47 research outputs found
Corrosion of diffusion zinc coatings in sodium chloride solutions
Diffusion galvanizing is widely used in the pipe industry for coating the threaded surface of pipe couplings, protecting water and gas pipelines, and other metal products. Diffusion coatings have a number of advantages over other types of zinc coatings. In this work, electrochemical and gravimetric methods are used to study the corrosion behavior of diffusion zinc coatings in sodium chloride solutions. The corrosion rate depends non-linearly on the thickness of the coating. At the initial stages, the corrosion rate of coatings depends on the structure of the phases on the surface, and with an increase in the holding time, the corrosion rate depends to a greater extent on the properties of the products formed during the corrosion process. Films of corrosion products of diffusion zinc coatings consist of zinc oxide/hydroxide and basic zinc salts, while the composition of the film changes with increasing coating thickness
Steering a multi-MeV positron beam with a curved crystal
We observe positron bending by a crystal lattice, presumably being guided by a channeling phenomenon, deflecting the beam by about 10 milliradian over a length of 1 mm of silicon. This technique may lead to the use of the channeling effect for steering particle beams at energies below 1 GeV, for the purpose of producing beams of low emittance with enhanced stability for medical and biological applications
Using a deformed crystal for bending a sub-GeV positron beam
Abstract We analyze the scattering of 480 MeV positrons in bent crystal lattices carried out at the Beam Test Facility of the INFN – Laboratori Nazionali di Frascati. We observe experimentally that some particles follow the bending of the crystal lattice, presumably being guided by channeling phenomenon, and are deflected through the angles of about 10 mrad over length of 1 mm of silicon. This technique may lead to the use of channeling effect for steering of particle beams at the energies under 1 GeV, aimed at the production of ultrastable beams of low emittance for medical and biological applications
The wireless communications systems in subterahertz frequency range
Background. The subterahertz and terahertz frequency ranges are very promising for development of high speed wireless communications systems because of possibility to get the bandwidth about some tens of GHz, which provides the high channel capacity. However fast signal attenuation at its propagation in atmosphere complicate the operation of communications systems in these ranges.
Aim. Use of fixed narrow-beam antennas with high antenna power gain allows to provide the direct surface communications distance to some kilometers. The communications distance limitation can be partially removed decreasing the frequency down to 200 GHz and narrowing the channel bandwidth down to some GHz.
Methods.The model of transmitter-receiver system (200-220 GHz) based of modern semiconductor devices is described in the manuscript. Results. The possibility of digital signals transmission with speed up to 1 Gbit/s at the distance of 1 km is experimentally shown.
Conclusion. According to calculations the output power of transmitter about some hundreds mW is enough for data transmission at the distance up to 1.5 km with antenna power gain of no less than 50 dB
Redução das ameaças à segurança financeira e desenvolvimento inovador de empresas sob influência do progresso científico e tecnológico
Among the problematic issues of enterprise management, the most relevant are the issues of managing the innovative development of enterprises (IDE) and controlling the processes of ensuring their financial security (FSE). The purpose of the article is to identify the key components of financial security and the innovative development of an industrial enterprise that need to be taken into account when making managerial decisions. The authors have concluded that the relationship between the prevention of threats of FSE and IDE has a dual character, which necessitates an integrated approach to their management, based on their consideration as two inextricably linked and mutually influencing levers of management efficiency, and the allocation based on their integration of the financial security of IDE as a separate research subject and object of management.Entre los temas problemáticos de la gestión empresarial, los más relevantes son los de gestionar el desarrollo innovador de las empresas y controlar los procesos para garantizar su seguridad financiera. El propósito del artículo es identificar los componentes clave de la seguridad financiera y el desarrollo innovador de una empresa industrial que deben tenerse en cuenta al tomar decisiones de gestión. Los autores han concluido que la relación entre la prevención de amenazas de seguridad financiera y desarrollo innovador de una empresa tiene un carácter dual, que requiere un enfoque integrado de su gestión, basado en su consideración como dos palancas de eficiencia de gestión indisolublemente vinculadas y que se influyen mutuamente, y la asignación basada en su integración de la seguridad financiera del desarrollo innovador de la empresa como sujeto de investigación separado y objeto de gestión.Dentre as questões problemáticas da gestão empresarial, as mais relevantes são as questões da gestão do desenvolvimento inovador das empresas e do controle dos processos de garantia de sua segurança financeira. O objetivo do artigo é identificar os principais componentes da segurança financeira e do desenvolvimento inovador de uma empresa industrial que precisam ser levados em consideração na tomada de decisões gerenciais. Os autores concluíram que a relação entre a prevenção de ameaças de segurança financeira e desenvolvimento inovador de uma empresa tem um caráter dual, que necessita de uma abordagem integrada para sua gestão, com base em sua consideração como duas alavancas de eficiência de gestão inextricavelmente ligadas e mutuamente influenciadas, e a alocação baseada em sua integração da segurança financeira do desenvolvimento inovador da empresa como um assunto de pesquisa separado e objeto de gestão
Findings to the flora of Russia and adjacent countries: New national and regional vascular plant records, 4
With this paper we continue a new annual series, the main purpose of which is to make significant floristic findings from Russia and neighboring countries more visible in Russia and abroad. In total, this paper presents new records for 48 vascular plant species from 6 Eurasian countries, obtained during field explorations, as well as during taxonomic revisions of herbarium materials. For the first time, a new locality of Leontopodium leiolepis is recorded for Russia, Rheum uzengukuushi for China, Rorippa prolifera for Lithuania, Lappula marginata for Kyrgyzstan and Tajikistan, Anthriscus caucalis, Chenopodium ficifolium, Euphorbia prostrata for Uzbekistan, Adonis × hybrida, Potamogeton × franconicus, Solidago × niederederi for the Asian part of Russia, Echinochloa esculenta, Poa jamalinensis, Puccinellia poecilantha for Siberia, Potentilla intermedia for the Caucasus, Rhynchospora alba for the Russian part of Altai, Poa sphondylodes, Veronica beccabunga for Eastern Siberia, Asclepias syriaca for the Republic of Altai, Chimaphila umbellata, Orobanche korshinskyi, Veronica scutellata for the Republic of Buryatia, Cirsium alatum, Thalictrum simplex for the Republic of Crimea, Thymus rariflorus, Th. terekensis for the Republic of Ingushetia, Berberis thunbergii, Crataegus maximowiczii, Prunus serotina for the Republic of Mordovia, Oenothera villosa for the Republic of Tatarstan, Astragalus sulcatus, Galium mollugo for the Republic of Tyva, Phragmites altissimus for the Chelyabinsk Region, Senecio dubitabilis for the Magadan Region, Asclepias syriaca, Galatella villosa, Potentilla recta for the Novosibirsk Region, Dodartia orientalis for the Omsk Region, Viola hultenii for the Sakhalin Region, Phragmites tzvelevii for the Samara Region and the Middle Volga, Jacobaea ferganensis for the Samara Region, Carex media, Impatiens parviflora for the Tyumen Region. There are some more findings which are not new for the region but they contribute significantly to the understanding of species distribution
Emission Monitoring Mobile Experiment (EMME): An overview and first results of the St. Petersburg megacity campaign 2019
Global climate change is one of the most important scientific, societal and economic contemporary challenges. Fundamental understanding of the major processes driving climate change is the key problem which is to be solved not only on a global but also on a regional scale. The accuracy of regional climate modelling depends on a number of factors. One of these factors is the adequate and comprehensive information on the anthropogenic impact which is highest in industrial regions and areas with dense population – modern megacities. Megacities are not only “heat islands”, but also significant sources of emissions of various substances into the atmosphere, including greenhouse and reactive gases. In 2019, the mobile experiment EMME (Emission Monitoring Mobile Experiment) was conducted within the St. Petersburg agglomeration (Russia) aiming to estimate the emission intensity of greenhouse (CO, CH) nd reactive (CO, NO) gases for St. Petersburg, which is the largest northern megacity. St. Petersburg State University (Russia), Karlsruhe Institute of Technology (Germany) and the University of Bremen (Germany) jointly ran this experiment. The core instruments of the campaign were two portable Bruker EM27/SUN Fourier transform infrared (FTIR) spectrometers which were used for ground-based remote sensing measurements of the total column amount of CO, CH and CO at upwind and downwind locations on opposite sides of the city. The NO tropospheric column amount was observed along a circular highway around the city by continuous mobile measurements of scattered solar visible radiation with an OceanOptics HR4000 spectrometer using the differential optical absorption spectroscopy (DOAS) technique. Simultaneously, air samples were collected in air bags for subsequent laboratory analysis. The air samples were taken at the locations of FTIR observations at the ground level and also at altitudes of about 100 m when air bags were lifted by a kite (in case of suitable landscape and favourable wind conditions). The entire campaign consisted of 11 mostly cloudless days of measurements in March–April 2019. Planning of measurements for each day included the determination of optimal location for FTIR spectrometers based on weather forecasts, combined with the numerical modelling of the pollution transport in the megacity area. The real-time corrections of the FTIR operation sites were performed depending on the actual evolution of the megacity NO plume as detected by the mobile DOAS observations. The estimates of the St. Petersburg emission intensities for the considered greenhouse and reactive gases were obtained by coupling a box model and the results of the EMME observational campaign using the mass balance approach. The CO emission flux for St. Petersburg as an area source was estimated to be 89 ± 28 ktkm yr , which is 2 times higher than the corresponding value in the EDGAR database. The experiment revealed the CH emission flux of 135 ± 68 tkm yr , which is about 1 order of magnitude greater than the value reported by the official inventories of St. Petersburg emissions (∼ 25 tkm yr or 2017). At the same time, for the urban territory of St. Petersburg, both the EMME experiment and the official inventories for 2017 give similar results for the CO anthropogenic flux (251 ± 104 tkm yr s. 410 tkm yr ) nd for the NO anthropogenic flux (66 ± 28 tkm yr vs. 69 tkm yr )
Transition from fireball to Poynting-flux-dominated outflow in the three-episode GRB 160625B
The ejecta composition is an open question in gamma-ray burst (GRB) physics . Some GRBs possess a quasi-thermal spectral component in the time-resolved spectral analysis , suggesting a hot fireball origin. Others show a featureless non-thermal spectrum known as the Band function , consistent with a synchrotron radiation origin and suggesting that the jet is Poynting-flux dominated at the central engine and probably in the emission region as well . There are also bursts showing a sub-dominant thermal component and a dominant synchrotron component , suggesting a probable hybrid jet composition . Here, we report an extraordinarily bright GRB 160625B, simultaneously observed in gamma-ray and optical wavelengths, whose prompt emission consists of three isolated episodes separated by long quiescent intervals, with the durations of each sub-burst being approximately 0.8 s, 35 s and 212 s, respectively. Its high brightness (with isotropic peak luminosity L ≈ 4 × 10 erg s) allows us to conduct detailed time-resolved spectral analysis in each episode, from precursor to main burst and to extended emission. The spectral properties of the first two sub-bursts are distinctly different, allowing us to observe the transition from thermal to non-thermal radiation between well-separated emission episodes within a single GRB. Such a transition is a clear indication of the change of jet composition from a fireball to a Poynting-flux-dominated jet.B.-B.Z. thanks Y.-Z. Fan, Y.-Z. Wang, H. Wang, K. D. Alexander and D. Lazzati for helpful discussions. We are grateful to K. Hurley, I. Mitrofanov, A. Sanin, M. Litvak and W. Boynton for the use of Mars Odyssey data in the triangulation. We acknowledge the use of the public data from the Swift and Fermi data archives. B.-B. Z. and A.J. C.-T. acknowledge support from the Spanish Ministry Projects AYA2012-39727-C03-01 and AYA2015-71718-R. Part of this work made use of B.-B.Z.'s personal Interactive Data Language (IDL) code library ZBBIDL and personal Python library ZBBPY. The computation resources used in this work are owned by Scientist Support LLC. B.Z. acknowledges NASA NNX14AF85G and NNX15AK85G for support. Z. G. D. acknowledges the National Natural Science Foundation of China(NSFC) (grant 11573014). Y.-D. H. acknowledges support by China Scholarships Council (grant 201406660015). Mini-MegaTORTORA belongs to Kazan Federal University, and the work is performed according to the Russian Government Program of Competitive Growth of Kazan Federal University. A. P., E.M., P. M. and A.V. are grateful to the Russian Foundation for Basic Research (grant 17-02-01388) for partial support. A. P. and S.B.P. acknowledge joint BRICS (Brazil, Russia, India, China and South Africa) grant RFBR 17-52-80139 and 388-ProFChEAP for partial support. R. I. is grateful to grant RUSTAVELI FR/379/6300/ 14 for partial support. Observations on Mini-MegaTORTORA are supported by the Russian Science Foundation (grant 14-50-00043). A.V.F. and A. M. thank the Russian Science Foundation (grant 14-50-00043). L.M. and A.F.Z. acknowledge support from INTA-CEDEA ESAt personnel hosting the Pi of the Sky facility at the BOOTES-1 station. H. G. and X.-Y.W. acknowledge NSFC (grants 11603003 and 11625312, respectively). Z. G. D., X.-F. W., B.Z., X.-Y. W.,L.S. and F.-W.Z. are also supported by the 973 program (grant 2014CB845800). F.-W.Z. is also supported in part by the NSFC (grants U1331101 and 11163003), the Guangxi Natural Science Foundation (grant 2013GXNSFAA019002) and the project of outstanding young teachers' training in higher education institutions of Guangxi. L.S. acknowledges support by the NSFC (grant 11103083) and the Joint NSFC-ISF Research Program (grant 11361140349). S.O. acknowledges the support of the Leverhulme Trust. S.J. acknowledges support from Korea Basic Science Research Program through NRF-2014R1A6A3A03057484 and NRF-2015R1D1A4A01020961, and I. H. P. through NRF-2015R1A2A1A01006870 and NRF-2015R1A2A1A15055344. R. A., D. F. and D. S. acknowledge support from RSF (grant 17-12-01378). A. K. acknowledges the Science and Education Ministry of Kazakhstan (grant 0075/GF4).Peer reviewe
Global, regional, and national burden of neurological disorders during 1990-2015 : a systematic analysis for the Global Burden of Disease Study 2015
Background Comparable data on the global and country-specific burden of neurological disorders and their trends are crucial for health-care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study provides such information but does not routinely aggregate results that are of interest to clinicians specialising in neurological conditions. In this systematic analysis, we quantified the global disease burden due to neurological disorders in 2015 and its relationship with country development level. Methods We estimated global and country-specific prevalence, mortality, disability-adjusted life-years (DALYs), years of life lost (YLLs), and years lived with disability (YLDs) for various neurological disorders that in the GBD classification have been previously spread across multiple disease groupings. The more inclusive grouping of neurological disorders included stroke, meningitis, encephalitis, tetanus, Alzheimer's disease and other dementias, Parkinson's disease, epilepsy, multiple sclerosis, motor neuron disease, migraine, tension-type headache, medication overuse headache, brain and nervous system cancers, and a residual category of other neurological disorders. We also analysed results based on the Socio-demographic Index (SDI), a compound measure of income per capita, education, and fertility, to identify patterns associated with development and how countries fare against expected outcomes relative to their level of development. Findings Neurological disorders ranked as the leading cause group of DALYs in 2015 (250.7 [95% uncertainty interval (UI) 229.1 to 274.7] million, comprising 10.2% of global DALYs) and the second-leading cause group of deaths (9.4 [9.1 to 9.7] million], comprising 16.8% of global deaths). The most prevalent neurological disorders were tensiontype headache (1505 9 [UI 1337.3 to 1681.6 million cases]), migraine (958.8 [872.1 to 1055.6] million), medication overuse headache (58.5 [50.8 to 67.4 million]), and Alzheimer's disease and other dementias (46.0 [40.2 to 52.7 million]). Between 1990 and 2015, the number of deaths from neurological disorders increased by 36.7%, and the number of DALYs by 7.4%. These increases occurred despite decreases in age-standardised rates of death and DALYs of 26.1% and 29.7%, respectively; stroke and communicable neurological disorders were responsible for most of these decreases. Communicable neurological disorders were the largest cause of DALYs in countries with low SDI. Stroke rates were highest at middle levels of SDI and lowest at the highest SDI. Most of the changes in DALY rates of neurological disorders with development were driven by changes in YLLs. Interpretation Neurological disorders are an important cause of disability and death worldwide. Globally, the burden of neurological disorders has increased substantially over the past 25 years because of expanding population numbers and ageing, despite substantial decreases in mortality rates from stroke and communicable neurological disorders. The number of patients who will need care by clinicians with expertise in neurological conditions will continue to grow in coming decades. Policy makers and health-care providers should be aware of these trends to provide adequate services.Peer reviewe
Measuring performance on the Healthcare Access and Quality Index for 195 countries and territories and selected subnational locations: A systematic analysis from the Global Burden of Disease Study 2016
Background: A key component of achieving universal health coverage is ensuring that all populations have access to quality health care. Examining where gains have occurred or progress has faltered across and within countries is crucial to guiding decisions and strategies for future improvement. We used the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016) to assess personal health-care access and quality with the Healthcare Access and Quality (HAQ) Index for 195 countries and territories, as well as subnational locations in seven countries, from 1990 to 2016. Methods Drawing from established methods and updated estimates from GBD 2016, we used 32 causes from which death should not occur in the presence of effective care to approximate personal health-care access and quality by location and over time. To better isolate potential effects of personal health-care access and quality from underlying risk factor patterns, we risk-standardised cause-specific deaths due to non-cancers by location-year, replacing the local joint exposure of environmental and behavioural risks with the global level of exposure. Supported by the expansion of cancer registry data in GBD 2016, we used mortality-to-incidence ratios for cancers instead of risk-standardised death rates to provide a stronger signal of the effects of personal health care and access on cancer survival. We transformed each cause to a scale of 0-100, with 0 as the first percentile (worst) observed between 1990 and 2016, and 100 as the 99th percentile (best); we set these thresholds at the country level, and then applied them to subnational locations. We applied a principal components analysis to construct the HAQ Index using all scaled cause values, providing an overall score of 0-100 of personal health-care access and quality by location over time. We then compared HAQ Index levels and trends by quintiles on the Socio-demographic Index (SDI), a summary measure of overall development. As derived from the broader GBD study and other data sources, we examined relationships between national HAQ Index scores and potential correlates of performance, such as total health spending per capita. Findings In 2016, HAQ Index performance spanned from a high of 97\ub71 (95% UI 95\ub78-98\ub71) in Iceland, followed by 96\ub76 (94\ub79-97\ub79) in Norway and 96\ub71 (94\ub75-97\ub73) in the Netherlands, to values as low as 18\ub76 (13\ub71-24\ub74) in the Central African Republic, 19\ub70 (14\ub73-23\ub77) in Somalia, and 23\ub74 (20\ub72-26\ub78) in Guinea-Bissau. The pace of progress achieved between 1990 and 2016 varied, with markedly faster improvements occurring between 2000 and 2016 for many countries in sub-Saharan Africa and southeast Asia, whereas several countries in Latin America and elsewhere saw progress stagnate after experiencing considerable advances in the HAQ Index between 1990 and 2000. Striking subnational disparities emerged in personal health-care access and quality, with China and India having particularly large gaps between locations with the highest and lowest scores in 2016. In China, performance ranged from 91\ub75 (89\ub71-93\ub76) in Beijing to 48\ub70 (43\ub74-53\ub72) in Tibet (a 43\ub75-point difference), while India saw a 30\ub78-point disparity, from 64\ub78 (59\ub76-68\ub78) in Goa to 34\ub70 (30\ub73-38\ub71) in Assam. Japan recorded the smallest range in subnational HAQ performance in 2016 (a 4\ub78-point difference), whereas differences between subnational locations with the highest and lowest HAQ Index values were more than two times as high for the USA and three times as high for England. State-level gaps in the HAQ Index in Mexico somewhat narrowed from 1990 to 2016 (from a 20\ub79-point to 17\ub70-point difference), whereas in Brazil, disparities slightly increased across states during this time (a 17\ub72-point to 20\ub74-point difference). Performance on the HAQ Index showed strong linkages to overall development, with high and high-middle SDI countries generally having higher scores and faster gains for non-communicable diseases. Nonetheless, countries across the development spectrum saw substantial gains in some key health service areas from 2000 to 2016, most notably vaccine-preventable diseases. Overall, national performance on the HAQ Index was positively associated with higher levels of total health spending per capita, as well as health systems inputs, but these relationships were quite heterogeneous, particularly among low-to-middle SDI countries. Interpretation GBD 2016 provides a more detailed understanding of past success and current challenges in improving personal health-care access and quality worldwide. Despite substantial gains since 2000, many low-SDI and middle- SDI countries face considerable challenges unless heightened policy action and investments focus on advancing access to and quality of health care across key health services, especially non-communicable diseases. Stagnating or minimal improvements experienced by several low-middle to high-middle SDI countries could reflect the complexities of re-orienting both primary and secondary health-care services beyond the more limited foci of the Millennium Development Goals. Alongside initiatives to strengthen public health programmes, the pursuit of universal health coverage hinges upon improving both access and quality worldwide, and thus requires adopting a more comprehensive view-and subsequent provision-of quality health care for all populations