3,494 research outputs found
Bipolar Nickel-hydrogen Batteries for Aerospace Applications
A bipolar nickel-hydrogen battery which effectively addresses all key requirements for a spacecraft power system, including long-term reliability and low mass, is discussed. The design of this battery is discussed in the context of system requirements and nickel-hydrogen battery technology in general. To achieve the ultimate goal of an aerospace application of a bipolar Ni-H2 battery several objectives must be met in the design and development of the system. These objectives include: maximization of reliability and life; high specific energy and energy density; reasonable cost of manufacture, test, and integration; and ease in scaling for growth in power requirements. These basic objectives translate into a number of specific design requirements, which are discussed
Two-Particle Microrheology of quasi-2D Viscous Systems
We study the correlated motions of colloidal particles in a quasi-2D system
(Human Serum Albumin (HSA) protein molecules at an air-water interface) for
different surface viscosities . We observe a transition in the
behavior of the correlated motion, from 2-D interface dominated at high
to bulk fluid-dependent at low . The correlated motions
can be scaled onto a master curve which captures the features of this
transition. This master curve also characterizes the spatial dependence of the
flow field of a viscous interface in response to a force. From the flow field
and the correlated particle motions, we calculate a two-particle MSD (mean
square displacement) for direct comparison with rheological measurements.Comment: 4 pages, 4 figures, submitted to PR
Symptoms and Control of Zinc Deficiency in Corn
The purpose of this publication is to describe zinc deficiency symptoms in corn and to present recommendations for applications of zinc fertilizer
Single-crystal X-ray structure analysis of the superionic conductor Li10GeP2S12
Tetragonal Li10GeP2S12 (LGPS) is the best solid Li ion conductor known to date. So far, the structure of the electrolyte was only determined from powder diffraction and Rietveld refinement. Here, we present the first single-crystal structure analysis of the tetragonal LGPS structure. The reported structure is largely verified. However, an additional Li position is clearly identified which might have a significant impact on the Li ion dynamics. All Li positions are partially occupied - a prerequisite for Li superionic conductors - and form a network of interconnected Li diffusion pathways. Therefore, we suggest that Li diffusion in this record solid electrolyte is less anisotropic than previously claimed
Magnetic behavior of EuCu2As2: Delicate balance between antiferromagnetic and ferromagnetic order
The Eu-based compound, EuCu2As2, crystallizing in the ThCr2Si2-type
tetragonal structure, has been synthesized and its magnetic behavior has been
investigated by magnetization (M), heat-capacity (C) and electrical resistivity
(rho) measurements as a function of temperature (T) and magnetic field (H) as
well as by 151Eu Moessbauer measurements. The results reveal that Eu is
divalent ordering antiferromagnetically below 15 K in the absence of magnetic
field, apparently with the formation of magnetic Brillouin-zone boundary gaps.
A fascinating observation is made in a narrow temperature range before
antiferromagnetism sets in: That is, there is a remarkable upturn just below 20
K in the plot of magnetic susceptibility versus T even at low fields, as though
the compound actually tends to order ferromagnetically. There are corresponding
anomalies in the magnetocaloric effect data as well. In addition, a small
application of magnetic field (around 1 kOe at 1.8 K) in the antiferromagnetic
state causes spin-reorientation effect. These results suggest that there is a
close balance between antiferromagnetism and ferromagnetism in this compoundComment: Phys. Rev. B, in pres
Regularities of vegetation cover self-rehabilitation in technogenically disrupted landscapes and technologies of their ecological restoration
Формирование жизнеспособного растительного покрова как условие достижения экологического баланса и уменьшения негативного воздействия на окружающую средуyesБелГ
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