Zhurnal inzhenernikh nauk最新文献

{"title":"Vacuum High-Temperature Brazing of 3003 Aluminum Alloy","authors":"Svitlana Maksymova, Vitalii Voronov, Petro Kovalchuk, Alexander Shapiro","doi":"10.21272/jes.2023.10(2).c1","DOIUrl":"https://doi.org/10.21272/jes.2023.10(2).c1","url":null,"abstract":"Brazing filler metals based on the Al-Si system are widely used for brazing aluminum alloys. Their melting point is 577 °С (eutectic). It is necessary to conduct comprehensive studies of the technological properties of experimental filler metals and brazed joints to create a brazing filler metal with a reduced melting temperature for vacuum brazing of thin-walled aluminum products made of alloy 3003. The paper presents the research results on high-temperature vacuum brazing of aluminum alloy 3003 with Al-Cu-(Si, Mg) filler metal. It was determined that the amount of magnesium in the filler should be limited due to the risk of porosity formation associated with magnesium vaporization. It was identified that reducing the magnesium content increases the liquidus temperature above 530–550 °C. Therefore, experimental alloys require additional alloying with depressant elements, particularly silicon, to achieve the required melting temperature level. The chemical inhomogeneity of the filler in the initial state (after rapid solidification from the liquid state) and the structure of the brazed joints were investigated using micro-X-ray spectral analysis. Through empirical means, it was determined that a magnesium content of 1.5 % by weight in the filler allows for producing high-quality brazed joints without visible defects. In this case, shear strength is in the range of 0.6–0.7 of the strength of the base material. Tests of brazed joints for three-point bending resulted in an angle close to 180°, which indicates the promising use of experimental brazing filler metal in vacuum brazing of aluminum alloy 3003.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135955017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication, Mechanical Characterization, and Ranking of Shell Ash Reinforced Al-7075-Based Hybrid Composites","authors":"E. V. Ratna Kumar G, Senthil Kumar K., Ranga Babu J. A.","doi":"10.21272/jes.2023.10(2).c5","DOIUrl":"https://doi.org/10.21272/jes.2023.10(2).c5","url":null,"abstract":"In the research article, the fabrication of Al-7075-based hybrid composites was done by stir casting technique with the addition of a mixture of crab shell ash (CSA), oyster shell ash (OSA), and snail shell ash (SSA). The mixtures of CSA, OSA, and SSA (MCOSA), CSA and OSA (MCOA), CSA and SSA (MCSA), as well as OSA and SSA (MOSA) with weight percentages in a range of 1–3% were added to the base material. The specimens were prepared according to the ASTM standards and tested for mechanical properties. The hardness, as well as impact, flexural, and tensile strengths of the composites, were increased as the amount of reinforcement to the base metal was increased, and compressive strength was decreased. The greatest tensile strength, tensile modulus, and compressive strength values were observed for the composite designated with AlOSA3. The maximum flexural strength and hardness values were observed for the compositions AlOS21 and AlCO12, respectively. Two techniques (TOPSIS and VIKOR) were successfully applied to the mechanical attributes of composites. The ranking results of both methods were compared. The ranking results for TOPSIS and VIKOR were the same for the index value 0.25. The composites filled with aquatic waste fillers can be used for automotive applications concerning their enhanced mechanical properties compared to the Al-7075 metal alloy properties.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135957729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Method of Evaluating the Destruction of a Reinforced Concrete Hollow Core Slab for Ensuring Fire Resistance","authors":"Stanislav Sidnei, Vitalii Nuianzin, Tetiana Kostenko, Andrii Berezovskyi, Wiktor Wąsik","doi":"10.21272/jes.2023.10(2).d1","DOIUrl":"https://doi.org/10.21272/jes.2023.10(2).d1","url":null,"abstract":"Fire tests of reinforced concrete floor slabs do not allow the detection of the onset of the boundary state due to loss of entirety because blocks are installed on the unheated surface to reproduce the design load. This prevents the formation of cracks through which toxic combustion products, smoke, and temperature spread can penetrate. Determining a building structure’s actual fire resistance limit was fixed at the onset of any fire resistance boundary state. It was proven that calculation methods for fire resistance assessment have significant advantages over experimental methods. To reduce the number of finite elements for a rational calculation of the fire resistance assessment of a reinforced concrete hollow core slab, a geometric model of 1/4 of this structure was built. The possibility of visualizing the studied structure at full scale was realized when obtaining the calculation results. The stress-strain state of the studied structure was evaluated based on the thermal and mechanical loading results applied to the reinforced concrete hollow core slab. Thus, the work’s objective was achieved based on the calculation experiments’ results. A methodology was developed for calculating the destruction of a reinforced concrete hollow core slab while assessing its fire resistance. Scientific fundamentals for determining the onset of the boundary state of loss of entirety were developed. The proposed methodology allowed for a reliable assessment of the fire resistance of such structures.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136003280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitriding of Long-Term Holes in the Cyclic-Commuted Discharge","authors":"Myroslav Stechyshyn, Aleksandr Dykha, Victor Oleksandrenko","doi":"10.21272/jes.2023.10(2).c2","DOIUrl":"https://doi.org/10.21272/jes.2023.10(2).c2","url":null,"abstract":"The effect of anhydrous nitriding in a glow discharge on microhardness, phase composition, and wear resistance of long holes in steels C45, 37Cr4, and 41CrAlMo7 with direct current supply and in cyclically switched discharge (CSD) was studied. Nitriding was carried out on a UATR-1 anhydrous nitriding unit with a discharge chamber diameter of 400 mm and a working height of 700 mm. Anhydrous nitriding in a glowing discharge was carried out at a temperature of 560 °С, a voltage of 730 V, a pressure in the chamber of 120 MPa, and the nitriding duration was 6 h. It was established that using holes with a relatively small diameter of glow discharge in a cyclically switched discharge for nitriding creates conditions for obtaining modified layers with higher physical, mechanical, and tribological characteristics. The results of microhardness measurement and their comparison with X-ray phase analysis data confirm the formation of ε, γ, and α phases during nitriding along the entire height of the samples placed in the experimental model. The tests carried out in the dry friction mode showed an increase in the wear resistance of samples made of steel C45, 37Cr4, and 41CrAlMo7 during nitriding in a cyclically switched discharge. To achieve 100 μm wear of 41CrAlMo7 steel during nitriding in CSD, 1400 m of friction path and 1000 m – during nitriding with direct current is required. It was established that using long holes of a glow discharge with different types of power for nitriding creates conditions for obtaining modified layers with variable characteristics. Nitriding of holes with a relatively small diameter of a glow discharge with a different power supply creates conditions for obtaining modified layers with different physicomechanical and tribological characteristics.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135952881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Cdx Transcription Factors Characteristics","authors":"Taraneh Javanbakht","doi":"10.21272/jes.2023.10(2).e1","DOIUrl":"https://doi.org/10.21272/jes.2023.10(2).e1","url":null,"abstract":"This study presents a new application of TOPSIS for the optimization of transcription factors characteristics. This application is essential as it can help compare the characteristics of these proteins and determine the optimized output of their comparison with this decision-making method. The hypothesis in this article was that according to the previous study of the Cdx transcription factors, as the Cdx2 transcription factor showed more robust characteristics than Cdx1 and Cdx4, the TOPSIS method would show a better rank position of these first proteins in comparison with the two other ones. Moreover, the engrailed repressor domain EnRCdx1 used in the plasmid showed the reduction of the pax3 gene expression in comparison with the induced regulation of the gene expression with the production of the Cdx1, Cdx2, and Cdx4 transcription factors using the corresponding plasmids, the worst rank position with TOPSIS was expected for this repressor domain. The results obtained with this ranking method showed that the rank positions of the transcription factors and the repressor domain corresponded to their compared properties. Moreover, the change in the weight values of the candidates showed the modification of their distances from the best and worst alternatives and closeness coefficients. However, as expected, the candidates’ rank positions were unchanged, and the Cdx2 transcription factor was still the best candidate. The results of this article can be used in computer engineering to improve biological applications of these proteins.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136002844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Justification of the Wood Polymer Material Application Conditions","authors":"Oleksandra Horbachova, Yuriy Tsapko, Yelena Tsarenko, Serhii Mazurchuk, Ivan Kasianchuk","doi":"10.21272/jes.2023.10(2).c6","DOIUrl":"https://doi.org/10.21272/jes.2023.10(2).c6","url":null,"abstract":"The production of heat-insulating materials based on wood was analyzed in this paper. The expediency and efficiency of using wood waste were established. A study of the operational properties of the sample obtained from wood shavings polymerized with mixtures of polyester and epoxy resins was carried out. It was proven that the process’s primary regulator is the material’s density and porosity. Also, an increase in humidity and wetting reduces heat-insulating indicators. Based on thermophysical dependences, the thermal insulation properties of the samples were calculated. Moreover, it was established that the thermal conductivity does not exceed 0.21·10–6 m2/s, and the thermal conductivity of the sample – 2.85·10–3 W/(m·K). Therefore, these products can be classified as heat-insulating materials. A through-thickness compressive strength study showed that the wood shavings and polyester resin material are more fragile, and the strength limit was reduced by more than 1.2 times compared to the epoxy resin-based material. The moisture absorption results showed that a heat-insulating product made of shavings polymerized with polyester resin. Moisture absorption was 5 % after 90 days of exposure to water. On the other hand, the heat-insulating products made of shavings with epoxy resin of 4.41 % showed their resistance to moisture absorption.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136002855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technological and Environmental Problems in the Stabilization Treatment of the Main Condenser Cooling Circuit by Sulfuric Acid","authors":"Pavlo Kuznietsov, Olha Biedunkova","doi":"10.21272/jes.2023.10(2).h1","DOIUrl":"https://doi.org/10.21272/jes.2023.10(2).h1","url":null,"abstract":"The method of anti-scale stabilization treatment of cooling water of the circulating cooling system (CCS) with sulphuric acid to reduce the content of bicarbonate and carbonate ions allows to effectively reduce scale formation processes in power plant’s cooling systems. The results of the research and analysis of the sulphuric acid dosage to ensure the water-chemical regime of the reversible cooling system are presented in the example of the Rivne NPP. The analysis of the results of the control of the technology of stabilization treatment of cooling water with sulphuric acid was carried out, as the influence of the technological changes on the content of sulfate ions in the discharge water and the influence of the water discharge into a water body were evaluated. The sulphuric acid stabilization treatment makes it possible to neutralize the alkalinity caused by the content of bicarbonate and carbonate ions and to convert the proportion of calcium ions bound to bicarbonate and carbonate ions into a permanent hardness that is not prone to scale formation under the influence of temperature and has a lower tendency to scale formation. The use of sulphuric acid may be suitable for the optimal choice of water chemistry regime for scale reduction in CCS, according to the criteria of acidification of additional cooling water, which is the dosing criterion. The technological regimes for CCS stabilization treatment with sulphuric acid introduced at the Rivne Nuclear Power Plant (NPP) ensured a decrease in the use of sulphuric acid and a decrease in discharges into the water body by an average of 220 t/year, a decrease in the increase in the content of sulfate ions before the water intake and after the water discharge of the Rivne NPP, which correlates with a decrease in the amount of sulphuric acid used for CCS water treatment and a decrease in the environmental impact on the water bodies of the Styr River.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136004228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Cryogenically Treated CFRP Composite on the Buckling Behavior in the Adhesively Bonded Beam","authors":"M. U. Uysal","doi":"10.21272/jes.2023.10(1).d1","DOIUrl":"https://doi.org/10.21272/jes.2023.10(1).d1","url":null,"abstract":"Carbon fiber reinforced plastic (CFRP) composite materials have favorable mechanical and physical properties such as low density, high strength-to-weight ratio, high fatigue resistance and high creep behavior, and high stiffness. Thanks to these unique properties, they produce aircraft parts such as outer flaps, carry-through structures, and center wing boxes and automotive parts such as body panels, engine components, and structure members. However, studies have been continuously performed on improving the properties of CFRP composite materials. Recently, investigation of the effects of cryogenic (LN2) cooling on the mechanical behavior and characteristic of these composite materials is getting a popular and important issue. In this sense, this study aims to examine the buckling behaviors of adhesively bonded beam-produced cryogenically treated carbon fiber reinforced plastic (Cryo-CFRP), CFRP, steel, and aluminum. Therefore, a new finite element model was adopted to evaluate the buckling capacity of Cryo-CFRP composite material in the adhesively bonded beam. The model is a supported adhesive beam subject to two opposite-edge compressions until the material buckles. The elastic, homogeneous adhesive was used in the assembly. Finite element models for the adhesively bonded beam having four different adherents (CRFP, Cryo-CFRP, steel, and aluminum) were established by ANSYS® software. The critical buckling loads of the adhesively bonded beam were predicted, and their mode shapes were presented for the first six modes. The effects of the usage of Cryo-CFRP on the critical buckling load were investigated. Among the adherents’ materials, the highest critical buckling load was determined for Cryo-CFRP/Steel adhesively bonded beam as 23.6 N. This value was obtained as 22.3 N for CFRP/Steel adherent samples. Thus, the critical buckling load was increased by 5.6 % when one adherent steel was constant and the other adherent material changed from CFRP to Cryo-CFRP. Also, the critical buckling load increased by 3.7 % when using a cryogenically treated Cryo-CFRP/Aluminum couple instead of a CFRP/Aluminum couple in the sandwich beam. The findings demonstrated that the cryogenic treatment positively affects the buckling behavior in the adhesively bonded beam.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135182920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Specified Parameters in Designing Porous Materials Using Magnetic Nanotechnologies","authors":"Mykola Riabchykov, Tetiana Furs, Alexandr Alexandrov, Iryna Tsykhanovska, Olha Hulai, Vasylyna Shemet","doi":"10.21272/jes.2023.10(2).c7","DOIUrl":"https://doi.org/10.21272/jes.2023.10(2).c7","url":null,"abstract":"The research is devoted to solving the problem of regulating the porosity parameters during the manufacturing process under magnetic field conditions. The process of synthesizing magnetic nanocomponents based on a mixture of divalent and trivalent iron oxides was given. The use of nanocomponents allowed for improving the conditions for creating porous materials. A device with adjustable magnetic induction was developed to produce porous materials in a magnetic field. The study of the porous material’s structure with the nanopowder content in the magnetic field conditions showed a clear dependence of the structure on the magnetic parameters. When the content of nanocomponents increased to 0.3 %, and the magnetic field induction increased to 2.5 mT, the dispersion of pore sizes decreased by 8–10 times, the density of pores – increased by 15–20 times, and the average diameter of pores – decreased by 12–15 times. Mathematical dependencies that determine the porosity parameters for different values of the magnetic nanopowder content and the level of magnetic induction in the ring electromagnet were proposed. The obtained dependencies allowed for assigning the level of magnetic technological parameters to ensure the given porosity parameters. The developed methods of magnetic technology for creating porous materials can increase the quality and ensure the required porosity level.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136002597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ways of Intensification of Grass Seed Production","authors":"A. Spirin, D. Borysiuk, O. Tsurkan, I. Tverdokhlib, N. Veselovska, M. Edl","doi":"10.21272/jes.2023.10(1).f3","DOIUrl":"https://doi.org/10.21272/jes.2023.10(1).f3","url":null,"abstract":"The main reason that restrains the development of seed production of perennial grasses is losses during harvesting, which depend on the agrotechnical properties of plants and the imperfection of existing means. There are no special grass seeds yet. Therefore, serial equipment with special devices is recommended for their collection. There are enough options for technologies for collecting grass seeds. In the article, six main options of technologies used in production were analyzed and compared according to the main indicators. The best results of a comprehensive comparison are those technologies that process the collected seed mass into a stationary one. The design of a device for wiping the seed mass was proposed to develop this direction of grass seed collection technologies. The article presents theoretical and experimental research results that allowed improving these devices based on rational design and operating parameters. Another way to intensify the production process of leguminous grass seeds is to combine the technological processes of wiping and separation in one machine. The analysis of various separating devices showed that machines with a rotating screen of cylindrical or conical shape are best suited for this purpose. The conducted theoretical studies confirmed the hypothesis that extending the time the material stays on the sieve by using a conical surface increases the yield of clean seeds and contributes to uniform loading of the sieve surface, improving the quality of the initial material. According to the research results, the design of the grating-separating block was proposed for the implementation of this scientific hypothesis. The theoretical and experimental studies presented in the article will allow for significantly intensifying the process of collecting grass seeds and outlining the further development of scientific research in this field.","PeriodicalId":31548,"journal":{"name":"Zhurnal inzhenernikh nauk","volume":"231 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135686284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}