Radiative decay width measurements of neutral kaon excitations using the primakoff effect

We use K(L)'s in the 100-200 GeV energy range to produce 147 candidate events of the axial vector pair K1(1270)-K1(1400) in the nuclear Coulomb field of a Pb target and determine the radiative widths Gamma(K1(1400)-->K0+gamma)=280.8+/-23.2(stat)+/-40.4(syst) keV and Gamma(K1(1270)-->K0+gamma)=73.2+/-6.1(stat)+/-28.3(syst) keV. These first measurements appear to be lower than the quark-model predictions. We also place upper limits on the radiative widths for K(*)(1410) and K(*)(2)(1430) and find that the latter is vanishingly small in accord with SU(3) invariance in the naive quark model.     

Measurement of the K(L) charge asymmetry

We present a measurement of the charge asymmetry delta(L) in the mode K(L)-->pi(+/-)e(-/+)nu based on 298 x 10(6) analyzed decays. We measure a value of delta(L) = [3322+/-58(stat)+/-47(syst)]x10(-6), in good agreement with previous measurements and 2.4 times more precise than the current best published result. The result is used to place more stringent limits on CPT and DeltaS = DeltaQ violation in the neutral kaon system.     

The mechanism of photolysis of n-methyldihydroberberine salts and a sequence for transposition of ring D substituents

Photolysis of N-deuteriomethyl dihydroberberine salt (1b) gave 1-o-toluyl-3,4-dihydroisoquinoline (5b) with a deuterium atom incorporation; a mechanism involving a 1,7-hydrogen shift step is proposed. The keto-imine (5a) on irradiation followed by reduction furnished 11,12-dimethoxy tetrahydroberberine (9a).     

Chirality and helix stability of polyglutamic acid enantiomers

In this work the chirality and the relative thermal stability of ordered micellar aggregates of poly-L- and poly-D-glutamic acids with the cationic surfactant C14TAB is examined. The complexed mesophases poly-L-Glu/C14TAB and poly-d-Glu/C14TAB were characterized by circular dichroism (CD) in the temperature range 10-70 degrees C for their chirality and thermal stability as well as by X-ray diffraction (XRD) for the micellar ordered structure. Low angle XRD analysis showed that both micellar aggregates poly-L-Glu/C14TAB and poly-D-Glu/C14TAB are hexagonally packed in a MCM-41 fashion with an intermicellar distance identical and equal to 3.55+/-0.10 nm. The CD spectra indicated that both complexes poly-L-Glu/C14TAB and poly-D-Glu/C14TAB possess a mainly alpha-helix structure and are exact mirror images to each other. The same mirror images and a mainly alpha-helix configuration were also observed by CD for the free poly-l- and poly-d-glutamic acids at room temperature. As the temperature increases from 10 up to 70 degrees C the alpha-helix of the poly-l-glutamic acid is gradually transformed to a mixture containing increased amounts of the 3(10)-helix while the alpha-helix structure of the poly-d-glutamic acid is constantly degenerated. In contrast the alpha-helices of the corresponding complexes poly-L-Glu/C14TAB and poly-d-Glu/C14TAB are degenerated upon heating without appreciable increase of the 3(10)-helices as an intermediate configuration. This difference in helix conservation is attributed to increase protection of the l-enantiomers, compared to d-enantiomers, which might be related to the survival of l-aminoacids in the living world.     

Synthesis and Structures of β‐Diketoiminate Complexes of Magnesium

The reaction of the β‐diketoiminate lithium complex (dipp)NacNacLi · OEt₂ ((dipp)NacNac = 2‐((2,6‐diisopropylphenyl)amino)‐4‐((2,6‐diisopropylphenyl)imino)‐pent‐2‐enyl) with iPrMgCl and MgI₂ yield the corresponding (dipp)NacNacMgiPr · OEt₂ ( 1 ) and (dipp)NacNacMgI · OEt₂ ( 2 ). The reaction of 2 with NaBH₄ in diethylether gives (dipp)NacNacMg(μ‐H)₃BH · OEt₂ ( 3 ). The core element of compounds 1 – 3 is a six‐membered ring formed by N(1)–C(1)–C(2)–C(3)–N(2) and magnesium. The structures of 1 and 2 show the β‐diketoiminate backbone in a boat‐conformation with the tetrahedrally coordinated metal center at the prow and the opposing carbon atom at the stern. The magnesium atom in 3 is octahedrally coordinated and out of the β‐diketoiminate plane.     

-theorems for fusion systems

For an odd prime, we generalise the Glauberman-Thompson -nilpotency theorem (Gorenstein, 1980) to arbitrary fusion systems. We define a notion of -free fusion systems and show that if is a -free fusion system on some finite -group , then is controlled by for any Glauberman functor , generalising Glauberman's -theorem (Glauberman, 1968) to arbitrary fusion systems.

     

Modelling of two-phase incompressible flows in ducts

An improved level-set method for capturing interfaces combined with a second-order projection method for solving the time-dependent incompressible Navier–Stokes equations is implemented to compute two-phase viscous flows of Newtonian fluids on Cartesian staggered meshes. Various arrays of deformable droplets are suspended in an ambient fluid of different viscosity in ducts and the deformation and migration of droplets as they move along the duct are computed and discussed.