[en] Considering the current scenario of petroleum fuels, it has been observed that, they will last for few years from now. On the other hand, the ever increasing cost of a gasoline fuels and their related adverse effects on environment caught the attention of researchers to find a supplementary source. For commercial fuels, supplementary source is not about replacing the entire fuel, instead enhancing efficiency by simply making use of it in lesser amount. From the recent research that has been carried out, focus on the use of Hydrogen rich gas as a supplementary source of fuel has increased. But the problem related to the storage of hydrogen gas confines the application of pure hydrogen in petrol engine. Using oxy-hydrogen gas (HHO) generator the difficulties of storing the hydrogen have overcome up to a certain limit. The present study highlights on performance evaluation of conventional petrol engine by using HHO gas as a supplementary fuel. HHO gas was generated from the electrolysis of water. KOH solution of 3 Molar concentration was used which act as a catalyst and accelerates the rate of generation of HHO gas. Quantity of gas to be supplied to the engine was controlled by varying amount of current. It was observed that, engine performance was improved on the introduction of HHO gas. (paper)

[en] A search was made for nucleon decays which result in multiple delayed muon decays using the HPW water Cerenkov detector. No contained events were found, which is consistent with the expected neutrino background of 0.7±0.2 events. Lower lifetime limits are calculated for eleven proton decay modes and five bound neutron decay modes, ranging from 2x10³⁰ yr to 1x10³¹ yr. (orig.)

[en] We have presented the Strong Lensing Legacy Survey – ARCS (SARCS) sample compiled from the T0006 data release of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) covering a total non-overlapping area of 159 deg². We have adopted a semi-automatic method to find gravitational arcs in the survey that makes use of an arc-finding algorithm. The SARCS sample consists of 127 lens candidates, out of which, 54 systems are promising lenses. From our sample, we have detected a systematic alignment of the giant arcs with the major axis of the baryonic component of the putative lens in concordance with previous studies. This alignment is also observed for all arcs in the sample and does not vary significantly with increasing arc radius. Owing to the large area and depth of the CFHTLS, we have found the largest sample of lenses probing mass scales that are intermediate to cluster and galaxy lenses for the first time. We have compared the observed image separation distribution (ISD) of our arcs with theoretical models. A two-component density profile for the lenses, which accounts for both the central galaxy and the dark matter component is required by the data to explain the observed ISD. Unfortunately, current levels of uncertainties and degeneracies accommodate models both with and without adiabatic contraction. We have also shown the effects of changing parameters of the model that predict the ISD and that a larger lens sample might constrain relations such as the concentration-mass relation, mass-luminosity relation and the faint-end slope of the luminosity function

[en] We report 10 lens candidates in the Extended Chandra Deep Field South from the GEMS survey. Nine of the systems are new detections and only one of the candidates is a known lens system. For the most promising five systems including the known lens system, we present results from preliminary lens mass modeling, which tests if the candidates are plausible lens systems. Photometric redshifts of the candidate lens galaxies are obtained from the COMBO-17 galaxy catalog. Stellar masses of the candidate lens galaxies within the Einstein radius are obtained by using the z-band luminosity and the V-z color-based stellar mass-to-light ratios. As expected, the lensing masses are found to be larger than the stellar masses of the candidate lens galaxies. These candidates have similar dark matter fractions as compared to lenses in SLACS and COSMOS. They also roughly follow the halo-mass-stellar-mass relation predicted by the subhalo abundance matching technique. One of the candidate lens galaxies qualifies as a luminous infrared galaxy and may not be a true lens because the arc-like feature in the system is likely to be an active region of star formation in the candidate lens galaxy. Among the five best candidates, one is a confirmed lens system, one is likely a lens system, two are less likely to be lenses, and the status of one of the candidates is ambiguous. Spectroscopic follow-up of these systems is still required to confirm lensing and/or for more accurate determination of the lens masses and mass density profiles.

[en] We present the Strong Lensing Legacy Survey-ARCS (SARCS) sample compiled from the final T0006 data release of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) covering a total non-overlapping area of 159 deg². We adopt a semi-automatic method to find gravitational arcs in the survey that makes use of an arc-finding algorithm. The candidate list is pruned by visual inspection and ranking to form the final SARCS sample. This list also includes some serendipitously discovered lens candidates which the automated algorithm did not detect. The SARCS sample consists of 127 lens candidates which span arc radii ∼2''-18'' within the unmasked area of ∼150 deg². Within the sample, 54 systems are promising lenses among which, we find 12 giant arcs (length-to-width ratio ≥8). We also find two radial arc candidates in SL2SJ141447+544704. From our sample, we detect a systematic alignment of the giant arcs with the major axis of the baryonic component of the putative lens in concordance with previous studies. This alignment is also observed for all arcs in the sample and does not vary significantly with increasing arc radius. The mean values of the photometric redshift distributions of lenses corresponding to the giant arcs and all arcs sample are at z ∼ 0.6. Owing to the large area and depth of the CFHTLS, we find the largest sample of lenses probing mass scales that are intermediate to cluster and galaxy lenses for the first time. We compare the observed image separation distribution (ISD) of our arcs with theoretical models. A two-component density profile for the lenses which accounts for both the central galaxy and the dark matter component is required by the data to explain the observed ISD. Unfortunately, current levels of uncertainties and degeneracies accommodate models both with and without adiabatic contraction. We also show the effects of changing parameters of the model that predict the ISD and that a larger lens sample might constrain relations such as the concentration-mass relation, mass-luminosity relation, and the faint-end slope of the luminosity function.

[en] We have presented a method that uses observations of galaxies to simultaneously constrain cosmological parameters, and the galaxy-dark matter connection (aka halo occupation statistics). The latter describes how galaxies are distributed over dark matter haloes, and is an imprint of the poorly understood physics of galaxy formation. A generic problem of using galaxies to constrain cosmology is that galaxies are a biased tracer of the mass distribution, and this bias is generally unknown. The great advantage of simultaneously constraining cosmology and halo occupation statistics is that this effectively allows cosmological constraints marginalized over the uncertainties regarding galaxy bias. We have used a combination of the analytical halo model and the conditional luminosity function to describe the galaxy-dark matter connection, which we have used to model the abundance, clustering and galaxy-galaxy lensing properties of the galaxy population. We have used a Fisher matrix analysis to gauge the complementarity of these different observables, and presented some preliminary results from an analysis based on data from the Sloan Digital Sky Survey. Our results are complementary to and perfectly consistent with the results from the WMAP mission, strengthening the case for a true 'concordance' cosmology

[en] We report the results of searches for strong gravitational lens systems in the Dark Energy Survey (DES) Science Verification and Year 1 observations. The Science Verification data span approximately 250 sq. deg. with a median i -band limiting magnitude for extended objects (10 σ ) of 23.0. The Year 1 data span approximately 2000 sq. deg. and have an i -band limiting magnitude for extended objects (10 σ ) of 22.9. As these data sets are both wide and deep, they are particularly useful for identifying strong gravitational lens candidates. Potential strong gravitational lens candidate systems were initially identified based on a color and magnitude selection in the DES object catalogs or because the system is at the location of a previously identified galaxy cluster. Cutout images of potential candidates were then visually scanned using an object viewer and numerically ranked according to whether or not we judged them to be likely strong gravitational lens systems. Having scanned nearly 400,000 cutouts, we present 374 candidate strong lens systems, of which 348 are identified for the first time. We provide the R.A. and decl., the magnitudes and photometric properties of the lens and source objects, and the distance (radius) of the source(s) from the lens center for each system.