3,097 research outputs found
Origin of stabilization of macrotwin boundaries in martensites
The origin of stabilization of complex microstructures along macrotwin
boundaries in martensites is explained by comparing two models based on
Ginzburg-Landau theory. The first model incorporates a geometrically nonlinear
strain tensor to ensure that the Landau energy is invariant under rigid body
rotations, while the second model uses a linearized strain tensor under the
assumption that deformations and rotations are small. We show that the
approximation in the second model does not always hold for martensites and that
the experimental observations along macrotwin boundaries can only be reproduced
by the geometrically nonlinear (exact) theory
Classification of the phases of 1D spin chains with commuting Hamiltonians
We consider the class of spin Hamiltonians on a 1D chain with periodic
boundary conditions that are (i) translational invariant, (ii) commuting and
(iii) scale invariant, where by the latter we mean that the ground state
degeneracy is independent of the system size. We correspond a directed graph to
a Hamiltonian of this form and show that the structure of its ground space can
be read from the cycles of the graph. We show that the ground state degeneracy
is the only parameter that distinguishes the phases of these Hamiltonians. Our
main tool in this paper is the idea of Bravyi and Vyalyi (2005) in using the
representation theory of finite dimensional C^*-algebras to study commuting
Hamiltonians.Comment: 8 pages, improved readability, added exampl
Unconventional superconductivity in CuxBi2Se3
We report point contact measurements in high quality single crystals of
Cu0.2Bi2Se3. We observe three different kinds of spectra: (1)
Andreev-reflection spectra, from which we infer a superconducting gap size of
0.6mV; (2) spectra with a large gap which closes above Tc at about 10K; and (3)
tunneling-like spectra with zero-bias conductance peaks. These tunneling
spectra show a very large gap of ~2meV (2Delta/KTc ~ 14)
Muon diffusion and electronic magnetism in YTiO
We report a SR study in a YTiO single crystal. We observe
slow local field fluctuations at low temperature which become faster as the
temperature is increased. Our analysis suggests that muon diffusion is present
in this system and becomes small below 40 K and therefore incoherent. A
surprisingly strong electronic magnetic signal is observed with features
typical for muons thermally diffusing towards magnetic traps below K and released from them above this temperature. We attribute the traps to
Ti defects in the diluted limit. Our observations are highly relevant to
the persistent spin dynamics debate on TiO pyrochlores and their
crystal quality
Ketepatan dan Kecepatan Pembidikan Pisir Penjera pada Latihan Bidik Kering Menggunakan Fuzzy Logic
Lesan Tembak Bidik Kering dibuat untuk mendukung tugas pokok TNI AD dalam rangka membantu prajurit pada bidang menembak untuk mendapatkan prajurit yang handal, dimana setiap prajurit harus mahir menembak.Perencanaan dan pembuatan alat dibangun dengan meggunakan alat perangkat keras dan perangkat lunak. Perangkat keras yang digunakan yaitu motor DC, mikrokontroler ATMega16, driver ULN2003, bluetooth, joystick, limit switch dan mekanik. Sedangkan perangkat lunak yang digunakan yaitu Software Code Vision AVR sebagai alat pengendali. Dalam pembuatan alat yang dimaksud supaya dapat berfungsi dengan baik, maka diperlukan pemahaman yang mendalam tentang karakteristik dan cara kerja komponen-komponen yang digunakan. Hal ini perlu dikuasa sebaik-baiknya untuk menghindari kesalan penggunaan komponen yang mengakibatkan kegagalan dalam pembuatan alat.Pada perencanaan hardware akan meliputi seluruh perihal yang digunakan pada sistem. Pada perencanaan software merupakan piranti lunak meliputi flowchart dan software secara umum. Perangkat tersebut saling terintegrasi sehingga dalam kerjanya akan maksimum sesuai apa yang diharapkan.Software ini diharapkan mampu memenuhi tugas pokok TNI AD khususnya keahlian menembak agar lebih efektif, akurat dan tepat dalam melaksanakan latihan menembak di satuan TNI AD
Evaluation and phytochemical screening and antibacterial activity of Ficus dalhousiae Miq
The aim of the present study was to isolate the Extract from the leaves of Ficus dalhousiae Miq and subse-quently evaluate their antibacterial and antifungal activity. The crude various extracts of the plant n-Hexane, Chloroform, Ethyl acetate, Methanol extract was obtained by using continuous soxhlation tech-nique using soxhlet apparatus. The antibacterial activity of plant extract were carried using cup plate method against three bacterial species Staphylococcus aures, Bacillus subtilis, Escherichia coli using agar diffusion method. those are compared with standard reference drug Ciprofloxacin. This study confirmed that bark extracts have more active constituents compare to leaf extracts. by pharmacological evaluation of Ficus dalhousea Miq. Various extracts, most of them are capable of showing moderate antibacterial activity
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