On reductions of soliton solutions of multi-component NLS models and spinor Bose-Einstein condensates

We consider a class of multicomponent nonlinear Schrodinger equations (MNLS) related to the symmetric BD.I-type symmetric spaces. As important particular case of these MNLS we obtain the Kulish-Sklyanin model. Some new reductions and their effects on the soliton solutions are obtained by proper modifying the Zakahrov-Shabat dressing method.Comment: AIP AMiTaNS'09 Proceedings

Conformational effects on the Circular Dichroism of Human Carbonic Anhydrase II: a multilevel computational study

Circular Dichroism (CD) spectroscopy is a powerful method for investigating conformational changes in proteins and therefore has numerous applications in structural and molecular biology. Here a computational investigation of the CD spectrum of the Human Carbonic Anhydrase II (HCAII), with main focus on the near-UV CD spectra of the wild-type enzyme and it seven tryptophan mutant forms, is presented and compared to experimental studies. Multilevel computational methods (Molecular Dynamics, Semiempirical Quantum Mechanics, Time-Dependent Density Functional Theory) were applied in order to gain insight into the mechanisms of interaction between the aromatic chromophores within the protein environment and understand how the conformational flexibility of the protein influences these mechanisms. The analysis suggests that combining CD semi empirical calculations, crystal structures and molecular dynamics (MD) could help in achieving a better agreement between the computed and experimental protein spectra and provide some unique insight into the dynamic nature of the mechanisms of chromophore interactions

Evaluation of scientific CMOS sensors for sky survey applications

Scientific CMOS image sensors are a modern alternative for a typical CCD detectors, as they offer both low read-out noise, large sensitive area, and high frame rates. All these makes them promising devices for a modern wide-field sky surveys. However, the peculiarities of CMOS technology have to be properly taken into account when analyzing the data. In order to characterize these, we performed an extensive laboratory testing of Andor Marana sCMOS camera. Here we report its results, especially on the temporal stability and linearity, and compare it to the previous versions of Andor sCMOS cameras. We also present the results of an on-sky testing of this sensor connected to a wide-field lens, and discuss its applications for an astronomical sky surveys.Comment: Accepted to Astronomische Nachrichte

Universality in Viscous Fluid Spreading and Leveling

Multiphase fluid flows, or flows where the dynamics of an interface between unlike fluids can be observed, require study to further understand the fundamental relationships of the fluids’ properties and their dynamics in multiple applications. The scope of this research project pertains to low Reynolds number flow, a dense fluid spreading through a less dense ambient fluid, with the spreading fluid movement being driven by gravitational buoyancy forces and density differences. The primary investigation involves studying the spreading and leveling of such fluids in shaped geometries, such as subsurface fractures. The objective is to determine the effect of a wide variety of crack geometries on these flows, both in its spreading and leveling phases, or pre and post “closure,” respectively. The methods involve understanding the basic governing partial differential equation, the transformation to an ordinary differential equation with the use of a self-similarity variable and requisite, rescaling, and verification of these mathematical predictions through direct simulation of the PDE in MATLAB. Self-similar behavior physically means “universality” holds across all fluid types and fracture geometries, and such behavior can be observed for a variety of crack widths and geometries. We verify the spreading and leveling relationships of viscous fluid flows (determined mathematically using the theory of self-similarity), and further compare these to previous experiments. Future research interests include study of particulate viscous flow in its spreading and leveling phases, the final distribution of particles in the flow, and the effect of varying crack geometries on these flows

Weak electricity of the Nucleon in the Chiral Quark-Soliton Model

The induced pseudotensor constant (weak electricity) of the nucleon is calculated in the framework of the chiral quark soliton model. This quantity originates from the G-parity violation and hence is proportional to $m_u-m_d$. We obtain for $m_u-m_d=-5 MeV$ a value of $g_T/g_A =-0.0038$.Comment: The final version. Accepted for publication in Phys. Rev.

Theory of Ion-Transfer Processes at Electrodes and Solution

An extensive review is given of the author\u27s theory of ion- transfer processes at electrodes and in solution. The exposition concerns only those features which are independent of any assumptions about the mechan1sm of the particular process. The theory allows extension to many specific cases by adoption of simple models

From random to rational: improving enzyme design through electric fields, second coordination sphere interactions, and conformational dynamics

Enzymes are versatile and efficient biological catalysts that drive numerous cellular processes, motivating the development of enzyme design approaches to tailor catalysts for diverse applications. In this perspective, we investigate the unique properties of natural, evolved, and designed enzymes, recognizing their strengths and shortcomings. We highlight the challenges and limitations of current enzyme design protocols, with a particular focus on their limited consideration of long-range electrostatic and dynamic effects. We then delve deeper into the impact of the protein environment on enzyme catalysis and explore the roles of preorganized electric fields, second coordination sphere interactions, and protein dynamics for enzyme function. Furthermore, we present several case studies illustrating successful enzyme-design efforts incorporating enzyme strategies mentioned above to achieve improved catalytic properties. Finally, we envision the future of enzyme design research, spotlighting the challenges yet to be overcome and the synergy of intrinsic electric fields, second coordination sphere interactions, and conformational dynamics to push the state-of-the-art boundaries

Alkaloids from Mongolian species of Peganum multisectum (Maxim) Bobrov

Alkaloids of the aerial parts of P. multisectum (Maxim) Bobrov (Zygophyllaceae) growing in Mongolia have been studied by capillary Gas Chromatography-Mass Spectrometry (GC-MS) and Column Chromatography (CC). Four compounds comprising of 2-methylquinoline (1), 9-amino-2, 3,5,6,7,8-hexahydro-1H-cyclopenta [b] quinoline (2), vasicinone (3) and harmine (4) have been determined by GC-MS, while harmine (4), peganine (5), deoxypeganine (6), deoxyvasicinone (7) and harmane (8) were isolated as pure compounds by the CC. The structures of the five alkaloids 4, 5, 6, 7 and 8 were elucidated by the MS and 1H and 13C NMR analysis. The alkaloids 1, 2 and 8 were identified for the first time from this species.Mongolian Journal of Chemistry 16 (42), 2015, 48-5

Self-Consistent Pushing and Cranking Corrections to the Meson Fields of the Chiral Quark-Loop Soliton

We study translational and spin-isospin symmetry restoration for the two-flavor chiral quark-loop soliton. Instead of a static soliton at rest we consider a boosted and rotating hedgehog soliton. Corrected classical meson fields are obtained by minimizing a corrected energy functional which has been derived by semi-classical methods ('variation after projection'). We evaluate corrected meson fields in the region 300 MeV \le M \le 600 MeV of constituent quark masses M and compare them with the uncorrected fields. We study the effect of the corrections on various expectation values of nuclear observables such as the root-mean square radius, the axial-vector coupling constant, magnetic moments and the delta-nucleon mass splitting.Comment: 19 pages, LaTeX, 7 postscript figures included using 'psfig.sty', to appear in Int.J.Mod.Phys.