1,363 research outputs found

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

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    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)

    An Evaluate of Pattern Identification Programs and Its Strategies

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    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

    In vitro multiplication of Ocimum gratissimum L. through direct regeneration

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    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

    Axigluons cannot explain the observed top quark forward-backward asymmetry

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    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

    High-resolution thermal expansion measurements under Helium-gas pressure

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    We report on the realization of a capacitive dilatometer, designed for high-resolution measurements of length changes of a material for temperatures 1.4 K T\leq T \leq 300 K and hydrostatic pressure PP \leq 250 MPa. Helium (4^4He) is used as a pressure-transmitting medium, ensuring hydrostatic-pressure conditions. Special emphasis has been given to guarantee, to a good approximation, constant-pressure conditions during temperature sweeps. The performance of the dilatometer is demonstrated by measurements of the coefficient of thermal expansion at pressures PP \simeq 0.1 MPa (ambient pressure) and 104 MPa on a single crystal of azurite, Cu3_3(CO3_3)2_2(OH)2_2, a quasi-one-dimensional spin S = 1/2 Heisenberg antiferromagnet. The results indicate a strong effect of pressure on the magnetic interactions in this system.Comment: 8 pages, 7 figures, published in Rev. Sci. Instrum with minor change

    Preparation and Characterization of Ni-Doped TiO2 Materials for Photocurrent and Photocatalytic Applications

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    Different amounts of Ni-doped TiO2 (Ni = 0.1 to 10%) powders and thin films were prepared by following a conventional coprecipitation and sol-gel dip coating techniques, respectively, at 400 to 800°C, and were thoroughly characterized by means of XRD, FT-IR, FT-Raman, DRS, UV-visible, BET surface area, zeta potential, flat band potential, and photocurrent measurement techniques. Photocatalytic abilities of Ni-doped TiO2 powders were evaluated by means of methylene blue (MB) degradation reaction under simulated solar light. Characterization results suggest that as a dopant, Ni stabilizes TiO2 in the form of anatase phase, reduces its bandgap energy, and adjusts its flat band potentials such that this material can be employed for photoelectrochemical (PEC) oxidation of water reaction. The photocatalytic activity and photocurrent ability of TiO2 have been enhanced by doping of Ni in TiO2. The kinetic studies revealed that the MB degradation reaction follows the Langmuir-Hinshelwood first-order reaction relationship

    Numerical Studies to Predict the Impact of Air Nozzle Position and Inclination on the Performance of Downdraft Gratifier

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    Biomass gasification is one of the promising technologies to produce energy from the renewable energy sources, and the downdraft biomass gasifier is a widely used biomass energy conversion device. Among the various components of a gasifier, the position and the inclination of air nozzle have a vital role in the generation of producer gas. Therefore, a proper design is needed to fix the position and angle of the air nozzle. Keeping the above aspects, the present work focuses on the numerical simulation to predict the appropriate position and inclination of the air nozzle in a 50kWth imbert type downdraft gasifier by the species transport approach. The nozzle inclination varies from 0°, 20°, 30°, 45° and 60°, and the nozzle position is considered from 50mm, 100mm, 150mm and 200mm respectively. Experiments were also conducted to validate the numerical study. Both the studies show that the nozzle inclination at 45° and its position at 100mm above the reduction zone gives a reasonable composition of producer gas

    Functional outcome and complications of surgically managed malleolar fractures at ankle

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    Background: If not treated properly the ankle injuries are a source of disability in the form of pain, instability and early degenerative arthritis of ankle. The aim and objectives of the study were to assess functional outcome of surgically managed malleolar fractures at ankle and to assess the results of complication.Methods: This study was undertaken from January 2012 to August 2015. In-patients who were admitted in Nizams institute of medical sciences Hyderabad, for surgical management of ankle fracture were taken for the present study. 61 patients were admitted during this period. Among them, 4 patients died, 5 patients were lost from follow up due to various reasons and 4 patients were not fulfilling the inclusion/exclusion criteria. The remaining 48 patients were included in the study.Results: Pronation abduction injury was more common, seen in 45% of patients. In terms of functional outcome 62% patients achieved excellent to good results as per subjective criteria. 75% good results as per objective criteria and 83% good results as per radiological criteria. Patients with unimalleolar fractures had the best outcome with mean Olerud Molander ankle score (OMA) Score of 94 With regards to lateral malleolar fracture fixation modality, patients with rush nail fixation had mean OMA Score of 86. With regards to medial malleolar fracture fixation modality, patients with Tension band wiring had mean OMA SCORE of 93. The patients with complications has poorer outcome with mean OMA Score of 76. Conclusions: There was a significant improvement in the functional outcome of the patients as assessed by radiological, subjective and objective parameters compared to preoperative condition

    Motion Sickness Manifestations and Prevention

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    Motion sickness is an ancient problem associated with transportation (ships and other vehicles), which is affecting humans since ages. Motion sickness is characteristically occurring during abnormal movements induced by the motion and when there is a conflict between various senses such as visual, vestibular and motor system. Depending on the type of motion, various kinds of sicknesses, such as air sickness, car sickness, train sickness, seasickness, etc. may occur. A very less per cent of individuals are highly susceptible to motion sickness and very less per cent of individuals are highly insusceptible for motion sickness. However, most of the population comes in between. The primary symptoms of motion sickness include nausea, vomiting, wanes, and cold sweating. Varieties of drugs are available to reduce susceptibility to motion sickness. However, nausea, pallor, sweating, headache, dizziness, malaise, increased salivation, apathy, drowsiness, belching, hyperventilation and stomach awareness are the other symptoms of motion sickness. Anti-cholinergics and anti-histamines are the most effective motion sickness prophylactics with apparent side effects such as dry mouth, drowsiness, and depression. There are theories and mechanisms which include intra-vestibular (Canal-Otolith) mismatch theory, sensory conflict theory, visual-vestibular mismatch theory, the poison theory, the postural instability theory, and the movement program theory. Benzodiazepines, anticholinergics, anti-histamines and monoamine antagonists have commonly used treatment regimes. The traditional way of tackling the problem is the consumption of ginger, peppermint, lemon, fennel, marjoram, rosemary, basil. This review summarizes prediction and evaluation, behavioural strategies to prevent or minimize symptoms of motion sickness and available countermeasures of motion sickness
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