Preparation of Freestanding Porous Silicon Photonic Crystals

Nowadays, the photonic crystals are of great interest and are widely used in photonics, biosensing, optoelectronics and other fields of research. The one-dimensional photonic crystals manufactured on the basis of porous silicon were proved to be the most suitable for applications due to their high sorption ability, large surface area, easiness of fabrication, and possibility to precisely control porosity and refractive index during electrochemical etching. However, the sensitivity of various kinds of gas and biological sensors as well as the performance of solar cells and other devices on the basis of porous silicon structures may be significantly increased by detaching the structures from the substrate. Here, we have developed and investigated the fabrication procedure of freestanding one-dimensional photonic crystals on the basis of porous silicon with the use of electropolishing method followed stabilization of freestanding porous silicon photonic structures through their oxidation. We have demonstrated that the developed and applied lift-off procedure does not violate the morphology and the photonic properties of the samples. Keywords: Porous silicon, photonic crystals, microcavity, thin films, freestanding photonic crystals

Diamond grinding wheels production study with the use of the finite element method

AbstractResearch results on 3D modeling of the diamond grain and its bearing layer when sintering diamond grinding wheels are provided in this paper. The influence of the main characteristics of the wheel materials and the wheel production process, namely the quantity of metallic phase within diamond grain, coefficient of thermal expansion of the metallic phase, the modulus of elasticity of bond material and sintering temperature, on the internal stresses arising in grains is investigated. The results indicate that the stresses in the grains are higher in the areas around the metallic phase. Additionally, sintering temperature has the greatest impact on the stresses of the grain-metallic phase-bond system regardless of the type of the bond. Furthermore, by employing factorial design for the carried out finite element model, a mathematical model that reflects the impact of these factors on the deflected mode of the diamond grain-metallic phase-bond material system is obtained. The results of the analysis allow for the identification of optimal conditions for the efficient production of improved diamond grinding wheels. More specifically, the smallest stresses are observed when using the metal bond with modulus of elasticity 204GPa, the quantity of metallic phase in diamond grain of not higher than 7% and coefficient of thermal expansion of 1.32×10−51/K or lower. The results obtained from the proposed 3D model can lead to the increase in the diamond grains utilization and improve the overall efficiency of diamond grinding

ЕКСПОРТНИЙ ПОТЕНЦІАЛ АГРАРНОГО СЕКТОРУ УКРАЇНИ В УМОВАХ КОНКУРЕНТНОГО СЕРЕДОВИЩА

The purpose of the paper is to investigate the level of competitiveness of agricultural and food products and to identify the possible areas of export development on the basis of scientific works and the existing system of national strategy of the agricultural sector development. The concept of «export potential of the agricultural sector” and its relation to the competitiveness of agricultural enterprises was revealed. The dynamics and the geography of Ukrainian export of agro-food products was investigated. The data of the State Statistics Committee of Ukraine for 2005—2016, Internet resources, and own observations served as the basis for the research. For the purposes of the research such groups of the most important product types were selected: cereals, namely: winter wheat, winter barley, corn; vegetable oil (sunflower, rapeseed, soybean), strawberry, sunflower and soya, etc., and as well as those that at the present stage are advocated and, thus, may significantly raise export potential in the long term (meat, poultry, dairy products, etc.). Change in the orientation of agro-export is associated with several factors: firstly, difficult political relationships with the Russian Federation resulted in a significant reduction in the volumes of exports to this country; secondly, the increase in exports to EU countries in connection to the signing of association agreement with the EU; thirdly, the continued growth of exports to the countries of Asia and Africa.It is the «competitiveness» that identifies the opportunities for the products supply on external markets, and this is a potential set of types of agro-food products, which domestic agricultural enterprises are able to export, that identifies the potential of the agricultural sector. Ukrainian producers have the advantage over the competitors in terms of the quality and products prices which is confirmed by the fact that domestic products are exported to more than 90 countries of the world. The use of the model of potential growth of export potential of the Ukrainian agro-products will able to fully provide growers with information about potential markets for products, to ensure the proper support for the promotion of products on foreign markets.Раскрыто понятие «экспортный потенциал аграрного сектора» и его взаимосвязь с «конкурентоспособностью сельскохозяйственных предприятий». Исследованы динамика и география экспорта агропродовольственной продукции в Украине. Использование предложенной модели потенциального роста экспортного потенциала украинской агропродовольственной продукции позволит полностью обеспечить аграриев информацией о возможных рынков сбыта продукции, обеспечить надлежащую поддержку при продвижении продукции на зарубежные рынки.Ціллю дослідження є дослідження на базі наукових доробків і чинної системи вітчизняної стратегії розвитку аграрного сектору економіки рівень розвитку конкурентоспроможності вітчизняної аграрної та продовольчої продукції і визначення можливих напрямів експортного розвитку. Розкрито поняття «експортний потенціал аграрного сектору» і його взаємозв’язок з «конкурентоспроможністю сільськогосподарських підприємств». Досліджено динаміку і географію експорту агропродовольчої продукції в Україні. Основою дослідження слугували дані Державного комітету статистики України за 2005—2016 роки, дані Інтернет-ресурсів і власні спостереження авторів. Для цілей роботи відібрано групи найбільш значущих видів продукції [озима пшениця, озимий ячмінь, кукурудза; рослинна олія (соняшникова, ріпакова, соєва), полуниця, насіння соняшнику та боби сої тощо] і тих, які на сучасному етапі виступають бюджетоформувальними та таких, що можуть суттєво наростити експортний потенціал у перспективі (м’ясо, птиця, молочні продукти тощо). Зміна орієнтирів експорту агропродовольчої продукції пов’язана з декількома основними чинниками: по-перше, важкі політичні стосунки з Російською Федерацією призвели до суттєвого скорочення обсягів продукції в цю країну; по-друге, збільшення експорту до країн ЄС у зв’язку з укладенням Угоди про асоціацію з ЄС; по-третє, подальше зростання експорту в країни Азії та Африки. Саме «конкурентоспроможність» визначає можливості постачання продуктів на зовнішні ринки і включає потенційний набір типів агропродовольчих товарів, які вітчизняні сільськогосподарські підприємства можуть експортувати, що визначає потенціал аграрного сектору. Українські виробники мають перевагу перед конкурентами щодо якості та цін виробів, що підтверджується тим фактом, що вітчизняна продукція експортується в більш ніж 90 країн світу. Використання запропонованої моделі потенційного зростання експортного потенціалу української агропродовольчої продукції дасть можливість повністю забезпечити аграріїв інформацією щодо можливих ринків збуту продукції, забезпечити належну підтримку при просуванні продукції на зарубіжні ринки

PROBLEMS AND PROSPECTS FOR THE DEVELOPMENT OF RURAL TOURISM IN THE VOLOGDA REGION

The paper considers scientific approaches to determining the essence of rural tourism and agrotourism. The authors conduct a review of the current state and trends in the development of tourism, including rural tourism, in the Vologda region. The article characterizes the activities of the government bodies of the Vologda region to create conditions for the development of the tourism industry. The study proves the prospects for the development of rural tourism in the region, shows the possibilities of forming complex tourist products. The article identifies the main problems of rural tourism development in the region and determines the directions of their solution. The  paper considers the role of local governments in the development of rural tourism. The authors justify the necessity of more active implementation of the project approach in the practice of municipal administration in order to fully apply the tourist potential of the region’s territories. The study emphasizes public-private and municipal-private partnerships as one of the most effective ways to attract investment in the development of  tourist infrastructure

The role of social programs in the implementation of corporate social responsibility

In recent years, the role of non-material factors in economic development has been growing: social policy and corporate social responsibility of companies are becoming increasingly important. Determining the forms, methods and amounts of contribution to the socio-economic component ofpublic relations is the prerogative of any company, and structuring activities in this area is a prerequisite for creating social programs. The study is devoted to the definition and justification of the role of social programs in the implementation of corporate social responsibility. The relevance of the research is due to the increasing influence of corporate social responsibility on the economic condition and development of companies, as well as on the socio-economic life of society. The constant interest of all interested parties in the disclosure of corporate information, including social orientation, further confirms the relevance of this study

BIOACTIVITY OF SYNTHETIC HUMIC-LIKE SUBSTANCES ON EARLY STAGES PLANT GROWTH

Biostimulating properties of humic acids and humic-like substances are of significant interest in the field of plant biochemistry, while the nature of their actions at various levels of the substance organization is not sufficiently studied. The use of natural humates as growth regulators is associated with a number of limitations, in particular, their preservation of natural genesis, low solubility in water, a narrow range of active concentrations, insufficient biological activity [1], as well as the labour intensity of substances isolation from natural raw materials, which suggests the relevance of the development of synthetic growth regulating compositions, including based on products of sugar-amine reactions [2]

Eco-oriented agriculture as a development driver of inclusive agribusiness

The relevance of the research is determined by the need to ensure food security, which led to the search for new models and forms of agricultural development. Among such forms inclusive models of agrarian business occupy a special place as today they are recognized as capable of solving the problems of poverty, inequality and overcoming hunger. The purpose of the research is to substantiate the mechanism of how to manage ecologically-oriented agrarian business as one of the drivers of inclusiveness, and further develop directions of organic agricultural production. When writing the article, the author used the following methods of scientific knowledge: monographic, analysis and synthesis, systematic approach, comparison, scientific-abstract systematization and concretization. Based on the results of the research, key trends and drivers of agricultural development have been revealed. The set of basic forms of inclusive agrarian business organization has been studied. A level system of standards of products, works and services for the industry has been substantiated. The author’s model of the institutional mechanism for managing ecologically-oriented agricultural production, with the certification and standardization of organic produce being the key elements of it, has been proposed. The current state of development of organic production has been studied, the structure of export of organic produce has been analyzed. It has been determined that Ukrainian organic agriculture has a significant potential for its future development and is important for the European food market. Prospective benchmarks for further development of organic production in terms of ecologically-oriented types of agrarian business have been substantiated. The results of the research can be used by all agricultural enterprises that search for new approaches to management and strive to increase the competitiveness of agricultural produce in modern conditions of transition to the concept of sustainable developmen