Computational chemistry is an important tool for signal assignment of 27Al nuclear magnetic resonance spectra in order to elucidate the species of aluminum(III) in aqueous solutions. The accuracy of the popular theoretical models for computing the 27Al chemical shifts was evaluated by comparing the calculated and experimental chemical shifts in more than one hundred aluminum(III) complexes. In ...

The complexation of metal cations into a host-guest situation is particularly well exemplified by [2.2.2]paracyclophane and Ag(I), which leads to a strong cation-π interaction with a specific face of the host molecule. Through this study we sought a deeper understanding of the effects the metal center has on the NMR spectroscopic properties of the prototypical organic host, generating theoretic...

NMR chemical shielding anisotropy (CSA) relaxation is an important tool in the study of dynamical processes in proteins and nucleic acids in solution. Herein, we investigate how dynamical variations in local geometry affect the chemical shielding anisotropy relaxation of the carbonyl carbon nucleus, using the following protocol: 1) Using density functional theory, the carbonyl (13)C' CSA is com...

Paramagnetic metal ions with fast-relaxing electronic spin and anisotropic susceptibility tensor provide a rich source of structural information that can be derived from pseudo-contact shifts, residual dipolar couplings, dipole-dipole Curie spin cross-correlation, and paramagnetic relaxation enhancements. The present study draws attention to a cross-correlation effect between nuclear relaxation...

We report a multinuclear solid-state ( (23)Na, (39)K, (87)Rb, (133)Cs) NMR study of tetraphenylborate salts, M[BPh 4] (M = Na, K, Rb, Cs). These compounds are isostructural in the solid state with the alkali metal ion surrounded by four phenyl groups resulting in strong cation-pi interactions. From analyses of solid-state NMR spectra obtained under stationary and magic-angle spinning (MAS) cond...

In this paper, we first show that the tensor product of a finite number of standard g-frames (resp. fusion frames, frames) is a standard g-frame (resp. fusion frame, frame) for the tensor product of Hilbert $C^ast-$ modules and vice versa, then we consider tensor products of g-Bessel multipliers, Bessel multipliers and Bessel fusion multipliers in Hilbert $C^ast-$modules. Moreover, we obtain so...

................................................................................................................................... iv 1.0 Introduction ...................................................................................................................... 1 2.0 Basic Concepts in Radiation Protection and Shielding .................................................... 1 2.1 Shieldin...

background: monte carlo simulations play a vital role in the calculation of the necessary shielding both for neutrons and photons. advanced and simple shielding materials against neutron and gamma rays were compared by simulation using the mcnb4b monte carlo code. the simulations were carried out for the three common neutron sources, namely the 252cf, the 241am/be and the dd neutron generator w...

Uncontrolled exposure to X-band frequency leads to health damage. One of the principles of radiation protection is shielding. But, conventional shielding materials have disadvantages. Therefore, studies of novel materials, as an alternative to conventional shielding materials, are required to obtain new electromagnetic shielding material. Therefore, this study investigated the electromagnetic s...

‎We consider Albeverio's linear representations of the braid groups $B_3$ and $B_4$‎. ‎We specialize the indeterminates used in defining these representations to non zero complex numbers‎. ‎We then consider the tensor products of the representations of $B_3$ and the tensor products of those of $B_4$‎. ‎We then determine necessary and sufficient conditions that guarantee the irreducibility of th...