THE USE OF A MAGNETIC FIELD IN THE ASSESSMENT OF THE OPERATING LOADS OF PNEUMATIC TIRES

Steel is a typical construction material with ferromagnetic properties. This material is often used as a structural component of composites whose task is to transfer mechanical loads. This function is performed by the steel wires placed inside the tires. The aim of the preliminary tests was to determine the influence of air pressure changes in the pneumatic wheel on the distribution of the magnetic field observed outside the tire. The research used a magnetostrictive sensor that reacts to changes in magnetic induction. A sensor with three perpendicular measurement directions was used, and the components of the magnetic induction vector were measured at selected measurement points located in the space surrounding the tested tire. During the tests, measurements were made of the tire’s magnetic field under various load conditions. The results confirmed the occurrence of measurable effects of changes in the magnetic field distribution of the tire depending on the pressure inside

The role of macrophage-inducible C-type lectin in different stages of chronic liver disease

The macrophage-inducible C-type lectin (mincle) is part of the innate immune system and acts as a pattern recognition receptor for pathogen-associated molecular patterns (PAMPS) and damage-associated molecular patterns (DAMPs). Ligand binding induces mincle activation which consequently interacts with the signaling adapter Fc receptor, SYK, and NF-kappa-B. There is also evidence that mincle expressed on macrophages promotes intestinal barrier integrity. However, little is known about the role of mincle in hepatic fibrosis, especially in more advanced disease stages. Mincle expression was measured in human liver samples from cirrhotic patients and donors collected at liver transplantation and in patients undergoing bariatric surgery. Human results were confirmed in rodent models of cirrhosis and acute-on-chronic liver failure (ACLF). In these models, the role of mincle was investigated in liver samples as well as in peripheral blood monocytes (PBMC), tissues from the kidney, spleen, small intestine, and heart. Additionally, mincle activation was stimulated in experimental non-alcoholic steatohepatitis (NASH) by treatment with mincle agonist trehalose-6,6-dibehenate (TDB). In human NASH, mincle is upregulated with increased collagen production. In ApoE deficient mice fed high-fat western diet (NASH model), mincle activation significantly increases hepatic collagen production. In human cirrhosis, mincle expression is also significantly upregulated. Furthermore, mincle expression is associated with the stage of chronic liver disease. This could be confirmed in rat models of cirrhosis and ACLF. ACLF was induced by LPS injection in cirrhotic rats. While mincle expression and downstream signaling via FC receptor gamma, SYK, and NF-kappa-B are upregulated in the liver, they are downregulated in PBMCs of these rats. Although mincle expressed on macrophages might be beneficial for intestinal barrier integrity, it seems to contribute to inflammation and fibrosis once the intestinal barrier becomes leaky in advanced stages of chronic liver disease

Application of Magnetic Sensor for Magnetic Profile (1D) and Surface (2D) Measurement of Automotive Wheels

This paper shows a report of over three years of intensive work on application of a 3-axis anisotropic magnetoresistive sensor with I2C interface for measurement of magnetic flux density distribution of automotive wheels. The work was undertaken to answer the question of whether is a possibility to effectively apply low-cost magnetic sensors with serial interface to measure the magnetic field surrounding the automotive wheel or tire. Two measurement techniques were discussed: Magnetic profile (1D) and magnetic surface measurement (2D) over tread, and also gear associated with the sensor, as well as its design, layout, operation, and control technique during (1D) and (2D) measurements. Three experiments were performed to asses accuracy and repeatability concerning component and resultant magnetic circumferential profiles and also magnetic surface. Differences between measurement outcomes in experiment were assessed. The results show that accuracy and repeatability lays below maximum admissible uncertainty declared by the producer. This proves directly that there is no measurable influence of motors, gear, operation, or measurement procedure on results obtained by magnetic sensors, and indirectly, that the assumed requirements regarding gear design and parameters are correct, and measurement of magnetic flux density distribution of automotive wheels and tires using (1D) and (2D) techniques is possible using a 3-axis anisotropic magnetoresistive sensor with I2C interface

Pressure Drops in Two-Phase Gas–Liquid Flow through Channels Filled with Open-Cell Metal Foams

This paper describes experimental investigations of single-phase and two-phase gas–liquid flow through channels with a diameter of 20 mm and length of 2690 mm, filled with metal foams. Three types of aluminium foams with pore densities of 20, 30 and 40 PPI and porosities ranging from 29.9% to 94.3% were used. Air, water and oil were pumped through the foams. The tests covered laminar, transitional and turbulent flow. We demonstrated that the Reynolds number, in which the hydraulic dimension should be defined based on foam porosity and pore diameter de = ϕdp/(1 − ϕ), can be used as a flow regime assessment criterion. It has been found that fluid pressure drops when flowing through metal foams significantly depends on the cell size and porosity of the foam, as well as the shape of the foam skeleton. The flow patterns had a significant influence on the pressure drop. Among other things, we observed a smaller pressure drop when plug flow changed to stratified flow. We developed a model to describe pressure drop in flow through metal foams. As per the proposed methodology, pressure drop in single-phase flow should be determined based on the friction factor, taking into account the geometrical parameters of the foams. We propose to calculate pressure drop in gas–liquid flow as the sum of pressure drops in gas and liquid pressure drop corrected by the drop amplification factor

Utilization of magnetic signature of automotive tire for exploitational wear assessment

The use of tires is limited, on the one hand, by their geometric wear, which is interpreted by vehicle users as the tread height, on the other hand, as a result of aging processes. There is an intrinsic magnetic field around the tire. This specific feature of the tire can be interpreted as the magnetic pattern of the tire. The aim of the research was to determine the influence of operation on the distribution of magnetic induction around the tire. The tests were carried out on new tires and after a specific operational mileage. The obtained results in the form of spatial images of the distribution of the magnetic field force lines of new tires and after a specific operational mileage allowed to visualize the differences in their technical condition, which were not possible to observe using other research methods