2,395 research outputs found
Transport in bacteriophage P22-infected Salmonella typhimurium
There was rapid efflux of L-leucine, L-phenylalanine, and α-methyl-D-glucoside after infection of Salmonella typhimurium with the clear plaque mutant C1 of phage P22. The efflux was similar to that observed with cyanide or arsenate treatment except that there was partial recovery in the case of phage infection and almost complete recovery under the condition of lysogeny. There was no efflux after infection with the temperature-sensitive mutant ts16C1 at nonpermissive temperature. Superinfection of superinfection exclusion negative lysogen (sie A - sie B-) with C1 led to efflux, whereas the efflux was much less on superinfection of sie A+ Sie B+ lysogen. These results indicate that an effective injection process is enough to cause depression in the cellular transport processes
Metal nanoplasmas as bright sources of hard x-ray pulses
We report significant enhancements in light coupling to intense-laser-created solid plasmas via surface plasmon and "lightning rod" effects. We demonstrate this in metal nanoparticle-coated solid targets irradiated with 100 fs, 806 nm laser pulses, focused to intensities ~1014-1015Wcm-2. Our experiments show a 13-fold enhancement in hard x-ray yield (10-200 keV) emitted by copper nanoparticle plasmas formed at the focal volume. A simple model explains the observed enhancement quantitatively and provides pointers to the design of structured surfaces for maximizing such emissions
The Present status and the projected programme on niobium-tantalum metallurgy in India
Niobium and tantalum which belong to the family of ref-ractory rare metals, have assumed great strategic impo-rtance in present day material development programmes, specially in industries like chemical and nuclear engineering, electronics and aerospace. The use of niob-ium as ferroniobium contributing to carbide stabilisat-ion in stainless steel is well established and accounts for the major demand for niobium in the world today. At the same time, niobium-based alloys have been considered excellent for high temperature service, and in particular two alloys (i) SU-16 (Nb- 11 W- 3Mo -21-If-0 - 08C), and (ii) Nb-752 (Nb-IOW- 25Zr)'--have been developed for application in aerospace structure components. With its relatively low neutron absorption cross-section (Q8= I 1 barns), compatibility both with uranium fuels and liquid metal coolants, and good high temperature strength and fabrication characteristics, niobium is also an attra-ctive candidate for nuclear energy application, parti-cularly in fast reactors. Also, a zirconium-alloy conta-ining 2.5% of niobium is a potential competitor to
zircaloy for structural core components in water-cooled thermal reactor systems
Zeroth Law compatibility of non-additive thermodynamics
Non-extensive thermodynamics was criticized among others by stating that the
Zeroth Law cannot be satisfied with non-additive composition rules. In this
paper we determine the general functional form of those non-additive
composition rules which are compatible with the Zeroth Law of thermodynamics.
We find that this general form is additive for the formal logarithms of the
original quantities and the familiar relations of thermodynamics apply to
these. Our result offers a possible solution to the longstanding problem about
equilibrium between extensive and non-extensive systems or systems with
different non-extensivity parameters.Comment: 18 pages, 1 figur
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