Global-in-time solutions for the isothermal Matovich-Pearson equations

In this paper we study the Matovich-Pearson equations describing the process of glass fiber drawing. These equations may be viewed as a 1D-reduction of the incompressible Navier-Stokes equations including free boundary, valid for the drawing of a long and thin glass fiber. We concentrate on the isothermal case without surface tension. Then the Matovich-Pearson equations represent a nonlinearly coupled system of an elliptic equation for the axial velocity and a hyperbolic transport equation for the fluid cross-sectional area. We first prove existence of a local solution, and, after constructing appropriate barrier functions, we deduce that the fluid radius is always strictly positive and that the local solution remains in the same regularity class. To the best of our knowledge, this is the first global existence and uniqueness result for this important system of equations

Unconventional superconductivity in the cage type compound Sc5_5Rh6_6Sn18_{18}

We have examined the superconducting ground state properties of the caged type compound Sc$_5$Rh$_6$Sn$_{18}$ using magnetization, heat capacity, and muon-spin relaxation or rotation ($\mu$SR) measurements. Magnetization measurements indicate type-II superconductivity with an upper critical field $\mu_0H_{c2}(0)$ = 7.24 T. The zero-field cooled and field cooled susceptibility measurements unveil an onset of diamagnetic signal below $T_{\bf c}$ = 4.4 K. The interpretation of the heat capacity results below $T_{\bf c}$ using the $\alpha-$BCS model unveils the value of $\alpha$ = 2.65, which gives the dimensionless ratio 2$\Delta(0)/k_B T_{\bf c}$ = 5.3, intimating that Sc$_5$Rh$_6$Sn$_{18}$ is a strong-coupling BCS superconductor. The zero-field $\mu$SR measurements in the longitudinal geometry exhibit a signature of a spontaneous appearance of the internal magnetic field below the superconducting transition temperature, indicating that the superconducting state is characterized by the broken time-reversal symmetry (TRS). We have compared the results of broken TRS in Sc$_5$Rh$_6$Sn$_{18}$ with that observed in R$_5$Rh$_6$Sn$_{18}$ (R = Lu and Y).Comment: 6 pages, 4 figures. arXiv admin note: text overlap with arXiv:1411.687

Product Yields for the Photofission of 238U, 237Np and 239Pu

開始ページ、終了ページ: 冊子体のページ付

Broken time-reversal symmetry probed by muon spin relaxation in the caged type superconductor Lu5Rh6Sn18

The superconducting state of the caged type compound Lu5Rh6Sn18 has been investigated by using magnetization, heat capacity, and muon spin relaxation or rotation (?SR) measurements, and the results interpreted on the basis of the group theoretical classifications of the possible pairing symmetries and a simple model of the resulting quasiparticle spectra. Our zero-field ?SR measurements clearly reveal the spontaneous appearance of an internal magnetic field below the transition temperature, which indicates that the superconducting state in this material is characterized by broken time-reversal symmetry. Further, the analysis of the temperature dependence of the magnetic penetration depth measured using the transverse-field ?SR measurements suggests an isotropic s?wave character for the superconducting gap. This is in agreement with the heat capacity behavior, and we show that it can be interpreted in terms of a nonunitary triplet state with point nodes and an open Fermi surface

Investigation of Superconducting Gap Structure in HfIrSi using muon spin relaxation/rotation

Appearance of strong spin-orbit coupling (SOC) is apparent in ternary equiatomic compounds with 5$d$-electrons due to the large atomic radii of transition metals. SOC plays a significant role in the emergence of unconventional superconductivity. Here we examined the superconducting state of HfIrSi using magnetization, specific heat, zero and transverse-field (ZF/TF) muon spin relaxation/rotation ($\mu$SR) measurements. Superconductivity is observed at $T_\mathrm{C}$ = 3.6 K as revealed by specific heat and magnetization measurements. From the TF$-\mu$SR analysis it is clear that superfluid density well described by an isotropic BCS type $s$-wave gap structure. Furthermore, from TF$-\mu$SR data we have also estimated the superconducting carrier density $n_\mathrm{s}$ = 6.6 $\times$10$^{26}$m$^{-3}$, London penetration depth $\lambda_{L}(0)$ = 259.59 nm and effective mass $m^{*}$ = 1.57 $m_{e}$. Our zero-field muon spin relaxation data indicate no clear sign of spontaneous internal field below $T_\mathrm{C}$, which implies that the time-reversal symmetry is preserved in HfIrSi. Theoretical investigation suggests Hf and Ir atoms hybridize strongly along the $c$-axis of the lattice, which is responsible for the strong three-dimensionality of this system which screens the Coulomb interaction. As a result despite the presence of correlated $d$-electrons in this system, the correlation effect is weakened, promoting electron-phonon coupling to gain importance.Comment: 8 pages, 4 figure

Probing the superconducting ground state of ZrIrSi: A μ\muSR study

The superconducting ground state of newly reported ZrIrSi is probed by means of $\mu$SR technique along with resistivity measurement. The occurrence of superconductivity at $T_\mathrm{C}$ = 1.7 K is confirmed by resistivity measurement. ZF-$\mu$SR study revealed that below $T_\mathrm{C}$, there is no spontaneous magnetic field in the superconducting state, indicates TRS is preserved in case of ZrIrSi. From TF-$\mu$SR measurement, we have estimated the superfluid density as a function of temperature, which is described by an isotropic $s-$wave model with a superconducting gap $2\Delta(0)/k_\mathrm{B}T_\mathrm{C}$ = 5.1, indicates the presence of strong spin-orbit coupling. {\it Ab-initio} electronic structure calculation indicates that there are four bands passing through the Fermi level, forming four Fermi surface pockets. We find that the low-energy bands are dominated by the $4d$-orbitals of transition metal Zr, with substantially lesser weight from the $5d$-orbitals of the Ir-atoms.Comment: 6 pages, 4 figure

Efficient and General Synthesis of Novel β-Polyfluoroalkoxy Vinamidinium Salts

Novel β-polyfluoroalkoxy vinamidinium salts 3 and/or 4 were synthesized in good yields by the reaction of N-(2- polyfluoroalkoxy-3 ,3-difluoro-1-propenyI)trimethylammonium iodides (2), prepared from N-(2,3,3-trifluoro-1-propenyl)trimethylammonium iodide (1), with secondary amines in MeCN at 70 °C for 1 h. The salts were also obtainable in comparable yields by the one-pot reaction of 1 with sodium polyfluoroalkoxide followed by treatment with amines

Analisa Kelayakan Tarif Angkutan Umum Dalam Kota Kupang

Penentuan besaran tarif angkutan membutuhkan penanganan dan kebijakan yang arif karena dapat menjembatani kepentingan penumpang selaku konsumen dan pengusaha selaku operator angkutan umum. Penelitian ini bertujuan untuk mengetahui Biaya Operasi Kendaraan (BOK) dan tarif yang layak diberlakukan untuk trayek angkutan umum Kota Kupang dengan jarak terpendek dan jarak terpanjang. Trayek Terminal Kupang-Penfui adalah trayek angkutan Kota Kupang dengan jarak terpanjang (28,30 km) yang melayani kawasan pertokoan, pendidikan dan kawasan Perumahan, sedangkan trayek Terminal Kupang-Perumnas merupakan trayek angkutan kota dengan jarak terpendek (7,68 km) yang melayani kawasan pendidikan dan Perumahan. Kedua trayek ini memiliki penentuan tarif angkutan yang sama yaitu Rp 2000,- untuk pelajar dan Rp 3000,- untuk masyarakat umum. Analisa BOK dan kelayakan tarif dilakukan dengan metode perhitungan berdasarkan Keputusan Direktur Jenderal Perhubungan Darat Nomor: SK.687/AJ.206 /DRJD/2002 tentang Pedoman Teknis Penyelenggaraan Angkutan Penumpang Umum di Wilayah Perkotaan Dalam Trayek Tetap dan Teratur. Hasil analisa BOK untuk trayek Terminal Kupang-Penfui sebesar Rp 2.165,42/penumpang dan tarif yang layak diberlakukan sebesar Rp 2.381,96/penumpang, sedangkan BOK untuk trayek Terminal Kupang-Perumnas sebesar Rp 1.956,31/penumpang dan tarif yang layak diberlakukan sebesar Rp 2.151,94/penumpang. Determining the amount of transport fares require wise policy for it can bridge the interests of passengers as consumers and businessman as public transport operators. This study aims to determine the Vehicle Operating Cost (VOC) and the decent fares applied in Kupang City for the shortest and the longest route. The route of Terminal Kupang-Penfui is the longest ones that has a distance of 28.30 km, that serves the shopping area and the educational and residential areas; while the route of Terminal Kupang-Perumnas is the shortest route (7.68 km) which serves educational and residential area. Nowadays these two routes have the same transport fares is Rp. 2000, - for students and Rp 3,000, - for public in general. VOC and feasibility fare analysis conducted by the method of the Directorate General of Land Transportation No. SK.687/AJ.206/DrJD/2002. The VOC analysis results for Terminal Kupang-Penfui route is Rp. 2165.42 / passenger and the decent fare imposed is Rp. 2381.96 / passenger; while the VOC for Terminal Kupang-Perumnas is Rp 1956.31 / passenger and the decent fare imposed is Rp. 2151.94 / passenger