Mesoscopic multiterminal Josephson structures: I. Effects of nonlocal weak coupling

We investigate nonlocal coherent transport in ballistic four-terminal Josephson structures (where bulk superconductors (terminals) are connected through a clean normal layer, e.g., a two-dimensional electron gas). Coherent anisotropic superposition of macroscopic wave functions of the superconductors in the normal region produces phase slip lines (2D analogs to phase slip centres) and time-reversal symmetry breaking 2D vortex states in it, as well as such effects as phase dragging and magnetic flux transfer. The tunneling density of local Andreev states in the normal layer was shown to contain peaks at the positions controlled by the phase differences between the terminals. We have obtained general dependence of these effects on the controlling supercurrent/phase differences between the terminals of the ballistic mesoscopic four-terminal SQUID.Comment: 18 pages, 11 figure

Quasiclassical calculation of spontaneous current in restricted geometries

Calculation of current and order parameter distribution in inhomogeneous superconductors is often based on a self-consistent solution of Eilenberger equations for quasiclassical Green's functions. Compared to the original Gorkov equations, the problem is much simplified due to the fact that the values of Green's functions at a given point are connected to the bulk ones at infinity (boundary values) by ``dragging'' along the classical trajectories of quasiparticles. In finite size systems, where classical trajectories undergo multiple reflections from surfaces and interfaces, the usefulness of the approach is no longer obvious, since there is no simple criterion to determine what boundary value a trajectory corresponds to, and whether it reaches infinity at all. Here, we demonstrate the modification of the approach based on the Schophol-Maki transformation, which provides the basis for stable numerical calculations in 2D. We apply it to two examples: generation of spontaneous currents and magnetic moments in isolated islands of d-wave superconductor with subdominant order-parameters s and d_{xy}, and in a grain boundary junction between two arbitrarily oriented d-wave superconductors. Both examples are relevant to the discussion of time-reversal symmetry breaking in unconventional superconductors, as well as for application in quantum computing.Comment: 6 pages, Submitted for publication in the proceedings of MS+S2002 conference, Japa

Hydrodynamics of Micro-swimmers in Films

One of the principal mechanisms by which surfaces and interfaces affect microbial life is by perturbing the hydrodynamic flows generated by swimming. By summing a recursive series of image systems we derive a numerically tractable approximation to the three-dimensional flow fields of a Stokeslet (point force) within a viscous film between a parallel no-slip surface and no-shear interface and, from this Green's function, we compute the flows produced by a force- and torque-free micro-swimmer. We also extend the exact solution of Liron & Mochon (1976) to the film geometry, which demonstrates that the image series gives a satisfactory approximation to the swimmer flow fields if the film is sufficiently thick compared to the swimmer size, and we derive the swimmer flows in the thin-film limit. Concentrating on the thick film case, we find that the dipole moment induces a bias towards swimmer accumulation at the no-slip wall rather than the water-air interface, but that higher-order multipole moments can oppose this. Based on the analytic predictions we propose an experimental method to find the multipole coefficient that induces circular swimming trajectories, allowing one to analytically determine the swimmer's three-dimensional position under a microscope.Comment: 35 pages, 11 figures, 5 table

The Expression of Heat Shock Protein (Hsp) 25 at Compression and Tension Area DuringAlveolar Bone Remodeling

The activation of orthodontic appliance will generate mechanical force. This forceis used to depress tooth and the tissues surrounding it then stimulates alveolarbone remodeling. Alveolar bone remodeling is divided into compression andtension area. This stress becomes a signal to activate heat shock responseyielding heat shock protein (HSP) synthesis, especiallyhsp25isessentialforalveolarboneremodelingprocessitself. The aim of this study was to comparehsp25 expression in compression and tension areas. This study using Guinea pigsmandibular first insicivus that given a mechanical force to see hsp25 expressionin both areas. The HSP25 expressionwas measured by counting this protein afterbeing conducted by immunohystochemistry method. It is analysed statisticallywith one way Anova with level of significant p = 0,05

The Prospect of Heat Shock Protein (Hsp) as Biomarker of Oral Disease

The prevalence of oral diseases is increasing and caused by many factors. It can be caused by environmental, genetic, Malignancy or side effects of dental treatment. The research detect these disease has been done, but still not getting satisfactory results. Heat shock proteins (HSP) are intracellular proteins that mediate the cytoprotective function and other essential functions. This protein is expressed and synthesized under conditions of stress/harmful or nonstress. The oral disease is a form of adverse conditions, and the course will also trigger HSP expression

Quantum Nondemolition Charge Measurement of a Josephson Qubit

In a qubit system, the measurement operator does not necessarily commute with the qubit Hamiltonian, so that the readout process demolishes (mixes) the qubit energy eigenstates. The readout time is therefore limited by such a mixing time and its fidelity will be reduced. A quantum nondemolition readout scheme is proposed in which the charge of a flux qubit is measured. The measurement operator is shown to commute with the qubit Hamiltonian in the reduced two-level Hilbert space, even though the Hamiltonian contains non-commuting charge and flux terms.Comment: 4 pages, 3 figures, a paragraph added to describe how the scheme works in charge regim

Numerical modeling of dynamic powder compaction using the Kawakita equation of state

Dynamic powder compaction is analyzed using the assumption that the powder behaves, while it is being compacted, like a hydrodynamic fluid in which deviatoric stress and heat conduction effects can be ignored throughout the process. This enables techniques of computational fluid dynamics such the equilibrium flux method to be used as a modeling tool. The equation of state of the powder under compression is assumed to be a modified version of the Kawakita loading curve. Computer simulations using this model are performed for conditions matching as closely as possible with those from experiments by Page and Killen [Powder Metall. 30, 233 (1987)]. The numerical and experimental results are compared and a surprising degree of qualitative agreement is observed

Aplikasi Pemilihan Rute Alternatif Akibat Kemacetan Lalu Lintas di Kota Makassar Menggunakan Google API dan ASP.Net

Persoalan kemacetan yang semakin parah di Kota Makassar saat ini perlu segera diatasi. Penelitian ini berusaha memberikan sebuah solusi aplikasi pemilihan rute alternatif untuk mengatasi kemacetan. Aplikasi ini dapat menampilkan lokasi kemacetan yang sedang terjadi beserta jalur alternatif yang memungkinkan untuk dilalui agar terhindar dari kemacetan tersebut. Rute alternatif diperoleh berdasarkan layanan yang telah disediakan oleh Google API. Sistem ini menggunakan beberapa bahasa pemrograman sesuai jenis aplikasinya. Penentuan titik kemacetan dilakukan melalui telepon seluler dengan aplikasi berbasis android menggunakan bahasa pemrograman eclipse. Sementara itu, aplikasi untuk mendesain rute alternatif menggunakan Active Server Pages (ASP.Net). ASP.Net dikompilasi dan berbasis .Net framework sehingga dapat membuat aplikasi dalam berbagai macam bahasa yang mendukung .Net. Pengujian hasil implementasi sistem dilakukan dengan menggunakan metode black box. Hasil pengujian pada setiap halaman utama menunjukkan bahwa keluaran yang dihasilkan melalui beberapa skenario pengujian sudah sesuai dengan yang diharapkan yang berarti halaman-halaman tersebut dapat berjalan dengan baik

Non-Equilibrium Quasiclassical Theory for Josephson Structures

We present a non-equilibrium quasiclassical formalism suitable for studying linear response ac properties of Josephson junctions. The non-equilibrium self-consistency equations are satisfied, to very good accuracy, already in zeroth iteration. We use the formalism to study ac Josephson effect in a ballistic superconducting point contact. The real and imaginary parts of the ac linear conductance are calculated both analytically (at low frequencies) and numerically (at arbitrary frequency). They show strong temperature, frequency, and phase dependence. Many anomalous properties appear near phi = pi. We ascribe them to the presence of zero energy bound states.Comment: 11 pages, 9 figures, Final version to appear in PR