40,801 research outputs found
Giant magnetoimpedance in crystalline Mumetal
We studied giant magnetoimpedance (GMI) effect in commercial crystalline
Mumetal, with the emphasis to sample thickness dependence and annealing
effects. By using appropriate heat treatment one can achieve GMI ratios as high
as 310%, and field sensitivity of about 20%/Oe, which is comparable to the best
GMI characteristics obtained for amorphous and nanocrystalline soft magnetic
materials.Comment: 8 pages, 3 figure
Strong energy enhancement in a laser-driven plasma-based accelerator through stochastic friction
Conventionally, friction is understood as an efficient dissipation mechanism
depleting a physical system of energy as an unavoidable feature of any
realistic device involving moving parts, e.g., in mechanical brakes. In this
work, we demonstrate that this intuitive picture loses validity in nonlinear
quantum electrodynamics, exemplified in a scenario where spatially random
friction counter-intuitively results in a highly directional energy flow. This
peculiar behavior is caused by radiation friction, i.e., the energy loss of an
accelerated charge due to the emission of radiation. We demonstrate
analytically and numerically how radiation friction can enhance the performance
of a specific class of laser-driven particle accelerators. We find the
unexpected directional energy boost to be due to the particles' energy being
reduced through friction whence the driving laser can accelerate them more
efficiently. In a quantitative case we find the energy of the laser-accelerated
particles to be enhanced by orders of magnitude.Comment: 14 pages, 3 figure
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Twisted Tales: Insights into Genome Diversity of Ciliates Using Single-Cell 'Omics.
The emergence of robust single-cell 'omics techniques enables studies of uncultivable species, allowing for the (re)discovery of diverse genomic features. In this study, we combine single-cell genomics and transcriptomics to explore genome evolution in ciliates (a > 1 Gy old clade). Analysis of the data resulting from these single-cell 'omics approaches show: 1) the description of the ciliates in the class Karyorelictea as "primitive" is inaccurate because their somatic macronuclei contain loci of varying copy number (i.e., they have been processed by genome rearrangements from the zygotic nucleus); 2) gene-sized somatic chromosomes exist in the class Litostomatea, consistent with Balbiani's (1890) observation of giant chromosomes in this lineage; and 3) gene scrambling exists in the underexplored Postciliodesmatophora (the classes Heterotrichea and Karyorelictea, abbreviated here as the Po-clade), one of two major clades of ciliates. Together these data highlight the complex evolutionary patterns underlying germline genome architectures in ciliates and provide a basis for further exploration of principles of genome evolution in diverse microbial lineages
Microflow valve control system design
A design synthesis for a microflow control system is presented based on the interrogation of an analytical model, testing, and observation. The key issues relating to controlling a microflow using a variable geometry flow channel are explored through the implementation and testing of open and closed-loop control systems. The reliance of closed-loop systems on accurate flow measurement and the need for an open-loop strategy are covered. A valve and control system capable of accurately controlling flowrates between 0.09 and 400 ml/h and with a range of 900:1 is demonstrated
Analysis of excited quark propagator effects on neutron charge form factor
The charge form factor and charge radius of neutron are investigated in the
perturbative chiral quark model (PCQM) with considering both the ground and
excited states in the quark propagator. A Cornell-like potential is extracted
in accordance with the predetermined ground state quark wavefunction, and the
excited quark states are derived by solving the Dirac equation with the
extracted PCQM potential numerically. The study reveals that the contributions
of the excited quark states are considerably influential in the charge form
factor and charge radius of neutron as expected, and the total results are
significantly improved and increased by nearly four times by including the
excited states in the quark propagator. The theoretical PCQM results are found,
including the ground and excited quark propagators, in good agreement with the
recent lattice QCD values at pion mass of about 130 MeV.Comment: 8 pages, 8 figure
Domain wall propagation through spin wave emission
We theoretically study field-induced domain wall (DW) motion in an
electrically insulating ferromagnet with hard- and easy-axis anisotropies. DWs
can propagate along a dissipationless wire through spin wave emission locked
into the known soliton velocity at low fields. In the presence of damping, the
mode appears before the Walker breakdown field for strong out-of-plane magnetic
anisotropy, and the usual Walker rigid-body propagation mode becomes unstable
when the field is between the maximal-DW-speed field and Walker breakdown
field.Comment: 4 pages, 4 figure
Optimal time-dependent polarized current pattern for fast domain wall propagation in nanowires: Exact solutions for biaxial and uniaxial anisotropies
One of the important issues in nanomagnetism is to lower the current needed
for a technologically useful domain wall (DW) propagation speed. Based on the
modified Landau-Lifshitz-Gilbert (LLG) equation with both Slonczewski
spin-transfer torque and the field-like torque, we derive the optimal spin
current pattern for fast DW propagation along nanowires. Under such conditions,
the DW velocity in biaxial wires can be enhanced as much as ten times compared
to the velocities achieved in experiments so far. Moreover, the fast variation
of spin polarization can help DW depinning. Possible experimental realizations
are discussed.Comment: 4 pages, 1 figur
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