Revisit of non-linear Landau damping for electrostatic instability driven by blazar-induced pair beams

We revisit the effect of non-linear Landau (NL) damping on the electrostatic instability of blazar-induced pair beams, using a realistic pair-beam distribution. We employ a simplified 2D model in ${\bf k}$-space to study the evolution of the electric-field spectrum and to calculate the relaxation time of the beam. We demonstrate that the 2D model is an adequate representation of the 3D physics. We find that non-linear Landau damping, once it operates efficiently, transports essentially the entire wave energy to small wavenumbers where wave driving is weak or absent. The relaxation time also strongly depends on the IGM temperature, $T_\mathrm{IGM}$, and for $T_\mathrm{IGM}\ll10$ eV, and in the absence of any other damping mechanism, the relaxation time of the pair beam is longer than the inverse Compton (IC) scattering time. The weak late-time beam energy losses arise from the accumulation of wave energy at small $k$, that non-linearly drains the wave energy at the resonant $\mathbf{k}$ of the pair-beam instability. Any other dissipation process operating at small $k$ would reduce that wave-energy drain and hence lead to stronger pair-beam energy losses. As an example, collisions reduce the relaxation time by an order of magnitude, although their rate is very small. Other non-linear processes, such as the modulation instability, could provide additional damping of the non-resonant waves and dramatically reduce the relaxation time of the pair beam. An accurate description of the spectral evolution of the electrostatic waves is crucial for calculating the relaxation time of the pair beam

Визначення кількісного вмісту основаних груп біологічно активних речовин у серіях плодів калини звичайної

Aim. To determine the quantitative content of the main groups of biologically active substances (BAS) in batches of Viburnum opulus fruits using pharmacopeial methods for their subsequent use in the standardization of the plant raw material.Materials and methods. For the study, 6 batches of air-dried Viburnum opulus fruits crushed to a particle size of 1 – 2 mm and harvested in different regions of Ukraine in the mass fruiting phase in October-November 2020 were used. The quantitative determination of polyphenols and tannins was performed using the spectrophotometric method at a wavelength of 760 nm calculated with reference to pyrogallol and dried substance. The total amount of hydroxycinnamic acids was determined according to the method of the SPhU (State Pharmacopoeia of Ukraine) 2.0 described in the monograph “Kidney TeaN” calculated with reference to rosemary acid. The total amount of organic acids was determined by the titrimetric method according to the method of the monograph of the SPhU 2.1 “Rose hipsN” calculated with reference to malic acid.Results and discussion. The quantitative content of polyphenols (calculated with reference to pyrogallol and dried substance) in batches of Viburnum opulus fruits varied by about 1.4 times from 1.74 ± 0.01 % to 2.36 ± 0.01 %. According to the results obtained, the quantitative content of tannins (calculated with reference to pyrogallol and dried substance) in batches of Viburnum opulus fruits varied by 1.7 times from 0.73 ± 0.01 % to 1.23 ± 0.01 %. The quantitative content of the total amount of hydroxycinnamic acids calculated with reference to rosemary acid in batches of Viburnum opulus fruits ranged by 1.2 times from 3.96 ± 0.01 % to 4.73 ± 0.01 %. The quantitative content of the total amount of organic acids calculated with reference to malic acid in batches of Viburnum opulus fruits fluctuated more than 1.3 times from 6.80 ± 0.01 % to 9.08 ± 0.01 %.Conclusions. The quantitative content of the main groups of biologically active substances has been determined in 6 batches of Viburnum opulus fruits harvested in different regions of Ukraine using pharmacopoeial methods: polyphenols (varied by 1.4 times), tannins (varied by 1.7 times), the total amount of hydroxycinnamic (varied by 1.2 times), and the total amount of organic acids (varied by 1.3 times) calculated with reference to dried substance. The content of the groups of biologically active substances in batches of Viburnum opulus fruits slightly correlates with the place of the raw material harvesting. Thus, the selected methods of the SPhU 2.0 are quite suitable for determining the quantitative content of polyphenols, tannins and of the total amount of hydroxycinnamic and organic acids in batches of Viburnum opulus fruits; they can be used in further studies to standardize the raw material.Мета. Визначити кількісний вміст основних груп біологічно активних речовин (БАР) у серіях плодів калини звичайної з використанням фармакопейних методик для подальшого їх застосування у стандартизації сировини.Матеріали та методи. Для дослідження використовували 6 серій повітряно сухих подрібнених до розміру частинок 1 – 2 мм плодів калини звичайної, заготовлених у різних регіонах України у фазі масового плодоносіння в жовтні-листопаді 2020 року. Кількісне визначення поліфенолів і танінів проводили за допомогою спектрофотометричного методу за довжини хвилі 760 нм у перерахунку на пірогалол і суху речовину, суми гідроксикоричних кислот – за методикою монографії Державної фармакопеї України 2.0 «Нирковий чайN» у перерахунку на розмаринову кислоту, суми органічних кислот проводили титриметричним методом за методикою монографії «Шипшини плодиN» Державної фармакопеї України 2.1 у перерахунку на яблучну кислоту.Результати та їх обговорення. Кількісний вміст поліфенолів (у перерахунку на пірогалол та суху речовину) у серіях плодів калини звичайної варіював майже в 1,4 раза – від 1,74 ± 0,01 % до 2,36 ± 0,01 %. Кількісний вміст танінів (у перерахунку на пірогалол та суху речовину) у серіях плодів калини звичайної варіював в 1,7 раза – від 0,73 ± 0,01 % до 1,23 ± 0,01 %. Кількісний вміст суми гідроксикоричних кислот у перерахунку на розмаринову кислоту в серіях плодів калини звичайної коливався в 1,2 раза – від 3,96 ± 0,01 % до 4,73 ± 0,01 %. Кількісний вміст суми органічних кислот у перерахунку на яблучну кислоту в серіях плодів калини звичайної коливався в більше ніж 1,3 раза – від 6,80 ± 0,01 % до 9,08 ± 0,01 %.Висновки. У 6 серіях плодів калини звичайної, заготовлених у різних регіонах України, з використанням фармакопейних методик визначено кількісний вміст основних груп БАР: поліфенолів (коливався в 1,4 раза), танінів (коливався в 1,7 раза), суми гідроксикоричних кислот (коливався в 1,2 раза) та суми органічних кислот (коливався в 1,3 раза) у перерахунку на суху сировину. Кількісний вміст груп БАР у серіях плодів калини звичайної незначно корелює з місцем заготівлі сировини. Отже, обрані методики ДФУ 2.0 цілком придатні для визначення кількісного вмісту поліфенолів, танінів та суми гідроксикоричних і органічних кислот у серіях плодів калини звичайної, що може бути використано в подальших роботах зі стандартизації сировини

Bulk Scalar Stabilization of the Radion without Metric Back-Reaction in the Randall-Sundrum Model

Generalizations of the Randall-Sundrum model containing a bulk scalar field $\Phi$ interacting with the curvature $R$ through the general coupling $R f(\Phi)$ are considered. We derive the general form of the effective 4D potential for the spin-zero fields and show that in the mass matrix the radion mixes with the Kaluza-Klein modes of the bulk scalar fluctuations. We demonstrate that it is possible to choose a non-trivial background form $\Phi_0(y)$ (where $y$ is the extra dimension coordinate) for the bulk scalar field such that the exact Randall-Sundrum metric is preserved (i.e. such that there is no back-reaction). We compute the mass matrix for the radion and the KK modes of the excitations of the bulk scalar relative to the background configuration $\Phi_0(y)$ and find that the resulting mass matrix implies a non-zero value for the mass of the radion (identified as the state with the lowest eigenvalue of the scalar mass matrix). We find that this mass is suppressed relative to the Planck scale by the standard warp factor needed to explain the hierarchy puzzle, implying that a mass \sim 1\tev is a natural order of magnitude for the radion mass. The general considerations are illustrated in the case of a model containing an $R\Phi^2$ interaction term.Comment: 22 pages, 3 figure

Non-linear power spectra of dark and luminous matter in halo model of structure formation

The late stages of large-scale structure evolution are treated semi-analytically within the framework of modified halo model. We suggest simple yet accurate approximation for relating the non-linear amplitude to linear one for spherical density perturbation. For halo concentration parameter, $c$, a new computation technique is proposed, which eliminates the need of interim evaluation of the $z_{col}$. Validity of the technique is proved for $\Lambda$CDM and $\Lambda$WDM cosmologies. Also, the parameters for Sheth-Tormen mass function are estimated. The modified and extended halo model is applied for determination of non-linear power spectrum of dark matter, as well as for galaxy power spectrum estimation. The semi-analytical techniques for dark matter power spectrum are verified by comparison with data from numerical simulations. Also, the predictions for the galaxy power spectra are confronted with 'observed' data from PSCz and SDSS galaxy catalogs, good accordance is found.Comment: 18 pages, 8 figures; major changes from the previous version; accepted for publivation in Phys. Rev.

The critical raw materials in cutting tools for machining applications: a review

A variety of cutting tool materials are used for the contact mode mechanical machining of components under extreme conditions of stress, temperature and/or corrosion, including operations such as drilling, milling turning and so on. These demanding conditions impose a seriously high strain rate (an order of magnitude higher than forming), and this limits the useful life of cutting tools, especially single-point cutting tools. Tungsten carbide is the most popularly used cutting tool material, and unfortunately its main ingredients of W and Co are at high risk in terms of material supply and are listed among critical raw materials (CRMs) for EU, for which sustainable use should be addressed. This paper highlights the evolution and the trend of use of CRMs) in cutting tools for mechanical machining through a timely review. The focus of this review and its motivation was driven by the four following themes: (i) the discussion of newly emerging hybrid machining processes offering performance enhancements and longevity in terms of tool life (laser and cryogenic incorporation); (ii) the development and synthesis of new CRM substitutes to minimise the use of tungsten; (iii) the improvement of the recycling of worn tools; and (iv) the accelerated use of modelling and simulation to design long-lasting tools in the Industry-4.0 framework, circular economy and cyber secure manufacturing. It may be noted that the scope of this paper is not to represent a completely exhaustive document concerning cutting tools for mechanical processing, but to raise awareness and pave the way for innovative thinking on the use of critical materials in mechanical processing tools with the aim of developing smart, timely control strategies and mitigation measures to suppress the use of CRMs

Probing Top-Quark Couplings at Polarized NLC

The energy spectrum of the lepton(s) in e^+e^- --> tt-bar --> l^{+-} ...../l^+l^-..... at next linear colliders (NLC) is studied for arbitrary longitudinal beam polarizations as a possible test of new physics in top-quark couplings. The most general non-standard couplings for gamma-tt-bar, Ztt-bar and Wtb vertices are considered. Expected precision of the non-standard-parameter determination is estimated applying the optimal-observable procedure.Comment: Final version, To appear in Phys. Rev.

C60 fullerenes increase the intensity of rotational movements in non-anesthetized hemiparkinsonic rats

The effect of C60 fullerene aqueous colloid solution (C60FAS) on the intensity of long-lasting (persisting for one hour) rotational movements in non-anesthetized rats was investigated. For this purpose, an experimental hemiparkinsonic animal model was used in the study. Rotational movements in hemiparkinsonic animals were initiated by the intraperitoneal administration of the dopamine receptor agonist apomorphine. It was shown that a preliminary injection of C60FAS (a substance with powerful antioxidant properties) in hemiparkinsonic rats induced distinct changes in animal motor behavior. It was revealed that fullerene-pretreated animals, in comparison with non-pretreated or vehicle-pretreated rats, rotated for 1 h at an approximately identical speed until the end of the experiment, whereas the rotation speed of control rats gradually decreased to 20–30% of the initial value. One can assume that the observed changes in the movement dynamics of the hemiparkinsonic rats after C60FAS pretreatment presumably can be induced by the influence of C60FAS on the dopaminergic system, although the isolated potentiation of the action of apomorphine C60FAS cannot be excluded. Nevertheless, earlier data on the action of C60FAS on muscle dynamics has suggested that C60FAS can activate a protective action of the antioxidant system in response to long-lasting muscular activity and that the antioxidant system in turn may directly decrease fatigue-related changes during long-lasting muscular activity

Bounds on the Higgs-Boson Mass in the Presence of Non-Standard Interactions

The triviality and vacuum stability bounds on the Higgs-boson mass are revisited in the presence of new interactions parameterized in a model-independent way by an effective lagrangian. When the scale of new physics is below 50 TeV the triviality bound is unchanged but the stability lower bound is increased by 40-60 GeV. Should the Higgs-boson mass be close to its current lower experimental limit, this leads to the possibility of new physics at the scale of a few TeV, even for modest values of the effective lagrangian parameters.Comment: 5 pages, 2 figures, RevTex, submitted to PR

Building the digital elevation vodels and definition other morphometric parametrs of Mizoch ridge means

Розглянуто можливості моделювання морфометричних параметрів Мізоцького кряжу (Рівненська область) за допомогою геоінформаційних технологій. Охарактеризовані методологічні підходи, використані для створення цифрових моделей унікальних регіонів. Рассмотрены возможности моделирования морфометрических параметров Мизочского кряжа (Ровенская область) с помощью геоинформационных технологий. Охарактеризованы методологические подходы, использованные при создании цифровых моделей уникальных регионов. The possibilities of modeling morphometric parameters of Mizoch ridge (Rivne region) using GIS technologies. Author examined methodological approaches used to create digital models of unique regions

The Evolving Landscape of the Economics of HIV Treatment and Prevention

Bohdan Nosyk and Julio Montaner argue that the cost-effectiveness of HAART roll out has been significantly underestimated because economic analyses haven't yet taken into account the beneficial impact of HAART on HIV transmission