Capturing the temperature gradients of GMAW hardfacing processes by employing CFD and FEM simulation procedures

Hardfacing is carried out whenever a local improvement of the mechanical properties of metallic parts is demanded. In this regard, gas metal arc welding technology is one of the most popular choices. One decisive factor of the welded joint quality is governed by the heat affected zone. The present paper proposes a simulation methodology that can be employed for capturing the temperature gradients in any location of the base metal, when such information is required. The model was developed by using ANSYS Workbench simulation software and is based on coupled CFD and Transient Thermal analysis. In the first stage, a welded sample is subjected to 3D scanning for recreating its constitutive surfaces in a CAD environment. In the next stage, the convective heat transfer occurring due to the velocity of the shielding gas is captured by means of CFD analysis. Experimentally derived temperatures are employed for developing a transient thermal analysis, having defined the exterior heat transfer coefficient. In the last stage, the simulation results are verified in an arbitrary location of the base metal that is located outside the heat affected zone

Microglial morphology in the somatosensory cortex across lifespan. A quantitative study

Background: Microglia are long-lived cells that constantly monitor their microenvironment. To accomplish this task, they constantly change their morphology both in the short and long term under physiological conditions. This makes the process of quantifying physiological microglial morphology difficult. Results: By using a semi-manual and a semi-automatic method to assess fine changes in cortical microglia morphology, we were able to quantify microglia changes in number, surveillance and branch tree starting from the fifth postnatal day to 2 years of life. We were able to identify a fluctuating behavior of most analyzed parameters characterized by a rapid cellular maturation, followed by a long period of relative stable morphology during the adult life with a final convergence to an aged phenotype. Detailed cellular arborization analysis revealed age-induced differences in microglia morphology, with mean branch length and the number of terminal processes changing constantly over time. Conclusions: Our study provides insight into microglia morphology changes across lifespan under physiological conditions. We were able to highlight, that due to the dynamic nature of microglia several morphological parameters are needed to establish the physiological state of these cells

Contributions to the modernization of fluid power field by integration of intelligent equipment

The article refers to some directions of modernization in the field of hydraulics focusing on digitalization and the transition to intelligent hydraulic equipment and systems. Before exposing the achievements, the authors try to remove some confusion related to digitization and digitalization. The article presents two intelligent equipment designed by IHP, a proportional directional valve and a digital actuator and two intelligent stands, one of servo-valves and one of digital hydraulic cylinders, existing in operation in laboratory and which by the endowment and working procedures represent solutions in the field of intelligent hydraulics.W artykule odniesiono się do wybranych kierunków modernizacji hydrauliki, koncentrując się na cyfryzacji i przejściu na inteligentne urządzenia oraz systemy hydrauliczne. Przed przedstawieniem osiągnięć autorzy artykułu starają się usunąć zamieszanie związane z pojęciami cyfryzacji i digitalizacji. W artykule przedstawiono dwa inteligentne urządzenia zaprojektowane przez IHP, rozdzielacz proporcjonalny i siłownik cyfrowy oraz dwa inteligentne stanowiska, jeden z serwozaworów oraz jeden z cyfrowych siłowników hydraulicznych, stosowane w laboratorium, które ze względu na wyposażenie i procedury robocze są rozwiązaniami inteligentnej hydrauliki

Capturing the temperature gradients of GMAW hardfacing processes by employing CFD and FEM simulation procedures

Hardfacing is carried out whenever a local improvement of the mechanical properties of metallic parts is demanded. In this regard, gas metal arc welding technology is one of the most popular choices. One decisive factor of the welded joint quality is governed by the heat affected zone. The present paper proposes a simulation methodology that can be employed for capturing the temperature gradients in any location of the base metal, when such information is required. The model was developed by using ANSYS Workbench simulation software and is based on coupled CFD and Transient Thermal analysis. In the first stage, a welded sample is subjected to 3D scanning for recreating its constitutive surfaces in a CAD environment. In the next stage, the convective heat transfer occurring due to the velocity of the shielding gas is captured by means of CFD analysis. Experimentally derived temperatures are employed for developing a transient thermal analysis, having defined the exterior heat transfer coefficient. In the last stage, the simulation results are verified in an arbitrary location of the base metal that is located outside the heat affected zone

Mechano-hydraulic pumping solutions for reduction off energy losses in agricultural mobile machinery

Hydraulic digital power consists in a hydraulic plant having one or more discreet valued components actively with which we are controlling the system output flow. In this paper authors study a solution of 4 fixed pumps parallel connected. This complex pumping system can achieve 15 flows. The pumping system consists in an electrical single speed motor, 4 fixed pumps, the repartition will achieve with the help of 4 electrohydraulic distributors and an electronic micro-controller. The hydraulic plant was made in our Research Institute in the digital hydraulic laboratory for conducting tests and experiments

Underground Economy’s Measurement Methods

It is argued that the underground economy is old as government itself. Many people know how the underground economy functions, but a few are those who know its level. This article analyzes the most important measurement methods of the underground economy, as well as the way these methods could be applied. The methods are grouped into three categories: direct methods (that are using micro-economy data, gathered through sociological investigations, fiscal audits and other direct investigation methods), indirect methods (that use macroeconomic indicators in order to highlight the evolution and the level of the informal economy) and causative methods. The paper also describes five indirect indicators which are used for the underground economy estimation, and presents the advantages as well as the limits of the methods

Intelligent module for monitoring proportional directional valves in hydraulic drive systems

Increased performance of hydraulic drive components, as well as easier maintenance and diagnostics, can be achieved through the use of intelligent devices. Introducing sensors, electronic blocks and control algorithms into the equipment will enable easier repairs in the case of failure, or can increase the efficiency of the installation by providing selected operating parameters to the machine controller. In the case of a malfunction, the smart device can provide error codes. Smart devices can receive and send via various communication protocols (RS232, CAN, Fieldbus, Modbus) commands and feedback signals of monitored parameters. This paper presents the construction of such a monitoring and diagnostics module, the test application and the obtained charts.Zwiększenie wydajności podzespołów hydraulicznych instalacji napędowych, jak również łatwiejsza konserwacja i diagnostyka mogą zostać osiągnięte poprzez zastosowanie inteligentnych urządzeń. Wprowadzenie czujników, bloków elektronicznych i algorytmów sterowania do urządzeń, umożliwi łatwiejsze naprawy w przypadku awarii lub może przyczynić się do zwiększenia wydajności instalacji dzięki dostarczeniu do sterownika maszyny wybranych parametrów roboczych. W przypadku nieprawidłowego działania, urządzenie inteligentne może dostarczyć kody błędów. Inteligentne urządzenia mogą odbierać i wysyłać przez różne protokoły komunikacyjne (RS232, CAN, Fieldbus, Modbus) polecenia i sygnały zwrotne monitorowanych parametrów. W artykule przedstawiono budowę takiego modułu monitoringu i diagnostyki, aplikację testową oraz uzyskane wykresy

Driver Drowsiness Multi-Method Detection for Vehicles with Autonomous Driving Functions

The article outlines various approaches to developing a fuzzy decision algorithm designed for monitoring and issuing warnings about driver drowsiness. This algorithm is based on analyzing EOG (electrooculography) signals and eye state images with the aim of preventing accidents. The drowsiness warning system comprises key components that learn about, analyze and make decisions regarding the driver’s alertness status. The outcomes of this analysis can then trigger warnings if the driver is identified as being in a drowsy state. Driver drowsiness is characterized by a gradual decline in attention to the road and traffic, diminishing driving skills and an increase in reaction time, all contributing to a higher risk of accidents. In cases where the driver does not respond to the warnings, the ADAS (advanced driver assistance systems) system should intervene, assuming control of the vehicle’s commands

Comparison between Digital Image Processing and Spectrophotometric Measurements Methods

Background: Spectrophotometer is a very common instrument in various scientific fields and gives accurate information about light absorbance and transmittance through materials using monochromatic light source. Though, devices used in spectrophotometry can be quite expensive, using components with high technical specifications and the procedure itself is time consuming. Regular digital image acquisition instruments like scanners and cameras on the other hand uses very cheap electronic components to record the information on 3 wide band channels (Red, Green, Blue). Purpose: This paper studies the possibility of correlating the measurements from the spectrophotometer with raw data from digital image acquisition instruments. Materials and Methods: Because the results will be used in protein electrophoresis, we prepared o set of plates with blood serum in different dilutions, stained with Coomassie Brilliant Blue. The absorbance of the resulting plates has been measured using a spectrophotometer and after that, the plates were scanned with a regular office scanner. The digital image was converted in different color spaces (gray scale, RGB, HSV, HSL, CIEXYZ and CIELAB) using custom developed software in C++. We statistically measured the correlation coefficient of different parameters from the color space with the absorption measured with the spectrophotometer. Results and Discussion: The findings of this work show that a consumer digital scanner can be used as a fast and inexpensive alternative to spectrophotometers. This offers the possibility of using scanned images of protein electrophoresis to make quantitative estimations regarding the proteinogram

Roles of Microglial Ion Channel in Neurodegenerative Diseases

As the average age and life expectancy increases, the incidence of both acute and chronic central nervous system (CNS) pathologies will increase. Understanding mechanisms underlying neuroinflammation as the common feature of any neurodegenerative pathology, we can exploit the pharmacology of cell specific ion channels to improve the outcome of many CNS diseases. As the main cellular player of neuroinflammation, microglia play a central role in this process. Although microglia are considered non-excitable cells, they express a variety of ion channels under both physiological and pathological conditions that seem to be involved in a plethora of cellular processes. Here, we discuss the impact of modulating microglia voltage-gated, potential transient receptor, chloride and proton channels on microglial proliferation, migration, and phagocytosis in neurodegenerative diseases