Lower dimensional volumes and the Kastler-Kalau-Walze type theorem for Manifolds with Boundary

In this paper, we define lower dimensional volumes of spin manifolds with boundary. We compute the lower dimensional volume ${\rm Vol}^{(2,2)}$ for 5-dimensional and 6-dimensional spin manifolds with boundary and we also get the Kastler-Kalau-Walze type theorem in this case

Structure of cadmium sulfide nanoparticle micelle in aqueous solutions

The structure of cadmium sulfide (CdS) micelle in stable aqueous solution of ethylenediaminetetraacetic acid was determined by dynamic light scattering, small-angle X-ray scattering and neutron scattering. The micelle aggregate is a single CdS nanoparticle with an average size of about 3 nm, the nanoparticle organic shell and the solvation shell are about 1 nm and 5 nm thick, respectively. These parameters were confirmed by the scanning semi-contact atomic force microscopy and powder X-ray diffraction studies of dry micelle cores isolated by high-speed centrifugation. The CdS micelle was correctly described by a simple double-shell model and was found to possess the structure corresponding to CdS quantum dots. © 2013 Springer Science+Business Media New York

Observation and Modeling of the Solar-Cycle Variation of the Meridional Flow

We present independent observations of the solar-cycle variation of flows near the solar surface and at a depth of about 60 Mm, in the latitude range $\pm45^\circ$. We show that the time-varying components of the meridional flow at these two depths have opposite sign, while the time-varying components of the zonal flow are in phase. This is in agreement with previous results. We then investigate whether the observations are consistent with a theoretical model of solar-cycle dependent meridional circulation based on a flux-transport dynamo combined with a geostrophic flow caused by increased radiative loss in the active region belt (the only existing quantitative model). We find that the model and the data are in qualitative agreement, although the amplitude of the solar-cycle variation of the meridional flow at 60 Mm is underestimated by the model.Comment: To be published in Solar Physcis Topical Issue "Helioseismology, Asteroseismology, and MHD Connections

Thermal expansion of a lead sulfide nanofilm

The thermal expansion of a lead sulfide nanofilm produced by chemical bath deposition was determined by X-ray diffraction (XRD). The thickness of the synthesized film was about 100 nm, and the average size of the coherent scattering regions as determined from XRD was about 40 nm. The lattice constant of the PbS nanofilm was measured as a function of the annealing temperature from 293 to 473 K and as a function of the annealing time at a constant temperature of 423 K. The thermal expansion coefficient derived was found almost twice as large as that for coarse-grained PbS. © 2013 Elsevier B.V. All rights reserved. All rights reserved

Positron annihilation sites in nano lead sulfide powders

The coincident Doppler broadening of the positron-electron annihilation radiation has been applied for the identification of vacancies in nano lead sulfide (nano-PbS) powders. The results of the positron annihilation studies on nano-PbS with different particle size are presented. Nano-PbS specimens have been synthesized by the chemical bath deposition in aqueous medium. Independently of the size of nanoparticles (from 12 to 16 nm) the positron lifetime (PLT) for all specimens has been found to be the same and equal to 391±1 ps. Independently of the size of nanoparticles the chemical surrounding of positron annihilation sites identified by coincident Doppler broadening measurements was the same, namely lead (Pb).Canberra;Orte

The effect of the tachocline on differential rotation in the Sun

In this paper, we present a model for the effects of the tachocline on the differential rotation in the solar convection zone. The mathematical technique relies on the assumption that entropy is nearly constant ("well-mixed") in isorotation surfaces both outside and within the tachocline. The resulting solutions exhibit nontrivial features that strikingly resemble the true tachocline isorotation contours in unexpected detail. This strengthens the mathematical premises of the theory. The observed rotation pattern in the tachocline shows strong quadrupolar structure, an important feature that is explicitly used in constructing our solutions. The tachocline is treated locally as an interior boundary layer of small but finite thickness, and an explicit global solution is then constructed. A dynamical link can thus be established between the internal jump in the angular velocity at the tachocline and the spread of angular velocities observed near the solar surface. In general, our results suggest that the bulk of the solar convection zone is in thermal wind balance, and that simple quadrupolar stresses, local in radius, mediate the tachocline transition from differential rotation to uniform rotation in the radiative interior.Comment: 20 Pages, 4 figures, to appear in MNRA

Are Split Tablet Keyboards Better? A Study of Soft Keyboard Layout and Hand Posture

acceptedVersio

Mechanism of spontaneous formation of stable magnetic structures on the Sun

One of the puzzling features of solar magnetism is formation of long-living compact magnetic structures; such as sunspots and pores, in the highly turbulent upper layer of the solar convective zone. We use realistic radiative 3D MHD simulations to investigate the interaction between magnetic field and turbulent convection. In the simulations, a weak vertical uniform magnetic field is imposed in a region of fully developed granular convection; and the total magnetic flux through the top and bottom boundaries is kept constant. The simulation results reveal a process of spontaneous formation of stable magnetic structures, which may be a key to understanding of the magnetic self-organization on the Sun and formation of pores and sunspots. This process consists of two basic steps: 1) formation of small-scale filamentary magnetic structures associated with concentrations of vorticity and whirlpool-type motions, and 2) merging of these structures due to the vortex attraction, caused by converging downdrafts around magnetic concentration below the surface. In the resulting large-scale structure maintained by the converging plasma motions, the magnetic field strength reaches ~1.5 kG at the surface and ~6 kG in the interior; and the surface structure resembles solar pores. The magnetic structure remains stable for the whole simulation run of several hours with no sign of decay.Comment: 13 pages, 4 figures, submitted to the Astrophysical Journa

MgCl2 and KCl Recovery from Brine Wastewater

This project’s aim was to design an improved brine wastewater treatment system for desalination facilities. While a multitude of methods exist to do so, General Electric (GE)’s brine concentrator is leading the market by providing a method that not only treats the brine waste, but also recovers anywhere from 60- 94% of the water from the feed. However, their brine concentrator is relatively inefficient from both a financial and energetic perspective; our goal was to develop a system to match their results, while limiting costs and energy usage as best possible. We subsequently designed a system (referred to from here on out as the ‘MgCl2 Separation Unit’) to accomplish the aforementioned objectives. In addition to recovering pure water from concentrated brine, our process also recovers high purity MgCl2 and KCl crystals that are later sold to alleviate the overall process costs. The MgCl2 Separation Unit saw an increased ROI by 22.53% as compared to the GE Brine Concentrator, as well as a surge in NPV of $20,749,200. Additionally, we estimate an aggregate equipment cost of roughly$6,960,000, significantly less than GE’s $8,980,000, and utilities costs of$1,590,000 relative to their $6,920,000. The GE process deals with vapor phase water and thus relies on compressors for pressure changes, which are costly in terms of energy consumption and capital costs, whereas our proposed MgCl2 Separator Unit is limited to liquid/aqueous streams, eliminating the need for costly compressors (from both an energy and economic standpoint). Finally, while both systems are fit to treat 1- 2mgd, the MgCl2 Separation Unit was optimized to recover roughly 84% of feed water, positioning itself in the upper limit of GE’s possible water recovery spectrum