solar System. Specifically, the ring material orbiting Saturn and Uranus appears to be much weaker than the material forming the innermost moons of Jupiter and Neptune. Also, the mean surface temperatures of Saturn's, Uranus' and Chariklo's rings are all close to 70 K. Thus the restricted distribution of dense rings in our Solar System may arise because icy materials are particularly weak around that temperature.

Are para-nitro-pyridine N-oxides quinonoid or benzenoid? An answer given by spatial NICS (TSNMRS)

The spatial magnetic properties (Through-Space NMR Shieldings—TSNMRS) of a number of substituted para-nitro-pyridine N-oxides have been computed, visualized as Iso–Chemical–Shielding–Surfaces (ICSS) of various size and direction, and were examined subject to the present quinonoid or benzenoid π-electron distribution of the six-membered ring.

3D EHD lubrication and wear for piston ring-cylinder liner on diesel engines

The three-dimensional EHD lubrication and wear loss of piston ring-cylinder liner components for five rings in the firing diesel engine was studied by using VC++ programs. The gas blowby, variable density and viscosity of lubricant, the surface roughness, friction heat flux and the normal elastic deformation are all considered in the EHD lubrication analysis algorithm. Meanwhile, the wear loss of the cylinder liner was also calculated when the diesel was started under cold starting condition in which the wearing was more serious than that in warm starting condition. The simulated results were compared with the wear measurement of the cylinder liner, and they matched well. It was found that the hydrodynamic friction force was larger than the asperity friction force, and the wear distribution of the barrel piston ring was very different from that of the rectangular piston ring. The distribution trend of the nominal oil film thickness was similar to the normal elastic deformation, but opposite to the wear loss of the piston rings. The wear loss caused by the first piston ring was the biggest and played a dominant role in the wear loss of cylinder liner. The greatest wear loss of the cylinder liner occurs at the time near top dead centre.

Ordinary mode instability associated with thermal ring distribution

The purely growing ordinary (O) mode instability driven by excessive parallel temperature anisotropy has recently received renewed attention owing to its potential applicability to the solar wind plasma. Previous studies of O mode instability have assumed either bi-Maxwellian or counter-streaming velocity distributions. For solar wind plasma trapped in magnetic mirror-like geometry such as magnetic clouds or in the vicinity of the Earth's collisionless bow shock environment, however, the velocity distribution function may possess a loss-cone feature. The O-mode instability in such a case may be excited for cyclotron harmonics as well as the purely growing branch. The present paper investigates the O-mode instability for plasmas characterized by the parallel Maxwellian distribution and perpendicular thermal ring velocity distribution in order to understand the general stability characteristics.

Influence of plasma beta on the generation of lower hybrid and whistler waves by an ion velocity ring distribution

We present results of three-dimensional electromagnetic particle-in-cell simulations of the lower hybrid ion ring instability, similar to our earlier results [D. Winske and W. Daughton, Phys. Plasma 19, 072109 (2012)], but at higher electron beta (βe = ratio of electron thermal pressure to magnetic pressure = 0.06, rather than at 0.006) with Ti = Te. At higher electron beta, the level of lower hybrid waves at saturation normalized to the ion thermal energy (βi = 0.06 also) is only slightly smaller, but the corresponding magnetic fluctuations are about an order of magnitude larger, consistent with linear theory. After saturation, the waves evolve into whistler waves, through a number of possible mechanisms, with an average growth rate considerably smaller than the linear growth rate of the lower hybrid waves, to a peak fluctuation level that is about 20% above the lower hybrid wave saturation level. The ratio of the peak magnetic fluctuations associated with the whistler waves relative to those of the saturated lower hybrid waves, the ratio of the nonlinear growth rate of whistlers relative to the linear growth rate of lower hybrid waves, the amount of energy extracted from the ring, and the amount of heating of the background ions and electrons are comparable to those in the lower electron beta 3D simulation. This suggests that even at higher electron beta, the linear and nonlinear physics of the lower hybrid ion ring instability is dominated by electrostatic, wave-particle rather than wave-wave interactions.

A tale of two haplotype groups: Evaluating the New World Junonia ring species hypothesis using the distribution of divergent COI haplotypes.

The New World Junonia butterflies are a possible ring species with a circum-Caribbean distribution. Previous reports suggest a steady transition between North and South American forms in Mesoamerica, but in Cuba the forms were thought to co-exist without interbreeding representing the overlapping ends of the ring. Three criteria establish the existence of a ring species: a ring-shaped geographic distribution, gene flow among intervening forms, and genetic isolation in the region of range overlap. We evaluated mitochondrial cytochrome oxidase I haplotypes in Junonia from 9 species in the Western Hemisphere to test the Junonia ring species hypothesis. Junonia species are generally not monophyletic with respect to COI haplotypes, which are shared across species. However, two major COI haplotype groups exist. Group A predominates in South America, and Group B predominates in North and Central America. Therefore, COI haplotypes can be used to assess the degree of genetic influence a population receives from each continent. Junonia shows a ring-shaped distribution around the Caribbean, and evidence is consistent with gene flow among forms of Junonia, including those from Mesoamerica. However, we detected no discontinuity in gene flow in Cuba or elsewhere in the Caribbean consistent with genetic isolation in the region of overlap. Though sampling is still very limited in the critical region, the only remaining possiblity for a circum-Caribbean discontinuity in gene flow is at the Isthmus of Panama, where there may be a transition from 98% Group B haplotypes in Costa Rica to 85-100% Group A haplotypes in South America.

A laser photoacoustic analysis of residual CO₂ and H₂O in larch stems.

Every so often, the results obtained from investigations into the effects of varying environmental conditions on the tree growth rate at the same sites and on the change in the carbon balance in plants, using traditional methods, are found to differ widely. We believe that the reason for the ambiguity of the data has to do with failure to account for the role of the residual CO2 (and H2O) in the tree wood exhibiting a climate response. In our earlier work, the results of a laser photoacoustic gas analysis of CO2 and H2O vacuum-desorbed from disc tree rings of evergreen conifer trees were presented. In this paper, laser photoacoustic measurements of tree ring gases in deciduous conifer trees and CO2 carbon isotope composition determined by means of a mass spectrometer are given. Conclusions are made regarding the response of annual larch CO2 disc tree ring distributions to climatic parameters (temperatures and precipitation). The data about the CO2 disc content for different sites are compared.

Image comparisons among analysis, simulation and experimental solutions about stress distribution in rings loaded by multiple symmetrical radial forces

The theorem of energy valley state and a particular solution of Airy biharmonic equation will be used in the stress analysis in the rings loaded by the multiple- fold symmetrical forces to obtain stresses formulas. The varied stress graphs have been plotted with these formulas and FEM, revealing their periods of symmetry of forces.

New Mutation in Chromosome 9 Associated with Familial Autosomal Recessive Macrothrombocytopenia

We report a family with new autosomal recessive disorder associated with macrothrombocytopenia which is different from all reported hereditary macrothrombocytopenia.Case report: The affected family members report mild bruising and epistaxis. The females’ family members report, in addition, severe menorrhagia and recurrent episodes of hemorrhagic corpus luteum. Two family members with macrothrombocytopenia and two without macrothrombocytopenia report hearing loss and cataracts.Methods: The study protocol was approved by our local Ethics committee and written consent was obtained to prepare and store DNA. Platelet morphology, FACS analysis, protein analysis and genome-wide association studies were used to characterize the disease and locate the genetic abnormality.Results: In a consanguineous family from Arab origin we identified 5 affected individuals (3 males and 2 females from three families) with platelet count ranging around 4-20 x109/L. Their shared grandparent died of post trauma bleeding (no data on his platelet count). Their parents have normal platelet count and platelet morphology. Blood film of effected family members show macrothrombocytopenia with occasional giant platelets. By flow cytometry CD41 and CD42b expressions were around 60% in effected family members and CD62 expression was around 20-30% in resting and thrombin-activated platelets (Figure 1). Immunoflurescence of platelets shows normal distribution of non-muscular mysoin IIA, GPIbIX, dense granules and lysosome markers Lamp-1, Lamp-2 and the dense granule CD63. Platelets diffusely stained for P-selectin and stained very low for VWF and thrombospondin. GPIIbIIIa staining revealed a ring distribution at the outer cell membrane (Prof. Andreas Greinacher, Greifswald, Germany). Transmission electron microscopy imaging shows abnormal distribution of platelet granules, with suspected protein accumulation in the cytoplasm (Figure 2). Protein analysis of platelet extracts by SDS-PAGE separation shows different band patterns in the effected individuals compared to controls (Figure 3). Mass spectrometry analysis of a representative band identified five candidate proteins that their over-expression may cause the defect in platelets organelles distribution and the defect of their function. Through whole genome analysis three large homogenous regions were found. To further narrow the search SNP analysis was added between two effected members. The search was narrowed to an area in chromosome 9p and centromere 9q with 201 candidate genes.Discussion: We present a large consanguineous family with previously non reported autosomal recessive macrothrombocytopenia. The functional and morphological pattern show dual platelet population. Further work is warranted. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.