Temperature and solvent variation of the 13C and 1H NMR spectra of r-1,t-2,c-3,t-4-tetrachlorotetralin

Vicinal coupling constants in the ¹H and ¹³C NMR spectra of r-1,t-2,c-3,t-4-tetrachlorotetralin change with temperature and solvent in a manner better explained by conformational equilibration than by intramolecular or solvent-determined distortions.     

Stability of equilibrium solution to inhomogeneous heat equation under a 3-point boundary condition

We consider a one-dimensional heat equation with inhomogeneous term, satisfying three-point boundary conditions, such that the temperature at the end is controlled by a sensor at the point η. We show that the integral solution, in the space of continuous functions satisfying the boundary values, converges to the equilibrium solution. This answers a question posed for nonlinear Laplacians, but in the linear case only.     

Solution of Lane–Emden type equations using rational Bernoulli functions

In this paper, a numerical method for solving Lane‐Emden type equations, which are nonlinear ordinary differential equations on the semi‐infinite domain, is presented. The method is based upon the modified rational Bernoulli functions; these functions are first introduced. Operational matrices of derivative and product of modified rational Bernoulli functions are then given and are utilized to reduce the solution of the Lane‐Emden type equations to a system of algebraic equations. Illustrative examples are included to demonstrate the validity and applicability of the technique. Copyright © 2015 John Wiley & Sons, Ltd.     

Fusion around the barrier for 7Li+12C

Fusion cross-sections for the ⁷Li + ¹²C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections due to the breakup of ⁷Li may not be significant for ⁷Li + ¹²C reaction at energies around the barrier.     

Comparing Classes of Finite Structures

We compare classes of structures using the notion of a computable embedding, which is a partial order on the classes of structures. Our attention is mainly, but not exclusively, focused on classes of finite structures. Also, a number of problems are formulated.     

Purification of human plasma lipid transfer protein using fast protein liquid chromatography

A system for the isolation of human plasma lipid transfer protein (LTP) has been devised using a combination of conventional and high-performance ion-exchange chromatography. Following initial purification by ammonium sulphate precipitation, ultracentrifugation, hydrophobic interaction and cation-exchange chromatography, appropriate fractions were further purified using the Pharmacia fast protein liquid chromatography system. Using this method of purification, human plasma LTP has been purified more rapidly and with greater recovery than with conventional column chromatography. Whereas two forms of LTP were previously reported from the authors' laboratory [LTP-I, molecular mass (Mr) 69,000 and LTP-II, Mr 55,000], with an improved chromatographic system only one form of LTP (LTP-I) has been isolated. This suggests that LTP-II may have been a fragment of LTP-I, produced during the previously used lengthy purification process.     

Initial Results From the Non-Methane Hydrocarbon Intercomparison Experiment

The Non-Methane Hydrocarbon Intercomparison Experiment (NOMHICE) is described. This experiment has been designed to evaluate analytical techniques currently being used by scientists throughout the world to measure ambient atmospheric hydrocarbon concentrations. NOMHICE consists of a series of planned experiments designed to identify existing problems in participating scientist's laboratories and to correct them. The various experimental steps (or phases) have been scheduled in order of increasing complexity so that problems can be addressed as they arise. Results are presented for the initial phases of this program. Phase 1 involved the circulation of a 2 component gravimetrically prepared standard to 40 laboratories throughout the world. Participants were asked to quantify but not identify the components. Phase 2 involved the circulation of a more complex 16 component gravimetrically prepared mixture to 32 participants. Participants were asked to identify and quantify the components. Further tasks are described which will be carried out in the future.