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    Research on surface defect detection method of metallurgical saw blade based on YOLOV5

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    As a typical cutting tool with good performance and high processing efficiency, metallurgical saw blades are widely used in various industries, but surface defects are inevitably generated in the manufacturing process. To solve this problem, this paper proposes a YOLOv5-based surface defect detection model for product quality, which can distinguish three common metallurgical sawblade surface defects with mAP value of 96,1 % in each defect category detection of metallurgical sawblades and detection time of 139,8 ms per image

    In memory Josip Črnko (1943 – 2023)

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    The influence of continuous casting and extrusion processes on the properties and structure of CuNi2Si alloy and the morphology of the Ni-Si phase precipitates

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    CuNiSi alloys are widely used in various mechanical and electrical applications. These group of materials, due to the phenomena of precipitation hardening, are able to obtain high mechanical properties with also relatively high electrical properties. In the article authors compare two different types of products, made from the CW111C alloy i.e. rods which were continuously cast on the horizontal laboratory casting set-up (low degree of structure refinement) and rods commercially extruded with high degree of structure refinement. The presented results of experimental work characterize the tested materials in terms of their chemical composition, mechanical and electrical properties depending on the manufacturing process, as well as reveal their structures and the effect of heat treatment on the morphology of the Ni-Si precipitates

    Studying the binder effect on the properties of briquettes of ferroalloy production waste

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    The paper shows the results of studies in searching for a binder for briquetting finely dispersed dust (FDD) of ferroalloy production of the Kazakhstan content. The fractional composition and shape of FDD particles were studied. Liquid glass and caustic soda were used as a binder. The research results showed the possibility of using liquid glass as a binder. Experimental briquettes have sufficiently high compressive strength and drop strength, which implies the possibility of their transportation and loading

    Numerical simulation and optimization of die casting for automotive shift tower cover

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    The structural characteristics of the car shift tower cover were analyzed, and the pouring system and overflow system were designed according to the empirical formula.The numerical simulation based on Anycasting software shows that the metal liquid flow and solidification rate of the initial process are not smooth.According to the simulation results, the shape of the runner and the number of the gate were modified, and the point cold water pipe was set at the position where the defects might occur to optimize the process.The numerical simulation of the optimized process scheme shows that the filling process is stable and there is no liquid spatter, and good quality die casting is obtained through actual production

    Structure optimization of ladle rotary table mounting device

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    As a widely used equipment in continuous casting process, the installation process of ladle rotary table is complicated and requires many installation equipment. According to the practical engineering application, this paper takes the installation device as the research object, and optimizes the original structure of the installation device. SolidWorks software was used to model the overall structure of the installation device, and the established model was imported into Hypermesh for mesh division, and finally into ANSYS for finite element analysis to compare the stress and deformation of the structure before and after optimization.The results show that the stress of the optimized structure is reduced to some extent, and the practical application requirements are met

    Investigation of functions characterizing the flow curves of cast magnesium alloy MgAl9Zn1

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    The article presents the results of testing the flow curves of cast magnesium alloy MgAl9Zn1. Experimental tests were carried out on a deformation dilatometer in a compression test of cylindrical specimens heated to 380 °C, 400 oC, 420 °C at strain rates of 0,1 s-1, 1 s-1, 10 s-1. The experimental curves were described by functions used in programs for simulating metal forming processes based on the finite element method. The Generalized Reduced Gradient optimization method (GRDM) implemented in Microsoft Excel was used to determine the function coefficients. Based on the results obtained, the best functions characterizing the flow curves were selected for use in describing the material models used in numerical simulations of cast magnesium alloy MgAl9Zn1

    A case of functional vitamin B12 deficiency after recreational nitrous oxide use

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    Highlights Vitamin B12 and holotranscobalamin may be normal in chronic nitrous oxide users Nitrous oxide induces a defect in vitamin B12-mediated functions Homocysteine and methylmalonic acid help identify N2O-users with B12 deficiency The recreational use of nitrous oxide as laughing gas becomes a real public health issue among adolescents and young adults. Chronic use is deleterious and can lead to severe neurological disorders. Nitrous oxide inactivates vitamin B12, and the functional defect of vitamin B12 plays a major role in the pathogenesis of nitrous oxide-related neurological disorders. Here we report the case of a 22-year-old woman who came to the hospital after an unexplained loss of consciousness. She exhibited typical features of vitamin B12 or folate deficiency such as macrocytic anemia and hypersegmented neutrophils. However, serum concentrations of folate and vitamin B12 were normal. In contrast, circulating concentrations of total homocysteine and methylmalonic acid were significantly increased. These results clearly indicated a defect in vitamin B12 functions. The reason for this defect was clarified when she revealed that she had been consuming nitrous oxide recreationally for over a year. The present case points out the challenges in diagnosing vitamin B12 deficiency in the context of nitrous oxide abuse due to normal concentrations of total serum vitamin B12 in a significant proportion of cases. The medical community should be aware of how difficult it can be to interpret B12 status in this specific population

    Electrochemical gas detection for dissolved gas analysis

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    In a previous article, gas chromatography was described as the most popular method for Dissolved Gas Analysis (DGA) conducted in laboratories. In this article, we describe the established and prevalent DGA method for online and portable devices. Over the last half-century, most DGA analyses were performed by electrochemical detection. Such methods are reliable, accurate, and provide simple, lowcost, and fast responses to most malfunctions. Despite these advantages, electromechanical detection has fallen out of favor over the last two decades, giving way to new gas measurement methods. This article describes the pros and cons of electrochemical gas detection for DGA

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