Influence of simultaneous doping of Sb & Pb on phase formation, superconducting and microstructural characteristics of HgBa2Ca2Cu3O8+\delta

We report systematic studies of structural, microstructural and transport properties of (Hg_0.80 Sb_0.2-x Pb_x)Ba_2 Ca_2 Cu_3O_8+\delta (where x = 0.0, 0.05, 0.1, 0.15, 0.2) compounds. Bulk polycrystalline samples have been prepared by two-step solid-state reaction route at ambient pressure. It has been observed that simultaneous substitution of Sb and Pb at Hg site in oxygen deficient HgO_\delta layer of HgBa2Ca2Cu3O8+\delta cuprate high-Tc superconductor leads to the formation of Hg-1223 as the dominant phase. Microstructural investigations of the as grown samples employing scanning electron microscopy reveal single crystal like large grains embodying spiral like features. Superconducting properties particularly transport current density (Jct) have been found to be sensitive to these microstructural features. As for example (Hg0.80Sb0.05Pb0.15)Ba2Ca2Cu3O8+\delta compound which exhibits single crystal like large grains (~ 50 micrometer) and appears to result through spiral growth mechanism, shows highest Jct (~ 1.85 x 103 A/cm2) at 77K. A possible mechanism for the generation of spiral like features and correlation between microstructural features and superconducting properties have been put forward.Comment: 16 pages, 6 figures. Accepted in Physica

Apixaban for the treatment of saphenous vein graft thrombosis presenting as unstable angina: a case report

Abstract Background Saphenous vein graft thrombosis can present as unstable angina. However, percutaneous coronary intervention for saphenous vein graft lesions poses a high risk of slow flow related to the procedure. Here we present the utilization of the novel oral anticoagulant, apixaban, in the treatment of unstable angina with extensive saphenous vein graft thrombus, leading to considerable thrombus resolution and eliminating the need of percutaneous coronary intervention. Case presentation A 72-year-old man with 3-vessel coronary artery bypass graft surgery using a saphenous vein graft and a left internal mammary artery, performed 25 years earlier, presented at our hospital with recurrent chest tightness. The echocardiography showed regional hypokinesis of the post-lateral wall with moderate left ventricular dysfunction, which had not been previously confirmed. Coronary angiography showed obstruction of the saphenous vein graft with a large thrombus burden. The left internal mammary artery was patent and other natives were the same as they had been 3 years ago. He was diagnosed with unstable angina due to acute saphenous vein graft thrombosis. Instead of percutaneous coronary intervention, he was treated with apixaban 5 mg twice a day. The angiography 3 weeks after starting apixaban showed considerable resolution of the thrombus and opening of the saphenous vein graft. Conclusions Apixaban could become a viable treatment option for acute saphenous vein graft thrombosis

The effect of charge fluctuation on a normal-superconducting-normal single-electron transistor

We theoretically investigate quantum fluctuation of charge between even and odd states of a normal-superconducting-normal single-electron tunneling transistor. It is shown that due to the superconducting gap, the charge fluctuation in the Coulomb blockade regime for even state is larger than that for odd state. We show that large energy correction in the former regime caused by charge fluctuation can be explained by considering the charging energy renormalization.Comment: 4 pages, 3 figures, prepared for Proccedings of International Symposium on Superconducting Device Physics (SDP 2001

Even-odd correlations in capacitance fluctuations of quantum dots

We investigate effects of short range interactions on the addition spectra of quantum dots using a disordered Hubbard model. A correlation function \cS(q) is defined on the inverse compressibility versus filling data, and computed numerically for small lattices. Two regimes of interaction strength are identified: the even/odd fluctuations regime typical of Fermi liquid ground states, and a regime of structureless \cS(q) at strong interactions. We propose to understand the latter regime in terms of magnetically correlated localized spins.Comment: 3 pages, Revtex, Without figure

Pair densities at contact in the quantum electron gas

The value of the pair distribution function g(r) at contact (r = 0) in a quantum electron gas is determined by the scattering events between pairs of electrons with antiparallel spins. The theoretical results for g(0) as a function of the coupling strength r_s in the paramagnetic electron gas in dimensionality D=2 and 3, that have been obtained from the solution of the two-body scattering problem with a variety of effective scattering potentials embodying many-body effects, are compared with the results of many-body calculations in the ladder approximation and with quantum Monte Carlo data.Comment: 7 pages, 2 figure

Magnetic Ground State of Pr0.89_{0.89}LaCe0.11_{0.11}CuO4+α−δ_{4+\alpha-\delta} with Varied Oxygen Depletion Probed by Muon Spin Relaxation

The magnetic ground state of an electron-doped cuprate superconductor Pr$_{1-x}$LaCe$_x$CuO$_{4+\alpha-\delta}$ ($x=0.11, \alpha\simeq0.04$) has been studied by means of muon spin rotation/relaxation (\msr) over a wide variety of oxygen depletion, $0.03\le\delta\le0.12$. Appearance of weak random magnetism over entire crystal volume has been revealed by a slow exponential relaxation. The absence of $\delta$-dependence for the random magnetism and the multiplet pattern of muon Knight shift at higher fields strongly suggest that the random moments are associated with excited Pr$^{3+}$ ions under crystal electric field.Comment: 6 pages, 4 figures, submitted to J. Phys. Soc. Jp

Weak localization in InSb thin films heavily doped with lead

The paper reports on the investigations of the weak localization (WL) effects in 3D polycrystalline thin films of InSb. The films are closely compensated showing the electron concentration n>10^{16} cm^{-3} at the total concentration of the donor and acceptor type structural defects >10^{18} cm^{-3}. Unless Pb-doped, the InSb films do not show any measurable or show very small WL effect at 4.2 K. The Pb-doping to the concentration of the order of 10^{18} cm^{-3} leads to pronounced WL effects below 7 K. In particular, a clearly manifested SO scattering is observed. From the comparison of the experimental data on temperature dependence of the magnetoresistivity and sample resistance with the WL theory, the temperature dependence of the phase destroying time is determined. The determination is performed by fitting theoretical terms obtained from Kawabata's theory to experimental data on magnetoresistance. It is concluded that the dephasing process is connected to three separate interaction processes. The first is due to the SO scatterings and is characterized by temperature-independent relaxation time. The second is associated with the electron-phonon interaction. The third dephasing process is characterized by independent on temperature relaxation time tau_c. This relaxation time is tentatively ascribed to inelastic scattering at extended structural defects, like grain boundaries. The resulting time dephasing time shows saturation in its temperature dependence. The temperature dependence of the resistance of the InSb films can be explained by the electron-electron interaction for T2 K.Comment: 15 pages with 5 figure

ANALISIS YURIDIS MENGENAI PERSEROAN PERORANGAN MENURUT PASAL 153A UNDANG-UNDANG NOMOR 11 TAHUN 2020 TENTANG CIPTA KERJA

Pada penelitian kali ini penulis mengangkat judul “ANALISIS YURIDIS MENGENAI PERSEROAN PERORANGAN MENURUT PASAL 153A UNDANG-UNDANG NOMOR 11 TAHUN 2020 TENTANG CIPTA KERJA”. Pembahasan mengenai pasal 153 tersebut dirasa perlu mengingat usia Undang-Undang ini yang masih terhitung baru karena disahkan pada tahun 2021. Berdasarkan latar belakang tersebut penulis membahas mengenai 3 rumusan masalah yaitu: Pertama,Apa saja perbedaan antara perseroan perorangan dengan bentuk perusahaan perorangan lainnya? Kedua,Apakah urgensi diberlakukannya pasal 153a uu cipta kerja tentang perseroan perorangan?Ketiga, Bagaimana akibat hukum dengan diberlakukannya pasal 153A uu cipta kerja tentang perseroan perorangan?Dalam penelitian ini penulis menggunakan metode penelitian yuridis normatif dengan menggunakan pendekatan perundang-undangan dan pendekatan konseptual. Pengumpulan bahan hukum melalui metode studi literatur, dengan bahan hukum primer maupun sekunder.Hasil penelitian ini menunjukkan bahwa terdapat perbedaan antara perseroan terbatas dan perseroan perseorangan yang menjadi entitas usaha baru yang diatur dalam pasal 153a UU Cipta Kerja. Alasan kemudahan berbisnis dan demi pemulihan ekonomi nasional pasca pandemic covid 19 dapat dijadikan sebagai alasan diberlakukannya uu tentang perseroan perorangan. Sejak berlakunya pasal 153A maka masyarakat dapat mendirikan usaha perseroan secara sendiri dengan hal-hal tertentu yang dipersyaratkan pemerintah. Dimana salah satu dari syarat tersebut adalah bahwa perseroan perorangan dapat didirikan oleh perusahan yang memenuhi persyaratan sebagai UKM menurut kriteria yang diberlakukan.Kata Kunci: Perseroan Perorangan, Cipta Kerja, Perseroan Terbatas, Usaha Mikro dan Keci