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Unsteady two-dimensional problem of a thin liquid layer with prescribed time-dependent influx into the layer, position of the influx section, and the thickness of the liquid at this section is studied by methods of asymptotic analysis. The ratio of the rate of the liquid thickness variation at the influx section to the influx velocity plays a role of a small parameter of the problem. The influx parameters are such that the flow in the thin layer is inertia dominated, with gravity, surface tension, and liquid viscosity being approximately negligible. Such flows were studied with respect to several applications, some of which are listed in the Introduction. One of the applications concerns with splashing during droplet impact onto a rigid substrate and related kinematic discontinuity propagating along the spray sheet, which is produced by the spreading droplet. This type of splashing was studied by Yarin and Weiss [“Impact of drops on solid surfaces: Self-similar capillary waves, and splashing as a new type of kinematic discontinuity,” J. Fluid Mech. 283, 141–173 (1995)] within a quasi-one-dimensional approach averaging the flow velocity over the layer thickness. We also start with the one-dimensional thin-layer approximation assuming the influx flow is accelerated. Such influx conditions lead to unbounded growth of the thickness of the liquid layer at a certain location and at a certain time instant within the one-dimensional approach. The present study recovers for the first time the structure of the flow close to this singularity using methods of asymptotic analysis. To this aim, the second-order outer solution, which is valid outside the region of the unbounded flow, is derived. The second-order outer solution is used to find proper stretched inner variables and the equations governing the inner flow at the leading order. It is shown that the inner free-surface flow in the stretched variables is two-dimensional, potential, non-linear, and independent of any parameters of the original problem.

The article is aimed at further harmonization of the national regulatory framework with international and European regulations on methods of testing roofs and roofing materials on fire safety. The aim of the article is to analyze the international experience of applying test methods in accordance with CEN/TS 1187 to substantiate and determine in Ukraine the feasibility of introducing a separate method of extended application of test results of roofs and roofing materials on fire safety. The analysis of the international experience of application methods of roofs and roofing materials tests is given. The ambiguity of the application of methods in other countries is determined. Each method is independent, without the possibility of replacing one method with another. To determine the characteristics of fire load of ignition sources, the corresponding calculations were performed by four methods of СEN/TS 1187. An analysis of the results of comparative tests conducted by EGOLF during classes on courses on CEN/TS 1187 tests 1 and 2 of four samples. It is emphasized that the repeatability and reproducibility of method 1 are assessed as relatively low. The modeling of heat transfer processes between the heat source and adjacent objects on the field model was carried out using the program FDS (Fire Dynamics Simulator), taking into account the provisions of domestic requirements. The stricter requirements of test method 2 according to CEN/TS 1187 have been confirmed. The expediency of using the second test method in accordance with CEN TS 1187 is emphasized in Ukraine. According to the results of the research, the urgency of setting a new research (development) work on the development of test equipment to determine the extent of the flame on the roofs and roofing materials. In order to harmonize European approaches in the sphere of fire safety of roofs and roofing materials in Ukraine, it is proposed to establish requirements for roofs as structures and make appropriate changes to state building codes in terms of fire classification of roofs.

Introduction. Viral infection is the main cause of damage to the ciliated epithelium of the nasal cavity mucosa, which in turn leads to disruption of mucociliary transport, increased viscosity and mucus hypersecretion in the sinuses and deceleration of its evacuation. Smokers suffer from chronic obstructive pulmonary diseases, in particular obstructive bronchitis. Their cough symptom complex sharply increases in acute respiratory viral infection (ARVI), especially when the mucociliary airway system is affected. The etiotropic treatment of this combined pathology is a therapy capable of affecting the entire mucociliary system of the upper and lower respiratory tract, including a drug based on ivy leaf extract, with the active ingredient of the saponin group.Aim of the study. To determine the effectiveness of phytopreparation in preventing exacerbation of chronic bronchitis of smokers in patients with acute viral rhinosinusitis.Materials and methods. Complex examination of 20 active smokers suffering from acute viral rhinosinusitis (AVR), including computed tomography of the lungs, was conducted. The randomized study included the use of phytopreparations in the complex therapy of acute rhinosinusitis in patients with obstructive bronchitis.Results and discussion. Use of medicines based on ivy extract in the complex treatment of acute rhinosinusitis in smokers allowed to achieve reduction of AVR symptom complex complicated by exacerbation of chronic bronchitis by the 5th day of the disease. Dynamics of cough complaints reduction in comparison groups reflects the beneficial effect of ivy extract in smokers with ARVI, complicated by AVR, and in the absolute majority of cases allows avoiding bacterial complications.Conclusion. The conducted study proved the effectiveness of Gedelix in the complex treatment of viral acute rhinosinusitis in smokers. In the absolute majority of cases (80% of the total number of patients in the group) it was possible to avoid long-term exacerbation of chronic bronchitis and bacterial complications.

We describe the results for full-scale experimental test production of high-basicity sinter (basicity 2.0–5.0) at the Enakievo Metallurgical Plant Sinter Shop. As sinter basicity increased from 2.0 to 5.0, the iron content of the sinter decreased from 53.05% to 32.24%, and the ferrous oxide concentration decreased from 17.55% to 9.29%. However, the strength specifications of the sinter were improved: The concentration of 0–5-mm fines decreased from 19.32% to 15.89%, and the yield of +5 mm size class in a drum test increased from 65.9% to 72.3% through optimization of the sintering process parameters. The use of high basicity sinter in blast-furnace smelting reduced the specific consumption of lime in the blast-furnace charge from 233.9 kg/metric ton of cast iron (at sinter basicity 2.0) to 103.5 kg/metric ton (at basicity 4.5) and, correspondingly, the specific feed rate for coke during castiron production decreased from 538.1 kg/metric ton to 476.6 kg/metric ton.

The paper considers the possible mechanism of the pathogenesis of COVID-19 caused by SARS-COV-2, associated with damage to red blood cells, which the authors attribute to the main key target that triggers a cascade of reactions leading to multiple organ failure The paper presents morphological evidence for the presence of pathological forms of erythrocytes characteristic of various anemias in the blood vessels and parenchyma of damaged lungs of patients with COVID-19 The death of red blood cells leads to cell ischemia and anemia The defeat of brain neurons, blood vessels and hematotissue barriers in organ systems is a consequence of ischemia due to the impossibility of transferring hemoglobin by damaged erythrocytes and ends at the terminal stages of the development of the disease with their dysfunction Adaptive erythropoiesis with an increase in erythropoietin secretion is especially dangerous for patients suffering from hypertension, and then it is impossible, since all organs involved in the synthesis of erythropoietin are damaged In this case, the synthesis of hemoglobin is also disrupted due to a deficiency of iron and cyancobolamin, whereas toxic iron and hemosiderin are deposited in the tissues

During the last six years production of high-fluxed sinter at sinter workshop of Enakievo metallurgical plant is accomplished by using sinter charge, comprising almost equal shares of iron ore concentrate and metallurgical wastes. It is done because of insufficient and non-regular supplies of iron ore concentrates. The experience gained can be of some interest for specialists of sintering and BF production of other plants to ensure the operation under conditions of breach of iron ore raw material supply as well as utilization of wastes. An analytical and statistical evaluation of technical and economical indices of sintering accomplished, while component content, the charge basicity and technological conditions of it preparation and sintering variation. Results of industrial study of technological conditions and sinter production parameters presented while its basicity was varied within the range of 1.7–4.1 abs. units in some periods of 2019. Results of pilot-industrial experiments on production in the IVQ-2019 of several batches of rather strong sinter highlighted, while their basicity was varied in series from 2.0 to 5.0 abs. units. A method of adjusting of sintering speed of a high-basic charge along the width of sintering machine proposed, comprising a rational forming of the charge layer in the charging funnel and the layer profile with a concave parabola surface form along the sintering machine width. The method comprised also an increase of the charge volume density in the upper elemental layers and particularly – in the peripheral zones of general charge layer at the sintering machines pallets. Description of the charging complex on the sintering machine pallets was given. Scientific and practical recommendations elaborated for modernization the technology and technological equipment for the charge loading on the sintering machine.

The description and results of experimental studies of rationality of using various computer control tools for the practice of developing a human-machine interface intended for automated workstations of system control operators for shipboard technical complexes are presented in the work.

Objective: Comparative analysis of the structure of the external auditory canal (EAC) according to computed tomography (CT) scans of the temporal bones in patients with acquired post-inflammatory atresia of the EAC and patients with safe chronic suppurative otitis media (SCSOM) without atresia. Patients and methods: 42 patients (43 ears) with acquired post-inflammatory atresia of the EAC and 11 patients (22 ears) with bilateral SCSOM without acquired atresia were included in the study. Based on the original axial СT images and multi-planar reformation images were measured: thickness of the anterior wall in bony part of EAC; anterior tympanomeatal angle and the distance from the lateral process of the malleus to the anterior wall of an EAC; lumen of the EAC in front of the tympanic sulcus. Results: The lumen of the bone part of the EAC in patients with acquired post-inflammatory atresia is 17,0% less than in patients with SCSOM without atresia; patients with acquired post-inflammatory atresia have a more acute anterior tympanomeatal angle (33° versus 68°) than patients with SCSOM without atresia. The thickness of the anterior wall of the EAC in the bone part in patients with acquired post-inflammatory atresia of the EAC does not statistically differ from the analogous parameter in patients with SCSOM without atresia. Conclusion: The revealed results indirectly indicate the presence of certain features of the structure of the external ear in patients with acquired post-inflammatory atresia of the EAC such as narrower anterior tympanomeatal angle and lumen of the bone part. These features of the EAC structure may contribute to the more likely development of post-inflammatory atresia development.

Detailed radiative transfer simulations of kilonovae are difficult to apply directly to observations; they only sparsely cover simulation parameters, such as the mass, velocity, morphology, and composition of the ejecta. On the other hand, semianalytic models for kilonovae can be evaluated continuously over model parameters, but neglect important physical details which are not incorporated in the simulations, thus introducing systematic bias. Starting with a grid of 2D anisotropic simulations of kilonova light curves covering a wide range of ejecta properties, we apply adaptive-learning techniques to iteratively choose new simulations and produce high-fidelity surrogate models for those simulations. These surrogate models allow for continuous evaluation across model parameters while retaining the microphysical details about the ejecta. Using a new code for multimessenger inference, we demonstrate how to use our interpolated models to infer kilonova parameters. Comparing to inferences using simplified analytic models, we recover different ejecta properties. We discuss the implications of this analysis which is qualitatively consistent with similar previous work using detailed ejecta opacity calculations and which illustrates systematic challenges for kilonova modeling. An associated data and code release provides our interpolated light-curve models, interpolation implementation which can be applied to reproduce our work or extend to new models, and our multimessenger parameter inference engine., Comment: 19 pages, 15 figures

Compact binary mergers involving neutron stars can eject a fraction of their mass to space. Being extremely neutron rich, this material undergoes rapid neutron capture nucleosynthesis, and the resulting radioactivity powers fast, short-lived electromagnetic transients known as kilonova or macronova. Such transients are exciting probes of the most extreme physical conditions and their observation signals the enrichment of the Universe with heavy elements. Here we review our current understanding of the mass ejection mechanisms, the properties of the ejecta and the resulting radioactive transients. The first well-observed event in the aftermath of GW170817 delivered a wealth of insights, but much of today's picture of such events is still based on a patchwork of theoretical studies. Apart from summarizing the current understanding, we also point out questions where no consensus has been reached yet, and we sketch possible directions for the future research. In an appendix, we describe a publicly available heating rate library based on the WinNet nuclear reaction network, and we provide a simple fit formula to alleviate the implementation in hydrodynamic simulations., Comment: 22 pages, updated according to the suggestions of two referees; accepted by Annalen der Physik

Additional file 1: Figure S1. Comparison of the anti-coagulant impact on NC incorporation to the growing thrombi. Figure S2. Instant NC velocities and averaged velocities. Figure S3. Comparison between heparin and hirudin impact on NCs. Figure S4. Classification of the NC cells among the thrombi. Figure S5. Analysis of the CD11b/CD18 distribution in granulocytes and MNCs. Figure S6. The number of NCs per FOV increased gradually up to the 20th minute of the experiment. Figure S7. Blood cell composition changes after perfusion through flow chamber with fibrillar collagen or BSA. Figure S8. Impact of platelet depletion on granulocyte crawling velocity. Figure S9. Fucoidan impact on platelet P-selectin exposure in growing thrombi. Figure S10. Granulocyte movement around thrombi. Figure S11. Thrombus area and percentage of highly activated granulocytes in the presence of leukocyte activators and in patients with WAS. Figure S12. Crawling granulocytes bear Annexin-V positive platelets. Figure S13. Annexin-V and CD66b staining. Figure S14. Assay of the granulocyte crawling in the blood of WAS patients in the presence of healthy donor platelets. Table S1. LAL-test results for endotoxin characterization in the protein samples. Table S2. Calibration of the LAL-test system.

The electromagnetic emission resulting from neutron star mergers have been shown to encode properties of the ejected material in their light curves. The ejecta properties inferred from the kilonova emission has been in tension with those calculated based on the gravitational wave signal and numerical relativity models. Motivated by this tension, we construct a broad set of surrogate light curve models derived for kilonova ejecta. The four-parameter family of two-dimensional anisotropic simulations and its associated surrogate explore different assumptions about the wind outflow morphology and outflow composition, keeping the dynamical ejecta component consistent. We present the capabilities of these surrogate models in interpolating kilonova light curves across various ejecta parameters and perform parameter estimation for AT2017gfo both without any assumptions on the outflow and under the assumption that the outflow must be representative of solar r-process abundance patterns. Our parameter estimation for AT2017gfo shows these surrogate models help alleviate the ejecta property discrepancy while also illustrating the impact of systematic modeling uncertainties on these properties, urging further investigation., Comment: 15 pages, 6 figures, data available in Zenodo (https://zenodo.org/record/7335961) and GitHub (https://github.com/markoris/surrogate_kne)

Short-time behavior of gravity-driven free surface flow of two fluids of equal depth and different densities is studied. Initially, the fluids are at rest and separated with a vertical rigid plate of negligible thickness. Then, the plate disappears suddenly and a gravity-driven flow of the fluids starts. The flow in an early stage is described by the potential theory. The initial flow in the leading order is described by a linear problem, which is solved by the Fourier series method. The motions of the interface between the fluids and their free surfaces are investigated. The singular behaviors of the velocity field at the bottom point, where the interface meets the rigid bottom, and the top point, where the interface meets both free surfaces, are analyzed in detail. The flow velocity is shown to be log-singular at the bottom point. The leading-order inner asymptotic solution is constructed in a small vicinity of this point. It is shown that the flow close to the bottom point is self-similar. The motion of the interface is independent of any parameters, including the density ratio, of the problem in specially stretched variables. In the limiting case of negligible density of one of the fluids, the results of the classical dam break problem are recovered. The Lagrangian representation is employed to capture the behavior of the interface and the free surfaces at the top, where the fluid interface meets the free surfaces. The shapes of the free surfaces and the interface in the leading order computed by using the Lagrangian variables show a jump discontinuity of the free surface near the top point where the free surfaces and the interface meet. Inner region formulation is derived near the top point.

Background. Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor of infancy commonly associated with Kasabach-Merritt phenomenon (KMP) that includes thrombocytopenia and coagulation dysfunction. Platelet receptor CLEC-2 -tumor cell podoplanin interaction is considered the key mechanism of thrombocytopenia in KMP, however, the effect of long-term exposure to podoplanin on platelet function is unknown. Procedure. Here we examined blood samples from 7 patients with KHE/KMP. Platelet calcium signaling and functional responses to conventional activation and CLEC-2 stimulation were analyzed by continuous and endpoint live cell flow cytometry. Platelet aggregation in response to ADP or rhodocytin was analyzed by low-angle light scattering approach (LaSca). Additionally, ex vivo thrombus formation on collagen was observed in parallel-plate flow chambers. Results. We demonstrate that in KHE/KMP platelet functional responses to strong stimulation were on the lower boundary of age-matched normal ranges, while calcium mobilization and fibrinogen binding upon stimulation with ADP alone were significantly lower than control values. Platelet di-aggregate formation in response to ADP was also diminished in most of the patients. Formation of platelet aggregates in collagen-coated parallel plate flow chambers was also noticeably lower than in the age-matched control group. Calcium mobilization in response to CLEC-2 stimulation was unaltered in the patients and could be blocked by low-molecular-weight inhibitors, 2CP and HB125. Conclusions. While platelet responsiveness in KHE/KMP is moderately altered, platelet CLEC-2 receptors remain functional and respond to inhibition. Therefore, our findings suggest that CLEC-2-targeting molecules are new potential agents in therapeutic management of this life-threatening condition.