1,856 research outputs found
Reservation System Design of Goods in PT. Power Cipta Lestari
PT. Daya Cipta Lestari is one company that is engaged in ordering furniture items, the company is domiciled in Jakarta. Since the inception of this company, its management system is done manually (system book) after the progress and technological development was so rapid, especially in the field of computers these companies take advantage of the development of computer systems by change of all books into a computerized system where the system is intended for data processing quickly and appropriately so useful to the users and also to avoid the mistakes that can be done on the system book. With the computerization and qualified human resources to achieve the desired results in accordance with
Spin interference effects in ring conductors subject to Rashba coupling
Quantum interference effects in rings provide suitable means for controlling
spin at mesoscopic scales. Here we apply such control mechanisms to coherent
spin-dependent transport in one- and two-dimensional rings subject to Rashba
spin-orbit coupling. We first study the spin-induced modulation of unpolarized
currents as a function of the Rashba coupling strength. The results suggest the
possibility of all-electrical spintronic devices. Moreover, we find signatures
of Berry phases in the conductance previously unnoticed. Second, we show that
the polarization direction of initially polarized, transmitted spins can be
tuned via an additional small magnetic control flux. In particular, this
enables to precisely reverse the polarization direction at half a flux quantum.
We present full numerical calculations for realistic two-dimensional ballistic
microstructures and explain our findings in a simple analytical model for
one-dimensional rings.Comment: 8 pages, 5 figures. Submitted to Phys. Rev. B, final versio
Nonlinear Transport of Bose-Einstein Condensates Through Waveguides with Disorder
We study the coherent flow of a guided Bose-Einstein condensate incident over
a disordered region of length L. We introduce a model of disordered potential
that originates from magnetic fluctuations inherent to microfabricated guides.
This model allows for analytical and numerical studies of realistic transport
experiments. The repulsive interaction among the condensate atoms in the beam
induces different transport regimes. Below some critical interaction (or for
sufficiently small L) a stationary flow is observed. In this regime, the
transmission decreases exponentially with L. For strong interaction (or large
L), the system displays a transition towards a time dependent flow with an
algebraic decay of the time averaged transmission.Comment: 15 pages, 9 figure
Magnitude of Magnetic Field Dependence of a Possible Selective Spin Filter in ZnSe/Zn_{1-x}Mn_{x}Se Multilayer Heterostructure
Spin-polarized transport through a band-gap-matched ZnSe/Zn_{1-x}Mn_{x}
Se/ZnSe/Zn_{1-x}Mn_{x}Se/ZnSe multilayer structure is investigated. The
resonant transport is shown to occur at different energies for different spins
owing to the split of spin subbands in the paramagnetic layers. It is found
that the polarization of current density can be reversed in a certain range of
magnetic field, with the peak of polarization moving towards a stronger
magnetic field for increasing the width of central ZnSe layer while shifting
towards an opposite direction for increasing the width of paramagnetic layer.
The reversal is limited in a small-size system. A strong suppression of the
spin up component of the current density is present at high magnetic field. It
is expected that such a reversal of the polarization could act as a possible
mechanism for a selective spin filter device
Perekayasaan Pesawat Sinar-x Fluoroscopy Berbasis Layar Pendar
AN ENGENEERING DEVELOPMENT OF FLUOROSCOPIC X-RAY MEDICALEQUIPMENT BASED-ON FLUORESCENT SCREEN, Fl uoroscopic x-ray medi cal equipment uses fluorescent screen to capture structural i mage of organs. Unlike conventional x-ray equi pment whi ch uses film, i n the fluoroscopi c x-ray, the resulti ng image i s vi sualized on the fluorescent screen and directly observed by physici ans in the pati ents' rooms. In thi s study, wedeveloped an image capture system that transforms the image on the fluorescent screen i nto digital data, which is then transferred to computer for visuali zati on and further processing. By using thi s system, the observation of the resulting i mage can be done on a computer that isplaced in the control room. The i mage can also be stored easily and at l ow cost compared to conventional film. The experiment shows that the system coul d be used to capture image of the object. However, it s qualit y needs to be improved. In the future, the system will be modifi ed andtested wit h di fferent types of cameras to obtain better results. PEREKAYASAAN PESAWAT SINAR-X FLUOROSCOPY BERBASIS LAYARPENDAR, Pesawat si nar-x fl uroscopy untuk diagnosa medis adalah pesawat si nar-X yang menggunakan layar pendar sebagai penangkap ci tra dari struktur organ tubuh. Berbeda dengan pesawat sinar-x konvensi onal yang menggunakan fi lm. Pada pesawat sinar-x fluroscopy, citrayang dihasil kan divisualisasi kan pada l ayar pendar dan diamati langsung ol eh dokter di ruang pasi en. Pada peneliti an i ni , dil akukan perekayasaan sistem pesawat sinar-x fluroscopy dengan cara engembangkan sistem penangkap citra yang mengubah citra pada l ayar pendar ke data digital, yang kemudian di transfer ke komputer untuk vi suali sasi dan pemrosesan l ebih lanj ut. Dengan menggunakan sistem ini, pengamatan hasil penci traan bisa dilakukan pada komputer yang diletakkan di ruang kontrol dan citra yang dihasilkan dapat disimpan dengan mudah serta biaya murah jika dibandingkan dengan fi lm. Hasil pengujian menunjukkan bahwa dengan sistem i ni cit ra dari objek sudah berhasil ditangkap, walaupun kual itasnya masi h perlu ditingkatkan. Kedepannya akan dil akukan modifi kasi dan penguj ian menggunakan kamera dengan tipe berbeda guna mendapatkan hasil yang lebi h baik
Pengembangan Video Pembelajaran Sains Bermuatan Nilai Ketuhanan Dan Kecintaan Terhadap Lingkungan
The purposes of this research were to produce science learning video in divinity and loving environment value contents for SMP/MTs students, to see the effectiveness of the product and to know the student’s responses about the product. The method of this research used research and development (R&D) method. The trial of the product consisted of one on one test and field test. This research produced the learning video “Perubahan di Sekitar Kita†in divinity and loving environment value contents which is containing physics changes, chemical changes, pollution, and global warming. The results of this research indicated that video were very interesting, very easy to use, and very useful. This learning video was declared effective to use as a multimedia learning based on N-gain average of 0,57 (medium category) and 80 % of students completed KKM result study from the test with average 78,67.Tujuan pengembangan ini adalah: (1) menghasilkan video pembelajaran sains bermuatan nilai ketuhanan dan kecintaan terhadap lingkungan bagi siswa SMP/MTs, (2) melihat efektivitas produk, dan (3) mengetahui tanggapan siswa terhadap produk. Metode yang digunakan adalah metode penelitian pengembangan atau research and development. Uji coba terdiri dari uji coba satu lawan satu dan uji lapangan. Dalam pengembangan ini, dihasilkan video pembelajaran “Perubahan di Sekitar Kita†bermuatan nilai ketuhanan dan kecintaan terhadap lingkungan, yang mencakup materi Perubahan fisika, Perubahan kimia, pencemaran, dan pemanasan global. Hasil uji coba menunjukkan bahwa video pembelajaran sangat menarik, sangat mudah digunakan, dan sangat bermanfaat. Video pembelajaran dinyatakan efektif digunakan sebagai media pembelajaran berdasarkan N-Gain rata-rata sebesar 0,57 (kategori sedang) dan 80% siswa uji tuntas KKM dengan hasil belajar rata-rata 78,67
Detection of spin polarized currents in quantum point contacts via transverse electron focusing
It has been predicted recently that an electron beam can be polarized when it
flows adiabatically through a quantum point contact in a system with spin-orbit
interaction. Here, we show that a simple transverse electron focusing setup can
be used to detect such polarized current. It uses the amplitude's asymmetry of
the spin-split transverse electron focusing peak to extract information about
the electron's spin polarization. On the other hand, and depending on the
quantum point contact geometry, including this one-body effect can be important
when using the focusing setup to study many-body effects in quantum point
contacts.Comment: 5 pages, 5 figure
Persistent holes in a fluid
We observe stable holes in a vertically oscillated 0.5 cm deep aqueous
suspension of cornstarch for accelerations a above 10g. Holes appear only if a
finite perturbation is applied to the layer. Holes are circular and
approximately 0.5 cm wide, and can persist for more than 10^5 cycles. Above a =
17g the rim of the hole becomes unstable producing finger-like protrusions or
hole division. At higher acceleration, the hole delocalizes, growing to cover
the entire surface with erratic undulations. We find similar behavior in an
aqueous suspension of glass microspheres.Comment: 4 pages, 6 figure
Rashba spin orbit interaction in a quantum wire superlattice
In this work we study the effects of a longitudinal periodic potential on a
parabolic quantum wire defined in a two-dimensional electron gas with Rashba
spin-orbit interaction. For an infinite wire superlattice we find, by direct
diagonalization, that the energy gaps are shifted away from the usual Bragg
planes due to the Rashba spin-orbit interaction. Interestingly, our results
show that the location of the band gaps in energy can be controlled via the
strength of the Rashba spin-orbit interaction. We have also calculated the
charge conductance through a periodic potential of a finite length via the
non-equilibrium Green's function method combined with the Landauer formalism.
We find dips in the conductance that correspond well to the energy gaps of the
infinite wire superlattice. From the infinite wire energy dispersion, we derive
an equation relating the location of the conductance dips as a function of the
(gate controllable) Fermi energy to the Rashba spin-orbit coupling strength. We
propose that the strength of the Rashba spin-orbit interaction can be extracted
via a charge conductance measurement.Comment: 9 pages, 9 figure
Spin polarization of electrons with Rashba double-refraction
We demonstrate how the Rashba spin-orbit coupling in semiconductor
heterostructures can produce and control a spin-polarized current without
ferromagnetic leads. Key idea is to use spin-double refraction of an electronic
beam with a nonzero incidence angle. A region where the spin-orbit coupling is
present separates the source and the drain without spin-orbit coupling. We show
how the transmission and the beam spin-polarization critically depend on the
incidence angle. The transmission halves when the incidence angle is greater
than a limit angle and a significant spin-polarization appears. Increasing the
spin-orbit coupling one can obtain the modulation of the intensity and of the
spin-polarization of the output electronic current when the input current is
unpolarized. Our analysis shows the possibility to realize a spin-field-effect
transistor based on the propagation of only one mode with the region with
spin-orbit coupling. Where the original Datta and Das device [Appl.Phys.Lett.
{\bf 56}, 665 (1990)] use the spin-precession that originates from the
interference between two modes with orthogonal spin.Comment: 12 pages with 7 figure
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