Assistance to farmer-managed irrigation system: Experiences from Nepal - Papers presented in the seminar on "Improving Farmer Managed Irrigation Systems: Experiences of different agencies and organizations" held on 27 June 1990

Farmer managed irrigation systems / Governmental interrelations / Development aid / Nepal

On the one-loop correction of "phi^4" theory in higher dimensions

We have considered phi^4 theory in higher dimensions. Using functional diagrammatic approach, we computed the one-loop correction to effective potential of the scalar field in five dimensions. It is shown that phi^4 theory can be regularised in five dimensions. Temperature dependent one-loop correction and critical temperature T_c are computed and T_c depends on the fundamental scale M of the theory. A brief discussion of symmetry restoration is also presented. The nature of phase transitions is examined and is of second orderComment: 8 pages, 5 figures. To appear in IJMP

Improved Detection Rates for Close Binaries Via Astrometric Observations of Gravitational Microlensing Events

In addition to constructing a Galactic matter mass function free from the bias induced by the hydrogen-burning limit, gravitational microlensing allows one to construct a mass function which is less affected by the problem of unresolved binaries (Gaudi & Gould). However, even with the method of microlensing, the photometric detection of binaries is limited to binary systems with relatively large separations of $b\gtrsim 0.4$ of their combined Einstein ring radius, and thus the mass function is still not totally free from the problem of unresolved binaries. In this paper, we show that by detecting distortions of the astrometric ellipse of a microlensing event with high precision instruments such as the {\it Space Interferometry Mission}, one can detect close binaries at a much higher rate than by the photometric method. We find that by astrometrically observing microlensing events, $\sim 50$ of binaries with separations of $0.1r_{\rm E}$ can be detected with the detection threshold of 3%. The proposed astrometric method is especially efficient at detecting very close binaries. With a detection threshold of 3% and a rate of 10%, one can astrometrically detect binaries with separations down to $\sim 0.01r_{\rm E}$.Comment: total 14 pages, including 5 Figures and no Table (For figure 1, please send a request mail to [email protected]), accepted to ApJ (Vol 525, 000), updated versio

Biodesulfurization of dibenzothiophene by Shewanella putrefaciens NCIMB 8768

The desulfurization ability of Shewanella putrefaciens strain NCIMB 8768 was studied and its activity profile was compared with the widely studied strain Rhodococcus erythropolis strain IGTS8. Dibenzothiophene (DBT) is a recalcitrant thiophenic component of fossil fuels especially among diesel blend stocks. DBT in basic salt medium (BSM) at a final concentration of 0.3, 0.6 and 0.9 mM was supplied to the microbes as the sole sulfur source. Experimental results showed that S. putrefaciens, similar to other biodesulfurization organisms, converted DBT to the end product 2-hydroxybiphenyl (HBP), as detected by the Gibbs assay and HPLC. Cells cultivated in medium containing 0.3 mM of DBT showed the highest desulfurization activity, with a maximum specific production rate 43.5 mmol/L of HBP

Seroprevalence Of Hepatitis-b Virus In Mid And Far Western Region In Nepal

Hepatitis B is significant health problems that might involve the late sequel of liver cirrhosis and hepatocellular carcinoma. The present study aimed to know the seroprevalence of hepatitis B virus (HBV) in mid and far western region in Nepal with various clinical conditions.This was a retrospective study conducted in mid and far western region in Nepal, which was performed in the Central Laboratory of Microbiology at Nepalgunj Medical College and Teaching Hospital, Banke, Nepal during the period of September 2010 to April 2012. The serum samples were tested for Hepatitis B surface Antigen (HBsAg) by Sandwich immunoassay. Total 7010 patients including 43.72% male and 56.28% female were tested for HBsAg. Of them, 135 were positive and 6875 were negative.In 135 positive cases 84 (62.22%) were male and 51 (37.77% )were female. In 6875 negative cases 2981 were male and 3894 were female. The seroprevalence rate of HBV was 1.93% in mid and far western region in Nepal. Seroprevalence of HBV seems to be higher in male then the female; it was 2.75% in male and 1.29% in female.The study revealed that the seroprevalence of HBV was alarmingly higher in such a population, which probably reflects a high background prevalence of HBV infections should be taken into consideration and Implementation of community-based preventive measures and improved strategies for safe blood supply might prove useful to decrease the seroprevalence

Bulk scalar field in DGP braneworld cosmology

We investigated the effects of bulk scalar field in the braneworld cosmological scenario. The Friedmann equations and acceleration condition in presence of the bulk scalar field for a zero tension brane and cosmological constant are studied. In DGP model the effective Einstein equation on the brane is obtained with bulk scalar field. The rescaled bulk scalar field on the brane in the DGP model behaves as an effective four dimensional field, thus standard type cosmology is recovered. In present study of the DGP model, the late-time accelerating phase of the universe can be explained .Comment: 10 pages, to appear in JCA

Second Backbend in the Mass A ~ 180 Region

Within the framework of selfconsistent cranked Hartree-Fock- Bogoliubov theory(one-dimensional) we predict second backbend in the yrast line of Os-182 at $I \approx 40$, which is even sharper than the first one observed experimentally at $I \approx 14$. Around such a high spin the structure becomes multi-quasiparticle type, but the main source of this strong discontinuity is a sudden large alignment of i_13/2 proton orbitals along the rotation axis followed soon by the alignment of j_15/2 neutron orbitals. This leads to drastic structural changes at such high spins. When experimentally confirmed, this will be observed for the first time in this mass region, and will be at the highest spin so far.Comment: 13 pages, 4 ps figure

A new class of two-channel biorthogonal filter banks and wavelet bases

We propose a novel framework for a new class of two-channel biorthogonal filter banks. The framework covers two useful subclasses: i) causal stable IIR filter banks. ii) linear phase FIR filter banks. There exists a very efficient structurally perfect reconstruction implementation for such a class. Filter banks of high frequency selectivity can be achieved by using the proposed framework with low complexity. The properties of such a class are discussed in detail. The design of the analysis/synthesis systems reduces to the design of a single transfer function. Very simple design methods are given both for FIR and IIR cases. Zeros of arbitrary multiplicity at aliasing frequency can be easily imposed, for the purpose of generating wavelets with regularity property. In the IIR case, two new classes of IIR maximally flat filters different from Butterworth filters are introduced. The filter coefficients are given in closed form. The wavelet bases corresponding to the biorthogonal systems are generated. the authors also provide a novel mapping of the proposed 1-D framework into 2-D. The mapping preserves the following: i) perfect reconstruction; ii) stability in the IIR case; iii) linear phase in the FIR case; iv) zeros at aliasing frequency; v) frequency characteristic of the filters

Experimental investigation of some aspects of insect-like flapping flight aerodynamics for application to micro air vehicles

Insect-like flapping flight offers a power-efficient and highly manoeuvrable basis for micro air vehicles for indoor applications. Some aspects of the aerodynamics associated with the sweeping phase of insect wing kinematics are examined by making particle image velocimetry measurements on a rotating wing immersed in a tank of seeded water. The work is motivated by the paucity of data with quantified error on insect-like flapping flight, and aims to fill this gap by providing a detailed description of the experimental setup, quantifying the uncertainties in the measurements and explaining the results. The experiments are carried out at two Reynolds numbers-500 and 15,000-accounting for scales pertaining to many insects and future flapping-wing micro air vehicles, respectively. The results from the experiments are used to describe prominent flow features, and Reynolds number-related differences are highlighted. In particular, the behaviour of the leading-edge vortex at these Reynolds numbers is studied and the presence of Kelvin-Helmholtz instability observed at the higher Reynolds number in computational fluid dynamics calculations is also verified