Stabilizing the Long-time Behavior of the Navier-Stokes Equations and Damped Euler Systems by Fast Oscillating Forces

The paper studies the issue of stability of solutions to the Navier-Stokes and damped Euler systems in periodic boxes. We show that under action of fast oscillating-in- time external forces all two dimensional regular solutions converge to a time periodic flow. Unexpectedly, effects of stabilization can be also obtained for systems with stationary forces with large total momentum (average of the velocity). Thanks to the Galilean transformation and space boundary conditions, the stationary force changes into one with time oscillations. In the three dimensional case we show an analogical result for weak solutions to the Navier- Stokes equations

Plastic Formed and Spot Welded Joints Strength of S350GD+Z Steel

This paper presents a research of the lap joint shear strength of S350GD+Z sheet material joined by resistance spot welding. The resistance spot welding process was done for five values of welding current. The joints strength structure analysis was done for the shearing curves. The influence of the welding current on the joints maximum strength and the shear curve of the resistance spot welded joints was presented. Welding current increase influence efficiency on the joints strength was analyzed. The analysis of the cold plastic formed joining technologies (clinching) was also presented. The clinching joints were made by using different tool types and uniform values of embossment minimum thickness. The influence of tool shape on the joint strength was described. In the case of round clinching joints the influence of forming force increase on the joints strength was studied

Comparison of the most popular operating systems in terms of functionalities

The main purpose of research is comparison of the following modern operating systems: Windows 10, Windows 11, MacOS Catalina and Linux Ubuntu 20.04 LTS. An analysis was made in terms of functionalities and time needed to perform basic activities. The systems were selected on the basis on performed popularity analysis, by using StatCounter [1] statistic. To study each operating system it was necessary to create two test stands corresponding to the requirements of the systems. Conducted research were divided on two sections. In the first one, analysis of the possessed functionalities, assessment of the advancement and ease of using them was performed. In the second section, examination was carried out to compare the operating system in terms of the time of performing specific activities

Database Replication for Disconnected Operations with Quasi Real-Time Synchronization

Database replication is a way to improve system throughput or achieve high availability. In most cases, using an active-active replica architecture is efficient and easy to deploy. Such a system has CP properties (from the CAP theorem: Consistency, Availability and network Partition tolerance). Creating an AP (available and partition tolerant) system requires using multi-primary replication. This approach, because of many difficulties in implementation, is not widely used. However, deployment of CCDB (experiment conditions and calibration database) needs to be an AP system in two locations. This necessity became an inspiration to examine the state-of-the-art in this field and to test the available solutions. The tests performed evaluate the performance of the chosen replication tools: Bucardo and EDB Replication Server. They show that the tested tools can be successfully used for continuous synchronization of two independent database instances

Obiekty sakralne przy Głównym Szlaku Beskidzkim

Sacred sites along the Main Beskidy Trail Sacred sites are a characteristic element of the Polish Carpathians. They are investigated by numerous art historians, ethnographers and also tourists who take a great interest in them. In the mountains, sacred sites are often situated on hiking trails. The purpose of this article is to present the results of an inventory of sacred sites along the Main Beskidy Trail, and classify areas through which the trail runs. The Main Beskidy Trail is the longest tourist trail in Poland, which connects Ustroń in the Silesian Beskid Mountains and Wołosate in the Western area of the Bieszczady Mountains. 181 sacred sites were classified using criteria specified by U. Janicka-Krzywda and changed by the authors. Numerous factors have a great influence on today’s location of sacred sites on The Main Beskidy Trail. The most important factors are : settlement distribution, population density, history of the region, religious affiliation of its inhabitants, and the tourist attractiveness of a given place