Buckling deformation of thin layer coverings of small curvatures used in aircraft construction

This paper presents the results of the experimental and numerical analysis in terms of the finite element method of plating components of aircraft load-bearing structures. The subject matter of the study was composite panels with stiffeners in the form of a regular grid of oriented longitudinal elements in accordance with the directions of the principal stresses in the covering. The analysis was conducted in the buckling states of structural deformation which showed that structures with stiffeners exhibit much more favorable behavior in buckling deformation states than in laminar structures.This translates into stress distributions and their gradients, which are milder in forms of stiffened structures

Performance Analysis of VPN Remote Access Tunnels

The purpose of the study is to analyze the efficiency of communication with the serverusing the methods of secure remote access, as well as checking and comparing the quality of servicesprovided by the server depending on the method of secure remote connection. The article focuses onVPN technology implemented in the latest Windows Server 2012 R2 operating system

APPLICATION OF FINITE DIFFERENCE METHOD FOR MEASUREMENT SIMULATION IN ULTRASOUND TRANSMISSION TOMOGRAPHY

In this work, we present a computer simulation model that generates the propagation of sound waves to solve a forward problem in ultrasound transmission tomography. The simulator can be used to create data sets used in the supervised learning process. A solution to the "free-space" boundary problem was proposed, and the memory consumption was significantly optimized from O(n2) to O(n). The given method of simulating wave scattering enables the control of the noise extinction time within the tomographic probe and the permeability of the sound wave. The presented version of the script simulates the classic variant of a circular probe with evenly distributed sensors around the circumference

Diagnostic hysteroscopy and the risk of malignant cells intraabdominal spread in women with endometrial cancer

Although hysteroscopy is currently the undisputed gold standard for the examination of the uterine cavity in women with suspected endometrial cancer, it remains controversial as a procedure that can enhance metastasis spread. Endometrial cancer cells may shed during hysteroscopy and be passively transported with fluid flow into the peritoneal cavity. The paper presents the review of current knowledge regarding the risk of neoplasm metastases in women who had diagnostic hysteroscopy and the conditions that have to be met for the procedure to be safe. We searched PubMed, Ovid, Medline and Scopus databases for data published in the years 1985–2017. The following browsing criteria, the “MeSH headings”: hysteroscopy, endometrial cancer, intraperitoneal or metastatic spread were used to find relevant papers. Based on the current data analysis we conclude that (1.) diagnostic hysteroscopy performed in women with endometrial cancer, especially in its early stages, is a very useful, efficient and safe diagnostic method and (2.) the distension media used for endoscopic procedures in the uterine cavity must be strictly controlled for relatively low pressures to prevent the increase in risk of endometrial cancer intraperitoneal spread

Polish Eastern Border as an External European Union Border

1. Apart from Finnish-Russian border, Polish eastern border is one of the longest external European Union and Schengen Agreement land borders under the control of a single country. 2. For the last few years, Polish Government has significantly improved the infrastructure of Border Guard at the eastern border in order to prevent “flooding” of Europe by illegal immigrants and smuggled goods. 3. Despite this fact, Polish eastern border does not have sufficient infrastructure, especially when the number of border checkpoints and roads is taken into consideration. The abovementioned, along with difficult border crossing procedures, may lead to creating a new symbolic “wall” separating Poland from its eastern neighbors. To avoid this, it seems necessary to introduce procedures, both on regional and international levels, to encourage trans-border regions’ integration. Co-operation should be dealt both in industry as well as in cultural and scientific fields 4. Border traffic at the polish eastern border has been relatively steady for the last few years and even in the case of Ukraine its intensity was increasing. Poland’s accession to Schengen Agreement dramatically reduced border traffic at all three borders. Initially, it was caused by the visas for the citizens of neighboring countries and difficult access to them. As a con-sequence, the number of crossings at the eastern border by the foreigners dropped in certain places even by 50%. To improve the situation it is necessary to simplify visa procedures. Moreover, works on introducing possibilities of crossing borders within so-called small border traffic guaranteed by the EU law, should be finished as quickly as possible. Otherwise, restrictions in border traffic may weaken economic development in border regions and decrease trade exchange, both on local and regional scale

The Schengen Agreement on the Polish-Czech Border

1. The extension of the Schengen Agreement to the countries of Central Europe is the historic event, which finally ended the isolation of the communist period, entirely changing the functions and perception of the state border in this region of Europe and accelerating the integration of European states. 2. Despite the border control removal, one should not expect immediate growth of the border traffic at the Polish-Czech border. However the smuggling of goods may still intensify. 3. Despite the great importance of the Schengen Agreement, the knowledge of Polish-Czech borderland citizens about this event several months before its introduction was scarce. One should hope, that introduction of a new legislation and its practical use, will significantly change the consciousness of citizens. 4. The majority of the respondents on both sides of the border expect that the opening of the border will positively change the image of the Polish-Czech borderland. However, there is also a large group of people, especially on Czech side of the border, who think that the Schengen Agreement will not introduce any changes, although the number of pessimists foreseeing the deterioration of the situation is scarce. 5. Respondents on the Polish side of the border have larger expectations towards functioning of the Schengen Agreement, while Czechs are more skeptical about it.6. There is a strong dependence between the age of the respondents and declaration of fears connected with the accession to the Schengen Zone – the older the respondents, the higher percentage of skeptical people. 7. Expectations and hopes connected with functioning of the Schengen Agreement are related mainly to the economic development of the border-land, especially trade, services, enterprises, as well as with the improvement of living conditions and facilitations in transboundary contacts and foreign travel. Among respondents’ expectations, economic benefits are the most popular. 8. The most frequently indicated fears, connected with the lack of border control, are the growth of crime rate, smuggling and deterioration of natural environment. Moreover, Polish citizens are afraid of the increase in an already high emigration rate

Right ventricle outflow tract stenting as a method of palliative treatment of severe tetralogy of Fallot

We present the case of a 3-month-old infant with tetralogy of Fallot (ToF) with pulmonary artery hypoplasia, critical right ventricle outflow tract (RVOT) obstruction and the presence of major aortopulmonary collateral arteries (MAPCA) and CATCH 22 syndrome. Due to anatomical conditions (severe pulmonary artery hypoplasia), the patient was not qualified for palliative operative treatment Blalock-Taussig shunt. We conducted catheterization with an attempt of balloon plasty and stent implantation into the right ventricle outflow tract and main pulmonary artery. Successful stent implantation into the right ventricle outflow tract was performed. The stent created a 4.1 mm diameter channel and allowed for unrestricted blood flow from the right ventricle to the pulmonary arteries. After the procedure we observed an increase in blood saturation of up to 89%. Control echocardiography revealed blood flow through the stent to the pulmonary arteries with a pressure gradient of 45 mm Hg. There were neither rhythm nor conduction disturbances in the control ECG after the procedure. After 6 days of observation the patient was discharged from our department. We conclude that successful stent implantation into the RVOT in patients with ToF and hypoplastic pulmonary arteries improves their clinical condition, increases pulmonary blood flow by physiological means and leads to an improvement of pulmonary artery development before surgical treatment

Classification of brown earths based on field and laboratory properties: Problematic issues and proposition of their solution

In this paper, the current problems associated with the classification of brown earths, are presented. According to the Polish Soil Classification (PSC) (1989, 2011), base saturation is the main parameter for identifying eutrophic and dystrophic brown soils. In practice, however, it is not possible to determine the base saturation value in the field. Therefore, the aim of this study was to estimate the base saturation using a regression equation and create a field guide for brown earths, based on the pH value, measured using a Hellige indicator, and the calcium carbonate content. Determination of the pH ranges enabled the classification of brown earth types in the field. These results suggest that pH can be used as a proxy for base saturation especially in the field. A change in the hierarchy of soil (sub)types is proposed for the new Polish Soil Classification