Study of a nonhomogeneous aerogel radiator in a proximity focusing RICH detector

The use of a nonhomogeneous aerogel radiator, i.e. one consisting of layers with different refractive indices, has been shown to improve the resolution of the Cherenkov angle measured with a proximity focusing RICH detector. In order to obtain further information on the performance of such a detector, a simple model has been used to calculate the resolution and search for optimal radiator parameters.Comment: Submitted to Nucl. Instr. Met

Thermal reversible breakdown and resistivityswitching in hafnium dioxide

HfO2 nanostructures are currently considered to be very promising for different applications including gate oxides in Si transistors and emerging nonvolatile memory cells such as resistive random access memory (RRAM). For RRAM development a clear understanding of switching mechanisms from a HRS to a LRS is demanding. Several models were proposed to explain the switching effect [1-3], however, they did not cover comprehensively experimental observations. It is experimentally shown by means of high resolution transmission electron microscopy that formation of CFs with diameters of 30-50 nm in HfO2 occurred by an electrical pretreatment [2]. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2055

Interpreting of software for automation of accounting at enterprises

Запропоновано програмне забезпечення для автоматизації бухгалтерського обліку на підприємстві. Розглянуто систему, яка є достатньо функціональною, завершеною з точки зору обліку (автоматизації обліку), універсальною, тобто враховувати специфіку галузевих особливостей підприємств даної праці. Досліджено поетапний перехід до створення інформаційної системи вибору програмного забезпечення, яке повинно спиратися на системну комплексну оцінку. Тільки за умови вибору правильного програмного забезпечення можна максимізувати ефективність та ведення облікової діяльності, що безумовно, є необхідним кроком на шляху до розвитку і процвітання підприємства.Software for automation of accounting at the enterprise has been proposed. The system, which is efficient enough, completed from the accounting point of view (accounting automation), universal, being able to take into account specific characteristics of the enterprise work. Stage-by-stage transition to the creation of information system of the software selection, which must be based on the system complex evaluation, has been investigated. Comparative analysis of software for automation of accounting has been carried out. Software for automation of accounting are of great need at both small and large enterprises. The interest for it is roused nowadays. Within the market economy and tough competition the application of the latest technologies is of great demand. These are automated book-keeping software, which should be available for every book-keeper. There is a dependence between the scale of the enterprise and the type of the information technologies, applied at the computer systems of book-keeping. This dependence is coused by both the needs of information technologies to realize the functions, of the computer systems of book- keeping, and the expenses for its creation and introduction. The important component of the economic activity characteristics is the analysis of technology of collection, processing, storing and taking out the information, which is used at modern enterprises of different branches of national economy. General characteristics of the information system of the enterprise must be determined according to the composition and properties of the information system components. They are typical functional structure and functional abilities of the conventional information base of the enterprise. Only the proper chosen software can improve the efficiency of book-keeping, which is sure to result in the growth of the enterprise effectiveness and efficieney

Hydrophobic silica aerogel production at KEK

We present herein a characterization of a standard method used at the High Energy Accelerator Research Organization (KEK) to produce hydrophobic silica aerogels and expand this method to obtain a wide range of refractive index (n = 1.006-1.14). We describe in detail the entire production process and explain the methods used to measure the characteristic parameters of aerogels, namely the refractive index, transmittance, and density. We use a small-angle X-ray scattering (SAXS) technique to relate the transparency to the fine structure of aerogels.Comment: To be published in Nucl. Instr. and Meth. A, 9 pages, 10 figures, 1 tabl

Charge properties and currents in the silicon/nanoparticles of zinc oxide heterostructure irradiated by the solar light

Silicon/zinc oxide heterostructures have shown themselves to be promising for use in photovoltaics. This paper presents the results of modeling the charge properties and currents in a Si/nanosized ZnO particle with different types of conductivity under sunlight irradiation. The simulation was carried out using the Comsol Multiphysics software package. The energy diagrams of the investigated heterostructures were plotted, the charge properties and currents flowing in the structure were investigated, the dependences of the rate of generation of charge carriers on wavelength on the surfaces of silicon, zinc oxide, and at the interface between silicon and zinc oxide, the rate of recombination of charge carriers at various wavelengths of incident radiation was obtained. The regularities of the influence of wavelength of the incident radiation on the charge density and electric potential on the surface of heterostructures have been established. It is shown that the potential on the surface of the p-Si / n-ZnO heterostructure is positive, depends on the wavelength of the incident radiation and reaches the maximum of 0.68 V. For other structures, it is negative and does not depend on the wavelength: n-Si / p-ZnO –0.78 V, p-Si / p-ZnO –0.65 V, n-Si / n-ZnO –0.25 V.Silicon/zinc oxide heterostructures have shown themselves to be promising for use in photovoltaics. This paper presents the results of modeling the charge properties and currents in a Si/nanosized ZnO particle with different types of conductivity under sunlight irradiation. The simulation was carried out using the Comsol Multiphysics software package. The energy diagrams of the investigated heterostructures were plotted, the charge properties and currents flowing in the structure were investigated, the dependences of the rate of generation of charge carriers on wavelength on the surfaces of silicon, zinc oxide, and at the interface between silicon and zinc oxide, the rate of recombination of charge carriers at various wavelengths of incident radiation was obtained. The regularities of the influence of wavelength of the incident radiation on the charge density and electric potential on the surface of heterostructures have been established. It is shown that the potential on the surface of the p-Si / n-ZnO heterostructure is positive, depends on the wavelength of the incident radiation and reaches the maximum of 0.68 V. For other structures, it is negative and does not depend on the wavelength: n-Si / p-ZnO –0.78 V, p-Si / p-ZnO –0.65 V, n-Si / n-ZnO –0.25 V

Asymptotic analysis of retrial queueing system M/M/1 with non-persistent customers and collisions

A queuing system with repeated calls, one server, collisions (conflicts) of calls, H-persistence and rejections is considered. A call that found the device free occupies it, and service begins, which ends successfully if no other requests were received during it. If the server is busy, then a conflict (collision) arises between the call that have come for service and the ones being serviced, and in the general case, both calls instantly go to the orbit and repeat the attempt to successfully serve after a random time. In this article, in the event of a collision, one of the calls, for example, which was in service (on the device), goes into the orbit with probability H1, the other goes into orbit with probability H2, and with probability (1−H1) and (1−H2) respectively refuses service and leaves the system. The problem is to find asymptotic probabilities distribution of the calls number in the orbit

Гуманітарна діяльність ООН в Африці: особливості геополітичних реалій

1. Intelligence and peacekeepink; The UN Operation in the Congo 196064 [Електронний ресурс]. – Режим доступу: https://www.walterdorn.net/40intelligence-and-peacekeeping-the-un-operation-inthe-congo-1960-64 2. UNAMIR, International Tribunal for Rwand [Електронний ресурс]. – Режим доступу: https://peacekeeping.un.org/en/mission/past/unamirS.htm 3. Тhe New York Times: The Un in Congo: The failure of a peacekeeping mission [Електронний ресурс]. – Режим доступу: https://www.nytimes. com/2004/05/10/opinion/the-un-in-congo-the-failure-of-a-peacekeeping-mission.htm 4. BBC News: The UN’s peacekeeping nightmare in Africa [Електронний ресурс]. – https://www.bbc.com/news/world-africa-3837261 5. United Nations Economic Commission for Africa: MDG REPORT 2015[Електронний ресурс]. – Режим доступу: https://www.sl.undp.org/content/ sierraleone/en/home/presscenter/pressreleases/2015/09/28/after-the-mdgsrenewedcommitment-and-financing-required-to-spur-africa-s-development-.html 6. Amina Mohammed: A world without poverty [Електронний ресурс]. – Режим доступу: https://www.theafricareport.com/2223/a-world-withoutpovertyamina-mohammed/ 7. William Easterly: How the Millenium Development Goals are Unfair to Africa [Електронний ресурс]. – Режим доступу: https://papers.ssrn.com/sol3/ papers.cfm?abstract_id=2066805 8. United Nations: Sustainable Development Goals [Електронний ресурс].– Режим доступу: https://www.un.org/sustainabledevelopment/sustainabledevelopment-goals/ 9. Trevor Hambayi: The SDGs Are Failing Short on African Poverty: SME Investment Could be a Game Changer [Електронний ресурс]. – Режим доступу: https://nextbillion.net/sme-investment-for-african-poverty/ 10. BBC News: Africa Sahel belt region faces «desperate food crisis» [Електронний ресурс]. – Режим доступу: https://www.bbc.com/news/worldafrica- The Guardian: UN sounds alarm over unprecedented levels of hunger in southern Africa [Електронний ресурс]. – Режим доступу: https://www.theguardian. com/global-development/2020/jan/16/un-sounds-alarmover-unprecedented-levelsof-hunger-in-southern-africaAfrica’s relationship with the United Nations began in 1960, when 15 African countries gained independence and 17 became UN member states. In an effort to remove the stain of Western colonialism, the UN embarked on an effort to assist newly independent African states in their right to sovereignty and self-determination. Many states lacked familiarity with democratic structures, were plagued by ethnic strife, and faced internal struggles for access to political power and access to resources. The first peacekeeping mission on the African continent was established in what is now the Democratic Republic of Congo (DRC) with the support of 20,000 troops.Відносини Африки з Організацією Об'єднаних Націй розпочалися в 1960 році, коли 15 африканських країн отримали незалежність, а 17 стали членами ООН. Прагнучи усунути пляму західного колоніалізму, ООН розпочала зусилля, щоб допомогти новим незалежним африканським державам у їх праві на суверенітет та самовизначення. Багато держав не знайомі з демократичними структурами, зазнали етнічних суперечок і стикалися з внутрішньою боротьбою за доступ до політичної влади та доступ до ресурсів. Перша миротворча місія на африканському континенті була створена в теперішній Демократичній Республіці Конго (ДРК) за підтримки 20 000 військовослужбовців