Thermal conductivity of gamma-irradiated ternary borate glasses

The thermal conductivity of a variety of ternary borate glasses before and after gamma irradiation has been measured by the steady-state method at 25°C.The results obtained show that the thermal conductivity decreases with the increase of alkali oxide content or when the glass structure becomes more disrupted. The effect of gamma radiation is believed to result from the creation of disorder and shortening of the phonon mean free path leading to a decrease in the thermal conductivity of the glass.     

Stereoselective 4-benzyloxybut-2-enylation of aldehydes via an allyl-transfer reaction using a chiral allyl donor

[reaction: see text] A direct and highly stereoselective (E)-4-benzyloxybut-2-enylation of aldehydes was successfully carried out to give 5-benzyloxyhomoallylic alcohol (11) via an allyl-transfer reaction using a chiral allyl donor (10). The chiral allyl donor (10) was prepared by catalytic Sharpless asymmetric epoxidation of 3-methylbut-2-en-1-ol, followed by a stereospecific vinyl Grignard reaction of the epoxide in the presence of CuBr and selective benzylation of the primary alcohol of diol.     

One-step synthesis of core(Cr)/shell(gamma-Fe(2)O(3)) nanoparticles

Core(Cr)/shell(gamma-Fe(2)O(3)) nanoparticles were synthesized by mixing Fe(CO)(5) and Cr(CO)(6) in the 9:1 ratio. These particles exhibit narrow size distribution with 13.5 nm as mean diameter and uniform spherical shape. The TEM image, which is in good agreement with the synchrotron powder XRD pattern, reveals the heterogeneous nature (core/shell structure). The analysis of the pattern reveals gamma-Fe(2)O(3) structure and a metal crystal structure. Mossbauer spectra, which support the superparamagnetic behavior determined by H-M measurement, do not show any traceable amount of Fe(0). This suggests that the metal component is Cr. EELS analysis and iron mapping suggest controlled stoichiometry and also confirm a core made of Cr and a shell made of gamma-Fe(2)O(3).     

Sensitive, Selective, Precise and Accurate LC–MS Method for Determination of Clonidine in Human Plasma

A selective and sensitive liquid chromatography–mass spectrometric method in ESI (+ve) mode was developed and validated completely in human plasma. Clonidine and IS, carbamazapine, were extracted from human plasma via liquid–liquid extraction with ethyl acetate. Following evaporation under nitrogen, the residue was reconstituted with mobile phase and analyzed using API 4000 LC–MS–MS system. An isocratic program with binary mobile phases (0.1% formic acid in water and acetonitrile) was used to separate interference peaks by a C18 analytical column. Linearity range was 0.49–73.98 ng mL^?1. The intra- and inter-day accuracy and precision were within acceptable limits (≤15%). This method was successfully applied to a single dose 25 μg tablets BE study of clonidine in healthy male volunteers.     

Small scale intermittency in a rough wall turbulent boundary layer

Relatively good quality isotropy is observed in the central region of a turbulent boundary layer developing over a mesh screen rough wall. Spectra of velocity and, more especially, vorticity fluctuations satisfy isotropy over a significant wavenumber range. Inertial range scaling exponents ζ _u2 (p) and ζ _u3 (p) of moments of order p(?8) of increments of the transverse velocity fluctuations u ₂ and u ₃ are significantly smaller than the exponents ζ _u1 (p) of increments of the longitudinal velocity fluctuation u ₁. Exponents inferred from the locally averaged values of squared transverse vorticity fluctuations are only slightly smaller than ζ _u1 (p). The difference between ζ _u1 (p) and ζ _u2 (p) [or ζ _u3 (p)] more likely reflects the departure from isotropy of inertial range scales. There is evidence to suggest that the difference decreases with an increase in the Reynolds number and/or a decrease in the magnitude of the mean shear.     

NMSSM and seesaw physics at LHC

We consider extensions of the next-to-minimal supersymmetric model (NMSSM) in which the observed neutrino masses are described in terms of effective dimension six (or seven) rather than dimension five operators. All such operators respect the discrete symmetries of the model. The new particles associated with the double (or triple) seesaw mechanism can have sizable couplings to the known leptons, even with a TeV seesaw scale. In the latter case some of these new short-lived particles could be produced and detected at the LHC.     

SU(5) monopoles,magnetic symmetry and confinement

The monopoles of the unified SU(5) gauge theory broken down to H_E = SU(3)_c ? U(1)_EM [or to K_E = SU(3)_c ? SU(2) ? U(1)_Y], are classified. They belong to representations of a magnetic group H_M(K_M), which is found to be isomorphic to H_E(K_E). For SU(5) broken down to H_E, there exists a regular and stable monopole which is a colour magnetic triplet, and carries a non-zero abelian magnetic charge. It is suggested that composite operators made out of this monopole and its antiparticle fields develop a non-zero vacuum expectation value, and so lead to a squeezing of the colour electric flux. Finally, we comment on the cosmological production of SU(5) monopoles.