Modification of Ti-Zr-Ni alloys by powerful plasma stream of different gases

The effects of irradiation by hydrogen, helium and argon plasma heat loads of 0.4 … 0.6 MJ/m2 on the change of morphology, structure and phase composition of Ti41.5Zr41.5Ni17 alloy are investigated. The initial state of such alloy is characterized by presence of a crystal- approximant 1/1 phase (W-phase) with lattice constant аW = 1.428 ±0.0003 nm, Laves phase (L phase) with the lattice period a = 0.6043 ± 0.0003 nm and an icosahedral quasi-crystalline phase (i-phase) with quasi-crystalline parameter aq= 0.5175 ±0.0003 nm. Plasma irradiation causes formation of the icosahedral quasi-crystalline phase in re-solidified layer with depth up to 100 μm. The substructure parameters: size of the coherence area, the value of micro-strain, phason defect concentration and the value of residual macro-stresses are determined by the plasma parameters.Исследовано влияние облучения водородными, гелиевыми, аргоновыми плазменными потоками с тепловыми нагрузками 0,4…0,6 MДж/м2 на изменение морфологии, структуры и фазового состава сплава Ti41,5Zr41,5Ni17. Исходное состояние такого сплава характеризуется присутствием фазы кристалла-аппроксиманта 1/1 (W-фазы) с периодом решетки аW = 1,428 ±0,0003 нм, фазы Лавеса (L-фаза) с периодом решётки a = 0,6043±0,0003 нм и икосаэдрической квазикристаллической фазы (i-фаза) с параметром квазикристалличности aq = 0,5175±0,0003 нм. Установлено, что плазменное облучение вызывает в поверхностном слое до 100 мкм формирование квазикристаллической икосаэдрической фазы. Установлено, что параметры субструктуры фазы: размер области когерентности, величина микронапряжений и плотность фазонов, а также уровень остаточных напряжений, определяются параметрами плазменного потока.Досліджено вплив опромінення водневими, гелієвими, аргонними плазмовими потоками з тепловими навантаженнями 0,4…0,6 MДж/м2 на зміну морфології, структури і фазового складу сплаву Ti41,5Zr41,5Ni17. Початковий стан такого сплаву характеризується присутністю фази кристала-апроксиманта 1/1 (W-фази) з періодом решітки аw = 1,428 ± 0,0003 нм, фази Лавеса (L-фаза) з періодом решітки a = 0,6043 ± 0,0003 нм і ікосаедричної квазікристалічної фази (i-фаза) з параметром квазікристалічності aq = 0,5175 ± 0,0003 нм. Встановлено, що опромінення плазмою викликає в поверхневому шарі до 100 мкм формування квазікристалічної ікосаедричної фази. Показано, що параметри субструктури фази: розмір області когерентності, величина мікронапружень, а також рівень залишкових макронапружень, визначаються параметрами плазми в потоці

Pion light-cone wave function and pion distribution amplitude in the Nambu-Jona-Lasinio model

We compute the pion light-cone wave function and the pion quark distribution amplitude in the Nambu-Jona-Lasinio model. We use the Pauli-Villars regularization method and as a result the distribution amplitude satisfies proper normalization and crossing properties. In the chiral limit we obtain the simple results, namely phi_pi(x)=1 for the pion distribution amplitude, and = -M / f_pi^2 for the second moment of the pion light-cone wave function, where M is the constituent quark mass and f_pi is the pion decay constant. After the QCD Gegenbauer evolution of the pion distribution amplitude good end-point behavior is recovered, and a satisfactory agreement with the analysis of the experimental data from CLEO is achieved. This allows us to determine the momentum scale corresponding to our model calculation, which is close to the value Q_0 = 313 MeV obtained earlier from the analogous analysis of the pion parton distribution function. The value of is, after the QCD evolution, around (400 MeV)^2. In addition, the model predicts a linear integral relation between the pion distribution amplitude and the parton distribution function of the pion, which holds at the leading-order QCD evolution.Comment: mistake in Eq.(38) correcte

TECHNOLOGICAL PROPERTIES OF MILK OF COWS WITH DIFFERENT GENOTYPES OF KAPPA-CASEIN AND BETA-LACTOGLOBULIN

The presence of the desirable alleles and genotypes of casein and whey protein genes in the genome of cows affects the milk protein content, quality and technological properties of their milk. Two important properties of milk its producibility is judged on are cheeseability and heat resistance. The present studies aimed at estimating the technological properties of milk of black-motley × Holstein and Kholmogorskaya breeds cows of the Tatarstan type with different kappa-casein (CSN3) and beta-lactoglobulin (BLG) genotypes. The study was carried out using a sampling of the first-calf cows of 5 cattle-breeding farms of the Republic of Tatarstan. In animals, the CSN3 and BLG genotypes have been determined by a PCR-RFLP analysis. The cheeseability, heat resistance and thermostability of milk have been estimated using standard methods. The studies have established that the CSN3 and BLG genotypes of cows affected the condition of a casein clot and duration of milk clotting time. The best cheese-making properties of milk were inherent in the animals with the BB and AB genotypes of the CSN3 and BLG genes. They were superior to the coevals with the AA genotype in terms of the highest yield of the desired dense casein clot and the shortest duration of milk clotting time. The first-calf cows, which are the carriers of an A allele of the CSN3 gene, were superior to the animals with the BB genotype of the CSN3 gene on the thermostability of milk including that on the proportion of animals with this milk characteristic. The BLG genotype of the studied animals did not significantly affect the thermostability of milk. Moreover, the highest thermostability of milk was characteristic of black-motley × Holstein cows with the AA genotype

Diffeomorphism Invariance in the Hamiltonian formulation of General Relativity

It is shown that when the Einstein-Hilbert Lagrangian is considered without any non-covariant modifications or change of variables, its Hamiltonian formulation leads to results consistent with principles of General Relativity. The first-class constraints of such a Hamiltonian formulation, with the metric tensor taken as a canonical variable, allow one to derive the generator of gauge transformations, which directly leads to diffeomorphism invariance. The given Hamiltonian formulation preserves general covariance of the transformations derivable from it. This characteristic should be used as the crucial consistency requirement that must be met by any Hamiltonian formulation of General Relativity.Comment: 13 page

Damaging of pure tungsten with different microstructure under sequential QSPA and LHD plasma loads

The cracking thresholds were evaluated for tungsten samples with different microstructure in the course of QSPA Kh – 50 repetitive plasma loads. No damage has been observed on the exposed surfaces under 0.1 MJ/m². Nevertheless, cracks were detected in the bulk of irradiated tungsten (with longitudinal grain orientation). Increasing heat load up to 0.2 MJ/m² caused the damaging of all types of tungsten targets. The observed cracks propagate to the bulk mainly transversely and parallel to the irradiated surface. The effect of the subsequent exposure with LHD divertor plasma on the tungsten samples was analyzed. The obtained results are discussed.Було оцінено пороги розтріскування для зразків вольфраму з різною мікроструктурою в процесі повторюваних плазмових навантажень КСПП Х–50. При навантаженнях менше 0,1 МДж/м², на відкритих поверхнях зразків вольфраму ушкоджень не спостерігається. Проте, тріщини спостерігаються в обсязі опроміненого зразка вольфраму з поздовжньою орієнтацією зерен. Підвищення теплового навантаження до 0,2 МДж/м² призводить до пошкодження всіх типів вольфрамових мішеней. Тріщини поширюються в обсязі в основному поперечно і паралельно до опромінюваної поверхні. Проаналізовано вплив діверторної плазми LHD на поверхню зразків вольфраму. Порівнюються результати впливу на зразки вольфраму з різною мікроструктурою.Были оценены пороги растрескивания для образцов вольфрама с различной микроструктурой в процессе повторяющихся плазменных нагрузок КСПУ Х–50. При нагрузках менее 0,1 МДж/м² на открытых поверхностях образцов вольфрама повреждений не наблюдается. Тем не менее трещины наблюдаются в объеме облученного образца вольфрама с продольной ориентацией зерен. Повышение тепловой нагрузки до 0,2 МДж/м² приводит к повреждению всех типов вольфрамовых мишеней. Наблюдаемые трещины распространяются в объеме в основном поперечно и параллельно облучаемой поверхности. Проанализировано влияние диверторной плазмы LHD на поверхность образцов вольфрама. Сравниваются результаты воздействия на образцы вольфрама с различной микроструктурой

Collective excitations of a two-dimensional interacting Bose gas in anti-trap and linear external potentials

We present a method of finding approximate analytical solutions for the spectra and eigenvectors of collective modes in a two-dimensional system of interacting bosons subjected to a linear external potential or the potential of a special form $u(x,y)=\mu -u \cosh^2 x/l$, where $\mu$ is the chemical potential. The eigenvalue problem is solved analytically for an artificial model allowing the unbounded density of the particles. The spectra of collective modes are calculated numerically for the stripe, the rare density valley and the edge geometry and compared with the analytical results. It is shown that the energies of the modes localized at the rare density region and at the edge are well approximated by the analytical expressions. We discuss Bose-Einstein condensation (BEC) in the systems under investigations at $T\ne 0$ and find that in case of a finite number of the particles the regime of BEC can be realized, whereas the condensate disappears in the thermodynamic limit.Comment: 10 pages, 2 figures include

Amphibole: A major carrier of helium isotopes in crustal rocks

The first evidence for a specific role of amphiboles in He isotope balance of crustal rocks was presented in early contributions by Gerling et al. (1971, 1976). Since then it was shown that 4He and 3He concentrations in amphiboles generally exceed those in the host rock samples. Recently amphibole was considered as an important carrier of noble gases and other volatiles components in the course of their subduction into the mantle. This paper presents new data on the balance and mobility of noble gas isotopes and major gas constituents in amphibole separates in order to understand sources and evolution of volatile components of 2666 Ma old alkaline granites from Ponoy massif (Kola Peninsula), which underwent metamorphism 1802 Ma ago.In the amphiboles 3He, 4He and 40Ar* were dominantly produced in situ due to radioactive decay of the parent isotopes and associated nuclear reactions. A small fraction of He (≈ 3% of the total) is liberated by crushing and shows 3He/4He ratio indistinguishable from that found by total extraction. The fraction of trapped 40Ar* amounts to ≈ 40%; both these fractions presumably occupy fluid inclusions and show rather low 4He/40Ar* ≈ 0.1, a factor of ≈ 150 below the production ratio (calculated assuming no loss / gain of the species has happened since the time of metamorphism).3He has been better preserved in amphiboles compared with 4He: the retention parameter (measured amount of He / totally produced amount) for 3He (≈ 0.4) exceeds that for 4He (≈ 0.15).He extraction by fast and slow linear heating of amphiboles resulted in different release patterns. The fast heating (within 12 to 40 °C min− 1) revealed a superposition of two peaks. When heating with slower heating rate (below 8 °C min− 1) was applied, the high-temperature peak disappeared (the “disappearing site”). Extractions of He atoms from grain and powder samples at different heating rates have shown that: (1) the “disappearing site” is revealed by the fast heating analyses of different amphibole samples but not only those from the Ponoy massif; (2) amount of He liberated from the “disappearing site” is variable and generally much less than the total amount of He in the sample; (3) analysis of the powder produced in the crushing experiments never reveals the “disappearing site”; the temperature of He release from the powder is lower than that from the mm grain size sample by ≈ 50 °C. Possible explanations of the nature of the “disappearing site” are discussed. However, independently on nature of this effect, repeated gas extractions by heating at different rates would give additional information about structure and its transformation during heating of amphiboles.The simplest explanation of the observed abundances of noble gas isotopes in the amphibole separates from Ponoy granites suggests local production, redistribution and partial loss of noble gases during evolution of the massif

Прогностическое значение коморбидной патологии в прогрессировании хронической обструктивной болезни легких в зависимости от фенотипических особенностей заболевания

Background: Chronic obstructive pulmonary disease (COPD) is characterized by progressive limitation of airflow rate, hyperergic inflammatory response of the respiratory tract, and systemic manifestations. Prognosis of the disease depends on the severity of these pathogenetic components. FEV1 which characterizes the speed limit airflow do not allow predicting the rate of COPD progression. Aims: comparison of the prognostic significance of such clinical parameters as frequency of exacerbations and the development of comorbid diseases to assess the nature of COPD progression by using different classification approaches. Materials and methods: The prospective comparative study included 98 patients with COPD. In the framework of the study protocol, 2 visits were required when a practitioner recruited patients who met inclusion/exclusion criteria, obtained the signed informed consent, collected the anamnestic data, and performed basic procedures of the study: spirometry, 6-minute stepper test, assessment of dyspnea on questionnaire mMRC, body plethysmography, lung diffusion capacity study, dopplerechocardiography, tomography of the chest. Visit 2 was conducted in 12 months after the first one to assess the dynamics of the disease. The dynamics of the disease was considered negative if, upon repeated examination, the patient was referred to the group with more severe COPD. Results: Our study demonstrates that comprehensive assessment of such factors as the frequency of COPD exacerbations in the preceding 12 months and the presence of comorbid diseases in a patient is reasonable for assessment of disease severity and determination of disease prognosis. At the same time the frequency of COPD exacerbations as one of the evaluated factors is most strongly associated with disease progression. Conclusions: Thus, a practitioner is recommended to use the proposed additional clinical criteria to assess the severity and degree of progression of COPD.Обоснование. Хроническая обструктивная болезнь легких (ХОБЛ) — хроническое заболевание с прогрессирующим ограничением скорости воздушного потока, гиперергическим воспалительным ответом дыхательных путей и системными проявлениями. От степени выраженности этих патогенетических компонентов зависит прогноз течения заболевания. Показано, что характеристика ограничения скорости воздушного потока (объем форсированного выдоха за первую секунду) не позволяет с высокой вероятностью предсказать скорость прогрессирования ХОБЛ.Цель исследования: сравнение прогностической значимости таких клинических показателей, как частота обострений и развитие коморбидных заболеваний, для оценки характера прогрессирования ХОБЛ при использовании различных классификационных подходов.Методы. На основании единого протокола в проспективное сравнительное исследование включены 98 больных ХОБЛ. В рамках протокола предусмотрено 2 визита, включающих оценку соответствия пациента критериям включения/исключения, подписание информированного согласия, сбор анамнестических данных и выполнение основных процедур исследования (оценка функции внешнего дыхания, 6-минутный шаговый тест, оценка одышки по опроснику mMRC, бодиплетизмография, исследование диффузионной способности легких, допплерэхокардиография, компьютерная томография органов грудной клетки). Второй визит проводился через 12 мес после первого с целью оценки динамики заболевания, которая считалась отрицательной, если по прошествии одного года наблюдения пациента переводили в группу ХОБЛ с более тяжелым течением. Коморбидными заболеваниями считались снижение индекса массы тела менее 21, наличие остеопороза, анемии, сердечно-сосудистых заболеваний, язвенной болезни желудка, сахарного диабета 2-го типа.Результаты. Проведенное нами исследование свидетельствует о целесообразности комплексной оценки таких факторов, как частота обострений ХОБЛ за предшествующие 12 мес и наличие коморбидных заболеваний у больного при оценке текущей тяжести течения заболевания и определении его прогноза. При этом частота обострений ХОБЛ среди оцениваемых факторов наиболее сильно связана с прогрессированием заболевания.Заключение. Таким образом, практическому врачу предложены дополнительные клинические критерии для комплексной оценки тяжести и степени прогрессирования ХОБЛ

Measurement of RudsR_{\text{uds}} and RR between 3.12 and 3.72 GeV at the KEDR detector

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have measured the values of $R_{\text{uds}}$ and $R$ at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or better than $3.3\%$ at most of energy points with a systematic uncertainty of about $2.1\%$. At the moment it is the most accurate measurement of $R(s)$ in this energy range

Transition form factors of the pion in light-cone QCD sum rules with next-to-next-to-leading order contributions

The transition pion-photon form factor is studied within the framework of Light-Cone QCD Sum Rules. The spectral density for the next-to-leading order corrections is calculated for any Gegenbauer harmonic. At the level of the next-to-next-to-leading (NNLO) radiative corrections, only that part of the hard-scattering amplitude is included that is proportional to the $\beta$-function, taking into account the leading zeroth-order harmonic. The relative size of the NNLO contribution in the prediction for the form factor $F^{\gamma^{*}\gamma\pi}(Q^2)$ has been analyzed, making use of the BLM scale-setting procedure. In addition, predictions for the form factor $F^{\gamma^{*}\rho\pi}$ are obtained that turn out to be sensitive to the endpoint behavior of the pion distribution amplitude, thus providing in connection with experimental data an additional adjudicator for the pion distribution amplitude. In a note added, we comment on the preliminary high-$Q^2$ BaBar data on $F^{\gamma^{*}\gamma\pi}$ arguing that the significant growth of the form factor between 10 and 40 GeV$^2$ cannot be explained in terms of higher-order perturbative corrections at the NNLO.Comment: 36 pages, 8 figures, 1 table. v2 new entry in Table I with reference added and replaced Fig. 6. v3 extended discussion of BaBar data (added 1 figure and references). v4 double reference removed; matches version published in Nucl. Phys. B. v5 corrected Ref. [62]; v6 corrects several errors (all boldfaced) and extended acknowledgment