350 research outputs found

    Heteroclinic cycles and chaos in a system of four identical phase oscillators with global biharmonic coupling

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    We study a system of four identical globally coupled phase oscillators with biharmonic coupling function. Its dimension and the type of coupling make it the minimal system of Kuramoto-type (both in the sense of the phase space's dimension and the number of harmonics) that supports chaotic dynamics. However, to the best of our knowledge, there is still no numerical evidence for the existence of chaos in this system. The dynamics of such systems is tightly connected with the action of the symmetry group on its phase space. The presence of symmetries might lead to an emergence of chaos due to scenarios involving specific heteroclinic cycles. We suggest an approach for searching such heteroclinic cycles and showcase first examples of chaos in this system found by using this approach.Comment: 18 pages, 8 figure

    Ozone and nitrogen dioxide above the northern Tien Shan

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    The results of systematic perennial measurements of the total ozone (since 1979) and nitrogen dioxide column (since 1983) in the atmosphere in the European-Asian continent center above the mountainmass of the Tien Shan are given. This region is distinguished by a great number of sunny days during a year. The observation station is at the Northern shore of Issyk Kul Lake (42.56 N 77.04 E 1650 m above the sea level). The measurement results are presented as the monthly averaged atmospheric total ozone and NO2 stratospheric column abundances (morning and evening). The peculiarities of seasonal variations of ozone and nitrogen dioxide atmospheric contents, their regular variances with a quasi-biennial cycles and trends have been noticed. Irregular variances of ozone and nitrogen dioxide atmospheric contents, i.e. their positive and negative anomalies in the monthly averaged contents relative to the perennial averaged monthly means, have been analyzed. The synchronous and opposite in phase anomalies in variations of ozone and nitrogen dioxide atmospheric contents were explained by the transport and zonal circulation in the stratosphere (Kamenogradsky et al., 1990)

    Анализ пула потенциальных доноров Московской области и случаев изъятия органов для трансплантации, подвергшихся судебно-медицинскому исследованию в 2017 году

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    Aim: to analyze the pool of potential donors in the Moscow region from among the corpses received for forensic medical examination, the effectiveness of their use, the assessment of the participation of the forensic service in transplantation coordination.Materials and methods. The potential donors from among the dead persons in 2017 from various injuries were analyzed, the conclusions of forensic experts in cases of the removal of internal organs from the corpse were studied.Results. In 2017, 417 forensic examinations of corpses with open and closed isolated traumatic brain injuries received as a result of various injuries were conducted. 328 corpses of males and 89 females, dominated by the age group of 61 and above – 170 (40.7%). The period of hospitalization 2–7 days – 173 (41.8%). In addition, 76 cases of no traumatic hemorrhages in the brain and under the matter of the brain caused by diseases were studied, the age was more than 60 years – 41 (53.9%) prevailed. In 29 cases, internal organs were taken for transplantation. Such corpses were investigated in 15 forensic departments out of 47 (31.9%), which are part of 8 departments of the Ministry of health of the Moscow region out of 15. Among donors, the prevalence of men 27 (93%) over women 2 (7%) in the 31–60 age group is 19 (65.5%). 17 were diagnosed with brain death (58.6%) and 12 asystolic donors (41.4%). Multiorgan removal was carried out in 13 cases (44.8%), in 15 cases kidneys were removal (51.7%), 1 case of refusal of the removal after visual inspection of the extracted organ.Conclusion. The Analysis allows to estimation a possible pool of potential donors in the Moscow region, to correlate with the volume of removal organs, which indicates insufficient efficiency of their use. Insufficiently active participation of medical institutions of Administrations of transplantological coordination in the territory of the Moscow region correlates with participation of medico legal experts in this coordination. In the conclusions of the experts found no evidence of traumatic damage to the organ and the obstruction of the expert when giving answers to the questions of the investigatory organizations.Целью работы явился анализ пула потенциальных и эффективных доноров на территории Московской области из числа трупов, поступивших на судебно-медицинское исследование, эффективность использования донорского потенциала региона, возможности современной судебно-медицинской службы в организации эффективной трансплантационной координации.Материалы и методы. Проанализированы потенциальные доноры из числа лиц, погибших в 2017 году от различных травм, изучены заключения судебно-медицинских экспертов в случаях забора внутренних органов у трупа.Результаты. В 2017 году было проведено 417 судебно-медицинских исследований трупов с открытыми и закрытыми изолированными черепно-мозговыми травмами, полученными в результате различных травм: 328 трупов мужского пола и 89 – женского, преобладала возрастная группа от 61 и выше – 170 (40,7%). Продолжительность пребывания в стационаре 2–7 сут – 173 (41,8%). Помимо этого, исследовано 76 случаев нетравматических кровоизлияний в мозг и под оболочки мозга, вызванных заболеваниями, преобладал возраст свыше 60 лет – 41 (53,9%). В 29 случаях проводился забор внутренних органов для трансплантации. Такие трупы исследовались в 15 судебно-медицинских отделениях из 47 (31,9%), входящих в состав 9 управлений Министерства здравоохранения Московской области из 15. Среди доноров отмечалось преобладание мужчин (27, или 93%) над женщинами (2, или 7%) и возрастной категории от 31 до 60 лет – 19 (65,5%); 17 были с диагнозом «смерть мозга» (58,6%) и 12 – асистолические доноры (41,4%). Мультиорганный забор органов проведен в 13 случаях (44,8%), в 15 случаях изымались почки (51,7%), 1 случай – отказ от извлеченного органа после его визуального осмотра.Заключение. Анализ позволяет судить о возможном пуле потенциальных доноров на территории Московской области, соотношение количества потенциальных доноров и проведенных заборов органов указывает на недостаточную эффективность организации трансплантационной координации в медицинских организациях на территории Московской области. В заключениях экспертов не выявлено фактов травматического повреждения органов и затруднения эксперта при ответах на вопросы следственных органов

    Synthesis of new pinane-type hetarylsulfides

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    © 2014 Springer Science+Business Media New York. New bicyclic thioterpenoids with heterocyclic fragments were prepared via reactions of (-)-β-pinene and its oxide with 1-phenyl-1H-tetrazole-5-thiol, 1-methylimidazole-2-thiol, and 4,6-dimethyl-2-pyrimidinesulfenylchloride

    Beam Test Results of the LHCb Electromagnetic Calorimeter.

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    The main properties of the LHCb electromagnetic calorimeter and a prototype of the monitoring system was studied at the X7 CERN test-beam facility. A dedicated MC simulation for light propagation in the scintillator tiles was developed and tuned with experimental data

    Characterisation of large area THGEMs and experimental measurement of the Townsend coefficients for CF4

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    Whilst the performance of small THGEMs is well known, here we consider the challenges in scaling these up to large area charge readouts. We first verify the expected gain of larger THGEMs by reporting experimental Townsend coefficients for a 10 cm diameter THGEM in low-pressure CF4_4. Large area 50 cm by 50 cm THGEMs were sourced from a commercial PCB supplier and geometrical imperfections were observed which we quantified using an optical camera setup. The large area THGEMs were experimentally characterised at Boulby Underground Laboratory through a series of gain calibrations and alpha spectrum measurements. ANSYS, Magboltz and Garfield++ simulations of the design of a TPC based on the large area THGEMs are presented. We also consider their implications for directional dark matter research and potential applications within nuclear security

    Design and Operation of Front-End Electronics for the HERA-B Muon Detector

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    We have implemented a cost-effective design for the readout electronics of both the anode wires and the cathode pads of large area proportional wire chambers for the HERA-B muon system based on the ASD-08 integrated circuit. To control and monitor the large number of readout channels, we have built a distributed control system based on Philips Semiconductors' I2C bus and microcontrollers. To date we have installed about 10800 channels of muon chambers and electronics. The average single channel noise occupancy is less than 10**-5, and the detectors have been operated with target interaction rates as high as 70 MHz

    Systematics of Inclusive Photon Production in 158 AGeV Pb Induced Reactions on Ni, Nb, and Pb Targets

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    The multiplicity of inclusive photons has been measured on an event-by-event basis for 158 AGeV Pb induced reactions on Ni, Nb, and Pb targets. The systematics of the pseudorapidity densities at midrapidity (rho_max) and the width of the pseudorapidity distributions have been studied for varying centralities for these collisions. A power law fit to the photon yield as a function of the number of participating nucleons gives a value of 1.13+-0.03 for the exponent. The mean transverse momentum, , of photons determined from the ratio of the measured electromagnetic transverse energy and photon multiplicity, remains almost constant with increasing rho_max. Results are compared with model predictions.Comment: 16 pages including 4 figure

    Scaling of Particle and Transverse Energy Production in 208Pb+208Pb collisions at 158 A GeV

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    Transverse energy, charged particle pseudorapidity distributions and photon transverse momentum spectra have been studied as a function of the number of participants (N_{part}) and the number of binary nucleon-nucleon collisions (N_{coll}) in 158 A GeV Pb+Pb collisions over a wide impact parameter range. A scaling of the transverse energy pseudorapidity density at midrapidity as N_{part}^{1.08 \pm 0.06} and N_{coll}^{0.83 \pm 0.05} is observed. For the charged particle pseudorapidity density at midrapidity we find a scaling as N_{part}^{1.07 \pm 0.04} and N_{coll}^{0.82 \pm 0.03}. This faster than linear scaling with N_{part} indicates a violation of the naive Wounded Nucleon Model.Comment: 13 pages, 16 figures, submitted to European Physical Journal C (revised results for scaling exponents

    Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP

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    Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~ events. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events. Decay-plane correlations, consistent with zero and with the Standard Model predictions, are measured
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