Predictive analysis of rotor machines fluid-film bearings operability

The present paper considers a multi-criteria analysis algorithm of turbo generator fluid-film bearing operability and its connection with rotor machine monitoring system data. It is substantiated that implementation of predictive analysis of load capacity, locus curves and dynamic displacements allows prognosis of useful life of a fluid-film bearings and improvement of reliability of a rotor machine

Increase of solubility and transmembrane permeability of niclosamide from its mechanochemically synthesized solid dispersions

More than 4.5 billion people worldwide are affected by parasitic diseases, with helminth infections accounting for 99% of the total number. Niclosamide (NS) is a weakly acidic active pharmaceutical ingredient (API) used to treat helminth infections. However, the pharmaceutical use of pure niclosamide is limited by its low bioavailability due to its poor aqueous solubility. The aim of this work is a mechanochemical preparation of niclosamide solid dispersions with increased solubility. Due to the pH dependence of NS water solubility and possible complexes formation, NS solid dispersions (SD) with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and alkalizing agents, such as calcium carbonate (CaCO3) and N-methyl-D-glucamine (MG) are mechanochemically prepared in this study. The physical properties of NS SD in solid state are characterized by differential scanning calorimetry, X-ray diffraction, FT-IR spectroscopy, and scanning electron microscopy studies. The characteristics of the water solutions formed from the obtained SDs are analyzed by HPLC. It is shown that the solubility increases for all studied compositions. These phenomena are obliged by complexation with HP-β-CD, which was shown by 1H-NMR methods, and enhanced ionization in the cases of using calcium carbonate and MG. Results of the parallel artificial membrane permeability assay (PAMPA) have shown that mechanochemically obtained NS/MG SD (1/1 mass ratio, 8 h milling) significantly enhances permeation of NS across an artificial membrane. Thus, the obtained compositions are a promising basis for the development of NS-based preparations for oral administration, with reduced dose and high pharmacological effect

Peculiarities of Electron Transfer in Chiral Linked Systems

Electron transfer (ET) is one of the most universal reactions in chemistry and biology. Recent studies conducted on the examples of photoinduced ET (PET) in chiral linked systems (dyads) have shown several important features indicative for ET in chiral systems. The peculiarity of processes with PET in such systems is primarily the stereoselectivity; there is difference in ET rates and fluorescence quantum yields in dyad diastereomers. The next feature is the spin selectivity of back ET in the biradical-zwitterions (BZs) that are formed under the dyad diastereomer UV irradiation. This is the difference in the enhancement coefficients of chemically induced dynamic nuclear polarization (CIDNP) originated in BZs. The probable cause of this effect is the variation in the spin density values, resulting from difference in the spatial structure of BZ in (R,S)- and (S,S)-configurations. The latter, in turn, is due to the fact that these dyads react in the form of associates—dimers. The impact of dimerization on the effectiveness of ET in chiral systems is an example of the chiral catalysis. The study of ET in chiral linked systems reveals reasons for the various reactivities of chiral molecules, including the difference in therapeutic activity of drug enantiomers

Strings as Multi-Particle States of Quantum Sigma-Models

We study the quantum Bethe ansatz equations in the O(2n) sigma-model for hysical particles on a circle, with the interaction given by the Zamolodchikovs' S-matrix, in view of its application to quantization of the string on the S^{2n-1} x R_t space. For a finite number of particles, the system looks like an inhomogeneous integrable O(2n) spin chain. Similarly to OSp(2m+n|2m) conformal sigma-model considered by Mann and Polchinski, we reproduce in the limit of large density of particles the finite gap Kazakov-Marshakov-Minahan-Zarembo solution for the classical string and its generalization to the S^5 x R_t sector of the Green-Schwarz-Metsaev-Tseytlin superstring. We also reproduce some quantum effects: the BMN limit and the quantum homogeneous spin chain similar to the one describing the bosonic sector of the one-loop N=4 super Yang-Mills theory. We discuss the prospects of generalization of these Bethe equations to the full superstring sigma-model.Comment: 52 pages, 10 figures, LaTe

Аутотрансплантация почки – метод лечения поражения мочеточника в урологической и онкологической практике

The first successful kidney autotransplantation was performed in 1902. The technique has undergone several changes since then. The indications and surgical technique are presented in this literature review. Kidney autotransplantation is the treatment of choice for preserving renal function. Three clinical observations on the use of kidney autotransplantation in urological and oncological practice are described: a patient after iatrogenic ureteral injury and two patients with primary retroperitoneal tumor. Literature analysis and clinical observations from urological and oncological practice show that kidney autotransplantation could be safely used for strictly selected indications.Первая аутотрансплантация почки была выполнена в 1902 г., с этого времени техника ее выполнения претерпела ряд изменений. В литературном обзоре представлены показания и хирургическая техника. Аутотрансплантация почки является методом выбора лечения, направленного на сохранение почечной функции. Описаны 3 клинических наблюдения по применению аутотрансплантации почки в урологической и онкологической практике: пациент после ятрогенного повреждения мочеточника и два пациента с неорганной опухолью забрюшинного пространства. Анализ литературы и клинические наблюдения из урологической и онкологической практики показывают возможность безопасного применения аутотрансплантации почки по строго выбранным показаниям

Impact of increased resolution on Arctic Ocean simulations in Ocean Model Intercomparison Project phase 2 (OMIP-2)

This study evaluates the impact of increasing resolution on Arctic Ocean simulations using five pairs of matched low- and high-resolution models within the OMIP-2 (Ocean Model Intercomparison Project phase 2) framework. The primary objective is to assess whether a higher resolution can mitigate typical biases in low-resolution models and improve the representation of key climate-relevant variables. We reveal that increasing the horizontal resolution contributes to a reduction in biases in mean temperature and salinity and improves the simulation of the Atlantic water layer and its decadal warming events. A higher resolution also leads to better agreement with observed surface mixed-layer depth, cold halocline base depth and Arctic gateway transports in the Fram and Davis straits. However, the simulation of the mean state and temporal changes in Arctic freshwater content does not show improvement with increased resolution. Not all models achieve improvements for all analyzed ocean variables when spatial resolution is increased so it is crucial to recognize that model numerics and parameterizations also play an important role in faithful simulations. Overall, a higher resolution shows promise in improving the simulation of key Arctic Ocean features and processes, but efforts in model development are required to achieve more accurate representations across all climate-relevant variables.</p

Analytic Solution of Bremsstrahlung TBA

We consider the quark--anti-quark potential on the three sphere or the generalized cusp anomalous dimension in planar N=4 SYM. We concentrate on the vacuum potential in the near BPS limit with $L$ units of R-charge. Equivalently, we study the anomalous dimension of a super-Wilson loop with L local fields inserted at a cusp. The system is described by a recently proposed infinite set of non-linear integral equations of the Thermodynamic Bethe Ansatz (TBA) type. That system of TBA equations is very similar to the one of the spectral problem but simplifies a bit in the near BPS limit. Using techniques based on the Y-system of functional equations we first reduced the infinite system of TBA equations to a Finite set of Nonlinear Integral Equations (FiNLIE). Then we solve the FiNLIE system analytically, obtaining a simple analytic result for the potential! Surprisingly, we find that the system has equivalent descriptions in terms of an effective Baxter equation and in terms of a matrix model. At L=0, our result matches the one obtained before using localization techniques. At all other L's, the result is new. Having a new parameter, L, allows us to take the large L classical limit. We use the matrix model description to solve the classical limit and match the result with a string theory computation. Moreover, we find that the classical string algebraic curve matches the algebraic curve arising from the matrix model.Comment: 50 pages, 5 figures. v2: references added, JHEP versio

Arctic Sea Ice Decline Significantly Contributed to the Unprecedented Liquid Freshwater Accumulation in the Beaufort Gyre of the Arctic Ocean

The Beaufort Gyre (BG) is the largest liquid freshwater reservoir of the Arctic Ocean. The liquid freshwater content (FWC) significantly increased in the BG in the 2000s during an anticyclonic wind regime and remained at a high level despite a transition to a more cyclonic state in the early 2010s. It is not well understood to what extent the rapid sea ice decline during this period has modified the trend and variability of the BG liquid FWC in the past decade. Our numerical simulations show that about 50% of the liquid freshwater accumulated in the BG in the 2000s can be explained by the sea ice decline caused by the Arctic atmospheric warming. Among this part of the FWC increase, 60% can be attributed to surface freshening associated with the reduction of the net sea ice thermodynamic growth rate, and 40% to changes in ocean circulation, which makes freshwater more accessible to the BG for storage. Thus, the rapid increase of the BG FWC in the 2000s was due to the concurrence of the anticyclonic wind regime and the high freshwater availability. We also find that if the Arctic sea ice had not declined, the liquid FWC in the BG would have shown a stronger decreasing tendency at the beginning of the 2010s owing to the cyclonic wind regime. From our results we argue that changes in sea ice conditions should be adequately taken into account when it comes to understanding and predicting variations of BG liquid FWC in a changing climate