12,672 research outputs found
Heisenberg limited Sagnac interferometry
We show how the entangled photons produced in parametric down conversion can
be used to improve the sensitivity of a Sagnac interferometer. Two-photon and
four-photon coincidences increases the sensitivity by a factor of two and four
respectively. Our results apply to sources with arbitrary pumping and squeezing
parameters.Comment: 11 pages, 5 figure
Quantum interferometry using coherent beam stimulated parametric down-conversion
We show how stimulated parametric processes can be employed in experiments on
beyond the diffraction limit to overcome the problem of low visibility obtained
by using spontaneous down conversion operating in the high gain regime. We
further show enhancement of the count rate by several orders when stimulated
parametric processes are used. Both the two photon counts and the visibility
can be controlled by the phase of the stimulating coherent beam.Comment: 7 pages, 4 figure
Iinfluence of Main Technological Parameters of Drying on Quality of Bagasse From Carrot and Beet
The work studies the drying process of vegetable bagasse, namely of carrot and beet. There is studied the moisture content kinetics of vegetable bagasse and determined the dependence of the process duration on main technological parameters in the work of a vibration vacuum dryer, namely, an amplitude and frequency. There were studied quality parameters of obtained concentrated products, namely the colorimetric estimation of dried bagasse of carrot and beet. Based on obtained results of the study, it was established, that the use of vibration in the process of drying bagasse favors conservation and formation of colorimetric characteristics of a dried product. Determined color characteristics gave a possibility to establish, that at thermal processing it is very important to decrease the drying process duration and temperature. Research data proved prospects of producing concentrated products, namely, dried bagasse of carrot and beet by the offered method. It allows to regulate quality parameters of a ready product: color, brightness, consistence, viscosity and physical-chemical properties. Obtained concentrated products are characterized with high organoleptic indices, food value. This product may be used in the wide spectrum of food industry, such as, for example: juice supplement, stuff for confectionary mass, filling for confectionary products, as biological supplement for healthy nutrition
Angular dependence of domain wall resistivity in artificial magnetic domain structures
We exploit the ability to precisely control the magnetic domain structure of
perpendicularly magnetized Pt/Co/Pt trilayers to fabricate artificial domain
wall arrays and study their transport properties. The scaling behaviour of this
model system confirms the intrinsic domain wall origin of the
magnetoresistance, and systematic studies using domains patterned at various
angles to the current flow are excellently described by an angular-dependent
resistivity tensor containing perpendicular and parallel domain wall
resistivities. We find that the latter are fully consistent with Levy-Zhang
theory, which allows us to estimate the ratio of minority to majority spin
carrier resistivities, rho-down/rho-up~5.5, in good agreement with thin film
band structure calculations.Comment: 14 pages, 3 figure
Quasi one dimensional He inside carbon nanotubes
We report results of diffusion Monte Carlo calculations for both He
absorbed in a narrow single walled carbon nanotube (R = 3.42 \AA) and strictly
one dimensional He. Inside the tube, the binding energy of liquid He is
approximately three times larger than on planar graphite. At low linear
densities, He in a nanotube is an experimental realization of a
one-dimensional quantum fluid. However, when the density increases the
structural and energetic properties of both systems differ. At high density, a
quasi-continuous liquid-solid phase transition is observed in both cases.Comment: 11 pages, 3ps figures, to appear in Phys. Rev. B (RC
On the biology and bioacoustic characteristic of spotted catfish arius maculatus (Thunberg 1792) from the Malaysian Estuary.
Estuaries of Matang mangrove reserves in Perak provide an ideal habitat for Arius maculatus
population. Results of our survey showed that most of the fish species caught were in their sub-adult
stages with size ranged between 11 – 21 cm SL as shown in length frequency analysis. The relative
growth condition of the fish population was allometrically negative with “b” value < 3.0 (W = 0.040L2.78)
respectively. Study on reproductive biology of the species showed that almost half of the specimens caught
were comprised of maturing males and female’s gonad development attained stage II – III. Stomach
content analysis demonstrated that A. maculatus was an excellent benthic feeder in muddy water
environment. Three major food items have been listed and dominated by zoobenthos and benthic
crustacean. Meanwhile bioacoustic study showed that the fish produced a distinct sound resulted from
stridulation of pectoral fins. The roles played by Matang mangrove systems as an integral breeding and
nursery ground for this particular species was also discussed
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