Performance of cylindrical converters with preferred-crystal-orientation emitters of chemically vapor deposited tungsten

Design and evaluation of cylindrical out-of-pile thermionic converter test vehicle to determine performance of tungsten emitters with preferred crystal orientatio

Self-excited Oscillations of Charge-Spin Accumulation Due to Single-electron Tunneling

We theoretically study electronic transport through a layer of quantum dots connecting two metallic leads. By the inclusion of an inductor in series with the junction, we show that steady electronic transport in such a system may be unstable with respect to temporal oscillations caused by an interplay between the Coulomb blockade of tunneling and spin accumulation in the dots. When this instability occurs, a new stable regime is reached, where the average spin and charge in the dots oscillate periodically in time. The frequency of these oscillations is typically of the order of 1GHz for realistic values of the junction parameters

Nanomechanical manipulation of superconducting charge-qubit quantum networks

We suggest a nanoelectromechanical setup and corresponding time-protocol for controlling parameters in order to demonstrate nanomechanical manipulation of superconducting charge-qubit quantum network. We illustrate it on an example reflecting important task for quantum information processing - transmission of quantum information between two charge-qubits facilitated by nanomechanics. The setup is based on terminals utilizing the AC Josephson effect between bias voltage-controlled bulk superconductors and mechanically vibrating mesoscopic superconducting grain in the regime of the Cooper pair box, controlled by the gate voltage. The described manipulation of quantum network is achieved by transduction of quantum information between charge-qubits and intentionally built nanomechanical coherent states, which facilitate its transmission between qubits. This performance is achieved using quantum entanglement between electrical and mechanical states.Comment: 8 pages, 4 figure

Регулююча функція непрямих податків та її вплив на фінансово-господарську діяльність підприємства

У статті розглянуто вплив регулюючої функції непрямого оподаткування на фінансово-господарську діяльність підприємств. Наведено основні фактори, що визначають регулюючу роль непрямих податків, та приклади їх застосування для впливу на діяльність господарюючих суб’єктів

Fermentative bio-hydrogen production from organic wastes and sugars

Utilization of renewable energy has been identified as a priority within the “European Energy Policy” which stresses the need to develop new sources of green energy. A follow-up of the programme “Intelligent Energy – Europe” (Decision No. 1230/2003/EC of the European Parliament and of the Council of 26 June 2003) is projected for the 7th Framework Programme (2007-2013). The main focus of the programme is the production of electricity from renewable sources of energy, as described in Directive 2001/77/EC of the European Parliament and of the Council of 27 September 2001. According to this document, Portugal has committed to raise the national electricity production exclusively from renewable sources to 39% by 2010. In addition, it constitutes an essential part of the package of measures necessary to comply with the commitments made by the EU under the 1997 Kyoto Protocol on the reduction of greenhouse gas emissions. Hydrogen is a CO2-neutral energy source with a very promising future as an alternative to fossil fuels for energy production. The treatment and disposal of wastes by conventional methods poses many problems throughout the world and may result in the consumption of energy. In addition, costs to dispose and treat wastes are escalating. Hydrogen can be produced, from undesirable waste products by bacterial fermentation, to generate electricity. The Centre for Biological Engineering at the University of Minho is studying bio-hydrogen production from organic wastes and sugars. The specific tasks of the project (FCT/POCI/ENR/57786/2004) include the utilization of different waste compositions from a real kitchen waste and sugars to produce and optimize H2 yields, methanogenesis inhibition strategies, design, construction and operation of batch and continuous lab scale reactors for mesophilic (37 °C), thermophilic (55 °C), and hyperthermophilic (70 °C) conditions. In addition, molecular ecology techniques are being used to study bacterial community dynamics in the different bioreactors, comparing the microbial communities developed at different temperatures and different OLR. One objective is to determine the optimal conditions to select the most important microorganisms involved in H2 production

Predictors of subgroups based on maximum drinks per occasion over six years for 833 adolescents and young adults in COGA.

ObjectiveA person's pattern of heavier drinking often changes over time, especially during the early drinking years, and reflects complex relationships among a wide range of characteristics. Optimal understanding of the predictors of drinking during times of change might come from studies of trajectories of alcohol intake rather than cross-sectional evaluations.MethodThe patterns of maximum drinks per occasion were evaluated every 2 years between the average ages of 18 and 24 years for 833 subjects from the Collaborative Study on the Genetics of Alcoholism. Latent class growth analysis identified latent classes for the trajectories of maximum drinks, and then logistic regression analyses highlighted variables that best predicted class membership.ResultsFour latent classes were found, including Class 1 (69%), with about 5 maximum drinks per occasion across time; Class 2 (15%), with about 9 drinks at baseline that increased to 18 across time; Class 3 (10%), who began with a maximum of 18 drinks per occasion but decreased to 9 over time; and Class 4 (6%), with a maximum of about 22 drinks across time. The most consistent predictors of higher drinking classes were female sex, a low baseline level of response to alcohol, externalizing characteristics, prior alcohol and tobacco use, and heavier drinking peers.ConclusionsFour trajectory classes were observed and were best predicted by a combination of items that reflected demography, substance use, level of response and externalizing phenotypes, and baseline environment and attitudes

ХАРАКТЕРИСТИКА ТЕРИТОРІАЛЬНОЇ ДОСТУПНОСТІ СІЛЬСЬКОМУ НАСЕЛЕННЮ ГІРСЬКОЇ І ПЕРЕДГІРСЬКОЇ ЗОН ПРОЖИВАННЯ ПЕРВИННОЇ ТА ДОЛІКАРСЬКОЇ МЕДИЧНОЇ ДОПОМОГИ

Purpose: to carry out a comprehensive assessment of the territorial availability of primary and pre-medical care for the rural population of the mountainous and submontane zone of Transcarpathian region. Materials and Methods. Materials of research: data from the State and sectoral statistical reports for the year 2018. Methods of research: medical-and-statistical method and the method of structural-and-logical analysis. Results. 503.1 thousand people live in 349 villages of mountainous and submontane zones of Transcarpathian region. The length of roads reaches 3814.0 km, 342.9 (8.99 %) km of which have asphalt coating, and 1107.0 (29.02 %) km in winter and spring and autumn period are conditionally travelable. In the submontane zone in terms of administrative territories the distance from the district center to the most remote village ranges from 24.5 km in Svaliava to 70 km in Tiachiv district. In Tiachiv district 20 km are conditionally travelable in spring, winter and autumn. This means that in this period of a year it is complicated, if necessary, to reach the abovementioned villages for emergency medical care teams and provision of hospitalization of sick persons. In the mountainous geographical zone in terms of administrative territories the distance from the district center to the most remote village ranges from 29 km in Mizhhiria to 51 km in the Volovets district. Of the total number of roads 26.12 % are conditionally travelable in spring, winter and autumn. 173 obstetric stations and 157 family medical outpatient clinics have been opened for providing pre-hospital care. In the submontane area for the provision of primary health care for 371.8 thousand of rural constant inhabitants 108 family outpatient clinics were opened with the level of provision 2.90 outpatient clinics per 10 thousand population. In the mountainous area to provide primary health care to 131.3 thousand of rural constant inhabitants 49 family outpatient clinics were opened with the level of provision 3.73 outpatient clinics per 10 thousand people. Conclusions. The results obtained indicate low level of territorial availability of primary and pre-medical care for the rural population of mountainous and submontane area of Transcarpathian region.Мета: провести комплексну оцінку територіальної доступності сільському населенню гірської і передгірської зон Закарпатської області первинної та долікарської медичної допомоги. Матеріали і методи. Матеріалами дослідження слугують дані державної та галузевої статистичної звітності за 2018 р., а методами – медико-статистичний метод та метод структурно-логічного аналізу. Результати. у 349 селах гірської та передгірської зон Закарпатської області проживає 503,1 тис. осіб. Протяжність доріг складає 3814,0 км, із яких з асфальтним покриттям – 342,9 (8,99 %) км, а 1107,0 (29,02 %) км у зимовий, весняний і осінній періоди є умовно проїзними. У передгірській зоні в розрізі адміністративних територій відстань від районного центру до найвіддаленішого села коливається від 24,5 км у Свалявському до 70 км у Тячівському районі. У Тячівському районі 20 км є умовно проїзними у весняний, зимовий та осінній періоди. Це означає, що в цей період року ускладнюється доїзд до вказаних сіл бригад екстреної медичної допомоги та забезпечення госпіталізації хворих осіб. У гірській географічній зоні в розрізі адміністративних територій відстань від районного центру до найвіддалені­шого села коливається від 29 км в Міжгірському до 51 км у Воловецькому районі. Із загальної кількості доріг 26,12 % є умовно проїзними у весняний, зимовий та осінній періоди. Для надання долікарської допомоги відкрито 173 фельдшерсько-акушерських пункти та первинної лікарської допомоги – 157 сімейних лікарських амбулаторій. У передгірській зоні для надання первинної медико-санітарної допомоги 371,8 тис. сільському постійному населенню відкрито 108 сімейних амбулаторій з рівнем забезпеченості 2,90 амбулаторій на 10 тис. населення. У гірській зоні для надання первинної медико-санітарної допомоги 131,3 тис. сільському постійному населенню відкрито 49 сімейних амбулаторій з рівнем забезпеченості 3,73 амбулаторій на 10 тис. населення. Висновки. Отримані результати вказують на низький рівень територіальної доступності сільському населенню гірської і передгірської зон Закарпатської області первинної та долікарської медичної допомоги

Risk Management of IT Projects: The Essence and Features of the Application of the PMBoK and AGILE Approaches

Recently, the relevance of risk management of IT projects has increased significantly, which is associated with their rapid development and a high level of uncertainty in the external environment. The purpose of the study is to determine the features of risk management of IT projects on the basis of modern theory and practice of project management. The paper analyzes the essence of the concept of «IT project», as well as identifies its features, including: non-standard life cycle; mobility and ambiguity of some areas in the IT field; high level of uniqueness of the project; dependence on other IT projects and technologies; low level of project expertise due to the uniqueness of the technologies on which the project is based; high level of project complexity and uncertainty. The essence of the concept of «IT project risk» is also defined, the main types of risks are characterized. The features of using the PMBoK (Project Management Body of Knowledge) methodology in project risk management are analyzed. A characterization of the stages of risk management in IT projects based on the PMBoK approach is provided, including: risk planning; risk identification; qualitative and quantitative risk assessment; planning a risk response strategy; monitoring and control of risks. It is determined that risk management of IT projects using the PMBoK approach has significant shortcomings if used in conditions of a high level of uncertainty and novelty of the project. The article also provides a characterization of flexible risk management of an IT project based on the Agile methodology, which in turn is based on an iterative approach, continuous risk assessment and the development of measures for their adaptation. A comparative characterization of the approaches of PMBoK and Agile to risk management of IT projects is provided: their strengths, weaknesses, and areas of application are identified. It is noted that the choice between PMBoK and Agile approaches should be based on the specific needs of the project and the organizational context. PMBoK will be appropriate for large, long-term projects, as well as in situations where predictability, adherence to the plan are crucial, while Agile is best suited for innovative projects that are implemented in an uncertain or dynamic environment and require flexibility, quick adaptation, and customer focus. A significant number of project managers in the IT field prefer a hybrid approach that combines the strengths of both methodologies

Land use changes in the Douro Valley and carbon emissions

Deforestation for economic development and urbanisation or urban sprawl as a result of human population growth is a common feature of land-use change and is an important source of increased atmospheric CO2. At the global level, carbon emissions from burning fossil fuels are two to three times higher than carbon sequestration by land systems, mainly forests and woody vegetation. The work presented herein focuses on the identification of carbon balance shifts due to land use changes in a group of municipalities located in the Douro River Valley in northern Portugal, where the dominance of vineyards and forestry uses over urban occupation is the norm. However, when urban sprawl occurs through the replacement of forested areas by urban uses, the ability to sequester carbon dioxide is reduced while its production rates increase. A thorough study (Lourenço et al., 2008) of land uses evolution between 1990 and 2000 shows that urban uses have been growing near Vila Real as well as vineyard plantations. Forest fires and a complex topography are major causes for the growth of abandonment, which make these areas more prone to erosion and desertification.Portuguese Foundation for Science and Technology in the scope of the research project PTDC/ECM/73069/200