Dynamics of Alfvén waves in the night-side ionospheric Alfvén resonator at mid-latitudes

International audienceA numerical solution of the problem on dynamics of shear-mode Alfvén waves in the ionospheric Alfvén resonator (IAR) region at middle latitudes at nighttime is presented for a case when a source emits a single pulse of duration ? into the resonator region. It is obtained that a part of the pulse energy is trapped by the IAR. As a result, there occur Alfvén waves trapped by the resonator which are being damped. It is established that the amplitude of the trapped waves depends essentially on the emitted pulse duration ? and it is maximum at ?=(3/4)T, where T is the IAR fundamental period. The maximum amplitude of these waves does not exceed 30% of the initial pulse even under optimum conditions. Relatively low efficiency of trapping the shear-mode Alfvén waves is caused by a difference between the optimum duration of the pulse and the fundamental period of the resonator. The period of oscillations of the trapped waves is approximately equal to T, irrespective of the pulse duration ?. The characteristic time of damping of the trapped waves ?dec is proportional to T, therefore the resonator Q-factor for such waves is independent of T. For a periodic source the amplitude-frequency characteristic of the IAR has a local minimum at the frequency ?/?=(3/4)T, and the waves of such frequency do not accumulate energy in the resonator region. At the fundamental frequency ?=2?/T the amplitude of the waves coming from the periodic source can be amplified in the resonator region by more than 50%. This alone is a basic difference between efficiencies of pulse and periodic sources of Alfvén waves. Explicit dependences of the IAR characteristics (T, ?dec, Q-factor and eigenfrequencies) on the altitudinal distribution of Alfvén velocity are presented which are analytical approximations of numerical results

APPLICATION OF AXIAL EXHAUST OF STEAM TURBINE FOR WASTE-TO-ENERGY PLANT

The paper presents the main results associated with steam turbine equipment, which is used in waste-to-energy plant. The article contains influence of the design of the exhaust on the efficiency of the steam turbine. Considered a number of technical solutions for exhaust of steam turbines of various manufacturers.В работе изложены проблемы связанные с паротурбинным оборудованием, которое используется на мусоросжигательных заводах. В работе проанализированы влияние конструкции выхлопного патрубка на эффективность работы паровой турбины. Рассмотрен ряд технических решений по выхлопным патрубкам паровых турбин различных производителей

Thickness dependence of the triplet spin-valve effect in superconductor-ferromagnet-ferromagnet heterostructures

© 2016 Lenk et al.Background: In nanoscale layered S/F1/N/F2/AF heterostructures, the generation of a long-range, odd-in-frequency spin-projection one triplet component of superconductivity, arising at non-collinear alignment of the magnetizations of F1 and F2, exhausts the singlet state. This yields the possibility of a global minimum of the superconducting transition temperature Tc, i.e., a superconducting triplet spin-valve effect, around mutually perpendicular alignment. Results: The superconducting triplet spin valve is realized with S = Nb a singlet superconductor, F1 = Cu41Ni59 and F2 = Co ferromagnetic metals, AF = CoOx an antiferromagnetic oxide, and N = nc-Nb a normal conducting (nc) non-magnetic metal, which serves to decouple F1 and F2. The non-collinear alignment of the magnetizations is obtained by applying an external magnetic field parallel to the layers of the heterostructure and exploiting the intrinsic perpendicular easy-axis of the magnetization of the Cu41Ni59 thin film in conjunction with the exchange bias between CoOx and Co. The magnetic configurations are confirmed by superconducting quantum interference device (SQUID) magnetic moment measurements. The triplet spin-valve effect has been investigated for different layer thicknesses, dF1, of F1 and was found to decay with increasing dF1. The data is described by an empirical model and, moreover, by calculations using the microscopic theory. Conclusion: The long-range triplet component of superconducting pairing is generated from the singlet component mainly at the N/F2 interface, where the amplitude of the singlet component is suppressed exponentially with increasing distance dF1. The decay length of the empirical model is found to be comparable to twice the electron mean free path of F1 and, thus, to the decay length of the singlet component in F1. Moreover, the obtained data is in qualitative agreement with the microscopic theory, which, however, predicts a (not investigated) breakdown of the triplet spin-valve effect for dF1 smaller than 0.3 to 0.4 times the magnetic coherence length, ζF1

The first experience of application of High-intensity focused ultrasound (HIFU) ablation for prostate cancer

In the clinic of urology of the Sverdlovsk regional hospital № 1 organized 32 HIFU therapy. The mean operative time 120 minutes (from 40 to 180 minutes). Intraoperative complications were not. The average time of hospitalization was 7 (6 to 10) days. Postoperative hospital stay from 5 to 7 days. Within 3 months all patients decreased PSA to 0.5 ng/ml and below. In 20 patients after 6 months, there has been a constantly low level of PSA is 0.2 ng/ml to 0.5 ng/ml. Thus, the use of high-intensity focused ultrasound ablation can be successfully treated various stages of prostate cancer with minimal side effects, provides opportunities for early assessment of the effectiveness of treatment.В клинике урологии ГБОУ ВПО УГМУ на базе ГБУЗ СО 'СОКБ1 №1 проведено 32 HIFU терапии. Среднее время операции 120 минут (от 40 до 180 мин.). Интраоперационных осложнений не было. Среднее время госпитализации составило 7 (от 6 до 10) дней. Послеоперационный койко-день от 5 до7 дней. В течение 3 месяцев у всех пациентов произошло снижение PSA до 0,5 нг/мл и ниже. У 20 пациентов после 6 месяцев наблюдается стабильно низкий уровень PSA от 0,2 нг/мл до 0,5 нг/мл. Таким образом, применение высокоинтенсивной фокусированной ультразвуковой абляции позволяет успешно лечить различные стадии рака простаты, с минимальными побочными эффектами, дает возможность ранней оценки эффективности лечения

Postoperative complications after percutaneous nephrolithotripsy in patients with urolithiasisd

Bleeding, damage to adjacent organs and structures, pleural injury when developing PNL, is a serious complication of surgical treatment of urolithiasis. The purpose of this study is a retrospective analysis of complications after the PNL. Most of the complications are associated with sub-optimal choices and conduct real-time access and inadequate assessment of the degree of bacteriuria. Nevertheless, the frequency of complications of PNL remains very low comparing with other treatments staghom nephrolithiasis.Кровотечение, повреждение соседних органов и структур, ранение плевральной полости, развивающееся при перкутанной нефролитотрипсии, являются серьезными осложнениями оперативного лечения мочекаменной болезни. Цель данной работы ретроспективный анализ осложнений после выполнения перкутанной нефролитотрипсии. Большинство осложнений связано с неоптимальным выбором и проведением оперативного доступа и неадекватной оценкой степени бактериурии. Тем не менее, частота осложнений при ЧНЛ остается весьма низкой по сравнению с другими методами лечения коралловидного нефролитиаза