Characterization of mechanical properties by inverse technique for composite reinforced by knitted fabric. Part 1. Material modeling and direct experimental evaluation of mechanical properties

Polymer composites reinforced with knitted fabrics are materials with high potential in aerospace and machine building industries [1-6]. Such materials are mechanically non-linear with a high dynamic energy absorption capacity. Accurate prediction of mechanical properties is of great importance for these materials when considering their applications in novel structures. Three different approaches were implemented to this aim in the reported research work and the results are presented in: Part 1- numerical structural modeling (FEM using Solid Works) based on application of experimentally measured mechanical and geometrical properties of reinforcement and matrix, accompanied by direct measurements of mechanical properties; Part 2 - application of inverse method for characterization of mechanical properties by means of vibration modal analysis. The goal was to obtain and predict mechanical behavior of a weft knitted fabric reinforced multilayered composite plate. Results of all three approaches were compared and discussed

Fiber orientation in viscous fluid flow with and without vibration

This early-stage investigation is related to determination of flow speed gradients of fresh steel fiber-reinforced concrete (SFRC). They are assumed to be the key parameters for computer modeling of orientation of steel fibers in form casting process. The aim of the research is to elaborate a computer model for evaluation of steel fiber orientation in casting process, which would provide an attractive possibility to predict concrete mechanical properties, optimization of casting process and costs due to proper use of ingredients. Fiber orientation in FRC is important for ensuring the best mechanical properties in the places where it is necessary. Task can be solved as: to obtain optimal fiber concentration and orientation or to use appropriate casting approach of concrete with the goal to obtain required mechanical properties in appropriate locations of the composite element. As an example the paper considers the case of trench filling by fiber concrete. Simulations provided distributions of vertical and horizontal velocities in real-time scale. Behavior of a single fiber in an inclined container with a viscous transparent liquid (potato-starch solution) was analyzed in order to confirm the possibility to obtain orientation of fibers on the basis of velocity gradients in viscous fluid. For precise modeling of potato-starch liquid, coefficient of dynamic viscosity was determined. The experiments performed on fibers in an inclined container demonstrated satisfactory agreement with the simulation results. Performed analysis indicates that velocity gradients can be applied for determination of position and orientation of fibers in fabrication of fiber-reinforced concrete product

Separate and parallel training as a factor of preserving the health of schoolchildren

In the article the results of comparative analysis of diagnostic classes separately, parallel studies that showed significant differences between the classes of boys and girls, which allows the teacher to consider gender various mechanisms of knowledge of pupils, allows boys and girls to realize the opportunities of his psyche, which is incorporated in them by natureВ статье приведены результаты сравнительного анализа диагностики в классах раздельно-параллельного обучения, которые показали существенные отличия между классами мальчиков и девочек, что позволяет педагогу учитывать гендерно различные механизмы познания учащихся, позволяет мальчикам и девочкам реализовать те возможности своей психики, которые заложены в них от природ

Fiber orientation in viscous fluid flow with and without vibration

This early-stage investigation is related to determination of flow speed gradients of fresh steel fiber-reinforced concrete (SFRC). They are assumed to be the key parameters for computer modeling of orientation of steel fibers in form casting process. The aim of the research is to elaborate a computer model for evaluation of steel fiber orientation in casting process, which would provide an attractive possibility to predict concrete mechanical properties, optimization of casting process and costs due to proper use of ingredients. Fiber orientation in FRC is important for ensuring the best mechanical properties in the places where it is necessary. Task can be solved as: to obtain optimal fiber concentration and orientation or to use appropriate casting approach of concrete with the goal to obtain required mechanical properties in appropriate locations of the composite element. As an example the paper considers the case of trench filling by fiber concrete. Simulations provided distributions of vertical and horizontal velocities in real-time scale. Behavior of a single fiber in an inclined container with a viscous transparent liquid (potato-starch solution) was analyzed in order to confirm the possibility to obtain orientation of fibers on the basis of velocity gradients in viscous fluid. For precise modeling of potato-starch liquid, coefficient of dynamic viscosity was determined. The experiments performed on fibers in an inclined container demonstrated satisfactory agreement with the simulation results. Performed analysis indicates that velocity gradients can be applied for determination of position and orientation of fibers in fabrication of fiber-reinforced concrete product

Linear and nonlinear optical properties of trigonal borate crystals K7MIn2-xYbx(B5O10)3 (M = Ca, Sr, Ba; x=0…2) with isolated B5O10 units

Noncentrosymmetric borates K7MIn2−xYbx(B5O10)3 (M = Ca, Sr, Ba; x = 0…2) were synthesized by the solid state reaction and the crystals were successfully grown by the top seeded solution growth method using the K2O-B2O3-MF2 flux. According to Rietveld refinement, the crystal structure belongs to the noncentrosymmetric R32 space group. Also, the octahedrally coordinated In atoms are located at wide ranges ∼8 Å which may be promising for phosphor and laser applications. Samples with ytterbium show a characteristic emission band in the range of 950–1050 nm related to the 2F5/2 → 2F7/2 transition of Yb3+ ions that is commonly used for laser generation. IR, Raman and absorption spectra were obtained for the samples as well. The short cut edge of UV absorption, SHG intensity comparable with KDP and low concentration quenching of luminescence suggest that the K7MIn2−xYbx(B5O10)3 borates are promising self-frequency doubling materials

Сarbohydrate metabolism disorders and their outcomes in the long-term period in hospitalized patients with COVID-19

BACKGROUND: Diabetes mellitus (DM) is a predisposing factor for the development of many infectious complications. Numerous studies have demonstrated the association of hyperglycemia in patients having DM with a high risk of a more unfavorable course of COVID-19. However, hyperglycemia is often detected in patients with a COVID-19 not having anamnesis of DM. The following remains unclear: the etiological factors causing such disorders of carbohydrate metabolism, the persistence of these disorders and the characteristics of the course, as well as their comparative effect on the outcomes of COVID-19 and the further prognosis of patients.AIM: To study the prevalence and nature of carbohydrate metabolism disorders in patients with moderate to severe course of COVID-19, as well as 6 months after it.MATERIALS AND METHODS: Hospitalized patients with a confirmed diagnosis of COVID-19 of moderate and severe course of the disease were examined. There were no medical interventions outside recommendations of patient management. The observation was carried out during two time periods: inpatient treatment of a COVID-19 and 6 months after discharge. The following were evaluated: anamnesis data, the level of fasting plasma glucose; HbA1c, the results of computed tomography of the lungs, the drug therapy taken in all patients. Descriptive statistics methods were used to evaluate the parameters.RESULTS: The study included 280 patients with a median age of 61.5±14,2 years. During the disease, a violation of  carbohydrate metabolism was detected in 188 people (67%), the remaining patients (33%) made up the normoglycemia group. Patients with hyperglycemia were stratified in a following way: a group with an established diagnosis of DM before COVID -19 included — 56 people (20%), a group with steroid-induced hyperglycemia (SIH) — 95 people (34%), a group of stress- induced hyperglycaemia — 20 people (7%), with undiagnosed diabetes — 17 people (6%). In the postcovid period (after 6 months), the normal level of glycemia in the same sample group was observed in 199 people (71.4%); 8 people (3%) were diagnosed with new cases of DM. The mortality rate was 10 people (3.6%) in the group of SIH (8 people) and undiagnosed DM (2 people).CONCLUSION: The use of glucocorticoids in hospitalized patients with COVID-19 leads to high incidence of SIH, which has reversible character. About 6% among hospitalized patients with a COVID-19 had undiagnosed DM and were not receiving antihyperglycemic therapy. The highest mortality was noted in the group of SIH, which allows us to conclude that SIH worsens the prognosis of patients to the greatest extent. Patients with newly diagnosed hyperglycemia, regardless of the level of hyperglycemia, are characterized by a more unfavorable course

Pharmacogenetic loci for rosuvastatin are associated with intima-media thickness change and coronary artery disease risk

The present study investigated whether polymorphisms at these genes are associated with the risk of coronary artery disease (CAD) development, and reduction of atherogenic lipids and carotid intima-media thickness (CIMT) in CAD patients, taking rosuvastati

Can compact optimisation algorithms be structurally biased?

In the field of stochastic optimisation, the so-called structural bias constitutes an undesired behaviour of an algorithm that is unable to explore the search space to a uniform extent. In this paper, we investigate whether algorithms from a subclass of estimation of distribution algorithms, the compact algorithms, exhibit structural bias. Our approach, justified in our earlier publications, is based on conducting experiments on a test function whose values are uniformly distributed in its domain. For the experiment, 81 combinations of compact algorithms and strategies of dealing with infeasible solutions have been selected as test cases. We have applied two approaches for determining the presence and severity of structural bias, namely an (existing) visual and an (updated) statistical (Anderson-Darling) test. Our results suggest that compact algorithms are more immune to structural bias than their counterparts maintaining explicit populations. Both tests indicate that strong structural bias is found only in the cBFO algorithm, regardless of the choice of strategy of dealing with infeasible solutions, and cPSO with mirror strategy. For other test cases, statistical and visual tests disagree on some cases classified as having mild or strong structural bias: the former one tends to make harsher decisions, thus needing further investigation

Representing Semantified Biological Assays in the Open Research Knowledge Graph

In the biotechnology and biomedical domains, recent text mining efforts advocate for machine-interpretable, and preferably, semantified, documentation formats of laboratory processes. This includes wet-lab protocols, (in)organic materials synthesis reactions, genetic manipulations and procedures for faster computer-mediated analysis and predictions. Herein, we present our work on the representation of semantified bioassays in the Open Research Knowledge Graph (ORKG). In particular, we describe a semantification system work-in-progress to generate, automatically and quickly, the critical semantified bioassay data mass needed to foster a consistent user audience to adopt the ORKG for recording their bioassays and facilitate the organisation of research, according to FAIR principles.Comment: In Proceedings of 'The 22nd International Conference on Asia-Pacific Digital Libraries