cosmic rays in the upper troposphere (9000 meters to 15000 meters) initiate the followingnuclear chemical reaction: 1n + 14n => 14c + 1h. previous research has shown a strong effect of latitude onthe abundance of neutrons from cosmic rays. however, to date, there has been little exploration of therelationship between the latitude effect for cosmic-ray neutrons and latitudinal variations of stab...

The electronic structures and the electrostatic potential of some amino derivatives of adamantane have been studied using the density functional theory. The partial atomic charges and nuclear quadrupole coupling constants (NQCC) of 14N nucleus of the considered molecules have been reported. The partial atomic charges are calculated with two methods for 14N nucleus: Mulliken charges and natural ...

In this paper experimental results obtained by both 75As NQR and EPR spectroscopy are presented for the three-component system As-Sb-Se. The 75As NQR spectra of glasses of structures (As2Se3)0.78(Sb2Se3)0.22, (As2Se3)0,75(Sb2Se3)0.25, (As2Se3)0.5(Sb2Se3)0.5 have broad lines with two Sb-NQR lines (corresponding to the Sb2Se3 units) and two 75As-NQR lines (corresponding to the As2Se3 units). Diff...

Solid-state 17O NMR spectra were obtained at 4.70, 11.75 and 19.60T for potassium hydrogen [17O(4)]dibenzoate (PHB) under both magic-angle spinning and stationary conditions. Spectral analyses yielded both the magnitude and orientation of the 17O chemical shift (CS) tensor and the electric field gradient (EFG) tensor for each of the two chemically distinct oxygen sites in PHB. For the oxygen si...

We describe the analysis of quantitative proteomic samples via multidimensional protein identification technology (MudPIT). Ratio amounts of the soluble portion of the S. cerevisiae proteome from cultures of S. cerevisiae strain S288C grown in either 14N minimal media or 15N-enriched minimal media were mixed and digested into a complex peptide mixture. A 1 x 14N/1 x 15N complex peptide mixture ...

The sodium -pumping NADH: ubiquinone oxidoreductase (Na+-NQR) is the main ion pump and the primary entry site for electrons into the respiratory chain of many different types of pathogenic bacteria. This enzymatic complex creates a transmembrane gradient of sodium that is used by the cell to sustain ionic homeostasis, nutrient transport, ATP synthesis, flagellum rotation and other essential pro...

An FPGA based NQR spectrometer has been designed for detection of N nuclei. The digital circuits required for NQR spectrometer i.e Pulse Programmer, DDS, digital receiver have been built inside FPGA. Combining FPGA chip with analog components, NQR spectrometer has been developed. N from NaNO2 is observed using same spectrometer. By adding a permanent magnet of uniform field NMR signal of proton...

The quinolinol derivatives clioquinol (5-chloro-7-iodo-8-quinolinol, Quinoform) and cloxiquine (5-chloro-8-quinolinol) were studied experimentally in the solid state via ³⁵Cl NQR, ¹H-¹⁷O and ¹H-¹⁴N NQDR spectroscopies, and theoretically by density functional theory (DFT). The supramolecular synthon pattern of O-H···N hydrogen bonds linking dimers and π-π stacking interactions were described wit...

Calculations of spin-spin coupling constants 1J(17O,13 C) in carbon dioxide (1) carbon monoxide (2) and several derivatives using density functional theory (DFT) have been carried out. This coupling constant possesses a positive sign [reduced coupling constant 1K(17O,13 C)< 0] except for the parent acylium cation [H-CO]+ (4a). It is shown that the Fermi contact term (FC) is positive [< 0 for 1K...

High pressure technique applied in studies of NQR frequency and quadrupole relaxation has been used for deriving information on the dynamical properties of crystals and the nature of their phase transitions. The ^Cl NQR pressure studies have been carried out and a detailed analysis is given for the following topics: 1) Symmetric and asymmetric hydrogen bonded systems under high pressure. 2) NQR...