5,471 research outputs found
CP-odd Weak Basis Invariants for Neutrino Mass Matrices with a Texture Zero and a Vanishing Minor
We construct the -odd weak basis invariants in the flavor basis for all
the phenomenologically viable neutrino mass matrices with a texture zero and a
vanishing minor and, also, find the necessary and sufficient conditions for
invariance . We examine the interrelationships between different -odd
weak basis invariants for these texture structures and investigate their
implications for Dirac- and Majorana-type violation.Comment: To appear in Journal of Physics
Lifetime Measurements in 120Xe
Lifetimes for the lowest three transitions in the nucleus Xe have
been measured using the Recoil Distance Technique. Our data indicate that the
lifetime for the transition is more than a factor of
two lower than the previously adopted value and is in keeping with more recent
measurements performed on this nucleus. The theoretical implications of this
discrepancy and the possible reason for the erroneous earlier results are
discussed. All measured lifetimes in Xe, as well as the systematics of
the lifetimes of the 2 states in Xe isotopes, are compared with
predictions of various models. The available data are best described by the
Fermion Dynamic Symmetry Model (FDSM).Comment: 9 pages, RevTeX, 3 figures with Postscript file available on request
at [email protected], [email protected]. Submitted to Phys.
Rev.
Quantum thermodynamics at critical points during melting and solidification processes
We systematically explore and show the existence of finite-temperature
continuous quantum phase transition (CTQPT) at a critical point, namely, during
solidification or melting such that the first-order thermal phase transition is
a special case within CTQPT. Infact, CTQPT is related to chemical reaction
where quantum fluctuation (due to wavefunction transformation) is caused by
thermal energy and it can occur maximally for temperatures much higher than
zero Kelvin. To extract the quantity related to CTQPT, we use the ionization
energy theory and the energy-level spacing renormalization group method to
derive the energy-level spacing entropy, renormalized Bose-Einstein
distribution and the time-dependent specific heat capacity. This work
unambiguously shows that the quantum phase transition applies for any finite
temperatures.Comment: To be published in Indian Journal of Physics (Kolkata
Thermal oxidation of Ti6Al4V alloy: Microstructural and electrochemical characterization
Thermal oxidation (TO) of Ti6Al4V alloy was performed at 500, 650 and 800 ◦C for 8, 16, 24 and 48 h in air.
The morphological features, structural characteristics, microhardness and corrosion resistance in Ringer’s
solution of TO Ti6Al4V alloy were evaluated and compared with those of the untreated one. The surface
morphological features reveal that the oxide film formed on Ti6Al4V alloy is adherent to the substrate at 500 and 650 ◦C irrespective of the oxidation time whereas it spalls off when the alloy is oxidized at 800◦C for more than 8 h. X-ray diffraction (XRD) measurement reveals the presence of Ti(O) and -Ti phases on alloy oxidized at 500 and 650◦C, with Ti(O) as the dominant phase at 650◦C whereas the alloy oxidized at 800◦C exhibits only the rutile phase. Almost a threefold increase in hardness is observed for the alloy oxidized at 650 ◦C for 48 h when compared to that of the untreated one. Thermally oxidized Ti6Al4V alloy offers excellent corrosion resistance in Ringer’s solution when compared to that of the untreated alloy
Sediment management for Horseshoe Lake and its watershed, Alexander County, Illinois
Illinois Department of Conservation Contract No. 1-5-39782published or submitted for publicationis peer reviewedOpe
Development, testing and plant trails of single reagent system for coal flotation
Flotation is an important means of upgrading the fine fraction of raw coal, typically particles finer than 0.5 mm. Due to increased use of highly mechanized mining techniques large quantities of fines (< 0.5 mm) are being generated. These fines presently account for approximately 20–30% of the total plant feed. More than 140 million tones of fine coals are beneficiated by flotation worldwide annually. In coal flotation, reagents are required to enhance the hydrophobicity of coal surface. In addition to hydrophobic character, the selectivity, proper froth structure, stability and less sensitive to water chemistry are important. Water insoluble hydrocarbons are widely used as collectors in coal flotation. These collectors are basically non-polar oils like diesel, kerosene, etc. along with some frothers. Thus, it is necessary to add collector and frother separately in coal flotation. It is generally accepted that in coal flotation a single reagent system is more advantageous than the present practice of two reagent system. National Metallurgical Laboratory is involved in the flotation of coal fines using alternative single collector systems to developed specially replace fuel oils and frothers. For this purpose NML has entered into an agreement with M/s Somu Organo-Chem Pvt. Ltd. (SOCPL) Bangalore, a leading reagent manufacturer. Under this collaboration M/s SOCPL developed reagents and NML evaluated their selectivity index and application in coal flotation. Among many reagents developed and evaluated one best reagent was selected and full scale plant trails were conducted. The paper deals with the results obtained with several reagents in the laboratory and the plant trails
Probing the isovector transition strength of the low-lying nuclear excitations induced by inverse kinematics proton scattering
A compact approach based on the folding model is suggested for the
determination of the isoscalar and isovector transition strengths of the
low-lying () excitations induced by inelastic proton
scattering measured with exotic beams. Our analysis of the recently measured
inelastic O+p scattering data at and 43 MeV/nucleon
has given for the first time an accurate estimate of the isoscalar
and isovector deformation parameters (which cannot be determined from
the (p,p') data alone by standard methods) for 2 and excited
states in O. Quite strong isovector mixing was found in the 2
inelastic O+p scattering channel, where the strength of the isovector
form factor (prototype of the Lane potential) corresponds to a
value almost 3 times larger than and a ratio of nuclear transition
matrix elements .Comment: 5 pages, 3 figure
Alpha-decay Rates of Yb and Gd in Solar Neutrino Detectors
The -decay rates for the nuclides Yb
and Gd have been estimated from transmission probabilities
in a systematic -nucleus potential and from an improved fit to
-decay rates in the rare-earth mass region. Whereas -decay of
Gd in natural gadolinium is a severe obstacle for the use of gadolinium
as a low-energy solar-neutrino detector, we show that
-decay does not contribute significantly to the background in a
ytterbium detector. An extremely long -decay lifetime of Yb
is obtained from calculation, which may be close to the sensitivity limit in a
low-background solar neutrino detector.Comment: 12 pages, 1 figure; An author name was correcte
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