Neutral-kaon mixing from (2+1)-flavor domain-wall QCD

We present the first results for neutral-kaon mixing using (2+1)-flavors of domain-wall fermions. A new approach is used to extrapolate to the physical up and down quark masses from our numerical studies with pion masses in the range 240-420 MeV; only SU(2)_{L}xSU(2)_{R} chiral symmetry is assumed and the kaon is not assumed to be light. Our main result is B_{K};{MS[over ]}(2 GeV)=0.524(10)(28) where the first error is statistical and the second incorporates estimates for all systematic errors.     

Origin of the satellite Kβ10 in X-ray spectra

The transition energies corresponding to the transition array KM_x→M_xM_2,3 (x = 1, 2, 3, 4, 5) have been calculated using Slater formulas for interaction between two holes in inner shells and HFS values of electrostatic Slater integrals. The initial and final state energies have been corrected for the adiabatic relaxation of atomic orbits, which take place due to creation of an inner vacancy. The value of this adiabatic relaxation energy for KM states has been calculated semi-empirically by comparing the KM₁³S₁→L₃M₁³P₂ transition energies with the measured Kα₁ line energies. For the final state, this value has been taken from available literature[21]. It is found that the satellite β₁₀ in the K-emission spectra of Zn, Ga, Ge, Mo and Rh is emitted by the superposition of more than one transition of the array. Consideration of the relative transition probabilities shows that the major contribution to β₁₀ comes from a K→M_2,3 transition in the presence of a 3d spectator vacancy. It has been suggested that the satellite β′₁ (7655.5 eV, Edamoto 1950) in the K-emission spectrum of cobalt, and the satellite β₇ (8271.2 eV) in the K-spectrum of nickel should be reidentified as β₁₀. It has been shown that the two lines β′₁ (8268.0 eV) and β″₁(8270.3 eV) observed[13] in the nickel Kβ spectrum are two components of the satellite β₁₀, and it is hence suggested that these should be renamed β₁₀⁽¹⁾ and β₁₀⁽²⁾ respectively. Similarly, the lines β″₍₁₎ (8909.3 eV) and β″₍₂₎(8913.0 eV) in the CuKβ spectrum are proved to be two components of β₁₀ and hence should be renamed β₁₀⁽¹⁾ and β₁₀⁽²⁾ respectively.     

An on-line TDC-312 computer-controlled neutron diffractometer

The design and fabrication of an indigenous on-line computer controlled four-circle neutron diffractometer at the CIRUS reactor in Trombay are described. The diffractometer has an 18 in dia full-circle crystal-orienter which is sturdy enough to carry a cryostat. Three crystal orientation angles χ, φ and ω and the detector angle 2θ can be set to an accuracy of 0·01°. The four angle shafts are driven through precision worm-gears by SCR-controlled DC motors and their instantaneous positions sensed by optical digitizers. The diffractometer is interfaced to an ECIL TDC-312 computer system consisting of the CPU with 4K-memory, ASR-35 teletype, X-Y plotter and the digital input/output system (DIOS). The DIOS which operates under program control is a real-time peripheral device used to exchange information in digital form between the computer and the diffractometer. A software package consisting of over 40 useroriented teletype commands has been developed for on-line control and automatic data-acquisition.     

Self-focusing of elliptically shaped high-power laser beams in a fully ionized plasma

The effect of self-focusing of a high-power light beam with an elliptical cross-section in a strongly ionised plasma has been evaluated. The mechanism of self-focusing considered is non-uniform heating of plasma by an electromagnetic wave having transverse variation of amplitude along its wave front. The heating causes redistribution of carriers which lead to a nonlinear relationship between the electron density and the electric vector and hence to a field-dependent effective dielectric constant. It is found that the beam gets focused at different focal points in different directions exhibiting the effect of astigmatism. There are several critical powers, below thex=0,y=0 planes; at higher powers one dimension focuses while the other defocusses, an oscillatory waveguide is formed in both dimensions. Above the highest critical power both dimensions self-focus, the dimensionless beam width parametersf ₁ andf ₂ forx andy focusing reach different minima corresponding to different self-focusing distances beyond which both dimensions continue diverging. The effect of energy loss through absorption from the beam has also been considered. It has been observed that absorption brings about a reduction in the extent of self-focusing and favours defocusing of the beam.     

Glueballs as bound states of massive gluons

Recent work in both lattice and continuum QCD shows that the gauge field is massive. We investigate the bound states of massive gluons with a Schrödinger equation and find M(0⁺⁺) ≈ 2.3 m, M(0⁻⁺) ≈ 2.7 m, M(2⁺⁺) ≈ 3.2 m, where m is the gluon mass; we expect from this as well as earlier work that m ≈ 500 MeV. These glueballs have widths typical of allowed hadronic decays.     

Modification of a mouldboard plough surface using arrays of polyethylene protuberances

Surface design modifications have recently exhibited a means of reducing soil-tool adhesion. The tribological characteristics of soil-burrowing animals were employed on tillage machinery to study the effect on adhesion. Considering the characteristics of dung beetles, ultra high molecular weight polyethylene (UHMW-PE) protuberances were mounted as embossed arrays on a mouldboard plough. To investigate a suitable geometry of such protuberances, five shapes were studied (flat, semi-spherical, semi-oblate, semi short-prolate and semi long-prolate) using a combination of base diameters and protrusion heights. The dimensionless height to diameter ratio (HDR) was used to characterize the geometry. Experiments were conducted to evaluate the resultant influence of various geometrical shapes and sizes of the protuberances (base diameter: 20–50 mm; protrusion height: 0–50 mm) on lowering the ploughing resistance of the mouldboard plough in Bangkok clay soil. A comparison was made between the modified and the conventional plough in dry (21.8% (d.b.)), sticky (37.2% (d.b.)), wet (49.1% (d.b.)) and flooded (64.3% (d.b.)) Bangkok clay soil at 1, 3 and 5 km/h forward speeds. Percent reduction in ploughing resistance of bionic mouldboard plough in these soil conditions with HDR = 0 was 1–6% in dry soil, 16–22% in sticky soil, 14–20% in wet soil and 8–12% in flooded soil. With HDR = 0.25 the ploughing resistance was reduced by 2–7% in dry soil, 18–36% in sticky soil, 17–33% in wet soil and 15–28% in flooded soil. Similarly with HDR = 0.5, it reduced by 10–16% in sticky soil, 6–17% in wet soil and 12–26% in flooded soil. Whereas, HDR > 0.5 increased the ploughing resistance by 7–29%.     

Production of Mycophenolic Acid by <Emphasis Type="Italic">Penicillium brevicompactum</Emphasis> Using Solid State Fermentation

Solid-state fermentation using the microfungus Penicillium brevicompactum for the production of mycophenolic acid is reported in this paper. Of the initial substrates tested (whole wheat, cracked wheat, long grain Basmati rice, and short grain Parmal rice), Parmal rice proved to be the best. Under initial conditions, using steamed Parmal rice with 80% (w/w) initial moisture content, a maximum mycophenolic acid concentration of 3.4 g/kg substrate was achieved in 12 days of fermentation at 25 °C. The above substrate was supplemented with the following additional nutrients (g/L packed substrate): glucose 40.0, peptone 54.0, KH₂PO₄ 8.0, MgSO4?7H₂O 2.0, glycine 7.0, and methionine 1.65 (initial pH 5.0). A small amount of a specified trace element solution was also added. The final mycophenolic acid concentration was increased to nearly 4 g/kg substrate by replacing glucose with molasses. Replacing Parmal rice with rice bran as substrate further improved the mycophenolic acid production to nearly 4.5 g/kg substrate.     

Understanding behaviour of vitamin-C guest binding with the cucurbit[6]uril host

The present study describes non-covalent interaction and complexation behaviour of sodium ascorbate (SA) with cucurbit[6]uril (CB[6]) at neutral pH in aqueous Na₂SO₄ solution. The interaction behaviour is investigated using various analytical techniques like NMR, UV–Vis, fluorescence, TGA and DRS. The substantial increase in the intensity of emission and absorption spectra of sodium ascorbate is observed. The Benesi–Hildebrand evaluation method is used to determine the stoichiometry and equilibrium constant of the cucurbit[6]uril–sodium ascorbate complex, which suggested the 1:1 complex. Time-dependent ¹H NMR, ¹³C CP MAS and CD studies also echoed non-covalent interaction between SA with CB[6].