Method of characteristics and solution of DGLAP evolution equation in leading order (LO) and next to leading order (NLO) at small-x

In this paper the singlet and non-singlet structure functions have been obtained by solving Dokshitzer, Gribove, Lipatov, Alterelli, Parisi (DGLAP) evolution equations in leading order (LO) and next to leading order (NLO) at the small x limit. Here we have used a Taylor Series expansion and then the method of characteristics to solve the evolution equations. We have also calculated t and x-evolutions of deuteron structure function and the results are compared with the New Muon Collaboration (NMC) data.Comment: 16 pages including 7 figure

Plasmons in coupled bilayer structures

We calculate the collective charge density excitation dispersion and spectral weight in bilayer semiconductor structures {\it including effects of interlayer tunneling}. The out-of-phase plasmon mode (the ``acoustic'' plasmon) develops a long wavelength gap in the presence of tunneling with the gap being proportional to the square root (linear power) of the tunneling amplitude in the weak (strong) tunneling limit. The in-phase plasmon mode is qualitatively unaffected by tunneling. The predicted plasmon gap should be a useful tool for studying many-body effects.Comment: 10 pages, 6 figures. to appear in Phys. Rev. Let

Dissipationless transport in low density bilayer systems

In a bilayer electronic system the layer index may be viewed as the z-component of an isospin-1/2. An XY isospin-ordered ferromagnetic phase was observed in quantum Hall systems and is predicted to exist at zero magnetic field at low density. This phase is a superfluid for opposite currents in the two layers. At B=0 the system is gapless but superfluidity is not destroyed by weak disorder. In the quantum Hall case, weak disorder generates a random gauge field which probably does not destroy superfluidity. Experimental signatures include Coulomb drag and collective mode measurements.Comment: 4 pages, no figures, submitted to Phys. Rev. Let

Methods for the estimation of pyrazinamide and pyrazinoic acid in body fluids

zinoic acid in urine using an anion-exchange resin (Dowex-1) have been described. Recoveries were quantitative, and the sensitivity was 5 μg/ml for ail 3 estimations. In serum, pyrazinoic acid at a concentration of 50 μg/ml did not interfere with the estimation of pyrazinamide. In urine, pyrazinamide and pyrazinoic acid could be separated from each other and estimated even when the 2 compounds were present together at concentrations of 2000 μg/ml each

Climate Resilient Agriculture Experiences from NICRA Implementation in North Bank Plains Zone of Assam

Not AvailableClimate change impacts on agriculture are being witnessed all over the world, but countries like India are more vulnerable in view of the huge population dependent on agriculture, excessive pressure on natural resources and poor coping mechanisms. The warming trend in India over the past 100 years has indicated an increase of 0.60°C. The projected impacts are likely to further aggravate field fluctuations of many crops thus impacting food security. There are already evidences of negative impacts on yield of wheat and paddy in parts of India due to increased temperature, water stress and reduction in number of rainy days. Increased abnormalities in amount and distribution of rainfall has also been observed in North Bank Plains Zone (NBPZ) of Assam along with increase in numbers of wet spell driven flash floods and seasonal droughts in recent years. Planned adaption is essential to increase the resilience of agricultural production to climate change. Several improved agricultural practices evolved over time for diverse agroecological regions in India have potential to enhance climate change adaptation, if deployed prudently. Management practices that increase agricultural production under adverse climatic conditions also tend to support climate change adaptation because they increase resilience and reduce yield variability under variable climate and extreme events. Keeping this in view, National Innovations on Climate Resilient Agriculture was implemented under All India Coordinated Research Project for Dryland Agriculture, Biswanath Chariali centre on 2011in two selected villages of North Lakhimpur, Chamua and Ganakdoloni. The main aim of the project is to enhance resilience of Indian agriculture to climate change and climate variability through strategic research and technology demonstration. In this bulletin the authors have penned down the experiences gained from implementation of NICRA in NBPZ of Assam. It is hoped that the bulletin will be able to serve the purposes towards achieving its objectives and act as a benchmark study for the entire area. It is expected that the information contained in this bulletin will be exploited by the scientist of different disciplines and extension officials for making rational recommendation. The authors will remain ever grateful to Project Coordinator, (AICRPDA), CRIDA, Hyderabad and Director of Research (Agri), AAU for their guidance, encouragement and sincere support. The authors extend thankfulness to the fellow Scientists, Research Associates and other technical staff for their cooperation and help. The authors express their thankfulness to Sharada Offset, Biswanath Chariali for printing the report.Not Availabl

Hall state quantization in a rotating frame

We derive electromagnetomotive force fields for charged particles moving in a rotating Hall sample, satisfying a twofold U(1) gauge invariance principle. It is then argued that the phase coherence property of quantization of the line integral of total collective particle momentum into multiples of Planck's quantum of action is solely responsible for quantization in the Hall state. As a consequence, the height of the Hall quantization steps should remain invariant in a rapidly rotating Hall probe. Quantum Hall particle conductivities do not depend on charge and mass of the electron, and are quantized in units of the inverse of Planck's action quantum.Comment: 6 pages, accepted for publication in Europhysics Letter

Possible evidence of non-Fermi liquid behavior from quasi-one-dimensional indium nanowires

We report possible evidence of non-Fermi liquid (NFL) observed at room temperature from the quasi one-dimensional (1D) indium (In) nanowires self-assembled on Si(111)-7$\times$7 surface. Using high-resolution electron-energy-loss spectroscopy, we have measured energy and width dispersions of a low energy intrasubband plasmon excitation in the In nanowires. We observe the energy-momentum dispersion $\omega$(q) in the low q limit exactly as predicted by both NFL theory and the random-phase-approximation. The unusual non-analytic width dispersion $\zeta(q) \sim q^{\alpha}$ measured with an exponent ${\alpha}$=1.40$\pm$0.24, however, is understood only by the NFL theory. Such an abnormal width dispersion of low energy excitations may probe the NFL feature of a non-ideal 1D interacting electron system despite the significantly suppressed spin-charge separation ($\leq$40 meV).Comment: 11 pages and 4 figure

Quantum-Classical Crossover and Apparent Metal-Insulator Transition in a Weakly Interacting 2D Fermi Liquid

We report the observation of a parallel magnetic field induced metal-insulator transition (MIT) in a high-mobility two-dimensional electron gas (2DEG) for which spin and localization physics most likely play no major role. The high-mobility metallic phase at low field is consistent with the established Fermi liquid transport theory including phonon scattering, whereas the insulating phase at higher field shows a large negative temperature dependence at resistances much smaller than the quantum of resistance, $h/e^2$. We argue that this observation is a direct manifestation of a quantum-classical crossover arising predominantly from the magneto-orbital coupling between the finite width of the 2DEG and the in-plane magnetic field.Comment: 4 pages, 2 figure

Generalized survival in equilibrium step fluctuations

We investigate the dynamics of a generalized survival probability $S(t,R)$ defined with respect to an arbitrary reference level $R$ (rather than the average) in equilibrium step fluctuations. The exponential decay at large time scales of the generalized survival probability is numerically analyzed. $S(t,R)$ is shown to exhibit simple scaling behavior as a function of system-size $L$, sampling time $\delta t$, and the reference level $R$. The generalized survival time scale, $\tau_s(R)$, associated with $S(t,R)$ is shown to decay exponentially as a function of $R$.Comment: 4 pages, 2 figure

Contrasting Behavior of the 5/2 and 7/3 Fractional Quantum Hall Effect in a Tilted Field

Using a tilted field geometry, the effect of an in-plane magnetic field on the even denominator nu = 5/2 fractional quantum Hall state is studied. The energy gap of the nu = 5/2 state is found to collapse linearly with the in-plane magnetic field above ~0.5 T. In contrast, a strong enhancement of the gap is observed for the nu = 7/3 state. The radically distinct tilted-field behaviour between the two states is discussed in terms of Zeeman and magneto-orbital coupling within the context of the proposed Moore-Read pfaffian wavefunction for the 5/2 fractional quantum Hall effect