6,139 research outputs found
Catalyst surfaces for the chromous/chromic redox couple
An electricity producing cell of the reduction-oxidation (REDOX) type is described. The cell is divided into two compartments by a membrane, each compartment containing a solid inert electrode. A ferrous/ferric couple in a chloride solution serves as a cathode fluid which is circulated through one of the compartments to produce a positive electric potential disposed therein. A chromic/chromous couple in a chloride solution serves as an anode fluid which is circulated through the second compartment to produce a negative potential on an electrode disposed therein. The electrode is an electrically conductive, inert material plated with copper, silver or gold. A thin layer of lead plates onto the copper, silver or gold layer when the cell is being charged, the lead ions being available from lead chloride which was added to the anode fluid. If the REDOX cell is then discharged, the current flows between the electrodes causing the lead to deplate from the negative electrode and the metal coating on the electrode will act as a catalyst to cause increased current density
Advanced screening of electrode couples
The chromium (Cr(3+)/Cr(2+)) redox couple (electrolyte and electrode) was investigated to determine its suitability as negative electrode for the iron (Fe(3+)/Fe(2+))-chromium (Cr(3+)/Cr(2+)) redox flow battery. Literature search and laboratory investigation established that the solubility and stability of aqueous acidic solutions of chromium(3) chloride and chromium(2) chloride are sufficient for redox battery application. Four categories of electrode materials were tested; namely, metals and metalloid materials (elements and compounds), alloys, plated materials, and Teflon-bonded materials. In all, the relative performance of 26 candidate electrode materials was evaluated on the basis of slow scan rate linear sweep voltammetry in stirred solution. No single material tested gave both acceptable anodic an acceptable cathodic performance. However, the identification of lead as a good cathodic electrocatalyst and gold as a good anodic electrocatalyst led to the invention of the lead/gold combination electrocatalyst. This type of catalyst can be fabricated in several ways and appears to offer the advantages of each metal without the disadvantages associated with their use as single materials. This lead/gold electrocatalyst was tested by NASA-Lewis Research Center in complete, flowing, redox batteries comprising a stack of several cells. A large improvement in the battery's coulombic and energy efficiency was observed
Collaboration : a key competence for competing in the 21st century
It is now an accepted fact that in the 21st century competition will be between networks of organisations and individuals, which efficiently and effectively integrate their competencies and resources in order to compete in a global economy (Bititci et al, 2004). Similarly the SME'2000 conference, which was held in Bologna, concluded that 'SMEs belonging to networks are often more competitive and innovative than those operating in isolation. When working together, SMEs can increase their focus through specialisation in functions that are complementary within their networks'
Distortion of the Magnetosphere During a Magnetic Storm on 30 September, 1961
Magnetosphere distortion during magnetic storm observed by Explorer XII satellit
The interplanetary magnetic field and polar magnetic disturbances
Interplanetary magnetic field and magnetic disturbances in polar regio
Synthetic Quantum Systems
So far proposed quantum computers use fragile and environmentally sensitive
natural quantum systems. Here we explore the new notion that synthetic quantum
systems suitable for quantum computation may be fabricated from smart
nanostructures using topological excitations of a stochastic neural-type
network that can mimic natural quantum systems. These developments are a
technological application of process physics which is an information theory of
reality in which space and quantum phenomena are emergent, and so indicates the
deep origins of quantum phenomena. Analogous complex stochastic dynamical
systems have recently been proposed within neurobiology to deal with the
emergent complexity of biosystems, particularly the biodynamics of higher brain
function. The reasons for analogous discoveries in fundamental physics and
neurobiology are discussed.Comment: 16 pages, Latex, 1 eps figure fil
Diquarks: condensation without bound states
We employ a bispinor gap equation to study superfluidity at nonzero chemical
potential: mu .neq. 0, in two- and three-colour QCD. The two-colour theory,
QC2D, is an excellent exemplar: the order of truncation of the quark-quark
scattering kernel: K, has no qualitative impact, which allows a straightforward
elucidation of the effects of mu when the coupling is strong. In rainbow-ladder
truncation, diquark bound states appear in the spectrum of the three-colour
theory, a defect that is eliminated by an improvement of K. The corrected gap
equation describes a superfluid phase that is semi-quantitatively similar to
that obtained using the rainbow truncation. A model study suggests that the
width of the superfluid gap and the transition point in QC2D provide reliable
quantitative estimates of those quantities in QCD.Comment: 7 pages, 3 figures, REVTEX, epsfi
A Micro-level Analysis of Recent Increases in Labor Force Participation among Older Workers
Aggregate data reveal a sizable increase in labor force participation rates since 2000 among workers on the cusp of retirement, reverting back to levels for older men not seen since the 1970s. These aggregate numbers are useful in that they document overall trends, but they lack the ability to identify the reasons behind workers’ decisions. The Health and Retirement Study (HRS) spans the last dozen years from 1992 to 2004, includes two cohorts of retirees, and provides micro-level data regarding these recent trends. Moreover, the HRS contains information on older Americans and the types of jobs they are taking (full-time versus part-time, self-employed versus wage-and-salary, low-paying versus high-paying, blue collar versus white collar, etc.). This study capitalizes on the richness of the HRS data and explores labor force determinants and outcomes of older Americans, with an emphasis on retirees' choices in recent years. We present a cross-sectional and longitudinal description of the financial, health, and employment situation of older Americans. We then explore retirement determinants using a multinomial approach to model gradual retirement and a two-step approach to model the work-leisure and hours intensity decisions of older workers. Evidence suggests that the majority of older Americans retire gradually, in stages, and that younger retirees continue to respond to financial incentives just as their predecessors did. In addition, recent macro-level changes appear to have blurred the distinction between younger and middle-aged retirees.Economics of Aging, Partial Retirement, Gradual Retirement
- …