Fast forward evolution in heat equation:Tunable heat transport in adiabatic regime

We consider the problem of fast forward evolution of the processes described in terms of the heat equation. The matter is considered on an adiabatically expanding time-dependent box. Attention is paid to acceleration of heat transfer processes. So called shortcuts to adiabaticity, implying fast forwarding of the adiabatic states are studied. Heat flux and temperature profiles are analyzed for standard and fast forwarded regimes

Slow-roll inflation in (R+R*4) gravity

We reconsider the toy-model of topological inflation, based on the R*4-modified gravity. By using its equivalence to the certain scalar-tensor gravity model in four space-time dimensions, we compute the inflaton scalar potential and investigate a possibility of inflation. We confirm the existence of the slow-roll inflation with an exit. However, the model suffers from the eta-problem that gives rise to the unacceptable value of the spectral index n_s of scalar perturbations.Comment: 12 pages, 3 figures, LaTeX, misprints corrected and references update

ИССЛЕДОВАНИЕ УСТАНОВИВШИХСЯ РЕЖИМОВ РАБОТЫ ЧАСТОТНО-УПРАВЛЯЕМОГО АСИНХРОННОГО ГЕНЕРАТОРА ВЕТРОЭЛЕКТРИЧЕСКИХ УСТАНОВОК

The paper proposes an analytical expression for calculating a manipulated variable of stator voltage in a frequency-controlled induction generator with a cage rotor of a wind power plant while regulating a constant value of the absolute slip of the generator. Comparison of the calculated results by the proposed expression and full differential equations of the generator (an equation of state) at steady state has confirmed a high accuracy of the analytical expression.Предложено аналитическое выражение для расчета регулируемой величины статорного напряжения частотно-управляемого асинхронного генератора с короткозамкнутым ротором ветроэлектрической установки при регулировании на постоянство величины абсолютного скольжения генератора. Сопоставление результатов расчета по предложенному выражению и по полным дифференциальным уравнениям генератора (уравнения состояния) при установившемся режиме подтвердило высокую точность аналитического выражения

Association of angiotensinogen and angiotensin II receptor type I polymorphisms with biomarkers of carbohydrate and lipid metabolism in Dagestan residents with type 2 diabetes and hypertension

Aim. To study the associations of angiotensinogen (AGT) (s4762(С521Т), rs699(Т704C)) and angiotensin II receptor type I (AGTR1) (rs5186(A1166C)) genetic polymorphisms with serum levels of insulin, glucagon, C-peptide, leptin, as well as with dyslipidemia and glycemic levels in Dagestan residents with combination of type 2 diabetes (T2D) and hypertension (HTN), as well as with isolated T2D/HTN.Material and methods. We examined 16 patients with isolated T2D, 59 patients with T2D+HTN and 51 patients with isolated HTN from Dagestan. Genetic polymorphisms of the AGT and AGTR1 genes were studied. The levels of insulin, glucagon, C-peptide, and leptin were studied by enzyme-linked immunosorbent assay (ELISA), while lipid and carbohydrate metabolism — by biochemical methods.Results. In patients with T2D, the association of CC genotype of AGT gene rs4762(С521Т) polymorphism with a leptin decrease was determined, while its CT genotype was associated with an increase in serum level of triglycerides. The TC genotype of AGT gene rs699(Т704C) polymorphism was associated with an increase in leptin, triglyceride and glucose levels. The AA genotype of AGTR1 gene rs5186(A1166C) polymorphism was associated with an increase in insulin and glucose levels, as well as a decrease in leptin level. In patients with a combination of T2D and HTN, CC and CT genotypes of AGT gene rs4762(С521Т) polymorphism was associated with a decrease in glucagon level. The TT genotype of AGT gene rs699(Т704C) polymorphism was associated with an increase in insulin, triglyceride, glucose and body mass index (BMI) levels. In isolated HTN, the CC and CT genotypes of AGT gene rs4762(С521Т) polymorphism were associated ith a decrease in glucagon level. The TT genotype of AGT gene rs699(Т704C) polymorphism was associated with increased levels of insulin, low density lipoproteins, and BMI.Conclusion. Associations of AGT (s4762(С521Т), rs699(Т704C)) and AGTR1 (rs5186(A1166C)) genetic polymorphisms with carbohydrate and lipid metabolism changes are an important pathogenetic link of T2D and HTN, which allows developing an individual prognosis of these diseases in Dagestan residents

Microhardness of Polyketone Irradiated by Gamma Rays Co60

The effect of radiation on the microhardness of polyketone has been studied. When ex-posed to gamma irradiation, the near-surface and bulk microhardness increases. The values of microhardness at a load of 10 g increased by 14%, and at a load of 100 g by 20%, respectively.Исследование проводилось в рамках программы научно-исследовательских работ Института ядерной физики Академии наук Республики Узбекистана на 2020-2024 годы, по теме «Радиационно - стимулированные процессы при ядерной трансмутации легированного монокристаллического кремния» в лаборатории радиационной физики и техники твердотельной электроники

f(R) theories

Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity - such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans-Dicke theory and Gauss-Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in Relativity, Published version, Comments are welcom

Profiling of Deformities Caused by the Loss of Molars in Children

In most cases, as a result of early diagnosis and lack of treatment of dental anomalies in children, the occurrence of these defects and the prevention of complications is one of the most pressing problems of our time [2.4.6]. The age of the child at the time of premature removal of baby teeth, the timing of eruption of permanent teeth are essential for the formation of dentoalveolar deformities of varying severity; the number of missing teeth and the intensity of the carious process, as well as the functional group of destroyed or removed temporary teeth