1,214 research outputs found
Influence of the Lower Hybrid Drift Instability on the onset of Magnetic Reconnection
Two-dimensional and three-dimensional kinetic simulation results reveal the
importance of the Lower-Hybrid Drift Instability LHDI to the onset of magnetic
reconnection. Both explicit and implicit kinetic simulations show that the LHDI
heats electrons anisotropically and increases the peak current density. Linear
theory predicts these modifications can increase the growth rate of the tearing
instability by almost two orders of magnitude and shift the fastest growing
modes to significantly shorter wavelengths. These predictions are confirmed by
nonlinear kinetic simulations in which the growth and coalescence of small
scale magnetic islands leads to a rapid onset of large scale reconnection
Разработка технологического процесса изготовления ротора ФЮРА.612322. 401.0.33.91.110
Выпускная квалификационная работа выполнена на тему «Разработка технологического процесса изготовления ротора» ФЮРА.612322.401.0.33.91.110 геохода в условиях мелкосерийного производства.
Выпускная квалификационная работа состоит из 8 листов графического материала, 77 листов пояснительной записки.
Целью работы является разработка технологического процесса, с использованием высокоэффективного оборудования, приспособлений, что позволяет сократить время на подготовку производства, снизить трудоемкость и затраты на производство.
Ключевые слова: ТЕХНОЛОГИЧЕСКИЙ ПРОЦЕСС, ЗАГОТОВКА, ДЕТАЛЬ, РОТОР, ИНСТРУМЕНТ, СТАНОК, ПРИСПОСОБЛЕНИЕ, СВЕРЛЕНИЕ.
Выпускная квалификационная работа состоит из следующих основных частей:
Аналитическая часть, где приводится описание: служебного назначения изделия, действуFinal qualifying work done on the topic "Development of technological process of manufacturing the rotor" FYURA.612322.401.0.33.91.110 geohoda in small-scale production.
Final qualifying work consists of 8 sheets of graphics, 77 pages of the explanatory note.
The aim is to develop a process, using high-performance equipment, devices, reducing the time to prepare production, reduce the complexity and costs of production.
Keywords: workflow, PROCESSING, PART ROTOR, TOOLS, MACHINES, TOOLS, DRILLING.
Final qualifying work consists of the following parts:
The analytical part, which describes: official purpose products, the current process, the completion of construction details on manufacturability.
The technological part of the project includes the following issues: selection of preparations
Nonideal strongly magnetized plasmas of neutron stars and their electromagnetic radiation
We study the equation of state, polarization and radiation properties for
nonideal, strongly magnetized plasmas which compose outer envelopes of magnetic
neutron stars. Detailed calculations are performed for partially ionized
hydrogen atmospheres and for condensed hydrogen or iron surfaces of these
stars. This is a companion paper to astro-ph/0511803Comment: 7 pages, 3 figures. Invited topical talk at Strongly Coupled Coulomb
Systems (Moscow, June 20-25, 2005); to appear in Journal of Physics
Inflation-Produced Magnetic Fields in Nonlinear Electrodynamics
We study the generation of primeval magnetic fields during inflation era in
nonlinear theories of electrodynamics. Although the intensity of the produced
fields strongly depends on characteristics of inflation and on the form of
electromagnetic Lagrangian, our results do not exclude the possibility that
these fields could be astrophysically interesting.Comment: 6 page
Curvature in Noncommutative Geometry
Our understanding of the notion of curvature in a noncommutative setting has
progressed substantially in the past ten years. This new episode in
noncommutative geometry started when a Gauss-Bonnet theorem was proved by
Connes and Tretkoff for a curved noncommutative two torus. Ideas from spectral
geometry and heat kernel asymptotic expansions suggest a general way of
defining local curvature invariants for noncommutative Riemannian type spaces
where the metric structure is encoded by a Dirac type operator. To carry
explicit computations however one needs quite intriguing new ideas. We give an
account of the most recent developments on the notion of curvature in
noncommutative geometry in this paper.Comment: 76 pages, 8 figures, final version, one section on open problems
added, and references expanded. Appears in "Advances in Noncommutative
Geometry - on the occasion of Alain Connes' 70th birthday
ROSAT Evidence for Intrinsic Oxygen Absorption in Cooling Flow Galaxies and Groups
Using spatially resolved, deprojected ROSAT PSPC spectra of 10 of the
brightest cooling flow galaxies and groups with low Galactic column densities
we have detected intrinsic absorption over energies ~0.4-0.8 keV in half of the
sample. Since no intrinsic absorption is indicated for energies below ~0.4 keV,
the most reasonable model for the absorber is collisionally ionized gas at
temperatures T=10^{5-6} K with most of the absorption arising from ionized
states of oxygen but with a significant contribution from carbon and nitrogen.
The soft X-ray emission of this warm gas can explain the sub-Galactic column
densities of cold gas inferred within the central regions of most of the
systems. Attributing the absorption to ionized gas reconciles the large columns
of cold H and He inferred from EINSTEIN and ASCA with the lack of such columns
inferred from ROSAT. Within the central ~10-20 kpc, where the constraints are
most secure, the estimated mass of the ionized absorber is consistent with most
(perhaps all) of the matter deposited by a cooling flow over the lifetime of
the flow. Since the warm absorber produces no significant H or He absorption
the large absorber masses are consistent with the negligible atomic and
molecular H inferred from HI and CO observations of cooling flows. It is also
found that if T > ~2x10^5 K then the optical and UV emission implied by the
warm gas does not violate published constraints. Finally, we discuss how the
prediction of warm ionized gas as the product of mass drop-out in these and
other cooling flows can be verified with new CHANDRA and XMM observations.
(Abridged)Comment: 17 pages (5 figures), Accepted for publication in ApJ, expanded
discussion of multiphase spectral models, theoretical implications of warm
gas in cooling flows, and the statistical significance of the oxygen
absorptio
Wodzicki Residue for Operators on Manifolds with Cylindrical Ends
We define the Wodzicki Residue TR(A) for A in a space of operators with
double order (m_1,m_2). Such operators are globally defined initially on R^n
and then, more generally, on a class of non-compact manifolds, namely, the
manifolds with cylindrical ends. The definition is based on the analysis of the
associate zeta function. Using this approach, under suitable ellipticity
assumptions, we also compute a two terms leading part of the Weyl formula for a
positive selfadjoint operator belonging the mentioned class in the case
m_1=m_2.Comment: 24 pages, picture changed, added references, corrected typo
Magnetic Field Limitations on Advection Dominated Flows
Recent papers discussing advection dominated accretion flows (ADAF) as a
solution for astrophysical accretion problems should be treated with some
caution because of their uncertain physical basis. The suggestions underlying
ADAF involve ignoring the magnetic field reconnection in heating of the plasma
flow, assuming electron heating due only to binary Coulomb collisions with
ions. Here, we analyze the physical processes in optically thin accretion flows
at low accretion rates including the influence of an equipartition turbulent
magnetic field. For these conditions there is continuous destruction of
magnetic flux by reconnection.
The reconnection is expected to significantly heat the electrons which can
efficiently emit magnetobremstrahlung radiation. Because of this electron
emission, the radiative efficiency of the ADAF is not small. We suggest that
the small luminosities of nearby galactic black holes is due to outflows rather
than ADAF accretion.Comment: 7 pages, 3 figures, Submitted to Ap
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