Establishment of the spectra of kinetic turbulence

An analysis of kinetic equations describing the establishment of Langmuir turbulence spectra is presented. Secondary turbulence occurs where stationary distribution consists of many peaks. The position of peaks is established and their amplitudes complete undamped oscillations. It is pointed out that establishing spectra can occur only during adiabatic inclusion of pumping. It is significant here that the adiabiatic condition is more rigid than the ordinary by several hundred times

Detection of Trace Amounts of Toxic Metals in Environmental Samples by Laser-excited Atomic Fluorescence Spectrometry

Results for the direct determination of trace amounts of Pb and Cd in Antarctic and Greenland ancient ice and recent snow by laser-excited atomic fluorescence spectrometry (LEAFS) are presented. The whole procedure starting from field sampling, mechanical decontamination of the samples in an ultra-clean laboratory and final analysis of the decontaminated samples is described. The measured concentrations varied in the ranges 0.1–3 pg ml^(–1) for Cd and 0.3–30 pg ml^(–1) for Pb. The results for direct analysis by LEAFS agree favourable with those obtained by isotope dilution mass spectrometry and electrothermal atomic absorption spectrometry, which require time-consuming pre-treatment and pre-concentration stages

Cost of human capital estimation and management in medical organization

© Medwell Journals, 2016.The purpose of this research is the analysis and improvement of technology of human capital cost management for maintaining efficient personnel policy in a modern organization. The study offers researchers method of assessment and management of investments in human capital. This method involves structure of cost behavior during formation and development of human capital, change history of investment risks on each stage of business career, modeling of volume of investments on various degrees of their riskiness, mathematical analysis and forecasting profitability of investments in human capital, development of recommendations on human capital cost management. Furthermore, it determines investment appeal of human capital development. The real method is assayed on the materials of a project on human capital development in "KORL" JSC. To maintain human capital cost management we offer systematic monitoring of its current value and change on the basis of the offered optimizing models, following the investment approach for personnel decision making, personalization in accounting the investments in human capital and its profitability

Possibilities and Limitations of ICP-Spectrometric Determination of the Total Content of Tin, Its Inorganic and Organic Speciations in Waters with Different Salinity Levels—Part 1: Determination of the Total Tin Content

This paper considers the features of determining the total tin content in waters with different salinity. Direct ICP-spectrometric analysis of sea waters with a salinity of more than 6‰ significantly reduced the analytical signal of tin by 70% (ICP-MS) and 30% (ICP-OES). The matrix effect of macrocomponents was eliminated by generating hydrides using 0.50 M sodium borohydride and 0.10 M hydrochloric acid. The effect of transition metals on the formation of tin hydrides was eliminated by applying L-cysteine at a concentration of 0.75 g/L. The total analyte concentrations, considering the content of organotin compounds, were determined after microwave digestion of sample with oxidizing mixtures based on nitric acid. The generation of hydrides with the ICP-spectrometric determination of tin leveled the influence of the sea water matrix and reduced its detection limit from 0.50 up to 0.05 µg/L for all digestion schemes. The developed analysis scheme made it possible to determine the total content of inorganic and organic forms of tin in sea waters. The total content of tin was determined in the waters of the Azov and Black seas at the levels of 0.17 and 0.24 µg/L, respectively. © 2023 by the authors.Ministry of Education and Science of the Russian Federation, Minobrnauka: FZEN-2023-0006This work was supported by the Ministry of Education and Science of the Russian Federation FZEN-2023-0006

Stochastic Pulse Switching in a Degenerate Resonant Optical Medium

Using the idealized integrable Maxwell-Bloch model, we describe random optical-pulse polarization switching along an active optical medium in the Lambda-configuration with disordered occupation numbers of its lower energy sub-level pair. The description combines complete integrability and stochastic dynamics. For the single-soliton pulse, we derive the statistics of the electric-field polarization ellipse at a given point along the medium in closed form. If the average initial population difference of the two lower sub-levels vanishes, we show that the pulse polarization will switch intermittently between the two circular polarizations as it travels along the medium. If this difference does not vanish, the pulse will eventually forever remain in the circular polarization determined by which sub-level is more occupied on average. We also derive the exact expressions for the statistics of the polarization-switching dynamics, such as the probability distribution of the distance between two consecutive switches and the percentage of the distance along the medium the pulse spends in the elliptical polarization of a given orientation in the case of vanishing average initial population difference. We find that the latter distribution is given in terms of the well-known arcsine law

Establishing the geographical origin of some dry white wines according to ICP spectrometric and chemometric analysis

Важным аспектом при оценке подлинности вин является определение их географического происхождения. Цель настоящей работы – установление географического происхождения вин, изготовленных из выращенных в различных регионах Краснодарского края сортов винограда Шардоне, Рислинг и Мускат, по данным ИСП-спектрометрического и хемометрического анализа. Установлено существенное отличие концентраций Al, Ba, Ca, Rb в винах в зависимости от сорта, и Al, Ba, Rb, Fe, Li, Sr – между регионами произрастания. При этом концентрации элементов отличались в различных группах вин также по величине их отклонения относительно среднего значения. Выявленная дискриминантным анализом кластерная структура образцов вин относительно регионов их происхождения позволила построить модели с высокими прогностическими свойствами для идентификации географического происхождения вин. Критерием качества построенных моделей служила точность классификации – доля правильно идентифицированных образцов вин. Максимальную точность классификации на всей совокупности 153 образцов вин показали автоматизированные нейронные сети (100 %), затем метод опорных векторов (98.69 %) и общий дискриминантный анализ (94.77 %). При предсказании географического происхождения вин по важности вклада концентраций металлов в построенных моделях доминировали Sr, Li и Fe. По результатам проведенных исследований заключили, что ориентированные на данные большой размерности методы машинного обучения совместно с ИСП-спектрометрическим анализом могут успешно решать задачи малой размерности, связанные с установлением географического происхождения вин по компонентному составу и их наименованию, превосходя по точности традиционный метод – общий дискриминантный анализ.An important aspect of assessing authenticity of wines is determining their geographical origin. The aim of the present work was establishing geographical origin of wines produced from grape varieties of Chardonnay, Riesling and Muscat grown in different districts of Krasnodar Territory, from the results of ICP-spectrometry and chemometric methods. A significant difference in the concentration of Al, Ba, Ca and Rb in wines was observed depending on the grape variety, and a difference in Al, Ba, Rb, Fe, Li and Sr concentration depending on region of the grape origin. Concentrations of the elements in different groups of wines also had different deviation from the average values. A cluster structure of wine samples relative their origin districts, revealed using discriminant analysis, allowed to develop models with high prognostic properties for identifying geographical origin of wines. A quality criterion of the developed models was precision of classification, i.e. fraction of correctly identified wine samples. Neural networks demonstrated the maximum precision of classification (100 %) for all 153 wine samples used, followed by support vector machine (98.69 %) and general discriminant analysis (94.77 %). Among all metal concentrations, Sr, Li and Fe dominated in the importance of their contribution in the constructed statistical models for predicting the geographical origin of wines. The results of the studies showed that the machine learning methods oriented to high dimensional data together with ICP-spectrometry analysis can successfully solve problems of small dimension related to determining the geographical origin of wines on the basis of their component composition and name with the precision exceeding the traditional method of general discriminant analysis.Работа выполнена при финансовой поддержке Российского Научного Фонда проект № 23-13-00056 ( https://rscf.ru/project/23-13-00056) с использованием научного оборудования ЦКП "Эколого-аналитический центр" Кубанского госуниверситета.This work was supported by the Russian Science Foundation, project no. 23-13-00056 (https://rscf.ru/ project/23-13-00056) and carried out with the use of scientific equipment of the Center for Shared Use “Ecological Analytical Center” of Kuban State University

Evidence for the exclusive decay Bc+- to J/psi pi+- and measurement of the mass of the Bc meson

We report first evidence for a fully reconstructed decay mode of the B_c^{\pm} meson in the channel B_c^{\pm} \to J/psi \pi^{\pm}, with J/psi \to mu^+mu^-. The analysis is based on an integrated luminosity of 360 pb$^{-1} in p\bar{p} collisions at 1.96 TeV center of mass energy collected by the Collider Detector at Fermilab. We observe 14.6 \pm 4.6 signal events with a background of 7.1 \pm 0.9 events, and a fit to the J/psi pi^{\pm} mass spectrum yields a B_c^{\pm} mass of 6285.7 \pm 5.3(stat) \pm 1.2(syst) MeV/c^2. The probability of a peak of this magnitude occurring by random fluctuation in the search region is estimated as 0.012%.Comment: 7 pages, 3 figures. Version 3, accepted by PR

Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV

We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use ~1 fb-1 integrated luminosity of proton-antiproton collisions at s**(1/2)=1.96 TeV recorded by the CDF II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248 +/- 43 (14.4 +/- 2.7) are expected from standard model background processes. We place 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115 GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model prediction.Comment: 8 pages, 2 figures, submitted to Phys. Rev. Let