674 research outputs found
Study of fast response thermocouple measurement of temperatures in cryogenic gases
Thermocouples fabricated from uninsulated small diameter wire have fast reproducible response times. The thermocouple is thermally isolated from its supports by making the leads of sufficient length so that the heat conduction down the leads is small and assuming that the leads adjacent to the junction are subjected to the same thermal conditions
Epigenetic mechanisms, trauma, and psychopathology: Targeting chromatin remodeling complexes
Environmental pressure affects the genotype throughout different epigenetic processes. There is currently ample evidence on the role of epigenetics in developing various mental disorders. A burden of environmental pressure, such as psychological trauma, and its influence on genotype can lead to a variety of psychopathologies. Thus, this study focuses on the epigenetic activity of the complex protein machinery operating on chromatin-the ATP-dependent chromatin remodeling complexes. Although there are several recent studies on the molecular structure, functions, and taxonomy of ATP-dependent chromatin remodeling complexes, the focus of this paper is to highlight the importance of those 'protein machines' in developing psychiatric disorders. Data were obtained from human preclinical and clinical studies. The results of this review indicate an importance of ATP-dependent chromatin remodeling complexes in the interaction between environmental factors, including traumatic events, and genetic vulnerability to stress. Several studies indicate that ATP-dependent chromatin remodeling complexes play a crucial role in the development and consolidation of memory, in neurodevelopmental processes, and in etiology depressive-like behavior. Thus, the activity of those 'protein machines' emerges as a key factor in the pathophysiology of various psychiatric diseases. It can also be concluded that the limitations of clinical studies may be explained by inappropriate laboratory methods and research paradigms due to the delayed timeframe of biochemical responses to environmental stimuli. Future research in this field may enable a better understanding of the pathophysiology of psychiatric diseases and contribute to the development of novel molecular treatment targets. - 2019 Walter de Gruyter GmbH, Berlin/Boston 2019
Liquid Hydrogen Pressurization Tests Final Test Report, 29 May 1963 - 27 Aug. 1964
Liquid hydrogen pressurization tests for application to heat exchanger design in Saturn missil
Inversion symmetric 3-monopoles and the Atiyah-Hitchin manifold
We consider 3-monopoles symmetric under inversion symmetry. We show that the
moduli space of these monopoles is an Atiyah-Hitchin submanifold of the
3-monopole moduli space. This allows what is known about 2-monopole dynamics to
be translated into results about the dynamics of 3-monopoles. Using a numerical
ADHMN construction we compute the monopole energy density at various points on
two interesting geodesics. The first is a geodesic over the two-dimensional
rounded cone submanifold corresponding to right angle scattering and the second
is a closed geodesic for three orbiting monopoles.Comment: latex, 22 pages, 2 figures. To appear in Nonlinearit
Memory difference control of unknown unstable fixed points: Drifting parameter conditions and delayed measurement
Difference control schemes for controlling unstable fixed points become
important if the exact position of the fixed point is unavailable or moving due
to drifting parameters. We propose a memory difference control method for
stabilization of a priori unknown unstable fixed points by introducing a memory
term. If the amplitude of the control applied in the previous time step is
added to the present control signal, fixed points with arbitrary Lyapunov
numbers can be controlled. This method is also extended to compensate arbitrary
time steps of measurement delay. We show that our method stabilizes orbits of
the Chua circuit where ordinary difference control fails.Comment: 5 pages, 8 figures. See also chao-dyn/9810029 (Phys. Rev. E 70,
056225) and nlin.CD/0204031 (Phys. Rev. E 70, 046205
The hypertoric intersection cohomology ring
We present a functorial computation of the equivariant intersection
cohomology of a hypertoric variety, and endow it with a natural ring structure.
When the hyperplane arrangement associated with the hypertoric variety is
unimodular, we show that this ring structure is induced by a ring structure on
the equivariant intersection cohomology sheaf in the equivariant derived
category. The computation is given in terms of a localization functor which
takes equivariant sheaves on a sufficiently nice stratified space to sheaves on
a poset.Comment: Significant revisions in Section 5, with several corrected proof
Global Structure of Moduli Space for BPS Walls
We study the global structure of the moduli space of BPS walls in the Higgs
branch of supersymmetric theories with eight supercharges. We examine the
structure in the neighborhood of a special Lagrangian submanifold M, and find
that the dimension of the moduli space can be larger than that naively
suggested by the index theorem, contrary to previous examples of BPS solitons.
We investigate BPS wall solutions in an explicit example of M using Abelian
gauge theory. Its Higgs branch turns out to contain several special Lagrangian
submanifolds including M. We show that the total moduli space of BPS walls is
the union of these submanifolds. We also find interesting dynamics between BPS
walls as a byproduct of the analysis. Namely, mutual repulsion and attraction
between BPS walls sometimes forbid a movement of a wall and lock it in a
certain position; we also find that a pair of walls can transmute to another
pair of walls with different tension after they pass through.Comment: 42 pages, 11 figures; a few comments adde
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Magnetic table for levitating food for entertainment
In this paper, we discuss our work towards a new dining platform that uses magnetic levitating food and magnetic utensils in an initial prototype device. The ultimate goal of the project is a complete table with dynamic levitating food, but the current implementation is a set of levitating magnets that can be encased in food hovering over static locations. We investigated different weights and shapes of 3-D printed objects to mimic food and found that the levitating magnets are strong enough to support lightweight food. This magnetic levitating table can produce a playful and entertaining dining experience by moving and rotating to stay in place. The key novelties of this paper are the integration of food with a magnetic levitating table for playful interactions and novel dining experiences
Polarization properties of laser-diode-pumped micro-grained Nd:YAG ceramic lasers
Detailed polarization properties have been examined in laser-diode-pumped
(LD-pumped) micro-grained ceramic Nd:YAG lasers in different microchip cavity
configurations. Stable linearly-polarized single-frequency oscillations, whose
polarization direction coincide with that of an LD pump light, were observed in
an external cavity scheme. While, in the case of a thin-slice laser scheme with
coated reflective ends, elliptically-polarized single-frequency operations took
place in the low pump-power regime and dynamic instabilities appeared,
featuring self-induced antiphase modulations among counter-rotating
circularly-polarized components having slightly different lasing frequencies,
with increasing the pump power.Comment: 9 pages, 5 figure
Chaos in free electron laser oscillators
The chaotic nature of a storage-ring Free Electron Laser (FEL) is
investigated. The derivation of a low embedding dimension for the dynamics
allows the low-dimensionality of this complex system to be observed, whereas
its unpredictability is demonstrated, in some ranges of parameters, by a
positive Lyapounov exponent. The route to chaos is then explored by tuning a
single control parameter, and a period-doubling cascade is evidenced, as well
as intermittence.Comment: Accepted in EPJ
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