Anisotropy driven ultrafast nanocluster burrowing

We explore the occurrence of low-energy and low-temperature transient cluster burrowing leading to intact cluster inclusions. In particular, the anomalously fast (ballistic) Pt nanocluster implantation into Al and Ti substrates has been found by molecular dynamics simulations using a tight-binding many-body potential with the 1-5 eV/atom low impact energy. Similar behavior has also been found for many other cluster/substrate couples such as Cu/Al and Ni/Ti, Co/Ti, etc. In particular, in Ni/Ti at already $\sim 0.5$ eV/atom impact energy burrowing takes place. At this few eV/atom low impact energy regime instead of the expected stopping at the surface we find the propagation of the cluster through a thin Al slab as thick as $\sim 50$ $\hbox{\AA}$ with a nearly constant speed ($\propto 1$ eV/atom). Hence the cluster moves far beyond the range of the impact energy which suggests that the mechanism of cluster burrowing can not be explained simply by collisional cascade effects. In the couples with reversed succession (e.g. Ti/Pt, Al/Pt) no burrowing has been found, the clusters remain on the surface (the asymmetry of burrowing). We argue that cluster penetration occurs at few eV/atom impact energy when the cluster/substrate interaction is size-mismatched and mass anisotropic atomically.Comment: 9 pages, 5 figures. submitted to Phys. Rev. B, preprint: http://www.mfa.kfki.hu/~sule/papers/cluster.pd

Prospects for the development of advanced grain processing in Russia

Purpose: The article is devoted to the identifying and evaluating promising areas of advanced grain and legumes processing development as a strategically important area for import substitution and food security of the agribusiness complex. Methodology/Approach: To achieve this goal, it is necessary to solve the following tasks: the analysis of advanced grain and legumes processing products; the evaluation of the current Russian market for advanced grain processing products; the identification of promising products and directions of the advanced grain processing industry development. Findings: According to the analysis in this article, this industry is in its infancy, despite the fact that in most developed countries of the world, advanced grain processing is widely elaborated. The key reasons for the Russia's lag there involve the lack of domestic techniques and highly qualified specialists in this field. Processing grain into flour, starches, glucose syrups, biofuels and organic acids makes possible manufacturing plastic and other products. To realize the Russia's potential in manufacturing high-value-added agricultural products, it is necessary to provide state support for investment projects for wheat deep processing through preferential lending and taxation, and co-financing of projects. The strategic goal of the Russian agribusiness in the medium and long term should be changing the structure of manufacturing and export in order to export finished products, but not raw materials. Practical implications: The results of this research could be introduced in the process of strategic planning of the agribusiness development and import substitution policy in Russia. Originality/Value: The key contribution of this study lies in the findings of the advanced grain processing industries’ analysis in Russia with the regional aspects taken into account.peer-reviewe

Regulation of the burning parameters for energetic materials based on ammonium nitrate and metal nanopowders and nonmetals

The results of study for the influence of metallic and nonmetallic nanopowders on the combustion parameters of mixed energetic materials based on ammonium nitrate are presented and compared with materials, containing micropowders of metals. The catalytic activity rank of the powders is plotted showing their effect on the combustion characteristics of mixed energetic materials

Specificity of silver nanoparticle synthesis in quartz glass upon low-energy ion implantation

Silica-based composite materials with silver nanoparticles (NPs) were studied. Synthesis of the NPs was carried out using a low-energy (30 keV) implantation of Ag + ions to high fluences. After the implantation, the samples were thermally annealed at 300°C for 1 hour in argon atmosphere. Synthesized NPs demonstrated an absorption band related to surface plasmon resonance (SPR). Shift of the SPR maximum towards longer wavelengths was found with an increase of ion fluence. This shift correlates with an enlargement of the hemispherical protrusions observed on the sample surface using atomic force microscopy. The obtained results were interpreted as increase of the NPs in size. It was shown that the post-implantation thermal annealing leads to change of size of the NPs thus allowing to develop a technological approach for controlled synthesis of NPs in shallow dielectric layers. © 2011 Pleiades Publishing, Ltd

Определение статуса беженцев и внутренне перемещенных лиц: зарубежный опыт

У статті досліджено проблему визначення статусу біженців і осіб, переміщених всередині країни у країнах Європейського Союзу. У зв’язку із зростанням проблеми внутрішніх недобровільних переміщень в інших країнах поступово формувалося розуміння необхідності вироблення спільних підходів до розв’язання проблем осіб, переміщених у межах власних країн, та надання суверенним державам міжнародної допомоги в цій сфері.Зазначено, що у багатьох країнах Західної Європи законодавство про біженців та внутрішньо переміщених осіб досить розвинене. Визначення поняття «біженець», дане в Конвенції про статус біженців 1951 р., в даний час інкорпоровані в національне право значної кількості держав. Охарактеризовано міграційну політику ЄС наступними положеннями:відсутність будь-яких перешкод для переміщення громадян ЄС у межах загальних кордонів ЄС; впровадження єдиних стандартів поводження з громадянами інших країн, що в’їжджають на територію ЄС, створення жорстких імміграційних правил по відношенню до біженців та осіб, які шукають притулку, формування загальної процедури визнання їхнього статусу; прийняття загальноєвропейських заходів по боротьбі з незаконною міграцією та її запобігання. Підкреслено, що в Європі спостерігається посилення заходів з надання статусу біженця та внутрішньо переміщеної особи. Автори доходять висновку, що європейські держави активно впроваджують норми міжнародного права, що регулюють правовий статус біженців та внутрішньопереміщених осіб у свої національні законодавства.This article explores the problem of determining the status of refugees and internally displaced persons in the countries of the European Union. Due to the increasing problem of internal involuntary displacement in other countries an understanding of the need to develop common approaches to solving the problems of persons displaced within their own countries and providing the sovereign states with international assistance in this area has gradually formed. It is noted that the legislation on refugees and internally displaced persons is quite developed in many Western European countries. The definition of a «refugee» concept is given in the Refugee Convention of 1951, currently incorporated into the domestic law of a significant number of states. The authors argue that the legal status of refugees has an international nature; in this case a negative decision on the recognition of any refugee status does not release another country to which he/she refers to consider the request for such recognition. The EU migration policy has been characterized by the following provisions: the absence of any obstacles for the movement of EU citizens within the EU common borders; the introduction of common standards of treatment of citizens of other countries entering the EU, creating tough immigration rules in relation to refugees and persons seeking asylum, and the formation of a common procedure for the recognition of their status; the adoption of common European measures to combat and prevent illegal migration. Europe is becoming increasingly closed. A supranational principle of this regulation collides with the provisions of the Convention on the Status of Refugees of 1951. It is emphasized that there has been increasing efforts to provide people with the status of refugees and internally displaced persons in Europe. The authors conclude that European countries actively integrate the provisions of the international law governing the legal status of refugees and internally displaced persons into their domestic law.В статье исследована проблема определения статуса беженцев и лиц, перемещенных внутри страны в странах Европейского Союза. В связи с ростом проблемы внутренних недобровольных перемещений в других странах постепенно формировалось понимание необходимости выработки общих подходов к решению проблем лиц, перемещенных внутри собственных стран и предоставление суверенным государствам международной помощи в этой сфере. Отмечено, что во многих странах Западной Европы законодательство о беженцах и внутренне перемещенных лиц является достаточно развитым. Определение понятия «беженец», данное в Конвенции о статусе беженцев 1951 г., в настоящее время инкорпорированы в национальное право значительного количества государств. Охарактеризована миграционная политика ЕС следующими положениями: отсутствие каких-либо препятствий для перемещения граждан ЕС в рамках общих границ ЕС; внедрение единых стандартов обращения с гражданами других стран, въезжающих на территорию ЕС, создание жестких иммиграционных правил в отношении беженцев и лиц, ищущих убежища, формирование общей процедуры признания их статуса; принятия общеевропейских мер по борьбе с незаконной миграцией и ее предотвращения. Подчеркнуто, что в Европе наблюдается усиление мер по предоставлению статуса беженца и внутренне перемещенного лица.Авторы приходят к выводу, что европейские государства активно внедряют нормы международного права, регулирующие правовой статус беженцев и внутренне перемещенных лиц в свои национальные законодательства

Copper nanoparticles synthesized in polymers by ion implantation: Surface morphology and optical properties of the nanocomposites

Copyright © Materials Research Society 2014. Polymethylmethacrylate (PMMA) and polyimide (PI) samples are implanted by 40 keV Cu+ ions with high fluences to synthesize copper nanoparticles in shallow polymer layers. The produced metal/polymer nanocomposites are studied using atomic force and scanning electron microscopies as well as optical transmission spectroscopy. It is found that nucleation and growth of copper nanoparticles are strongly fluence-dependent as well as they are affected by the polymer properties, in particular, by radiation stability yielding different nanostructures for the implanted PI and PMMA. Shallow synthesized nanoparticles are observed to partly tower above the sample surface due to a side effect of high-fluence irradiation leading to considerable sputtering of polymers. Implantation and particle formation significantly change optical properties of both polymers reducing transmittance in the UV-visible range due to structural and compositional change as well as causing an absorption band related to localized surface plasmon resonance (LSPR) of the nanoparticles. The role of polymer type and its degradation under the implantation on LSPR is studied to optimize conditions for the formation of nanoplasmonic materials

Copper nanoparticles synthesized in polymers by ion implantation: Surface morphology and optical properties of the nanocomposites

© Materials Research Society 2015. Polymethylmethacrylate (PMMA) and polyimide (PI) samples are implanted by 40 keV Cu+ ions with high fluences to synthesize copper nanoparticles in shallow polymer layers. The produced metal/polymer nanocomposites are studied using atomic force and scanning electron microscopies as well as optical transmission spectroscopy. It is found that nucleation and growth of copper nanoparticles are strongly fluence-dependent as well as they are affected by the polymer properties, in particular, by radiation stability yielding different nanostructures for the implanted PI and PMMA. Shallow synthesized nanoparticles are observed to partly tower above the sample surface due to a side effect of high-fluence irradiation leading to considerable sputtering of polymers. Implantation and particle formation significantly change optical properties of both polymers reducing transmittance in the UV-visible range due to structural and compositional change as well as causing an absorption band related to localized surface plasmon resonance (LSPR) of the nanoparticles. The role of polymer type and its degradation under the implantation on LSPR is studied to optimize conditions for the formation of nanoplasmonic materials