Analytical method for parameterizing the random profile components of nanosurfaces imaged by atomic force microscopy

The functional properties of many technological surfaces in biotechnology, electronics, and mechanical engineering depend to a large degree on the individual features of their nanoscale surface texture, which in turn are a function of the surface manufacturing process. Among these features, the surface irregularities and self-similarity structures at different spatial scales, especially in the range of 1 to 100 nm, are of high importance because they greatly affect the surface interaction forces acting at a nanoscale distance. An analytical method for parameterizing the surface irregularities and their correlations in nanosurfaces imaged by atomic force microscopy (AFM) is proposed. In this method, flicker noise spectroscopy - a statistical physics approach - is used to develop six nanometrological parameters characterizing the high-frequency contributions of jump- and spike-like irregularities into the surface texture. These contributions reflect the stochastic processes of anomalous diffusion and inertial effects, respectively, in the process of surface manufacturing. The AFM images of the texture of corrosion-resistant magnetite coatings formed on low-carbon steel in hot nitrate solutions with coating growth promoters at different temperatures are analyzed. It is shown that the parameters characterizing surface spikiness are able to quantify the effect of process temperature on the corrosion resistance of the coatings. It is suggested that these parameters can be used for predicting and characterizing the corrosion-resistant properties of magnetite coatings.Comment: 7 pages, 3 figures, 2 tables; to be published in Analys

Control of LED Emission with Functional Dielectric Metasurfaces

The improvement of light-emitting diodes (LEDs) is one of the major goals of optoelectronics and photonics research. While emission rate enhancement is certainly one of the targets, in this regard, for LED integration to complex photonic devices, one would require to have, additionally, precise control of the wavefront of the emitted light. Metasurfaces are spatial arrangements of engineered scatters that may enable this light manipulation capability with unprecedented resolution. Most of these devices, however, are only able to function properly under irradiation of light with a large spatial coherence, typically normally incident lasers. LEDs, on the other hand, have angularly broad, Lambertian-like emission patterns characterized by a low spatial coherence, which makes the integration of metasurface devices on LED architectures extremely challenging. A novel concept for metasurface integration on LED is proposed, using a cavity to increase the LED spatial coherence through an angular collimation. Due to the resonant character of the cavity, extending the spatial coherence of the emitted light does not come at the price of any reduction in the total emitted power. The experimental demonstration of the proposed concept is implemented on a GaP LED architecture including a hybrid metallic-Bragg cavity. By integrating a silicon metasurface on top we demonstrate two different functionalities of these compact devices: directional LED emission at a desired angle and LED emission of a vortex beam with an orbital angular momentum. The presented concept is general, being applicable to other incoherent light sources and enabling metasurfaces designed for plane waves to work with incoherent light emitters.Comment: 29 pages, 6 figure

Определение долговечности конструкций малых и скоростных судов с использованием распределения Вейбулла

Грабенко, А. А. Определение долговечности конструкций малых и скоростных судов с использованием распределения Вейбулла = Determination of long-term designs of small and speed vessels using the weibull distribution / А. А. Грабенко, Ю. Н. Коробанов, А. И. Кузнецов // Зб. наук. пр. НУК. – Миколаїв : НУК, 2020. – № 1 (479). – С. 3–12.Анотація. Мета. Робота має оглядовий характер, оскільки питання надійності, довговічності та життєздатності конструкцій суднового призначення, а також їх окремих вузлів виникає стосовно найрізноманітніших типів суден. Для малих суден з урахуванням їх особливостей взаємодії із зовнішнім середовищем, за наявності надлишкового ресурсу довговічності порівняно із запланованим життєвим циклом з’являється можливість спрощення конструкцій в районах можливих концентраторів напружень. Необхідне створення коректного інструменту оцінювання довговічності конструкцій. Зближення меж ресурсу довговічності конструкцій і запланованого життєвого циклу приведе до оптимізації корпусних конструкцій, спрощення конструкцій і мінімізації їх маси. Методика. За основу аналізу беруться результати експериментальних і теоретичних досліджень, отримані різними авторами в різний час. Особливу увагу приділено можливості застосування аналізованих досліджень щодо особливостей експлуатації малих та швидкісних суден. Результати. Встановлено, що втомні криві типових з’єднань і переривчастих зв’язків, ефективні коефіцієнти концентрації напружень та деформацій, розподіл допустимих і небезпечних напруг, а також їх забезпеченість можуть служити основою для визначення передбачуваного ресурсу корпусних конструкцій малих і швидкісних суден. На базі дослідження можна створити алгоритм оцінки довговічності конструкцій малих суден. Наукова новизна. Виникає питання про шляхи оцінювання надійності та довговічності суднових конструкцій малих і швидкісних суден. Можливим є створення коректного алгоритму оцінки довговічності корпусних конструкцій розглянутих суден. Практична значимість. Розподіл закону Вейбулла досить широко використовується в задачах довговічності та надійності корпусних конструкцій, а також під час оцінювання їх життєздатності. Передбачається, що надійність, довговічність малих і швидкісних суден залежать від життєвого ресурсу переривчастих зв’язків, деяких типових вузлів з’єднання окремих конструктивних елементів, а також від якості технологічних процесів. Правильне оцінювання довговічності розглянутих корпусних конструкцій порівняно з життєвим циклом судна може дати змогу спростити корпусні конструкції в районах переривчастих зв’язків, підвищити експлуатаційні якості проєктованого судна.Abstract. Purpose. The purpose of this article is overview of reliability, durability and viability of ship construction purposes, as well as their individual nodes, arises in connection with a wide variety of types of vessels. For small vessels, taking into account their characteristics of interaction with the environment, if there is an excess durability resource compared to the planned life cycle, it becomes possible to simplify structures in the areas of possible stress concentrators. It is necessary to create the right tool for assessing the durability of structures. The rapprochement of the boundaries of the resource of durability of structures and the planned life cycle will lead to optimization of hull structures, simplification of structures and minimization of their mass. Method. The analysis is based on the results of experimental and theoretical studies obtained by different authors at different times. Particular attention is paid to the applicability of the analyzed studies to the features of operation of small and high-speed vessels. Results. It is established that the fatigue curves of typical joints and discontinuous bonds, effective coefficients of stress and strain concentration, distribution of permissible and dangerous stresses, and also their availability can serve as a basis for determining the expected resource of hull structures of small and high-speed vessels. Based on this research, it is possible to create an algorithm for assessing the durability of structures of small vessels. Scientific novelty. The question arises as to the ways of assessing the reliability and durability of ship structures of small and high-speed vessels. It is possible to create the correct algorithm for assessing the durability of the hull structures of the ships in question. Practical importance. The distribution of the Weibull law is widely used in problems of durability and reliability of hull structures, as well as in assessing their viability. It is assumed that the reliability, durability of small and high-speed vessels depends on the life-time of interrupted connections, some typical nodes of connection of individual structural elements, and also on the quality of technological processes. A correct assessment of the durability of the hull structures under consideration in comparison with the life cycle of the vessel can allow the simplification of the hull structures in the areas of intermittent communications, improving the performance of the designed vessel.Аннотация. Цель. Работа имеет обзорный характер, поскольку вопрос надежности, долговечности и жизнеспособности конструкций судового назначения, а также их отдельных узлов, возникает применительно к самым разнообразным типам судов. Методика. За основу анализа принимаются результаты экспериментальных и теоретических исследований, полученные разными авторами в разное время. Результаты. Установлено, что усталостные кривые типовых соединений и прерывистых связей, эффективные коэффициенты концентрации напряжений и деформаций, распределение допускаемых и опасных напряжений, а также их обеспеченность могут служить основой для определения предполагаемого ресурса корпусных конструкций малых и скоростных судов. Научная новизна. Возникает вопрос о путях оценивания надежности и долговечности судовых конструкций малых и скоростных судов. Практическая значимость. Распределение закона Вейбулла достаточно широко используется в задачах долговечности и надежности корпусных конструкций, а также при оценивании их жизнеспособности. Предполагается, что надежность, долговечность малых и скоростных судов зависят от жизненного ресурса прерывистых связей, некоторых типовых узлов соединения отдельных конструктивных элементов, а также от качества технологических процессов

« Benefits and risks for Russian industries and individual enterprises from the implementation of trade and economic agreements of the CIS countries»

The CIS countries, or more broadly the former republics of the USSR, are effectively making a choice between European (EU) and Eurasian (EAEU) integration, which leads to certain benefits and risks for all CIS+ countries (including Ukraine and Georgia), especially for Russia. The cases of Ukraine, Georgia and Moldova are of primary interest. Termination of trade and economic cooperation, disruption of value chains, etc. entail a serious threat to industrial development for Russian industries and individual enterprises. Crisis phenomena such as the COVID-19 pandemic, for example, only exacerbate these trends. Great Britain’s departure from the EU (Brexit) at the end of January 2020 is also of research interest. The topics of the post-Soviet countries and their trade and economic cooperation with different countries have been studied by various authors since the collapse of the USSR. In the past ten years, there has been an increase in the activity of studying these problems, in connection with the development of the European Neighborhood Policy on the one hand and Eurasian integration on the other. Research by foreign and domestic authors can be distinguished into the following groups

Integrative analysis of the human cis-antisense gene pairs, miRNAs and their transcription regulation patterns

Cis-antisense gene pairs (CASGPs) can transcribe mRNAs from an opposite strand of a given locus. To classify and understand diverse CASGP phenomena in the human we compiled a genome-wide catalog of CASGPs and integrated these sequences with microarray, SAGE and miRNA data. Using the concept of overlapping regions and clustering of SA transcripts by chromosome coordinates, we identified up to 9000 overlapping antisense loci. Four thousand three hundred and seventy-four of these CASGPs form 1759 complex gene architectures. We found that ∼35% (6347/18160) of RefSeq genes are overlapped with the antisense transcripts. About 30% of Affymetrix U133 microarray initial sequences map transcripts of ∼35% CASGPs and reveal mostly concordant expression in CASGPs. We found strong significant overrepresentation of human miRNA genes in loci of CASGPs. We developed a data-driven model of cross-talk between co-expressed CASGPs and DICER1-mediated miRNA pathway in normal spermatogenesis and in severe teratozoospermia. Specifically, we revealed complex SA structural–functional gene module composing the protein-coding genes, WDR6, DALRD3, NDUFAF3 and ncRNA precursors, mir-425 and mir-191, which could provide downregulation of ncRNA pathway via direct targeting DICER1 and basonuclin 2 transcripts by mir-425 and mir-191 in normal spermatogenesis, but this mechanism is switched off in severe teratozoospermia. The database is available from http://globalisland.bii.a-star.edu.sg/∼jiangtao/sas/index3.php?link =abou

3D Mueller matrix mapping of layered distributions of depolarisation degree for analysis of prostate adenoma and carcinoma diffuse tissues

Prostate cancer is the second most common cancer globally in men, and in some countries is now the most diagnosed form of cancer. It is necessary to differentiate between benign and malignant prostate conditions to give accurate diagnoses. We aim to demonstrate the use of a 3D Mueller matrix method to allow quick and easy clinical differentiation between prostate adenoma and carcinoma tissues with different grades and Gleason scores. Histological sections of benign and malignant prostate tumours, obtained by radical prostatectomy, were investigated. We map the degree of depolarisation in the different prostate tumour tissues using a Mueller matrix polarimeter set-up, based on the superposition of a reference laser beam with the interference pattern of the sample in the image plane. The depolarisation distributions can be directly related to the morphology of the biological tissues. The dependences of the magnitude of the 1st to 4th order statistical moments of the depolarisation distribution are determined, which characterise the distributions of the depolarisation values. To determine the diagnostic potential of the method three groups of histological sections of prostate tumour biopsies were formed. The first group contained 36 adenoma tissue samples, while the second contained 36 carcinoma tissue samples of a high grade (grade 4: poorly differentiated-4 + 4 Gleason score), and the third group contained 36 carcinoma tissue samples of a low grade (grade 1: moderately differentiated-3 + 3 Gleason score). Using the calculated values of the statistical moments, tumour tissues are categorised as either adenoma or carcinoma. A high level (> 90%) accuracy of differentiation between adenoma and carcinoma samples was achieved for each group. Differentiation between the high-grade and low-grade carcinoma samples was achieved with an accuracy of 87.5%. The results demonstrate that Mueller matrix mapping of the depolarisation distribution of prostate tumour tissues can accurately differentiate between adenoma and carcinoma, and between different grades of carcinoma. This represents a first step towards the implementation of 3D Mueller matrix mapping for clinical analysis and diagnosis of prostate tumours

3D Mueller Matrix Reconstruction of the Optical Anisotropy Parameters of Myocardial Histopathology Tissue Samples

Diseases affecting myocardial tissues are currently a leading cause of death in developed nations. Fast and reliable techniques for analysing and understanding how tissues are affected by disease and respond to treatment are fundamental to combating the effects of heart disease. A 3D Mueller matrix method that reconstructs the linear and circular birefringence and dichroism parameters has been developed to image the biological structures in myocardial tissues. The required optical data is gathered using a Stokes polarimeter and then processed mathematically to recover the individual optical anisotropy parameters, expanding on existing 2D Mueller matrix implementations by combining with a digital holography approach. Changes in the different optical anisotropy parameters are rationalised with reference to the general tissue structure, such that the structures can be identified from the anisotropy distributions. The first to fourth order statistical moments characterising the distribution of the parameters of the optical anisotropy of the polycrystalline structure of the partially depolarising layer of tissues in different phase sections of their volumes are investigated and analysed. The third and fourth order statistical moments are found to be the most sensitive to changes in the phase and amplitude anisotropy. The possibility of forensic medical differentiation of death in cases of acute coronary insufficiency (ACI) and coronary heart disease (CHD) is considered as a diagnostic application. The optimal phase plane ( θ ∗ = 0.7 r a d ) has been found, in which excellent differentiation accuracy is achieved ACI and CHD - A c ( Δ Z 4 ( θ ∗ , Φ L , Δ L ) ) = 93.05 % ÷ 95.8 % . A comparative analysis of the accuracy of the Mueller-matrix reconstruction of the parameters of the optical anisotropy of the myocardium in different phase planes ( θ = 0.9 r a d and θ = 1.2 r a d ), as well as the 2D Mueller-matrix reconstruction method was carried out. This work demonstrates that a 3D Mueller matrix method can be used to effectively analyse the optical anisotropy parameters of myocardial tissues with potential for definitive diagnostics in forensic medicine