The study of stress-strain state of stabilized layered soil foundations

Herein presented are the results of modeling and analysis of stress-strain state of layered inhomogeneous foundation soil when it is stabilised by injection to different depths. Produced qualitative and quantitative analysis of the components of the field of isolines of stresses, strains, stress concentration and the difference between the strain at the boundary of different elastic horizontal layers. Recommendations are given for the location of stabilised zones in relation to the border of different elastic layers. In particular, it found that stabilization of soil within the weak layer is inappropriate, since it practically provides no increase in the stability of the soil foundation, and when performing stabilisation of soil foundations, it is recommended to place the lower border of the stabilisation zone below the border of a stronger layer, at this the distribution of stresses and strains occurs more evenly, and load-bearing capacity of this layer is used to the maximum

The study of stress-strain state of stabilized layered soil foundations

Herein presented are the results of modeling and analysis of stress-strain state of layered inhomogeneous foundation soil when it is stabilised by injection to different depths. Produced qualitative and quantitative analysis of the components of the field of isolines of stresses, strains, stress concentration and the difference between the strain at the boundary of different elastic horizontal layers. Recommendations are given for the location of stabilised zones in relation to the border of different elastic layers. In particular, it found that stabilization of soil within the weak layer is inappropriate, since it practically provides no increase in the stability of the soil foundation, and when performing stabilisation of soil foundations, it is recommended to place the lower border of the stabilisation zone below the border of a stronger layer, at this the distribution of stresses and strains occurs more evenly, and load-bearing capacity of this layer is used to the maximum

The Prognostic Value of Peripheral Artery Diseases in Patients with ST-Segment Elevation Myocardial Infarction

Hypothesis. To evaluate the clinical and prognostic role of haemodynamically insignificant stenosis of the extracranial arteries (ECA) and lower extremity arteries (LEA) among patients with ST-segment elevation myocardial infarction (STEMI). Patients and Methods. The study sample consisted of 423 patients with STEMI who were consecutively admitted to the Kemerovo Cardiological Centre. Results. The prevalence of polyvascular diseases (PVD), as defined by an increased intima-media thickness (IMT) of the common carotid artery or by stenosis of the ECA or LEA, was 95%. Among patients with ECA or LEA, the case fatality rate of those with stenosis with occlusion of less than 30% of the vessel lumen was 5.7%, whereas the case fatality rate among patients with stenosis with occlusion of more than 30% of the vessel lumen was 15.1% (χ2=13.68, P=0.003). Using the GRACE score model, together with the determination of additional factors (congestive heart failure, PVD, prior stroke, and smoking status), we developed an improved model (KemScore) for death risk stratification for a 12-month period. The value of the AUC for our model (KemScore) was 0.83 (95% CI = 0.76–0.90), which was significantly higher than the initial GRACE score value of 0.71 (95% CI = 0.63–0.79)

The Prognostic Value of Peripheral Artery Diseases in Patients with ST-Segment Elevation Myocardial Infarction

Hypothesis. To evaluate the clinical and prognostic role of haemodynamically insignificant stenosis of the extracranial arteries (ECA) and lower extremity arteries (LEA) among patients with ST-segment elevation myocardial infarction (STEMI). Patients and Methods. The study sample consisted of 423 patients with STEMI who were consecutively admitted to the Kemerovo Cardiological Centre. Results. The prevalence of polyvascular diseases (PVD), as defined by an increased intima-media thickness (IMT) of the common carotid artery or by stenosis of the ECA or LEA, was 95%. Among patients with ECA or LEA, the case fatality rate of those with stenosis with occlusion of less than 30% of the vessel lumen was 5.7%, whereas the case fatality rate among patients with stenosis with occlusion of more than 30% of the vessel lumen was 15.1% ( 2 = 13.68, = 0.003). Using the GRACE score model, together with the determination of additional factors (congestive heart failure, PVD, prior stroke, and smoking status), we developed an improved model (KemScore) for death risk stratification for a 12-month period. The value of the AUC for our model (KemScore) was 0.83 (95% CI = 0.76-0.90), which was significantly higher than the initial GRACE score value of 0.71 (95% CI = 0.63-0.79)

Development of oral cancer tissue-mimicking phantom based on polyvinyl chloride plastisol and graphite for terahertz frequencies

SIGNIFICANCE: A new concept of a biotissue phantom for terahertz (THz) biomedical applications is needed for reliable and long-term usage. AIM: We aimed to develop a new type of biotissue phantom without water content and with controllable THz optical properties by applying graphite powders into a polyvinyl chloride plastisol (PVCP) matrix and to give a numerical description to the THz optical properties of the phantoms using the Bruggeman model (BM) of the effective medium theory (EMT). APPROACH: The THz optical properties of graphite and the PVCP matrix were measured using THz time-domain spectroscopy, which works in the frequency range from 0.1 to 1 THz. Two phantoms with 10% and 12.5% graphite were fabricated to evaluate the feasibility of describing phantoms using the EMT. The EMT then was used to determine the concentration of graphite required to mimic the THz optical properties of human cancerous and healthy oral tissue. RESULTS: The phantom with 16.7% of graphite has the similar THz optical properties as human cancerous oral tissue in the frequency range of 0.2 to 0.7 THz. The THz optical properties of the phantom with 21.9% of graphite are close to those of human healthy oral tissue in the bandwidth from 0.6 to 0.8 THz. Both the refractive index and absorption coefficient of the samples increase with an increase of graphite concentration. The BM of the EMT was used as the numerical model to describe the THz optical properties of the phantoms. The relative error of the BM for the refractive index estimation and the absorption coefficient is up to 4% and 8%, respectively. CONCLUSIONS: A water-free biotissue phantom that mimics the THz optical properties of human cancerous oral tissue was developed. With 21.9% of graphite, the phantom also mimics human healthy oral tissue in a narrow frequency range. The BM proved to be a suitable numerical model of the phantom

Characterization of silver nanowire layers in the terahertz frequency range

Funding Information: Funding: The work was supported by the European Union’s Horizon 2020 FET Open project TERAmeasure (grant agreement No 862788), by the “International Research Agendas” program of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund (No. MAB/2018/9), by the statutory sources of the Department of Structural Materials, Military University of Technology (project no. UGB 22–846/2021/WAT) and by the Ministry of Science and Higher Education of the Russian Federation (project no. FSRR-2020-0004), (Igor S. Nefedov). A. Krajewska was supported by the Foundation for Polish Science (FNP). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Thin layers of silver nanowires are commonly studied for transparent electronics. However, reports of their terahertz (THz) properties are scarce. Here, we present the electrical and optical properties of thin silver nanowire layers with increasing densities at THz frequencies. We demonstrate that the absorbance, transmittance and reflectance of the metal nanowire layers in the frequency range of 0.2 THz to 1.3 THz is non-monotonic and depends on the nanowire dimensions and filling factor. We also present and validate a theoretical approach describing well the experimental results and allowing the fitting of the THz response of the nanowire layers by a Drude–Smith model of conductivity. Our results pave the way toward the application of silver nanowires as a prospective material for transparent and conductive coatings, and printable antennas operating in the terahertz range—significant for future wireless communication devices.Peer reviewe