Phase conjugation by degenerate four wave mixing in disodium fluorescein solution in methanol

Organic dyes are known to show the resonant type of nonlinear optical properties, including phase conjugation. In the present work, disodium fluorescein in methanol is used as an organic nonlinear medium for degenerate four wave mixing at 532 nm to see the intensity dependence of the phase conjugate signal at different concentrations of the solution. It is observed that the maximum reflectivity of the signal occurs in a concentration range of 5 x 10(exp -3)/cu cm to 1.2 x 10(exp -2) g/cu cm. It is also observed that the intensity of the signal drops suddenly to less than half of its maximum outside the concentration range mentioned above. An investigation of the phase conjugate signal intensity by changing the delay time between probe signal and the forward pump is also examined. Briefly discussed is the possibility of population grating in dye liquids as a source of enhancing the third order susceptibility besides the other techniques mentioned in reference. The experiment is done by beam splitting the second harmonic (532 nm) of Nd:YAG laser, Q-switched at 20 pulses/sec (pulse width is approximately 8 and 200 mJ per pulse)

Hydro tropes as promoters in soap flotation

Soaps, the salts of fatty acids are generally used as collectors in the flotation process to separate salt type minerals. Some times light diesel oil is mixed with soaps and the emulsion is used as collector. Addition of detergents to soaps not only enhances the collector efficiency but also reduces the consumption of soap. Urea a known hydro trope is found to improve the flotation efficiency of soaps. Our current testing is indicating that other hydro tropes such as tri sodium citrate and sodium salicylate are also effective in improving the flotation efficiency of soap and also the soap-LDO emulsion

Photoemission studies of the near Fermi level spectral weight shifts in FeSe1-xTex superconductor

Our valence band photoelectron spectroscopic studies show a temperature dependent spectral weight transfer near the Fermi level in the Fe-based superconductor FeSe1-xTex. Using theoretical band structure calculations we have shown that the weight transfer is due to the temperature induced changes in the Fe(Se,Te)4 tetrahedra. These structural changes lead to shifts in the electron occupancy from the xz/yz and x2-y2 orbitals to the 3z2-r2 orbitals indicating a temperature induced crossover from a metallic state to an Orbital Selective Mott (OSM) Phase. Our study presents the observation of a temperature induced crossover to a low temperature OSM phase in the family of Fe chalcogenides.Comment: 10 pages, 4 figure

An Evaluate of Pattern Identification Programs and Its Strategies

At the moment existence, Pattern Recognition has turned into an essential idea from analyst perspective. It is utilized as a part of numerous applications like Speech acknowledgment, facade acknowledgment, Biometrics and numerous other moreover. This survey paper will clarify numerous applications and methodologies of the example acknowledgment. Primarily four sorts of methodologies measurable, layout, auxiliary and neural approach. Furthermore, promote factual approach order is likewise done

Supercell studies of the Fermi surface changes in the electron-doped superconductor LaFeAsO1‑xFx

We study the changes in the Fermi surface with electron doping in the LaFeAsO1‑xFx superconductors with density-functional supercell calculations using the linearized augmented plane-wave method. The supercell calculations with explicit F substitution are compared with those obtained from the virtual-crystal approximation (VCA) and from a simple rigid-band shift. We find significant differences between the supercell results and those obtained from the rigid-band shift with electron doping, although quite remarkably the supercell results are in good agreement with the VCA where the nuclear charges of the O atoms are slightly increased to mimic the addition of the extra electrons. With electron doping, the two cylindrical hole pockets along Γ-Z shrink in size, and the third hole pocket around Z disappears for an electron-doping concentration in excess of about 7%-8%, while the two elliptical electron cylinders along M-A expand in size. The spin-orbit coupling does not affect the Fermi surface much except a somewhat reduction in the size of the third hole pocket in the undoped case. We find that with the addition of the electrons the antiferromagnetic state becomes energetically less stable as compared to the nonmagnetic state, indicating that the electron doping may provide an extra degree of stability to the formation of the superconducting ground state.This work was supported by the U.S. Department of Energy under Grant No. DE-FG02-00ER45818

Axigluons cannot explain the observed top quark forward-backward asymmetry

We study an SU(3)^2 axigluon model introduced by Frampton, Shu, and Wang to explain the recent Fermilab Tevatron observation of a significant positive enhancement in the top quark forward-backward asymmetry relative to standard model predictions. First, we demonstrate that data on neutral B_d-meson mixing excludes the region of model parameter space where the top asymmetry is predicted to be the largest. Keeping the gauge couplings below the critical value that would lead to fermion condensation imposes further limits at large axigluon mass, while precision electroweak constraints on the model are relatively mild. Furthermore, by considering an extension to an SU(3)^3 color group, we demonstrate that embedding the model in an extra-dimensional framework can only dilute the axigluon effect on the forward-backward asymmetry. We conclude that axigluon models are unlikely to be the source of the observed top quark asymmetry.Comment: 12 pages, 7 eps figures included. Minor changes to conform with published versio

Comparison of Dual Frequency Antenna in Ka-Band with and without Shorting pin

Volume 2 Issue 8 (August 2014

In vitro multiplication of Ocimum gratissimum L. through direct regeneration

The objective of this study was to develop a rapid system for regeneration of the important medicinal plant, Ocimum gratissimum L, from nodal explant. Single node explants were inoculated on basal MS (Murashige and Skoog, 1962) medium containing 3% (w/v) sucrose, supplemented with differentconcentrations and combinations of 6-benzylaminopurine (BAP), kinetin (KN), indole-3-acetic acid (IAA) or indole-3-butyric acid (IBA) for direct plant regeneration. Maximum numbers of shoot (14.3±1.5) were observed on the medium containing 0.5 mg/l BAP and 0.25 mg/l IAA after four weeks of culture. Regenerated shoots were separated and rooted on same half strength MS medium supplemented with 0.5 mg/l of IAA alone for three weeks. Well-developed complete plantlets were transferred on to speciallymade plastic cup containing soilrite. Acclimatized plantlets were successfully grown in garden soi

Study On Strength And Stress Strain Behaviour Of Self Curing Concrete

The concrete dilution process assumes a remarkable role in the construction of solid microstructure and pore structure. The idea of self-comfort is to reduce the water dissipation of the concrete and thus increase the water holding limit of the solid compared to normal cement. An unwise restoration can reduce the quality of the cement without too much stretching. It was found that the water soluble polymers used as additives in solid effects, the dilution quality characteristics of hard cement take a prominent role in the construction of a compact solid structure and thus improve its rigidity and workmanship. The quality of compression does not decrease with the use of SAP in self-healing concretes. The excision flexibility with SAP is not reduced in self-curing concrete. SAP can be used up to 0.6% of the bond weight without changing the different quality of the cement