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This is the model output forTurbulence, Particle Acceleration, and Heating due to the Lower Hybrid Mode near Magnetic Reconnection Regions in Magnetopause.&nbsp

Let A bean additively cancellative semialgebra over an additively cancellative semifield K as defined in [9]. For a given partial action α of a group G on an algebra, the associativity of partial skew group ring together with the existence and uniqueness of enveloping (global) action were studied by M. Dokuchaev and R. Exel [2] which were extended for semialgebras with some restriction by Sharma et. al. using the ring of differences. In a similar way, we extend the results of [2,3] for semialgebras regarding partial representations.

In the present paper, we have studied the nonlinear Kinetic Alfv'en Waves (KAW) in the vicinity of the null point. We have considered the nonlinearity due to ponderomotive effects associated with KAW in the solar corona. A 3D model equation representing the dynamics of KAW is developed in this Null point scenario. Using numerical methods, we have solved the model equation for solar corona parameters. The pseudospectral method and the finite difference method have been applied to tackle spatial integration and temporal evaluation, respectively. The outcome of the simulation demonstrates the formation of localized structures. With the evolution of time, these localized structures become more chaotic. Chaotic structures (turbulent) can efficiently transfer energy. The power spectrum of these turbulent structures shows the Kolmogorov spectral index of nearly -5/3 in the inertial range followed by a steeper spectrum of nearly -3.3 (in the range of -2 to -4). These structures also lead to the generation of the current sheet. To understand the physics of our model, we have also done a semi-analytical study for our model equation. Semi-analytical calculations reveal that the current sheet structures have scale sizes of the order of ion gyro-radius. The relevance of this investigation to the current observations by Parker Solar Probe has also been discussed.

Phthalates are widely used as plasticisers in flexible plastics and containers for food and personal care products (PCPs) and contaminates foods and PCPs. A human biomonitoring (BM) study was performed to study exposure of chemicals from foods and PCPs. For two 24-h periods, adult volunteers (n = 144) in Norway kept diaries on food eaten and usage of PCPs, and collected 24-h urine. Aggregated exposure to di(2-ethylhexyl) phthalate (DEHP) from dietary and PCPs was estimated by Monte-Carlo simulation using Oracle Crystal Ball©. Simulated urinary concentrations using physiologically based pharmacokinetic (PBPK) models were compared with measured urinary metabolites of DEHP, mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP) and mono-2-ethyl 5-carboxypentyl phthalate (MECCP). DEHP exposure from food are approximately 10 times higher than exposure than from PCPs. The main contributors to dietary exposure are dairy, grain, fruits and vegetables, meat and fish. Body lotion contribute most to the exposure of DEHP from PCPs. Forward-dosimetry gives good convergence with 24-h urinary concentrations of simulated and measured BM data. The measured concentration of the MECCP metabolite correlated well with simulated high exposure, while the measured concentrations of MEHP, MEHHP and MEOHP partly overlapped with both simulated low, medium and high metabolite exposure.

Medium Entropy Alloy AlCuFeMn possesses high room temperature strength and oxidation endurance. In present work, the aqueous corrosion resistance of the as-cast as well as low temperature oxidized AlCuFeMn alloy in 3.5 wt% NaCl solution, is explored. Equimolar proportions of high purity copper, manganese, iron, and aluminum were arc melted and cast in a copper mold. The alloy primarily consists of a face-centered cubic and a body-centered cubic phase. Potentiodynamic polarization tests on the alloy after low temperature surface oxidation reveal an aqueous corrosion resistance comparable to AISI 304 steel and CoCrFeMnNi high entropy alloy. The X-ray photoelectron spectroscopic studies confirmed that the free surface in the as-cast alloy is in partially oxidized state. The same completely oxidizes after low-temperature surface oxidation. Such low temperature surface oxidation improves pitting corrosion resistance in AlCuFeMn alloy due to increased metal/oxide layer resistance. The electrochemical impedance spectroscopy tests coupled with microscopy confirmed that the principal corrosion mechanisms in the alloy are of the uniform and pitting type. The energy dispersive spectroscopy experiments indicate that a copper oxide enriched layer is formed on the surface oxidized specimen during corrosion.

There is a continuing demand for the development of fast, sensitive and reliable sensors for applications in harsh industrial environments. Gas sensors are finding great importance in fuel and energy sectors. Monitoring and control of combustion related emissions result in efficient use of fuels and subsequent energy savings. Microelectronic gas sensors have advantages like small size, low power combustion, and possibility of in situ control and monitoring. These gas sensors are commonly employed in fire detectors, emission control system, CO 2 operated enhanced geothermal system (EGS), supercritical water systems, organic rankine cycles used in binary power plants, high temperature gas-reactors in next-generation nuclear power plants and in gas processing. Packaging of microelectronic devices is equally important to the development practice. Input/Output connections are fabricated on these systems during this process. Thermo-mechanically strong lead attachments on sensor devices are necessary for high temperature applications. The conventional joining techniques like soldering, wire bonding, flip chip bonding and lead welding show failure in high temperature operative microelectronic systems. Present work is focused on the development and characterization of Pb free packaging of Pt micro-heaters, a main functionary of the gas sensors. Thick film Pt heater printed on ceramics substrate has been interconnected to Cu metal using Indium interlayer. The thermal and mechanical strengths of the interconnect specimen are determined and analyzed. The ultimate tensile strength (UTS) and ultimate shear strength (USS) values are plotted for different reaction parameters. The isothermal solidification morphology and crystallography are examined and discussed. The tests of thermal shock, pressure, operating life and vibration have been performed in an environmental lab to predict the compatibility of the packaging for deployment in harsh environments.

This paper presents the dynamic equation of a laser pulse in the human crystalline lens when plasma generation by a laser, the nonlinearity due to Kerr effect and the gradient index (GRIN) structure are simultaneously taken into account. Plasma generation affects beam propagation mainly on account of two factors. Firstly, because of the electron heavy particles collisions in the plasma, laser energy is absorbed and hence the laser beam gets attenuated. Secondly, plasma electrons also contribute to the nonlinearity. Therefore, laser beam propagation in the crystalline lens with plasma becomes a complex process. For typical lens and laser parameters, the effect of changing the plasma parameters on beam dynamics is studied here. It is found that the laser power has to be increased by a factor around 3 as compared to without plasma, to cause self-focusing of the laser beam in the lens.

This paper presents a model for excitation of electron plasma wave and resulting stimulated Raman scattering due to presence of a laser beam carrying null intensity in center (hollow Gaussian beam) in a collisionless plasma. We have studied the self-focusing of the hollow Gaussian beam and its effect on back stimulated Raman scattering process in the presence of ponderomotive nonlinearity. To understand the nature of propagation of the hollow Gaussian beam, electron plasma wave and back reflectivity, a paraxial-ray approximation has been invoked. It is predicted that self-focusing and back reflectivity reduces for higher order of hollow Gaussian beam.

Among the various alternative fuels, biodiesel is emerging as a promising choice for compression ignition engines due to its renewable nature and superior emission characteristics. The experimental investigations conducted by various researchers on variety of biodiesel fuels show a wide variation in engine performance and emission characteristics. The lack of correlations predicting various physical properties of biodiesel fuels derived from different feed stocks is posing a serious limitation to the combustion modelers. The present study attempts to evolve a comprehensive methodology for estimating the properties of biodiesel fuels based on their composition and chemical structure. � 2010 Elsevier Ltd. All rights reserved.

The increased focus on alternative fuels research in the recent years are mainly driven by escalating crude oil prices, stringent emission norms and the concern on clean environment. The processed form of vegetable oil (biodiesel) has emerged as a potential substitute for diesel fuel on account of its renewable source and lesser emissions. The experimental work reported here has been carried out on a turbocharged, direct injection, multi-cylinder truck diesel engine fitted with mechanical distributor type fuel injection pump using biodiesel-methanol blend and neat karanji oil derived biodiesel under constant speed and varying load conditions without altering injection timings. The results of the experimental investigation indicate that the ignition delay for biodiesel-methanol blend is slightly higher as compared to neat biodiesel and the maximum increase is limited to 1 deg. CA. The maximum rate of pressure rise follow a trend of the ignition delay variations at these operating conditions. However, the peak cylinder pressure and peak energy release rate decreases for biodiesel-methanol blend. In general, a delayed start of combustion and lower combustion duration are observed for biodiesel-methanol blend compared to neat biodiesel fuel. A maximum thermal efficiency increase of 4.2% due to 10% methanol addition in the biodiesel is seen at 80% load and 16.67 s-1 engine speed. The unburnt hydrocarbon and carbon monoxide emissions are slightly higher for the methanol blend compared to neat biodiesel at low load conditions whereas at higher load conditions unburnt hydrocarbon emissions are comparable for the two fuels and carbon monoxide emissions decrease significantly for the methanol blend. A significant reduction in nitric oxide and smoke emissions are observed with the biodiesel-methanol blend investigated. � 2010 Elsevier Ltd.

This paper presents an investigation of the excitation of a Tera hertz (THz) radiation by nonlinear interaction of a circularly polarized high power laser beam and density ripple in collisionless magneto plasma. The ponderomotive force due to the nonlinear interaction between the laser and density ripple generates a nonlinear current at a difference frequency. If the appropriate phase matching conditions are satisfied and the frequency of the ripple is appropriate, then this difference frequency can be brought in the THz range. Filamentation (self focusing) of a circularly polarized beam propagating along the direction of ambient magnetic field in plasma is first investigated within paraxial ray approximation. The beam gets focused when the initial power of the laser beam is greater than its critical power. Resulting localized beam couples with the pre-existing density ripple to produce a nonlinear current driving the THz radiation. Analytical expressions for the beam width of the laser beam, electric vector of the THz wave have been obtained. By changing the strength of the magnetic field, one can enhance or suppress the THz emission. For typical laser beam and plasma parameters with the incident laser power flux = 1014 W/cm2, laser beam radius (r0) = 40 µm, laser frequency (ω0) = 1014 rad/s and plasma density (n0) = 3 × 1018 cm−3, normalized ripple density amplitude (μ) = 0.3, the produced THz emission can be at the level of Giga watt in power.

Suitability of vegetable oil as an alternative to diesel fuel in compression ignition engines has become attractive, and research in this area has gained momentum because of concerns on energy security, high oil prices, and increased emphasis on clean environment. The experimental work reported here has been carried out on a turbocharged direct-injection multicylinder truck diesel engine using diesel fuel and jatropha methyl ester (JME)-diesel blends. The results of the experimental investigation indicate that an increase in JME quantity in the blend slightly advances the dynamic fuel injection timing and lowers the ignition delay compared with the diesel fuel. A maximum rise in peak pressure limited to 6.5 per cent is observed for fuel blends up to 40 per cent JME for part-load (up to about 50 per cent load) operations. However, for a higher-JME blend, the peak pressures decrease at higher loads remained within 4.5 per cent. With increasing proportion of JME in the blend, the peak pressure occurrence slightly advances and the maximum rate of pressure rise, combustion duration, and exhaust gas temperature decrease by 9 per cent, 15 per cent and 17 per cent respectively. Although the changes in brake thermal efficiencies for 20 per cent and 40 per cent JME blends compared with diesel fuel remain insignificant, the 60 per cent JME blend showed about 2.7 per cent improvement in the brake thermal efficiency. In general, it is observed that the overall performance and combustion characteristics of the engine do not alter significantly for 20 per cent and 40 per cent JME blends but show an improvement over diesel performance when fuelled with 60 per cent JME blend.

Environmental degradation and depleting oil reserves are matters of great concern round the globe. Developing countries like India depend heavily on oil import. Diesel being the main transport fuel in India, finding a suitable alternative to diesel is an urgent need. Jatropha based bio-diesel (JBD) is a non-edible, renewable fuel suitable for diesel engines and is receiving increasing attention in India because of its potential to generate large-scale employment and relatively low environmental degradation. Diesel engines running on JBD are found to emit higher oxides of nitrogen, NOx. HOT EGR, a low cost technique of exhaust gas recirculation, is effectively used in this work to overcome this environmental penalty. Practical problems faced while using a COOLED EGR system are avoided with HOT EGR. Results indicated higher nitric oxide (NO) emissions when a single cylinder diesel engine was fuelled with JBD, without EGR. NO emissions were reduced when the engine was operated under HOT EGR levels of 5-25%. However, EGR level was optimized as 15% based on adequate reduction in NO emissions, minimum possible smoke, CO, HC emissions and reasonable brake thermal efficiency. Smoke emissions of JBD in the higher load region were lower than diesel, irrespective of the EGR levels. However, smoke emission was higher in the lower load region. CO and HC emissions were found to be lower for JBD irrespective of EGR levels. Combustion parameters were found to be comparable for both fuels. � 2006 Elsevier Ltd. All rights reserved.

This paper presents the performance of the human crystalline lens having gradient index (GRIN) structure in the presence of a moderate power laser pulse. Nonlinear dynamical equations have been set-up governing the laser pulse propagation in the lens by taking into account the nonlinearity introduced by the laser pulse. Semi-analytical results have been obtained by using the paraxial ray approximation when GRIN and nonlinearity effects are simultaneously present. Performance of the lens has been analyzed in two explicit cases. In the first case, only the GRIN structure is considered while in the second case the nonlinearity and the GRIN both are considered. A moderate power laser pulse can be used for self-focusing in the crystalline lens when GRIN effects alone are not sufficient to focus the laser pulse in the crystalline lens.

Aluminum, a known neurotoxic substance, has been suggested as a possible contributing factor in the pathogenesis of Alzheimer's disease. Ground-water pollution by aluminum has been recently reported. In the current study groups of 5 male BALB/c mice were administered aluminum ammonium sulfate in drinking water ad libitum at 0, 5, 25, and 125 mg/L aluminum for 4 weeks. At the termination of aluminum exposure, their brains were removed and dissected into cerebrum, cerebellum, medulla oblongata, midbrain, corpus striatum, and hypothalamus. The concentration of norepinephrine (NE), dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA), were determined in each brain area. DA, DOPAC, and HVA levels were lower in the hypothalamus of aluminum-treated mice, most notably in the low-dose group, as compared with control. No marked alterations in NE, 5-HT, and 5-HIAA levels were detected in any brain region. Changes in the concentration of DA and its metabolites measured in the hypothalamus suggest an inhibition of DA synthesis by aluminum.

Channeling dips for 7.6 MeV He ions in YBa 2 Cu 3 O 7− x have been measured for all constituents to investigate possible anomalies in thermal vibrations near the transition to superconductivity. Quantitative agreement with simulations is obtained for all the dips with a single set of structural parameters. Angular scans for crystal temperatures in the range 30–220 K confirm the presence of an anomaly at T c for the width of CuYBa backscattering dips, which can be interpreted as a freeze-out of Cu vibrations at the transition to superconductivity. A detailed temperature scan reveals for the first time that the change in width takes place over a temperature interval of ∼15 K below the transition temperature, in agreement with recent EXAFS measurements of relative Y–Cu vibrations. Our data for oxygen are not conclusive but may indicate a similar small anomaly.

In order to obtain an enhancement of low field magnetoresistance (MR) in Nd/sub 0.7/Sr/sub 0.3/MnO/sub 3/ (NSMO) films, two kinds of superconducting flux focusing devices made of YBa/sub 2/Cu/sub 3/O/sub 7/ (YBCO) have been fabricated. In the superconducting state, YBCO expels magnetic flux from its interior and focuses the magnetic flux on a bridge of NSMO film. Using such a magnetic "lens", at temperatures below 77 K, /spl sim/900% enhancement in MR was observed. This corresponds to more than 15% change in the MR of NSMO in the presence of a couple of hundred Gauss. In order to successfully integrate high-T/sub c/ superconductivity with the magnetoresistive effect, bilayers of YBCO/NSMO were in situ deposited on (100) LaAlO/sub 3/ substrates by pulsed laser deposition so that the peak resistance temperature (T/sub p/) of NSMO was below the superconducting transition temperature (T/sub c/) of YBCO. X-ray diffraction and Rutherford Backscattering Spectroscopy (RBS) measurements provide evidence of epitaxial growth of YBCO/NSMO heterostructures.

Sr/sub 2/RuO/sub 4/ is the only known layered perovskite that is free of copper, yet superconducting. Its low metallic resistivity and excellent lattice match with YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// make it an attractive candidate for use as conductive electrodes to YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//-based superconducting devices or as a normal metal in YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//-based SNS junctions. We have determined optimal deposition conditions for growth of single-domain epitaxial films of Sr/sub 2/RuO/sub 4/. Films with excellent crystallinity are readily grown at substrate temperatures exceeding 1000/spl deg/C at low pressures. At lower temperatures and higher pressures, films predominantly consist of the SrRuO/sub 3/ phase. Resistivity versus temperature measurements reveal that the as-grown Sr/sub 2/RuO/sub 4/ films are metallic, but not superconducting. Epitaxial YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta///Sr/sub 2/RuO/sub 4/ heterostructures have also been grown. X-ray and resistivity measurements show that the YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// films are of high quality.

Pt/Pb(Zr/sub 0.5/Ti/sub 0.5/)O/sub 3//YBa/sub 2/Cu/sub 3/O/sub 7/ (Pt/PZT/YBCO) heterostructures were made by pulsed laser deposition on (100) SrTiO/sub 3/ or (100) LaSrGaO/sub 4/ substrates for studies of ferroelectric field effects in high-T/sub c/ superconducting thin films. X-ray diffraction data, including /spl Phi/ scans, indicated that the PZT layer grew with c-axis orientation epitaxially on top of the YBCO layers. Polarization measurements at room temperature and 77 K showed similar hysteretic loops in the PZT layer. The remanent polarization field can induce as many as 10/sup 14/ carriers/cm/sup 2/ in the bottom superconducting channel at the interface. Both c-axis and in-plane-aligned a-axis-oriented YBCO films, typically exhibiting zero resistance transition temperature of /spl sim/85 K, were used as superconducting channels. By polarizing the PZT film, a 2-5% change in both the channel resistance and the critical current at 77-85 K was obtained in /spl sim/100 nm thick films. Device operation at microsecond speeds was observed.

By using the intense 16 O( 4 He, 4 He) elastic scattering resonance at 7.3–7.6 MeV, we have been able to extend the earlier investigations [1–4] of the channeling behaviour in YBa 2 Cu 3 O 7 − x around T c to include the backscattering signal from the oxygen sublattice. We have also developed a computer code enabling us to simulate c -axis angular scans for each atomic sublattice as a function of depth. These simulations reproduce very well the observed oxygen angular scans at 70 K (below T c ) and at 100 K (above T c ), with magnitudes of the thermal vibrational amplitudes which are in reasonable agreement with neutron-scattering data. Concerning small changes at T c , as observed in earlier channeling investigations, we have concentrated on the analysis of oxygen scans. A direct fit of the simulations to our measurements indicates an increase above T c of about 0.5 pm in the amplitude of oxygen vibrations perpendicular to the c -axis, or a smaller increase combined with a static displacement. Within the estimated uncertainties, this result is consistent with the neutron data. The oxygen (O4) atoms on the CuO rows along the c -axis contribute a wider channeling dip than the other oxygen atoms (O1, O2 and O3), which form pure oxygen rows along the c -axis. Hence, the magnitude of the O4 vibrational amplitude is important only for the yield in the shoulders of the combined oxygen dip and it can be determined independently from the fit to measurements. Our results do not confirm the large change of this amplitude at T c suggested by Remmel et al. [8].

Realisation of good quality diamond and diamond-like carbon (DLC) coatings on different substrates is of considerable importance in the context of their wide variety of applications. The results of our study of the dependence of the film quality on substrate surfaces and barrier layers are reported. The mechanism of CVD diamond deposition on Si(100) with barrier layers of epitaxial Y-ZrO 2 and C-N films is discussed. The film growth on transition metal surfaces in the context of the surface chemistry is also reported. Good quality (high wear resistance and high optical transmittance) DLC coating has been achieved on float glass. The effect of the initial DLC layer on further film growth is discussed.

In the present paper, the parametric decay instability of an extraordinary electromagnetic wave (X-wave) into an electron Bernstein wave (EBW) and an electrostatic whistler wave (W-wave) has been studied. Expressions are derived for homogeneous threshold, growth rate, and convective threshold for this instability. The relevance of the present parametric process has been pointed out to explain the generation of whistler mode radiations in the SL-2 experiment, ionospheric modification experiment, in the polar cusp region of the magnetosphere, as well as during intense electron cyclotron resonance heating in the MTX tokamak.