Existing standards require welded joints with full penetration. It is considered that welded joints with complete penetration minimize the stress concentration in the root passage. However, there are numerous situations in the industry, in which the load-bearing capacity of the welded joint with partial penetration is satisfactory. If the tests of partially penetrated welds show satisfactory load capacity, the benefits compared to fully penetrated welds are reflected in lower costs, ie less time is required to prepare the joint, less additional material is needed, ie shorter time is required to make the welded joint. The paper presents the testing of butt welded joints of structural steel S355N, with partial penetration, achieved by the MAG welding in the overhead position (PD) in the protection of the gas mixture. The samples were welded with different welding parameters and with different joint preparation, and the tests were performed by non destructive methods (visual inspection, testing with penetrants and magnetic particles) and destructive methods - tension and bending tests, Vickers hardness testing.
Abstract Predicting history-dependent materials’ responses is crucial, as path-dependent behavior appears while characterizing or geometrically designing many materials (e.g., metallic and polymeric cellular materials), and it takes place in manufacturing and processing of many materials (e.g., metal solidification). Such phenomena can be computationally intensive and challenging when numerical schemes such as the finite element method are used. Here, we have applied a variety of sequence learning models to almost instantly predict the history-dependent responses (stresses and energy) of a class of cellular materials as well as the multiphysics problem of steel solidification with multiple thermo-viscoplasticity constitutive models accounting for substantial temperature, time, and path dependencies, and phase transformation. We have shown the gated recurrent unit (GRU) as well as the temporal convolutional network (TCN), can both accurately learn and almost instantly predict these irreversible, and history- and time-dependent phenomena, while TCN is more computationally efficient during the training process. This work may open the door for the broader adoption of data-driven models in similar computationally challenging constitutive models in plasticity and inelasticity.
The authors present the life and work of prof. dr. Radoslav Živić - Rade who will be remembered as an exceptional pediatrician, professor of lofty pride and morals and a writer who occupies a special place in the contemporary Serbian narrative milieu in which it is difficult to find a prose writer and sensitivity to the meaning of words and the ability to visualize and fruitful grafting in the literary art of Serbia.
Radiological examination methods in the diagnosis of kidney disease, thanks to their objectivity and their capabilities, have taken their place in the diagnosis of urosystems and kidney disease. Radiological methods of examination in the diagnosis of the kidney are numerous and diverse. They are sovereign, dominant and unrivaled. However, the dangers that lurk and threaten in their application, especially ionization and complications from iodine contrast agents, indicate and say that they should be used in strict indications, with well-educated staff and with full protection measures. The aim of this paper is to show and point out the number, variety, advantages and disadvantages of radiological methods of examination in kidney diagnostics. The material and method of work is the experience gained in the profession based on urographic examinations and other radiological methods of examination of the urogenital system, primarily in 18,000 IVUs performed in the period 1994-2021. at the Center for Radiology of the University Medical Center Nis and numerous literal announcements of authors and co-authors written in domestic and foreign journals. The results of the work are shown illustratively, with pictures - nephrocalcinosis, renal cyst, pheochromocytoma, VUR V 0 , kidney tumor, color doppler of the renal artery, a series of native and contrast spiral CT tomograms of the kidney. The development of radiological techniques in recent decades has enriched radiological diagnostics with new diagnostic possibilities. Therefore, we received new radiological images, in which our results are compatible with numerous literal world releases. In conclusion, the authors point out that radiological methods in the diagnosis of kidneys are indispensable and, among other methods of examination, indispensable.
From ancient times the natural plant Cornelian cherry is used for various purposes. The healing properties of Cornelian cherry suit the human body and give it the necessary vitamins, acids, and everything else it needs for the body to function normally and healthily. Due to its antioxidant, antiallergic, antimicrobial, and antihistamine properties, it is increasingly used as a dietary supplement, as well as for medical and pharmaceutical purposes. In addition to the fruit of the Cornelian cherry, in the past, the oil of Cornelian cherry seeds was used, the content of which can be up to 30%. However, the data available in the literature are scanty and do not show true values because the oil content depends on many factors, such as the geographical origin of the Cornelian cherry, the harvest period, varieties, etc., which also affects the oil content in the seeds. Therefore, the aim of this study is to determine the average oil content of Cornelian cherry seeds, and to determine the obtained oil physico-chemical parameters that show the quality of the oil, namely oil viscosity, iodine value, peroxide value, acid value, and saponification value. Based on the obtained results, more information is clearly given about the quality of the obtained oil, as well as its use in the production of cosmetic preparations. Based on the conducted analyzes, it was shown that the oil obtained from the Cornelian cherry seeds was high quality, and that it was analyzed in its fatty acid composition similar to other vegetable oils such as sunflower oil, pumpkin oil, corn oil. The low of the peroxide value showed that the oil used has good resistance to oxidative spoilage, which is attributed to the composition of fatty acids and the presence of oil components that have a pronounced antioxidant effect, while the iodine value indicates that it is oil rich in saturated fatty acids such as palmitic, stearic and arachid, etc. where genotype plays an important role. The saponification value showed that these are fatty acids present in the triacylglycerols of this oil, which are low molecular weight, ie there are fewer of those with a larger number of C atoms. All obtained values of the analyzed physical and chemical parameters are in accordance with the requirements imposed by the Regulations on edible vegetable oils (Official Gazette of the Federation Bosnia and Herzegovina No.21/11.), and as such can be used for cosmetic purposes.
Biological markers (BMs) are organic compounds in oils in which a precursor is known, and during the transformation of organic matter these compounds undergo certain structural and stereochemical changes. Based on the established precursors of BMs, the origin of the examined oils can be estimated, and based on the intensity and the type of changes and also geological history. It includes defining the deposition medium, the degree of maturation, the length of the oil migration path, the degree of biodegradation. The most studied and applied BMs are normal alkanes, isoprenoid aliphatic alkanes pristane and phytane, and polycyclic alkanes of the sterane and terapane type. On the other hand, in the environmental chemistry, these compounds can significantly contribute to the identification of petroleum pollutants, as well as to the assessment of the migration mechanism and the intensity of biodegradation. This review paper first presents the results related to the application of BMs in the organic geochemical correlations of oil in the south-eastern part of the Pannonian Basin (I). The second part provides an overview of those researches in which the same BMs were used in the identification of oil pollutants and in monitoring their changes during the migration and the biodegradation in rivers and river sediments of Serbia (II).
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