One-beam dynamic ion mixing applied to coat elements onto sophistically shaped objects

Recently suggested single-ion-beam setup for ion-beam assisted deposition (IBAD) of layers with various composition including the sputter target in a form of hollow truncated cone made of the material to be deposited allows the use of a single ion beam (e.g., noble gas) for simultaneous layer deposition and ion-beam mixing. Such a setup can also be applied for coating deposition on the surfaces having sophisticated geometric shape. In the present work single-beam IBAD was used for deposition of Ni and Mo coatings onto the surface of ball fingers. The Rutherford backscattering was used for evaluating the coating thickness distributions along the spherical surface of the aluminium ball fingers. It is shown that the results can be explained in terms of space distribution of the sputtered atoms inside the conical target.Запропоновано систему з одним іонним пучком для іонно-асистуємого нанесення (ІАН) шарів різної композиції, яка включає мішень, що розпорошується, у формі усіченого порожнього конуса, виготовленого з матеріалу, що буде наноситися. У цій системі одночасно реалізується як нанесення шару, так і іонно-променеве перемішування його з підкладинкою. Така система може використовуватися і для нанесення покриттів на вироби довільної геометричної форми. У цій роботі однопучкове ІАН застосовувалося для осадження шарів Ni і Mo на поверхню алюмінієвих кульових пальців. За допомогою зворотного резерфордівського розсіювання іонів He+ визначався розподіл товщини покриття уздовж сферичної поверхні кульових пальців. Показано, що отримані результати можна пояснити на основі даних по просторовому розподілі рос-пилених атомів усередині полою конічної мішені.Предложена система с одним ионным пучком для ионно-ассистируемого нанесения (ИАН) слоев различной композиции, которая включает распыляемую мишень в форме усеченного полого конуса, изготовленного из материала, который будет наноситься. В этой системе одновременно реализуется как нанесение слоя, так и ионно-луче- вое перемешивание его с подложкой. Такая система может использоваться и для нанесения покрытий на изделия произвольной геометрической формы. В настоящей работе однопучковое ИАН применялось для осаждения слоев Ni и Mo на поверхность алюминиевых шаровых пальцев. С помощью обратного резерфордовского рассеяния ионов He+ определялось распределение толщины покрытия вдоль сферической поверхности шаровых пальцев. Показано, что полученные результаты можно объяснить с точки зрения пространственного распределения распыленных атомов внутри полой конической мишени

Structure and Optical Properties of Silicon Layers with GaSb Nanocrystals Created by Ion-Beam Synthesis

We have studied the ion-beam synthesis of GaSb nanocrystals in Si by high-fluence “hot” implantation of Sb and Ga ions followed by thermal annealing. The Rutherford backscattering, transmission electron microscopy/ transmission electron di˙raction, Raman spectroscopy and photoluminescence were used to characterize the implanted layers. It was found that the nanocrystal size increases from 5 to 60 nm in the samples annealed at 900 ±C up to 20–90 nm in those annealed at 1100 ±C. For the samples annealed at 900 ±C a broad band in the region of 0.75–1.05 eV is registered in the photoluminescence spectra. The nature of this photoluminescence band is discussed

Effect of Thermal Treatment on the Structure and Mechanical Properties of Coatings Based on (Ti, Hf, Nb, Si)N

Current paper presents the results of investigating of nanostructured cathode arc vacuum evaporation coatings, based on (Ti, Hf, Nb, Si)N. Several methods of the structural and elemental analysis were used: proton microbeam, nano- and micro-electron beam, X-ray diffraction analysis. To determine tribological properties (scratch resistance, adhesive and cohesive strength) of the coatings, scratch testing were conducting. Influence of thermal annealing at temperatures 300, 500, 800, 1000 C on elemental composition, microstructure, residual stress, phase composition, profiles of atomic distribution in the coatings were investigated

Multicomponent (Ti-Zr-Hf-V-Nb)N nanostructure coatings fabrication, high hardness and wear resistance

First results in the field of synthesis and research of the multicomponent (Ti-Zr-Hf-V-Nb)N nanostructured coatings are presented in the paper. Influence of processes of spinodal segregation and mass-transfer on single--layered or multilayered crystal boundary (second phase) forming were explored. Superhard nanostructured coatings were investigated before and after annealing at the temperature 600 C using unique methods (slow positron beam, proton microbeam particle induced X-ray emission, Rutherford backscattering-analysis, scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction analysis was performed using DRON-4 and nanoindentor). Di raction spectra were taken point-by-point, with a scanning step 2 = 0.05 to 0.1. We detected that positron trapping by defects was observed on the nanograins boundaries and interfaces (vacancies and nanopores which are the part of triple and larger grain's boundary junction). The 3D distribution maps of elements obtained by the proton microbeam (particle induced X-ray emission- ) together with the results obtained by slow positron microbeam gave us comprehensive information about physical basis of the processes, connected with diffusion and spinodal segregation in superhard coatings. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3393

A composite approach to produce reference datasets for extratropical cyclone tracks: application to Mediterranean cyclones

Many cyclone detection and tracking methods (CDTMs) have been developed in the past to study the climatology of extratropical cyclones. However, all CDTMs have different approaches in defining and tracking cyclone centers. This naturally leads to cyclone track climatologies with inconsistent physical characteristics. More than that, it is typical for CDTMs to produce a non-negligible number of tracks of weak atmospheric features, which do not correspond to large-scale or mesoscale vortices and can differ significantly between CDTMs. Lack of consensus in CDTM outputs and the inclusion of significant numbers of uncertain tracks therein have long prohibited the production of a commonly accepted reference dataset of extratropical cyclone tracks. Such a dataset could allow comparable results on the analysis of storm track climatologies and could also contribute to the evaluation and improvement of CDTMs. To cover this gap, we present a new methodological approach that combines overlapping tracks from different CDTMs and produces composite tracks that concentrate the agreement of more than one CDTM. In this study we apply this methodology to the outputs of 10 well-established CDTMs which were originally applied to ERA5 reanalysis in the 42-year period of 1979-2020. We tested the sensitivity of our results to the spatiotemporal criteria that identify overlapping cyclone tracks, and for benchmarking reasons, we produced five reference datasets of subjectively tracked cyclones. Results show that climatological numbers of composite tracks are substantially lower than the ones of individual CDTMs, while benchmarking scores remain high (i.e., counting the number of subjectively tracked cyclones captured by the composite tracks). Our results show that composite tracks tend to describe more intense and longer-lasting cyclones with more distinguished early, mature and decay stages than the cyclone tracks produced by individual CDTMs. Ranking the composite tracks according to their confidence level (defined by the number of contributing CDTMs), it is shown that the higher the confidence level, the more intense and long-lasting cyclones are produced. Given the advantage of our methodology in producing cyclone tracks with physically meaningful and distinctive life stages, we propose composite tracks as reference datasets for climatological research in the Mediterranean. The Supplement provides the composite Mediterranean tracks for all confidence levels, and in the conclusion we discuss their adequate use for scientific research and applications

Review article: A European perspective on wind and storm damage – from the meteorological background to index-based approaches to assess impacts

Wind and windstorms cause severe damage to natural and human-made environments. Thus, wind-related risk assessment is vital for the preparation and mitigation of calamities. However, the cascade of events leading to damage depends on many factors that are environment-specific and the available methods to address wind-related damage often require sophisticated analysis and specialization. Fortunately, simple indices and thresholds are as effective as complex mechanistic models for many applications. Nonetheless, the multitude of indices and thresholds available requires a careful selection process according to the target sector. Here, we first provide a basic background on wind and storm formation and characteristics, followed by a comprehensive collection of both indices and thresholds that can be used to predict the occurrence and magnitude of wind and storm damage. We focused on five key sectors: forests, urban areas, transport, agriculture and wind-based energy production. For each sector we described indices and thresholds relating to physical properties such as topography and land cover but also to economic aspects (e.g. disruptions in transportation or energy production). In the face of increased climatic variability, the promotion of more effective analysis of wind and storm damage could reduce the impact on society and the environment.</p

Prisoners of the Capitalist Machine: Captivity and the Corporate Engineer

This chapter will focus on how engineering practice is conditioned by an economic system which promotes production for profit and economic growth as an end in itself. As such it will focus on the notion of the captivity of engineering which emanates from features of the economic system. By drawing on Critical Realism and a Marxist literature, and by focusing on the issues of safety and sustainability (in particular the issue of climate change), it will examine the extent to which disasters and workplace accidents result from the economic imperative for profitable production and how efforts by engineers to address climate change are undermined by an on-going commitment to growth. It will conclude by arguing that the structural constraints on engineering practice require new approaches to teaching engineers about ethics and social responsibility. It will argue that Critical Realism offers a framework for the teaching of engineering ethics which would pay proper attention to the structural context of engineers work without eliminating the possibility of engineers working for radical change

A composite approach to produce reference datasets for extratropical cyclone tracks: application to Mediterranean cyclones

Many cyclone detection and tracking methods (CDTMs) have been developed in the past to study the climatology of extratropical cyclones. However, all CDTMs have different approaches in defining and tracking cyclone centers. This naturally leads to cyclone track climatologies with inconsistent physical characteristics. More than that, it is typical for CDTMs to produce a non-negligible number of tracks of weak atmospheric features, which do not correspond to large-scale or mesoscale vortices and can differ significantly between CDTMs. Lack of consensus in CDTM outputs and the inclusion of significant numbers of uncertain tracks therein have long prohibited the production of a commonly accepted reference dataset of extratropical cyclone tracks. Such a dataset could allow comparable results on the analysis of storm track climatologies and could also contribute to the evaluation and improvement of CDTMs. To cover this gap, we present a new methodological approach that combines overlapping tracks from different CDTMs and produces composite tracks that concentrate the agreement of more than one CDTM. In this study we apply this methodology to the outputs of 10 well-established CDTMs which were originally applied to ERA5 reanalysis in the 42-year period of 1979–2020. We tested the sensitivity of our results to the spatiotemporal criteria that identify overlapping cyclone tracks, and for benchmarking reasons, we produced five reference datasets of subjectively tracked cyclones. Results show that climatological numbers of composite tracks are substantially lower than the ones of individual CDTMs, while benchmarking scores remain high (i.e., counting the number of subjectively tracked cyclones captured by the composite tracks). Our results show that composite tracks tend to describe more intense and longer-lasting cyclones with more distinguished early, mature and decay stages than the cyclone tracks produced by individual CDTMs. Ranking the composite tracks according to their confidence level (defined by the number of contributing CDTMs), it is shown that the higher the confidence level, the more intense and long-lasting cyclones are produced. Given the advantage of our methodology in producing cyclone tracks with physically meaningful and distinctive life stages, we propose composite tracks as reference datasets for climatological research in the Mediterranean. The Supplement provides the composite Mediterranean tracks for all confidence levels, and in the conclusion we discuss their adequate use for scientific research and applications.</p