The equivalence of the Strutinsky type smoothing and the temperature averaging method

The Fermi gas model of the nucleus at high temperatures can be used to define a ground state shell correction. We demonstrate analytically that the shell correction so obtained is the same as that obtained from the Strutinsky type method.     

Studies on the nef reaction induced by organic bases

Studies of the Nef reaction in the presence of primary, secondary and tertiary amines have been described. A convenient synthesis of N-substituted pyrroles and 3,6-dimethyl-4-hydrazinocarbonyl-5-(4-amino-3-nitrophenyl)-pyridazine 16 has been developed.     

Mathematical modelling of flows in recessed wall flame holder

A finite difference procedure has been employed to predict the flow situation in a recessed wall flame holder with and without combustion. Turbulence has been modelled by an ad hoc effective viscosity law. A single step chemical reaction has been assumed in dealing with the flows involving combustion. The predicted physical parameters have been compared with the experimental results. It has been argued that with the simplifying assumptions on turbulence and chemical kinetics the numerical procedure is adequately accurate to predict the important design parameters such as flame length and blow-off velocity. However, there are significant discrepancies between the predicted and measured distribution of velocity and temperature which could be attributed mainly to the inadequate turbulence modelling.     

Investigation of the quantitative properties of the quadrupole orthogonal acceleration time-of-flight mass spectrometer with electrospray ionisation using 3,4-methylenedioxymethamphetamine

This paper describes the investigation of the potential of a quadrupole orthogonal acceleration time-of-flight mass spectrometer (Q-TOF) equipped with an atmospheric pressure ionisation interface for quantitative measurements of small molecules separated by reversed phase liquid chromatography. To this end, the detection limits and linear dynamic range in particular were studied in an LC/MS/MS experiment using 3,4-methylenedioxymethamphetamine standards and 3,4-methylenedioxyethylamphetamine for internal standardisation. In a second phase, the experiment was repeated with real biological extracts (whole blood, serum, and vitreous humour). A calibration for 3,4-methylenedioxymethamphetamine and its metabolite 3,4-methylenedioxyamphetamine was prepared in each of these matrices again using 3,4-methylenedioxyethylamphetamine as internal standard. The resulting quantitative data were compared with those obtained by liquid chromatography with fluorescence detection for the same extracts. The Q-TOF results revealed excellent sensitivity and a linear dynamic range of nearly four decades (2-10 000 pg on-column, r(2) = 0.9998, 1/x weighting). Furthermore, all the calibration curves prepared in biological material were superimposable, LC/MS/MS and LC-fluorescence, and the quantitative results for actual samples compared very favourably. It was concluded that the Q-TOF achieves a linear dynamic range for quantitative LC/MS/MS work exceeding that of fluorescence detection and at much better absolute sensitivity. Copyright 1999 John Wiley & Sons, Ltd.     

Synthesis of Cu–Ni Alloy Powder Directly from Metal Salts Solution

Cu–Ni alloy powders were synthesized directly from metal nitrate solution. Combustion, ultrasonic mist combustion and ultrasonic pyrolysis processes were applied and Cu–Ni alloy powder was successfully synthesized by mist combustion and ultrasonic pyrolysis of nitrate salts in a reducing atmosphere. X-ray diffraction data showed that the copper and the nickel atoms were completely mixed. For Cu–Ni alloy powder prepared by ultrasonic mist combustion, powder was a hollow sphere and consisted of nano-sized particles. For Cu–Ni alloy powder prepared by ultrasonic pyrolysis, particles consisted of nano-scale particles loosely coagulated. The synthesis temperature was 800°C, which is much lower than the liquidus of a Cu–Ni binary system. Metal alloying by mist pyrolysis, named chemical alloying, has many advantages: (1) no crucible, ball or jar is needed, (2) low synthesis temperature below the liquidus of the alloy system, (3) no extraction step is needed, (4) no cation contamination, (5) direct synthesis of fine powder from metal salts and (6) a simple and inexpensive process. The disadvantage is the contamination of organic elements from the solvent and the salt.