51,098 research outputs found
Controlling Mixing Inside a Droplet by Time Dependent Rigid-body Rotation
The use of microscopic discrete fluid volumes (i.e., droplets) as
microreactors for digital microfluidic applications often requires mixing
enhancement and control within droplets. In this work, we consider a
translating spherical liquid droplet to which we impose a time periodic
rigid-body rotation which we model using the superposition of a Hill vortex and
an unsteady rigid body rotation. This perturbation in the form of a rotation
not only creates a three-dimensional chaotic mixing region, which operates
through the stretching and folding of material lines, but also offers the
possibility of controlling both the size and the location of the mixing. Such a
control is achieved by judiciously adjusting the three parameters that
characterize the rotation, i.e., the rotation amplitude, frequency and
orientation of the rotation. As the size of the mixing region is increased,
complete mixing within the drop is obtained.Comment: 6 pages, 6 figure
Eficácia do ivermectin no controle do piolho (Haematopinus tuberculatus) em búfalos.
bitstream/item/40428/1/Boletim-Pesquisa-66-CPATU.pd
Perfil hemático de bezerros búfalos lactentes naturalmente parasitados pelo Neoascaris vitulorum.
bitstream/item/31934/1/CPATU-BP69.pd
DYNAMIC AND STEADY STATE PERFORMANCE OF UPFLOW ANAEROBIC SLUDGE BLANKET REACTOR
The simultaneous dynamic and steady state equations for substrate and biomass mass were used to assess the upflow anaerobic sludge blanket (UASB) reactor performance of municipal wastewater. The dynamic model equations were solved by using a m.file in MATLAB2011a software and dynamic equations for substrate and biomass concentrations. The objectives of this paper are (1) To develop a simple CSTR model for performance of UASB reactors (2) To evaluate the dynamic and steady state performances of UASB reactor treating municipal wastewater using the experimental results of Álveraz et al. (2008)
Tracking Data Acquisition System (TDAS) for the 1990's. Volume 6: TDAS navigation system architecture
One-way range and Doppler methods for providing user orbit and time determination are examined. Forward link beacon tracking, with on-board processing of independent navigation signals broadcast continuously by TDAS spacecraft; forward link scheduled tracking; with on-board processing of navigation data received during scheduled TDAS forward link service intervals; and return link scheduled tracking; with ground-based processing of user generated navigation data during scheduled TDAS return link service intervals are discussed. A system level definition and requirements assessment for each alternative, an evaluation of potential navigation performance and comparison with TDAS mission model requirements is included. TDAS satellite tracking is also addressed for two alternatives: BRTS and VLBI tracking
Phase transition and hybrid star in a SU(2) chiral sigma model
We use a modified SU(2) chiral sigma model to study nuclear matter at high
density using mean field approach. We also study the phase transition of
nuclear matter to quark matter in the interior of highly dense neutron stars.
Stable solutions of Tolman-Oppenheimer-Volkoff equations representing hybrid
stars are obtained with a maximum mass of 1.69 , radii around 9.3
kms and a quark matter core constituting nearly 55-85 % of the star radii.Comment: 19 pages, 9 figures, accepted for Mod. Phys. Letts.
Room Temperature Ferrimagnetism, Magnetodielectric and Exchange Bias Effect in CoFeRhO
Geometrically frustrated structures combined with competing exchange
interactions that have different magnitudes are known ingredients for achieving
exotic properties. Herein, we studied detailed structural, magnetic, thermal
(specific heat), magneto-dielectric, and magnetic exchange bias properties of a
mixed 3d - 4d spinel oxide with composition CoFeRhO. Detailed
magnetization, heat capacity, and neutron powder diffraction studies (NPD)
highlight long-range ferrimagnetic ordering with an onset at 355 K. The
magnetic structure is established using a ferrimagnetic model (collinear-type)
that has a propagation vector k = 0, 0, 0. The magneto-dielectric effect
appears below the magnetic ordering temperature, and the exchange bias (EB)
effect is observed in field cooled (FC) conditions below 355 K. The
magneto-dielectric coupling in CoFeRhO originates due to the frustration in
the structure, collinear ferrimagnetic ordering, and uncompensated magnetic
moments. The unidirectional anisotropy resulting from the uncompensated
magnetic moments causes the room-temperature exchange bias effect. Remarkably,
the appearance of technologically important properties (ferromagnetism,
magnetodielectric effect, and EB) at room temperature in CoFeRhO indicates
its potential use in sensors or spintronics.Comment: 8 pages, 11 Figure
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