1,647 research outputs found
Magnetic forming studies
Investigation of the tensile strength dependability on the characteristic time over which a pressure pulse is applied to a metal workpiece shows that the mechanical properties of these materials are functions of the rate at which the material is undergoing strain. These results and techniques are used in magnetomotive metal forming
An equilibrium model for RFP plasmas in the presence of resonant tearing modes
The equilibrium of a finite-beta RFP plasma in the presence of
saturated-amplitude tearing modes is investigated. The singularities of the MHD
force balance equation JXB=grad(p) at the modes rational surfaces are resolved
through a proper regularization of the zeroth-order (equilibrium) profiles, by
setting to zero there the gradient of the pressure and parallel current
density. An equilibrium model, which satisfies the regularization rule at the
various rational surfaces, is developed. The comparison with the experimental
data from the Reversed Field eXperiment (RFX) gives encouraging results. The
model provides an easy tool for magnetic analysis: many aspects of the
perturbations can be analyzed and reconstructed.Comment: Final accepted version. 36 page
Magnetic Reconnection Triggered by the Parker Instability in the Galaxy: Two-Dimensional Numerical Magnetohydrodynamic Simulations and Application to the Origin of X-Ray Gas in the Galactic Halo
We propose the Galactic flare model for the origin of the X-ray gas in the
Galactic halo. For this purpose, we examine the magnetic reconnection triggered
by Parker instability (magnetic buoyancy instability), by performing the
two-dimensional resistive numerical magnetohydrodynamic simulations. As a
result of numerical simulations, the system evolves as following phases: Parker
instability occurs in the Galactic disk. In the nonlinear phase of Parker
instability, the magnetic loop inflates from the Galactic disk into the
Galactic halo, and collides with the anti-parallel magnetic field, so that the
current sheets are created in the Galactic halo. The tearing instability
occurs, and creates the plasmoids (magnetic islands). Just after the plasmoid
ejection, further current-sheet thinning occurs in the sheet, and the anomalous
resistivity sets in. Petschek reconnection starts, and heats the gas quickly in
the Galactic halo. It also creates the slow and fast shock regions in the
Galactic halo. The magnetic field (G), for example, can heat the
gas ( cm) to temperature of K via the
reconnection in the Galactic halo. The gas is accelerated to Alfv\'en velocity
( km s). Such high velocity jets are the evidence of the
Galactic flare model we present in this paper, if the Doppler shift of the
bipolar jet is detected in the Galactic halo. Full size figures are available
at http://www.kwasan.kyoto-u.ac.jp/~tanuma/study/ApJ2002/ApJ2002.htmlComment: 13 pages, 12 figures, uses emulateapj.sty, accepted by Ap
In situ proliferation and differentiation of macrophages in dental pulp
The presence of macrophages in dental pulp is well known. However, whether these macrophages proliferate and differentiate in the dental pulp in situ, or whether they constantly migrate from the blood stream into the dental pulp remains unknown. We have examined and compared the development of dental pulp macrophages in an organ culture system with in vivo tooth organs to clarify the developmental mechanism of these macrophages. The first mandibular molar tooth organs from ICR mice aged between 16 days of gestation (E16) to 5 days postnatally were used for in vivo experiments. Those from E16 were cultured for up to 14 days with or without 10% fetal bovine serum. Dental pulp tissues were analyzed with immunohistochemistry to detect the macrophages and with reverse transcription and the polymerase chain reaction (RT-PCR) for the detection of factors related to macrophage development. The growth curves for the in vivo and in vitro cultured cells revealed similar numbers of F4/80-positive macrophages in the dental pulp. RT-PCR analysis indicated the constant expression of myeloid colony-stimulating factor (M-CSF) in both in-vivo- and in-vitro-cultured dental pulp tissues. Anti-M-CSF antibodies significantly inhibited the increase in the number of macrophages in the dental pulp. These results suggest that (1) most of the dental pulp macrophages proliferate and differentiate in the dental pulp without a supply of precursor cells from the blood stream, (2) M-CSF might be a candidate molecule for dental pulp macrophage development, and (3) serum factors might not directly affect the development of macrophages
Rethinking the politics of gender and agency: an encounter with the ‘otherness’ of medieval Japan
This article engages with recent debates within feminism itself to rethink women, gender, body, and agency as conceptual categories for reading medieval Japanese literary/Buddhist texts. It questions the unreflexive transposition of contemporary understandings of concepts to the past, on the grounds that this produces anachronistic readings of the worlds we seek to understand. It argues that in medieval Japanese texts gender did not function as a ‘social’ category posited against the ‘natural’ fact of sex, and that gender was a kind of script and that it was the specificity of the gendered performance, rather than the sexual attributes and reproductive functions of the body, that gave substance to the categories ‘male’ and ‘female.’
The article also offers a critique of contemporary uses of the term agency in analyses of women and Buddhism in medieval Japan, arguing that agency here is defined as something possessed by autonomous individuals with free will, whose natural inclination is to strive to resist against the oppressive conditions of their lives. This modern liberal conception of agency, which is secular in nature, grants agency to humans alone. This anthropocentric view of the world necessitates the evisceration of the agency of gods, buddhas, dreams and material objects, all of whom are central actors in the cosmological/social world of medieval Japan
Practical, Microfabrication-Free Device for Single-Cell Isolation
Microfabricated devices have great potential in cell-level studies, but are not easily accessible for the broad biology community. This paper introduces the Microscale Oil-Covered Cell Array (MOCCA) as a low-cost device for high throughput single-cell analysis that can be easily produced by researchers without microengineering knowledge. Instead of using microfabricated structures to capture cells, MOCCA isolates cells in discrete aqueous droplets that are separated by oil on patterned hydrophilic areas across a relatively more hydrophobic substrate. The number of randomly seeded Escherichia coli bacteria in each discrete droplet approaches single-cell levels. The cell distribution on MOCCA is well-fit with Poisson distribution. In this pioneer study, we created an array of 900-picoliter droplets. The total time needed to seed cells in ∼3000 droplets was less than 10 minutes. Compared to traditional microfabrication techniques, MOCCA dramatically lowers the cost of microscale cell arrays, yet enhances the fabrication and operational efficiency for single-cell analysis
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