Weak interactions with large dimensionless constant (« neutral currents » as second-order processes?)

1977 ◽  
Vol 19 (8) ◽  
pp. 303-308 ◽  
Author(s):  
V. S. Berezinsky ◽  
A. Yu. Smirnov
Keyword(s):  
Weak Interactions ◽  
Second Order ◽  
Neutral Currents ◽  
Dimensionless Constant

scholarly journals Biosequestration of chromium (VI) from aqueous medium using carbonaceous adsorbents derived from Eichhornia crassipes

2021 ◽  
Author(s):  
E PARAMESWARI ◽  
R.P. Premalatha ◽  
V. Davamani ◽  
S.Paul Sebastian
Keyword(s):  
Eichhornia Crassipes ◽  
Kinetic Studies ◽  
Solute Concentration ◽  
Second Order ◽  
Solution Ph ◽  
Chromium Vi ◽  
Dimensionless Constant ◽  
Before And After ◽  
Intra Particle Diffusion ◽  
Favorable Conditions

Abstract Utilization of the biochar that are derived from Eichhornia crassipes (water hyacinth) as biosorbent for Cr (VI) adsorption was investigated. The biochar was characterized before and after Cr (VI) adsorption by SEM, FTIR and EDX. The influencing parameters viz., solution pH, solute concentrations, reaction duration, adsorbent dose and size have been examined. The most favorable conditions for Cr (VI) removal were found to be pH = 2.0, adsorbent size = 0.2 mm, adsorbent dosage = 2.5g/100ml, adsorbate/solute concentration = 100mg/L of Cr (VI) at 25ºC at 250 rpm. Rate of adsorption was rapid and equilibrium was reached at 36 hours. The equilibrium relationship between the sorbent and sorbate was determined using the isotherms Langmuir, Freundlich and Temkin models. The Langmuir dimensionless constant (KR) for each of the solute concentration was ranged between 0 and 1, it indicates the favourable adsorption of Cr (VI) onto the adsorbent. Adsorption data was very well explained through Langmuir isotherm where sorption occurs on monolayer with the maximum biosorption capacity of 55.55 mg/g. Adsorption rate and its mechanisms were elucidated through kinetic studies viz., Pseudo first order, second order, elovich and intra particle diffusion models. On comparison with various kinetic models, results fitted excellently with pseudo second order model (R2 = 0.999). It suggests that Cr (VI) adsorption by could be better described by chemisorption which involves sharing of electrons between adsorbents and adsorbate. Hence, the biochar derived from E. crassipes are efficiently used as an ecofriendly biosorbent for the management of Cr (VI) rich waste water.

scholarly journals Comments on Parity Violating Neutral Currents in Weak Interactions

1973 ◽  
Vol 49 (6) ◽  
pp. 2160-2162 ◽  
Author(s):  
Masaaki Kuroda ◽  
Yoshio Yamaguchi
Keyword(s):  
Weak Interactions ◽  
Neutral Currents

scholarly journals Orientation-Selective Adaptation to First- and Second-Order Patterns in Human Visual Cortex

2006 ◽  
Vol 95 (2) ◽  
pp. 862-881 ◽  
Author(s):  
Jonas Larsson ◽  
Michael S. Landy ◽  
David J. Heeger
Keyword(s):  
Visual Processing ◽  
Computational Models ◽  
Weak Interactions ◽  
Selective Adaptation ◽  
Second Order ◽  
First Order ◽  
Neuronal Mechanisms ◽  
Additional Processing ◽  
Extrastriate Areas ◽  
Cortical Visual Areas

Second-order textures—patterns that cannot be detected by mechanisms sensitive only to luminance changes—are ubiquitous in visual scenes, but the neuronal mechanisms mediating perception of such stimuli are not well understood. We used an adaptation protocol to measure neural activity in the human brain selective for the orientation of second-order textures. Functional MRI (fMRI) responses were measured in three subjects to presentations of first- and second-order probe gratings after adapting to a high-contrast first- or second-order grating that was either parallel or orthogonal to the probe gratings. First-order (LM) stimuli were generated by modulating the stimulus luminance. Second-order stimuli were generated by modulating the contrast (CM) or orientation (OM) of a first-order carrier. We used four combinations of adapter and probe stimuli: LM:LM, CM:CM, OM:OM, and LM:OM. The fourth condition tested for cross-modal adaptation with first-order adapter and second-order probe stimuli. Attention was diverted from the stimulus by a demanding task at fixation. Both first- and second-order stimuli elicited orientation-selective adaptation in multiple cortical visual areas, including V1, V2, V3, V3A/B, a newly identified visual area anterior to dorsal V3 that we have termed LO1, hV4, and VO1. For first-order stimuli (condition LM:LM), the adaptation was no larger in extrastriate areas than in V1, implying that the orientation-selective first-order (luminance) adaptation originated in V1. For second-order stimuli (conditions CM:CM and OM:OM), the magnitude of adaptation, relative to the absolute response magnitude, was significantly larger in VO1 (and for condition CM:CM, also in V3A/B and LO1) than in V1, suggesting that second-order stimulus orientation was extracted by additional processing after V1. There was little difference in the amplitude of adaptation between the second-order conditions. No consistent effect of adaptation was found in the cross-modal condition LM:OM, in agreement with psychophysical evidence for weak interactions between first- and second-order stimuli and computational models of separate mechanisms for first- and second-order visual processing.

THEORY OF WEAK INTERACTIONS: RECENT DEVELOPMENT AND PROBLEMS

1988 ◽  
Vol 03 (12) ◽  
pp. 2769-2826 ◽  
Author(s):  
M.A. SHIFMAN
Keyword(s):  
Experimental Data ◽  
Quantum Chromodynamics ◽  
Current Literature ◽  
Quark Mass ◽  
Weak Interactions ◽  
Heavy Quarks ◽  
Second Order ◽  
The Other ◽  
Considerable Progress ◽  
K Meson

Accumulation of theoretical experience, on one hand, and experimental data, on the other, resulted in a considerable progress in weak interactions. The current literature concentrates mainly on such issues as the study of the Kobayashi-Maskawa matrix and the application of quantum chromodynamics to concrete processes. Here I discuss the most interesting developing fields referring both to old (light) and new (heavy) hadrons. The first part is devoted to [Formula: see text] oscillations and other processes of the second order yielding information on Vbu and the t quark mass. The second and the largest part describes the modern QCD-based approaches in the traditional problems (K meson and hyperon physics) and in new problems associated with heavy quarks.

On the effect of strong interactions at small distances on the amplitudes of the second order in weak interactions

1975 ◽  
Vol 60 (1) ◽  
pp. 71-73 ◽  
Author(s):  
A.I. Vainshtein ◽  
V.I. Zakharov ◽  
V.A. Novikov ◽  
M.A. Shifman
Keyword(s):  
Weak Interactions ◽  
Second Order ◽  
Strong Interactions
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