1,248,684 research outputs found
Comparison Study in Using Plough, Tractor and Cultivator for Rice Field\u27 Land Preparation
Land preparation of the rice field is one of the most important steps for paddyplantation. Formerly plough is one of the main tools for land preparation, but now thefarmer used tractor or cultivator. From the farmer experience who are used that tools forland preparation there had advantages and disadvantages. The used of plough for landpreparation for long time ago the deep of rice field soil is constant because the ploughblade can be adjusted up and down. The plough can be turn to the right or left side so thatall part of rice field except the corner can be cultivate. But for pulling the plough must bedifficult to find two cows. While if using tractor or cultivator the right or left side and thecorner of the rice field can\u27t be cultivate. Deep of rice filed soil become shallow so thefertility of soil reduced. Beside that using tractor or cultivator for land preparation needmore fuel. The plough were easy to carry out, but tractor and cultivator difficult to carryout because the weight more that 200 kg
Cultural Approach to Reduced Traffic Accident in Bali
Safety on traveling is needed by all travelers. Safety on traveling is determined bymany factors such as the drivers, vehicles, road, environment and it relation each other.Balinese culture which influence by Hinduism, believe that traffics accidents occurred asa result of not harmonize the relation between human as a driver to vehicle or car, humanto the god and human to the environment. So in Balinese daily of life there is an effort toharmonize the relation of all components using cultural approach. In doing that manyactivities such as doing an offering to the new or after reparation of car, to offer sajen inthe car everyday during traveler, every 210 days during “ tumpek landep day” aftercleaning the car offer sajen, ring the bell or offer sajen during passing the sacral place ortemple, offer sajen and look after during night where the accident were happen, offersajen (mlaspas) the new road, forbidden to travel during wedding ceremony or get familydied. These activities mean to making the tools more humane so that the tools harmonizeto the user, forgive to the magic spirit around the road. By practicing the culturalapproach the traffic accident at many places can be reduced. One taxi company shownthat annually maintenance cost lower compared than the same company in Java
Isotopically engineered silicon/silicon-germanium nanostructures as basic elements for a nuclear spin quantum computer
The idea of quantum computation is the most promising recent developments in
the high-tech domain, while experimental realization of a quantum computer
poses a formidable challenge. Among the proposed models especially attractive
are semiconductor based nuclear spin quantum computer's (S-NSQC), where nuclear
spins are used as quantum bistable elements, ''qubits'', coupled to the
electron spin and orbital dynamics. We propose here a scheme for implementation
of basic elements for S-NSQC's which are realizable within achievements of the
modern nanotechnology. These elements are expected to be based on a
nuclear-spin-controlled isotopically engineered Si/SiGe heterojunction, because
in these semiconductors one can vary the abundance of nuclear spins by
engineering the isotopic composition. A specific device is suggested, which
allows one to model the processes of recording, reading and information
transfer on a quantum level using the technique of electrical detection of the
magnetic state of nuclear spins. Improvement of this technique for a
semiconductor system with a relatively small number of nuclei might be applied
to the manipulation of nuclear spin ''qubits'' in the future S-NSQC.Comment: 11 pages, 2 figures, PostScript, GS vie
On steady compressible flows with compact vorticity; the compressible Stuart vortex
Numerical and analytical solutions to the steady compressible Euler equations corresponding to a compressible analogue of the linear Stuart vortex array are presented. These correspond to a homentropic continuation, to finite Mach number, of the Stuart solution describing a linear vortex array in an incompressible fluid. The appropriate partial differential equations describing the flow correspond to the compressible homentropic Euler equations in two dimensions, with a prescribed vorticity–density–streamfunction relationship. In order to construct a well-posed problem for this continuation, it was found, unexpectedly, to be necessary to introduce an eigenvalue into the vorticity–density–streamfunction equation. In the Rayleigh–Janzen expansion of solutions in even powers of the free-stream Mach number M[infty infinity], this eigenvalue is determined by a solvability condition. Accurate numerical solution by both finite-difference and spectral methods are presented for the compressible Stuart vortex, over a range of M[infty infinity], and of a parameter corresponding to a confined mass-flow rate. These also confirm the nonlinear eigenvalue character of the governing equations. All solution branches followed numerically were found to terminate when the maximum local Mach number just exceeded unity. For one such branch we present evidence for the existence of a very small range of M[infty infinity] over which smooth transonic shock-free flow can occur
Dyakonov-Perel spin relaxation near metal-insulator transition and in hopping transport
In a heavily doped semiconductor with weak spin-orbital interaction the
Dyakonov-Perel spin relaxation rate is known to be proportional to the Drude
conductivity. We argue that in the case of weak spin-orbital interaction this
proportionality goes beyond the Drude mechanism: it stays valid through the
metal-insulator transition and in the range of the exponentially small hopping
conductivity.Comment: 3 page
Convergence towards linear combinations of chi-squared random variables: a Malliavin-based approach
We investigate the problem of finding necessary and sufficient conditions for
convergence in distribution towards a general finite linear combination of
independent chi-squared random variables, within the framework of random
objects living on a fixed Gaussian space. Using a recent representation of
cumulants in terms of the Malliavin calculus operators (introduced
by Nourdin and Peccati in \cite{n-pe-3}), we provide conditions that apply to
random variables living in a finite sum of Wiener chaoses. As an important
by-product of our analysis, we shall derive a new proof and a new
interpretation of a recent finding by Nourdin and Poly \cite{n-po-1},
concerning the limiting behaviour of random variables living in a Wiener chaos
of order two. Our analysis contributes to a fertile line of research, that
originates from questions raised by Marc Yor, in the framework of limit
theorems for non-linear functionals of Brownian local times
Steady compressible vortex flows: the hollow-core vortex array
We examine the effects of compressiblity on the structure of a single row of hollowcore, constant-pressure vortices. The problem is formulated and solved in the hodograph plane. The transformation from the physical plane to the hodograph plane results in a linear problem that is solved numerically. The numerical solution is checked via a Rayleigh-Janzen expansion. It is observed that for an appropriate choice of the parameters M[infty infinity] = q[infty infinity]/c[infty infinity], and the speed ratio, a = q[infty infinity]/qv, where qv is the speed on the vortex boundary, transonic shock-free flow exists. Also, for a given fixed speed ratio, a, the vortices shrink in size and get closer as the Mach number at infinity, M[infty infinity], is increased. In the limit of an evacuated vortex core, we find that all such solutions exhibit cuspidal behaviour corresponding to the onset of limit lines
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