Influence of vibrational treatment on thermomechanical response of material under conditions identical to friction stir welding

A molecular dynamics model was constructed to describe material loading on the atomic scale by the mode identical to friction stir welding. It was shown that additional vibration applied to the tool during the loading mode provides specified intensity values and continuous thermomechanical action during welding. An increase in additional vibration intensity causes an increase both in the force acting on the workpiece from the rotating tool and in temperature within the welded area

Bifurcation structure of a swept source laser

We numerically analyze a delay differential equation model of a short-cavity semiconductor laser with an intracavity frequency swept filter and reveal a complex bifurcation structure responsible for the asymmetry of the output characteristics of this laser. We show that depending on the direction of the frequency sweep of a narrowband filter, there exist two bursting cycles determined by different parts of a continuous-wave solutions branch

Experimental observation of Dyakonov plasmons in the mid-infrared

AbstractIn this work, we report on observation of Dyakonov plasmons at an interface with a hyperbolic metamaterial in the mid-IR. The hyperbolic metamaterial is implemented as a CMOS-compatible high aspect ratio grating structure with aluminium-doped ZnO (AZO) ridges grown by atomic layer deposition in deep trench silicon matrix. The dispersion of Dyakonov plasmons is characterized by the attenuated total reflection method in the Otto configuration. We demonstrate that Dyakonov plasmons propagate in a broad range of directions (a few tens of degrees) in contrast to the classical Dyakonov surface waves (about one tenth of degree). The obtained results provide useful guidelines for practical implementations of structures supporting Dyakonov plasmons in the mid-IR. </jats:p

Belagash: A Newly Discovered Kipchak-Era Site in Central Kazakhstan

Introduction. Despite the long history of archaeological research in Central Kazakhstan, many aspects of culture inherent to its medieval nomadic population remain understudied. So, the ninety-year-long excavations of eighth-to-twelfth century sites have shaped certain ideas about the latter primarily on the basis of statuary objects and thirteen sanctuary-type facilities with varying structural patterns. Funeral rites can be traced only in one attributed burial discovered in cultural layers of the Bronze Age settlement of Kent. Goals. The study attempts a complete historical summary of investigations into eighth-to-twelfth century sites across Central Kazakhstan, and introduces into scientific circulation some newly discovered material from the site of Belagash. Materials and methods. All the studied objects of Belagash are rather similar graveside structures in the form of unsodded stone mounds sized 2–3 to 13 m. Unfortunately, facilities nos. 1–3 were looted and have yielded only scarce finds that provide insufficient data for any reconstruction of rituals. And since such graveside structures can to some extent be traced in both Early Iron Age and medieval monuments, the question of their dating shall be left open for the time being. Results. Facility no. 4 is of utmost interest. Its formal typological features attest to it may cluster with eighth/ninth-to-eleventh century sites. It was containing some scattered horse remains accompanied by an iron stirrup, a buckle, a bronze belt tip, and an appliqué plaque. Typological characteristics of the stirrup are crucial to identifying the historical period in question: analogues from the Irtysh River valley and the Altai may date the investigated site to the eighth/ninth throughout eleventh centuries CE. Conclusions. It is urgent to emphasize the significance of the material from Belagash since the latter does add to the meager data on the culture of Central Kazakhstan’s population at the final stage of the Early Middle Ages

Features of interface formation in crystallites under mechanically activated diffusion. A molecular dynamics study.

In this paper, we carried out investigation of behavior of the material under loading condition identical those used in FSW using molecular dynamic method. The loading was modelled by a rigid rotating “tool” that movies along boundary between two grains. We considered pairing of two crystallites of copper, crystallites of copper and iron, and two crystallites of aluminum 2024. Analysis of the structure of the sample showed the intermixing and stirring of dissimilar atoms as a result the FSW tool pass at the inter-crystallite boundary. It was shown, that under certain condition of loading when tool passes there a region where atoms can occupying the original position of the crystal lattice. We also show influence of an additional oscillating impact applied to the moving tool on the structure of the resulting weld. The simulation results obtained can be used for understanding the processes realized under mechanically activated diffusion

Midinfrared Surface Waves on a High Aspect Ratio Nanotrench Platform

Optical surface waves, highly localized modes bound to the surface of media, enable manipulation of light at nanoscale, thus impacting a wide range of areas in nanoscience. By applying metamaterials, artificially designed optical materials, as contacting media at the interface, we can significantly ameliorate surface wave propagation and even generate new types of waves. Here, we demonstrate that high aspect ratio (1:20) grating structures with plasmonic lamellas in deep nanoscale trenches, whose pitch is 1/10–1/35 of a wavelength, function as a versatile platform supporting both surface and guided bulk infrared waves. The surface waves exhibit a unique combination of properties: directionality, broadband existence (from 4 μm to at least 14 μm and beyond) and high localization, making them an attractive tool for effective control of light in an extended range of infrared frequencies

Modeling Changes in the Enterprise Information Capital in the Digital Economy

The global COVID-19 pandemic has led to the self-isolation of people and the transformation of many economic and social processes into an electronic version thus contributing to the digitalization of all spheres. Being part of this environment, enterprises generate information resources to develop their desired image, which may vary according to the factors characterizing the information environment. Information capital is a comprehensive characteristic of an enterprise and determines its effectiveness and sustainability. The purpose of this study is to develop a toolkit that allows one to assess the information capital of an enterprise, reflecting its perception within the digital information environment. It is necessary to develop the methodology for the formation of such tools. As a result, a fuzzy-plural approach has been developed to evaluate the index of external information capital. This model allows us to assess the external information capital and to simulate its changes caused by various kinds of information events. The study of key elements, for example, the stability and tonality indices, index of target perception made it possible to systematize chaotic changes in the external environment and describe them using the Chen–Lee attractor model. The results of this study can be useful for researchers in the field of digital information analysis, in particular for the comparative analysis of enterprises and the assessment of their information capital

The Influence of the CES1 Genotype on the Pharmacokinetics of Enalapril in Patients with Arterial Hypertension

The angiotensin-converting enzyme inhibitor enalapril is hydrolysed to an active metabolite, enalaprilat, in the liver via carboxylesterase 1 (CES1). Previous studies show that variant rs71647871 in the CES1 gene affects the pharmacokinetics of enalapril on liver samples as well as healthy volunteers. This study included 286 Caucasian patients with arterial hypertension who received enalapril. The concentrations of enalapril and enalaprilat were determined before subsequent intake of the drug and 4 h after it with high-performance liquid chromatography (HPLC) and mass spectrometric detection. The study included genetic markers as follows: rs2244613, rs71647871 (c.428G&gt;A, p.G143E) and three SNPs indicating the presence of a subtype CES1A1c (rs12149368, rs111604615 and rs201577108). Mean peak and trough enalaprilat concentrations, adjusted by clinical variables, were significantly lower in CES1 rs2244613 heterozygotes (by 16.6% and 19.6%) and in CC homozygotes (by 32.7% and 41.4%) vs. the AA genotype. In CES1A1c homozygotes, adjusted mean enalaprilat concentrations were 75% lower vs. heterozygotes and wild-type (WT) homozygotes. Pharmacogenetic markers of the CES1 gene may be a promising predictor for individualisation when prescribing enalapril

The Influence of Structural Variants of the CES1 Gene on the Pharmacokinetics of Enalapril, Presumably Due to Linkage Disequilibrium with the Intronic rs2244613

Variants in the CES1 gene encoding carboxylesterase 1 may affect the metabolism of enalapril to the active metabolite enalaprilat. It was shown that the A allele of rs71647871 and the C allele of rs2244613 led to a decrease in plasma enalaprilat concentrations. This study aimed to estimate the effect of structural haplotypes of CES1 containing the pseudogene CES1P1, or a hybrid of the gene and the pseudogene CES1A2, on the pharmacokinetics of enalapril. We included 286 Caucasian patients with arterial hypertension treated with enalapril. Genotyping was performed using real-time PCR and long-range PCR. Peak and trough plasma enalaprilat concentrations were lower in carriers of CES1A2. The studied haplotypes were in linkage disequilibrium with rs2244613: generally, the A allele was in the haplotype containing the CES1P1, and the C allele was in the haplotype with the CES1A2. Thus, carriers of CES1A2 have reduced CES1 activity against enalapril. Linkage disequilibrium of the haplotype containing the CES1P1 or CES1A2 with rs2244613 should be taken into account when genotyping the CES1 gene

Correlation Processing Cuboid Infrared Images from Unmanned Aerial Vehicle. Part 2. Processing Method of Infrared Signatures of Reference Objects on the Basis of the Numerical Solution of the Nonlinear Heat Transfer Problems

Представлен вариант построения математической модели теплового поля многослойного изотропного материала, основанный на решении двумерной прямой задачи теплопроводности численным методом с использованием неявных разностных схем с учетом смешанных граничных условий сопряжения и контактного термического сопротивления. Приведены результаты обработки корреляционным алгоритмом динамических инфракрасных сигнатур, полученных в результате суточной тепловизионной съемки «эталонного полигона»A version of a mathematical model of the thermal field of multilayer isotropic material, based on the solution of two-dimensional heat conduction problem of direct numerical method using implicit difference schemes, taking into account the mixed boundary conditions and interface thermal contact resistance. The results of the correlation processing algorithm of dynamic infrared signatures obtained by the daily thermographing “reference zones