12,575 research outputs found
Phase coherence and the Nernst effect at magic angles in organic conductors
A giant Nernst signal was recently observed for fields near crystallographic
directions in (TMTSF)PF. Such large Nernst signals are most naturally
associated with the motion of pancake vortices. We propose a model in which
phase coherence is destroyed throughout the sample except in planes closely
aligned with the applied field . A small tilt above or below the plane
changes the direction and density of the penetrating vortices and leads to a
Nernst signal that varies with the tilt angle of as observed. The
resistance notches at magic angles are understood in terms of flux-flow
dissipation from field-induced vortices.Comment: 4 pages, 4 figure
Efektifitas Program Pusat Kegiatan Belajar Masyarakat Dinas Pendidikan Kota Manado dalam Meningkatkan Sumber Daya Manusia1
Dijelaskan dalam Bab 1 Pasal 1 Undang-Undang no 20 tahun 2003 tentang sistempendidikan nasional, pendidikan adalah USAha sadar dan berencana untuk mewujudkan suasanabelajar dan proses pembelajaran agar peserta didik secara aktif mengembangkan potensi dirinyauntuk memiliki kekuatan spiritual keagamaan, pengendalian diri, kepribadian , kecerdasan ,akhlak mulia serta ketrampilan yang diperlukan dirinya, masyarakat, bangsa dan negara.Pendidikan termasuk dalam kegiatan investasi masa depan. Investasi pendidikan padaumumnya dilakukan sejak usia anak-anak sampai usia muda atau pemuda. Pendidikanmerupakan faktor yang berkaitan langsung dengan pemuda mengingat usia muda merupakanusia sekolah. Problem yang terutama muncul adalah penyediaan fasilitas pendidikan meliputigedung sekolah, tenaga guru, buku-buku dan lain sarana pendidikan dalam jumlah yang lebihbanyak. Didapati berdasarkan data yang ada bahwa rendahnya pendidikan di Indonesiadisebabkan oleh berbagai faktor. Biaya pendidikan yang mahal dan dan terus meningkatdianggap sebagai faktor utama namun secara psikologis didapati juga faktor yang beranggapanbahwa juga pendidikan tidak dianggap penting karena tidak bisa menghasilkan peningkatanekonomi.Efektifitas pendidikan dalam hal ini karakter tidak cukup hanya dilaksanakan disekolah ataulembaga-lembaga formal. Bahkan dalam langkah selajutnya pendidikan perlu dilaksanakan olehseluruh lapisan masyarakat diseluruh instansi pemerintah, ormas, parpol, lembaga swadayamasyarakat dan kelompok masyarakat Pusat Kegiatan Belajar Masyarakat
The Nernst effect in high- superconductors
The observation of a large Nernst signal in an extended region above
the critical temperature in hole-doped cuprates provides evidence that
vortex excitations survive above . The results support the scenario that
superfluidity vanishes because long-range phase coherence is destroyed by
thermally-created vortices (in zero field), and that the pair condensate
extends high into the pseudogap state in the underdoped (UD) regime. We present
a series of measurements to high fields which provide strong evidence for
this phase-disordering scenario.Comment: 21 pages, 28 figure
Unusual Nernst effect suggestive of time-reversal violation in the striped cuprate LaBaCuO
The striped cuprate LaBaCuO ( undergoes several
transitions below the charge-ordering temperature = 54 K. From Nernst
experiments, we find that, below , there exists a large, anomalous
Nernst signal that is symmetric in field , and remains
finite as . The time-reversal violating signal suggests that, below
, vortices of one sign are spontaneously created to relieve interlayer
phase frustration.Comment: 5 pages, 4 figure
A 3-D Multilateration: A Precision Geodetic Measurement System
A system was designed with the capability of determining 1-cm accuracy station positions in three dimensions using pulsed laser earth satellite tracking stations coupled with strictly geometric data reduction. With this high accuracy, several crucial geodetic applications become possible, including earthquake hazards assessment, precision surveying, plate tectonics, and orbital determination
Field-Tuning of the electron and hole populations in the ruthenate Bi_3Ru_3O_11
Experiments on the Hall coefficient R_H and heat capactity C reveal an
unusual, compensated electronic ground state in the ruthenate Bi_3Ru_3O_11. At
low temperature T, R_H decreases linearly with magnetic field |H| for fields
larger than the field scale set by the Zeeman energy. The results suggest that
the electron and hole populations are tuned by H in opposite directions via
coupling of the spins to the field. As T is decreased below 5 K, the curve
C(T)/T vs. T^2 shows an anomalous flattening consistent with a rapidly growing
Sommerfeld parameter \gamma(T). We discuss shifts of the electron and hole
chemical potentials by H to interpret the observed behavior of R_H.Comment: 5 pages, 6 figures, reference adde
Heat capacity anomaly at the quantum critical point of the Transverse Ising Magnet CoNb_2O_6
The transverse Ising magnet Hamiltonian describing the Ising chain in a
transverse magnetic field is the archetypal example of a system that undergoes
a transition at a quantum critical point (QCP). The columbite CoNbO is
the closest realization of the transverse Ising magnet found to date. At low
temperatures, neutron diffraction has observed a set of discrete collective
spin modes near the QCP. We ask if there are low-lying spin excitations
distinct from these relatively high energy modes. Using the heat capacity, we
show that a significant band of gapless spin excitations exists. At the QCP,
their spin entropy rises to a prominent peak that accounts for 30 of the
total spin degrees of freedom. In a narrow field interval below the QCP, the
gapless excitations display a fermion-like, temperature-linear heat capacity
below 1 K. These novel gapless modes are the main spin excitations
participating in, and affected, by the quantum transition.Comment: 14 pages total, 8 figure
Three-D multilateration: A precision geodetic measurement system
A technique of satellite geodesy for determining the relative three dimensional coordinates of ground stations within one centimeter over baselines of 20 to 10,000 kilometers is discussed. The system is referred to as 3-D Multilateration and has applications in earthquake hazard assessment, precision surveying, plate tectonics, and orbital mechanics. The accuracy is obtained by using pulsed lasers to obtain simultaneous slant ranges between several ground stations and a moving retroreflector with known trajectory for aiming the lasers
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