The molecular electronic structure of the twenty-six lowest lying states of Li2 at short and intermediate internuclear separations

We compute and analyze the potential energy for the 26 lowest lying states of Li₂ which correspond asymptotically to the interaction of Li(2s²S) with Li(2s²S), Li(2p²P) or Li(3s²S), and the interaction of Li(2p²P) with Li(2p²P). Results are compared with available experimental and quantum mechanical potential energy curves and molecular constants. The errors in the present calculations are of nearly equal magnitude to, and in the opposite sense of, the optimized valence configuration calculations of Konowalow and Olson. Thus, a composite of the two forms a “most likely” ab initio potential curve which compares favorably with the most recent experimental results.     

Biological production of acetaldehyde from ethanol using non-growingPichia pastoris whole cells

Acetaldehyde has been produced biologically using whole-cellPichia pastoris in a semibatch fermentor. Ethanol and air were fed continuously, and the product, acetaldehyde, was removed by the air stream. Operation of the reactor exceeded 100 h, maintaining high alcohol oxidase activity. Low cell-mass concentration (9.9 g/L) minimized product inhibition. Ethanol concentration in the broth, oxygen concentration in the air, and pH were evaluated for their effects on the fermentation process.     

Measurement of the ground state 2n pickup probability for 28Si+68Zn and its role in sub-barrier fusion enhancement

The ground state and excited state transfer yields for the 2-neutron pickup channel in the ²⁸Si+⁶⁸Zn system have been measured explicitly. The recoil mass separator at the nuclear Science Centre, New Delhi was used for the measurement. A NaI(T1) detector was used for detecting the deexcitation γ’s from the transfer products. The kinematic coincidence technique was employed for the transfer measurement. Simplified coupled channels calculations show that out of all transfer channels the major contribution to the sub-barrier enhancement comes from the ground state 2 neutron pickup channel with a ground state Q-value of+1.83 MeV.     

Free Convective Nonaligned Non-Newtonian Flow with Non-linear Thermal Radiation

The present study explores the free convective oblique Casson fluid over a stretching surface with non-linear thermal radiation effects. The governing physical problem is modelled and transformed into a set of coupled non-linear ordinary differential equations by suitable similarity transformation, which are solved numerically with the help of shooting method keeping the convergence control of 10^-5 in computations. Influence of pertinent physical parameters on normal, tangential velocity profiles and temperature are expressed through graphs. Physical quantities of interest such as skin friction coefficients and local heat flux are investigated numerically.     

An application of the trost reaction to the stereoselective synthesis of trans-tetrasubstituted fluoroalkenes

The coupling of β-fluoroallylic acetates (1) with stabilised ester-enolates (3), in the presence of catalytic palladium(0), gave tetrasubstituted fluoroalkenes (2) in good yield and with generally satisfactory trans-stereoselectivity.     

Chromatographic screening for drugs of abuse using capillary columns II. Peak identification on support coated open tubular columns for a series of central nervous system stimulant drugs

Summary A system based on Kovats' Retention Indices is described for the identification of CNS stimulant drugs recovered from body fluids. Use is made of the difference in retention indices found on polar and non-polar GLC columns (l values) and the effect of operating temperature is discussed.     

Nucleophilic substitution reactions of the tricyclic triphosphorus cage P3(CBu(t))2: a novel route to polyphosphorus phosphenium complexes

Substitution of Cl(-) in the tricyclic triphosphorus cage Cl(P(1))-P3(CBu(t))2 by a range of both anionic and neutral nucleophiles has been investigated. With anionic nucleophiles, reaction with fluoride and hydride anion was shown to afford F(P(1))-P3(CBu(t)) and H(P(1))-P3(CBu(t))2 respectively. Subsequent deprotonation of the latter results in the formation of the aromatic anion [1,2,4-P3(CBu(t))2]-. With neutral nucleophiles, addition of either PMe3 or PEt3 to Cl(P(1))-P3(CBu(t))2 in the presence of TlOTf results in the formation of the phosphine-phosphenium complexes [(R3P(P(1))-P3(CBu(t))2][OTf] (R = Me or Et): the structure of the methyl-substituted compound was determined by a single crystal X-ray diffraction study. The phosphine ligand in these complexes is extremely labile and addition of I2 to [(Me3P(P(1))-P3(CBu(t))2]+ results in the formation of I(P(1))-P3(CBu(t))2.