Starter culture technology: fermented foods

Practice of starter culture is an age old practice but without any scientific basis. With the awareness of need of microbial inoculations for regulation of fermentation process for quality production of desired quality foods innovative development have taken place. Development of new strains for elite strain which can improve the quality, stability, flavor, texture and phage resistant starter cultures are raised on a variety of medium depending organism as well as product to be developed. The starter culture are classified based on their composition growth requirement and methods of propagation. These starter cultures are preserved by different methods they can be available all the time. Though commercial strains are available their isolation and subsequent improvement through different genetical methods are desirable to get a novel strains with unique properties of commercial importance. Among different microorganisms such as lactic acid bacteria, yeast (Saccharomyce cerevisae, Penicillium camembertii, P. roquefortii) and Rhyzopus (R. oryzae, R. sojae) are extensively used for this purpose. Perfection in the preparation, storage and propagation need to be improved. Mixed starters with symbiotic activity have to be formulated

Spatial and temporal characterization of a Bessel beam produced using a conical mirror

We experimentally analyze a Bessel beam produced with a conical mirror, paying particular attention to its superluminal and diffraction-free properties. We spatially characterized the beam in the radial and on-axis dimensions, and verified that the central peak does not spread over a propagation distance of 73 cm. In addition, we measured the superluminal phase and group velocities of the beam in free space. Both spatial and temporal measurements show good agreement with the theoretical predictions.Comment: 5 pages, 6 figure

Noise temperature measurements for axion haloscope experiments at IBS/CAPP

The axion was first introduced as a consequence of the Peccei-Quinn mechanism to solve the CP problem in strong interactions of particle physics and is a well motivated cold dark matter candidate. This particle is expected to interact extremely weakly with matter and its mass is expected to lie in $\mu$eV range with the corresponding frequency roughly in GHz range. In 1983 P. Sikivie proposed a detection scheme, so called axion haloscope, where axions resonantly convert to photons in a tunable microwave cavity permeated by a strong magnetic field. A major source of the experimental noise is attributed to added noise by RF amplifiers, and thus precise understandings of amplifiers' noise is of importance. We present the measurements of noise temperatures of various low noise amplifiers broadly used for axion dark matter searches.Comment: 7 pages, 3 figure

Fermi surface of the colossal magnetoresistance perovskite La_{0.7}Sr_{0.3}MnO_{3}

Materials that exhibit colossal magnetoresistance (CMR) are currently the focus of an intense research effort, driven by the technological applications that their sensitivity lends them to. Using the angular correlation of photons from electron-positron annihilation, we present a first glimpse of the Fermi surface of a material that exhibits CMR, supported by ``virtual crystal'' electronic structure calculations. The Fermi surface is shown to be sufficiently cubic in nature that it is likely to support nesting.Comment: 5 pages, 5 PS figure

Appearance of Half-Metallicity in the Quaternary Heusler Alloys

I report systematic first-principle calculations of the quaternary Heusler alloys like Co$_2$[Cr$_{1-x}$Mn$_x$]Al, Co$_2$Mn[Al$_{1-x}$Sn$_x$] and [Fe$_{1-x}$Co$_x$]$_2$MnAl. I show that when the two limiting cases (x=0 or 1) correspond to a half-metallic compound, so do the intermediate cases. Moreover the total spin moment $M_t$ in $\mu_B$ scales linearly with the total number of valence electrons $Z_t$ (and thus with the concentration $x$) following the relation $M_t=Z_t-24$, independently of the origin of the extra valence electrons, confirming the Slater-Pauling behavior of the normal Heusler alloys. Finally I discuss in all cases the trends in the atomic projected DOSs and in the atomic spin moments.Comment: 4 pages, 3 figures, 2 Table