Karakteristik Endapan Cairan Rumen Sapi Asal Rumah Potong Hewan Sebagai Feed Supplement

The aims of this experiment were to identify and characterize of sediment product from cattle rumen liquor as a source of amino acids, minerals and vitamins. The sediment were obtained as pellets upon centrifugation of rumen liquor at 10,000 g for 10 minutes for collection of supernatant. The sediment were evaluated for amino acids, minerals and vitamins composition and chararacterized for the pH, solubility of dry matter, specific density, bulk and compacted bulk densities and angle of response. Result of the experiment showed that sediment contained higher minerals: Na, K and Fe compared with the commercial premix, but lower in B-vitamins and amino acids. The composition of mineral Na, K, and Fe from rumen liquor of local cattle was 13.47%, 7.73 % and 14.52 %, while Na, K, and Fe from rumen liquor of imported cattle was 18.40%, 10.25%, and 14.52% respectively. The sediment had pH range from 10.01-10.03, the dry matter solubility was 35.5% up to 39.1%. The sediment from imported cattle had higher specific density, bulk and compacted bulk densities and angle of response than that of local cattle. It is concluded that sediment from cattle rumen liquor contained high Na, K and Fe, low amino acids and B-vitamin, high pH and low solubility

Optical observations of the bright long duration peculiar GRB 021004 afterglow

The CCD magnitudes in Johnson $B,V$ and Cousins $R$ and $I$ photometric passbands are determined for the bright long duration GRB 021004 afterglow from 2002 October 4 to 16 starting $\sim$ 3 hours after the $\gamma-$ray burst. Light curves of the afterglow emission in $B$,$V$,$R$ and $I$ passbands are obtained by combining these measurements with other published data. The earliest optical emission appears to originate in a revese shock. Flux decay of the afterglow shows a very uncommon variation relative to other well-observed GRBs. Rapid light variations, especially during early times ($\Delta t < 2$ days) is superposed on an underlying broken power law decay typical of a jetted afterglow. The flux decay constants at early and late times derived from least square fits to the light curve are $0.99\pm0.05$ and $2.0\pm0.2$ respectively, with a jet break at around 7 day. Comparison with a standard fireball model indicates a total extinction of $E(B-V)=0.20$ mag in the direction of the burst. Our low-resolution spectra corrected for this extinction provide a spectral slope $\beta = 0.6\pm0.02$. This value and the flux decay constants agree well with the electron energy index $p\sim 2.27$ used in the model. The derived jet opening angle of about $7^{\circ}$ implies a total emitted gamma-ray energy $E_{\gamma} = 3.5\times10^{50}$ erg at a cosmological distance of about 20 Gpc. Multiwavelength observations indicate association of this GRB with a star forming region, supporting the case for collapsar origin of long duration GRBs.Comment: 19 pages, 3 figures, BASI, 31, 1

General mechanism for amplitude death in coupled systems

We introduce a general mechanism for amplitude death in coupled synchronizable dynamical systems. It is known that when two systems are coupled directly, they can synchronize under suitable conditions. When an indirect feedback coupling through an environment or an external system is introduced in them, it is found to induce a tendency for anti-synchronization. We show that, for sufficient strengths, these two competing effects can lead to amplitude death. We provide a general stability analysis that gives the threshold values for onset of amplitude death. We study in detail the nature of the transition to death in several specific cases and find that the transitions can be of two types - continuous and discontinuous. By choosing a variety of dynamics for example, periodic, chaotic, hyper chaotic, and time-delay systems, we illustrate that this mechanism is quite general and works for different types of direct coupling, such as diffusive, replacement, and synaptic couplings and for different damped dynamics of the environment.Comment: 12 pages, 17 figure

Impact of sodium ion impregnation on the photocatalytic hydrogen evolution activities of anatase/rutile mixed phase TiO₂ nanomaterials

1159-1163Sodium ion impregnated anatase/rutile mixed phase TiO2 material has been synthesised by sol-gel method and characterised for understanding the solar hydrogen production activities. The presence of sodium ion can influence the crystallinity, crystallite size and photocatalytic efficiency of mixed phase TiO2. The hydrogen evolution activities of the sodium impregnated TiO2 and bare TiO2 materials are compared by calculating the yield of H2 gas evolved from the dissociation of H2O. Even though the presence of rutile/anatase mixed phase TiO2 is suitable for hydrogen evolution under UV/visible light irradiation, it is found that bare TiO2 can act as a good catalyst and gives a hydrogen evolution value of 134 μmol after 5 h of irradiation from 20 mg of the catalyst. However, the sodium impregnated TiO2 material show lower hydrogen evolution as compared to bare TiO2 and a value of 34 μmol under similar experimental condition. The variation in hydrogen evolution may be exhibited due to high crystallinity, large crystallite size and higher percentage of the rutile phase in bare TiO2 compared to sodium impregnated TiO2 material. This study will be helpful for understanding the effect of alkali metal ion in metal oxide semiconductor and further understanding their detrimental effect on photocatalytic water splitting and related applications

Comprehensive multi-wavelength modelling of the afterglow of GRB050525A

The Swift era has posed a challenge to the standard blast-wave model of Gamma Ray Burst (GRB) afterglows. The key observational features expected within the model are rarely observed, such as the achromatic steepening (`jet-break') of the light curves. The observed afterglow light curves showcase additional complex features requiring modifications within the standard model. Here we present optical/NIR observations, millimeter upper limits and comprehensive broadband modelling of the afterglow of the bright GRB 0505025A, detected by Swift. This afterglow cannot be explained by the simplistic form of the standard blast-wave model. We attempt modelling the multi-wavelength light curves using (i) a forward-reverse shock model, (ii) a two-component outflow model and (iii) blast-wave model with a wind termination shock. The forward-reverse shock model cannot explain the evolution of the afterglow. The two component model is able to explain the average behaviour of the afterglow very well but cannot reproduce the fluctuations in the early X-ray light curve. The wind termination shock model reproduces the early light curves well but deviates from the global behaviour of the late-time afterglow.Comment: 20 pages, 6 figures, accepted for publication in MNRA

Performance studies of the Belle II Silicon Vertex Detector with data taken at the DESY test beam in April 2016

Belle II is a multipurpose detector currently under construction which will be operated at the next generation B-factory SuberKEKB in Japan. Its main devices for the vertex reconstruction are the Silicon Vertex Detector (SVD) and the Pixel Detector (PXD). In April 2016 a sector of the Belle II SVD and PXD have been tested in a beam of high energetic electrons at the test beam facility at DESY Hamburg (Germany). We report here the results for the hit efficiency estimation and the measurement of the resolution for the Belle II silicon vertex etector. We find that the hit efficiencies are on average above 99.5% and that the measured resolution is within the expectations