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This research examines the life cycle costing (LCC) of concrete produced using recycled concrete aggregates (RCA) combined with sustainable fibers, including carbon nanofibers and natural sisal fibers, as substitutes for traditional natural aggregates. A series of concrete mixtures were formulated with RCA content levels of 0%, 50%, and 100%, incorporating various fiber combinations, while some mixtures were further enhanced with supplementary cementitious materials such as fly ash (FA) or silica fume (SF). The study included a thorough assessment of mechanical properties, including compressive strength, flexural strength, and split tensile strength, to evaluate the performance of these concrete mixtures. The findings indicated that the integration of sisal and carbon nanofibers significantly improved mechanical properties, suggesting that while using 100% RCA (Mix C9) resulted in a slight reduction in strength, it still outperformed conventional concrete. This research highlights the economic advantages of utilizing RCA and sustainable fibers in concrete formulations, demonstrating how life cycle costing can provide a framework for promoting sustainable construction practices that enhance resource efficiency and minimize overall project costs in the context of a circular economy.

This research examines the amalgamation of Circular Economy concepts with Lean Six Sigma approaches to enhance manufacturing operations, emphasizing waste minimization, resource efficiency, and economic performance. The study assesses the influence of Lean Six Sigma on production efficiency and environmental sustainability via empirical analysis and process optimization methodologies. Conventional manufacturing procedures, including machining, milling, and grinding, were assessed for resource utilization and waste production, revealing that Lean Six Sigma methodologies markedly decreased material waste, especially in milling operations, where waste was curtailed by 20%. Advanced precision techniques, including CNC and laser cutting, were evaluated for their efficiency, with CNC cutting realizing a 15% decrease in energy usage and a 30% enhancement in material utilization. Laser cutting exhibited improved accuracy, resulting in a 35% decrease in rework and scrap. The economic study indicated that the application of Lean Six Sigma in CNC operations resulted in a 25% reduction in operating expenses over time, albeit greater initial expenditures. These results provide significant insights into the enhancement of industrial efficiency and the promotion of sustainable production practices via the integration of Circular Economy concepts with Lean Six Sigma methodologies. Keywords: Circular Economy, Precision Manufacturing, Comparative Analysis, Tool Life, Economic Implications.

Using a mixed-methods approach, we examine the complex link between user happiness and technology adoption in the context of smart homes. Our tests show that user happiness and adoption are highly influenced by the versions of smart home technologies, with Version A producing better user satisfaction (7.2) and adoption rates (68%) than Version B (6.8, 62%). Furthermore, consumers engaging with Features A and C reported the greatest adoption rates (80%) and satisfaction (8.1), indicating that certain features, particularly when paired, have a significant influence on user pleasure. Extended training times resulted in higher user satisfaction and adoption rates of the technology; the 6-hour training group had the greatest adoption rate (84%), and the highest satisfaction (8.3%). Furthermore, user age demographics have a substantial impact on adoption and happiness; young adults have the greatest adoption rate (70%) and contentment (7.6). These results highlight the necessity of developing smart home technologies that are appropriate for various age groups, as well as the significance of feature customization, thorough training, and user-centric design in improving user satisfaction and encouraging technology adoption. Introduction

In this study, "Real-Time Information Access in Urban Environments: A User Interaction Study Using the Real-Time Information Test," participant data revealed a diverse group with an average age of 31, a balanced gender distribution, varying education levels (40% Bachelor's, 20% Master's, 40% PhD), and an average of 6 years of experience with urban navigation. The findings of the Real-Time Information Test (RTIT) showed an average job completion time of 140 seconds and a low average error count of 1.2, demonstrating competency in interacting with real-time information systems. Furthermore, the User Satisfaction Survey found an average of 8.4 overall satisfaction ratings, 8.4 user-friendliness ratings, and 7.8 information accuracy ratings, indicating excellent user experiences. These results highlight user variety, increases in job efficiency and accuracy, and high user satisfaction, all of which contribute to a comprehensive knowledge of real-time information access in urban contexts, with implications for system advancements and urban planning.

Under the project National Heliogeophysical Complex of the Russian Academy of Sciences, it is planned to create several coherent decameter radars. ISTP SB RAS developed a network of coherent decameter radars well before the start of financing this project. This has provided extensive experience in operating such radars, has enabled us to identify their technological problems, which should be solved when creating radars of own design, and to develop a project of radars with broader capabilities for diagnostics of the ionosphere as compared to existing radars of similar types. The paper analyzes the existing EKB ISTP SB RAS radar, reviews its technological problems, and proposes the structure of a new radar of SECIRA type. We report the results of prototyping of elements of the SECIRA radar, which demonstrate the possibility of its implementation. We discuss the potential applicability of the radar to ionospheric studies on the territory of the Russian Federation, in particular in high-latitude regions.

The problem of ensuring the stability of rock mass is of particular importance in the conditions of thermal interaction of mine workings with permafrost rocks. The paper presents the results of studying the effectiveness of passive thermal protection system of permafrost massif. Based on a numerical modeling by use of ANSYS FLUENT software complex, studies of thermal interaction of a large-span chamber working and permafrost massif have been performed. On the example of a hypothetical three-dimensional model of mine working with different variations in the material composition of the protective structure (lining) of working and the use of convective heat transfer in the technological channel (air gap), it has been performed the calculated study of the features of the temperature regime of the lining structural elements. There has been carried the estimation of the predicted depth of thawing of rock depending on the design and material composition of the lining and the duration of the thermal impact on the rock massif. The influence of the thermal resistance of the mine working protective structure on the depth and dynamics of thawing rock massif has been studied, the structure determines the conditions of preservation of its cryogenic state and requirements for mining systems of regulation of the thermal regime. The temperature gradients formed in the structural elements of the lining, which can contribute to the occurrence of thermal stresses that have a negative impact on the stress-strain state of the protective structure of the mine working have been founded. On the example of the accepted model representations of the technological channel (temperature of the entering air, width of the channel) the weak influence of heat exchange due to free convection on the intensity of thermal interaction of the working and rock massif has been shown. To reduce the thermal impact on the protective structure of the mine working and the permafrost massif it is necessary to increase the intensity of heat exchange in the technological channel by decreasing the temperature of the air entering the channel, or using the forced convection based on the organization of a special ventilation system.

In the steppe zone of the Omsk region from 2020 to 2022 two sowing periods (May, 15 and 25) of Severny oilseed flax with a seeding rate of five million germinated seeds per hectare on four chemicalization backgrounds were tested. With the norm for the steppe zone of the HTC 0.78 all the years of the experiments this indicator was only 0.37-0.58. Having sowed in the third decade of May, the yield of oilseed flax seeds with the use of a tank mixture of herbicides (Agritox, WC 1 l/ha and Legion, EC 0,4 l/ha) with a working fluid flow rate of 200 l/ha 0.868 tons of oilseeds were obtained from 1 ha and 1.009 t/ha were obtained with the help of a complex chemicalization, where Lingohumate 100 g/ha was used during the leaf development phase in a mixture of herbicides and Isagry Bor 0.5 l/ha during the building phase. They provided a profitability level of 197 %. Similar results were obtained having used only herbicides – 179.9 %. Ammophos’s introduction during sowing did not bring a significant increase in yield and reduced economic indicators. Having sowed in the second decade of May, the annual oilseeds yield was significantly lower and, accordingly, the level of profitability was decreasing sharply from 27.8 to 87.8 %.

Supply chain project management is a comprehensive process allowing managers to coordinate resources, functions and actions to achieve a specific goal within a set time frame, scope and budget. One of the problems in the context of improving the quality of the Supply Chain Project Management is the creation of a favorable social environment for employees who are a crucial part of the supply chain management (SCM) system. In this article, this issue is considered from the perspective of the assignment problem. First, this article proposes the Corporate Social Responsibility (CSR) as a platform for introducing Lean practices within the supply chain. It strongly contributes to filling the research gap in the field of the CSR and Lean philosophy coordination. The ultimate goal is to promote the culture of continuous improvements, human resources (HR) development and satisfaction of workers’ social needs for the sustainability of the Supply Chain Project Management. Second, the Hungarian method is implemented in the context of the coordination of CSR and Lean management for right decisions in assignment problem concerning the issues of supply chain employees’ engagement and development. The results reveal the possibility of achieving positive effects in creating an employee-friendly supply chain environment and unlocking untapped human potential while maintaining long-term benefits. The research findings would assist the scientific community and practitioners in applying proposed ways to enhance labor productivity and ensure the development of employee-friendly social environment.

In recent years, the issues of preserving the health of the population and prevention of certain diseases leading to a significant deterioration in the life quality and human activity have been keenly discussed all over the world. This circumstance has significantly activated the scientific research in development and testing of educational programs, which are based on the development of the need for systematic independent physical exercises that contribute to the formation of general cultural competencies among students of educational institutions. At the same time, the level of formation of this knowledge, skills and abilities should contribute to the further continuous process of formation of universal competencies in physical culture and sports of university students. This paper aims to analyze and experimentally substantiate the need for continuity in the formation of universal competencies among schoolchildren and university students in physical culture, as the basis for successful professionally applied physical training of future specialists in various fields of economics. The conducted research shows the need to improve the organizational and content provision of physical culture in general education institutions to increase the effectiveness of organized physical culture classes, and to improve the quality of the formation of general cultural competencies (knowledge, skills, abilities).

According to statistics, up to 80% of all fixed metal structure accidents are associated with welded joints. However, most of the emergency destructions, usually caused by non-metallic inclusions in the weld metal, are fragile. The probability of brittle fracture decreases with increasing plasticity. And plasticity, that depends on the mobility of dislocations to a great degree, decreases with temperature decrease and increase in the strain rate. The plasticity of the metal is a structurally sensitive property and depends on the type of crystal lattice that determines the number of densely packed directions and slip planes. Low-alloy steels, mainly used in welded steel structures, have a volume-centered cubic lattice with a relatively small number of planes and sliding direction. These steels are ductile at relatively high temperatures and become brittle at negative temperatures. The only way to improve the ductility of the metal without significantly reducing its strength is to grind grain. One of the effective ways to obtain finegrained structure of the weld metal is to introduce modifiers into the weld pool. The modifiers should be in the form of refractory compounds (oxides, carbides, nitrides), which in the crystallization zone of the weld pool are crystallization centers and increase the number of grains per unit volume. Studies of the modification of the crystallizing metal in the conditions of casting and fusion welding have shown that the melt overheating reduces the effect of modification. In electric arc welding with an arc temperature of more than 6000K, the danger of deactivation of the modifier is high. One way to reduce overheating and improve the efficiency of modifiers in welding is the introduction of modifying particles in the weld pool in combination with more massive granules in the form of chopped wire, serving as micro-refrigerators. This method, called welding with a metalchemical additive (MCA), is successfully used in bridge construction. Modification of the weld pool with refractory particles, along with the positive effect of grinding grain in the weld there is also a negative moment: modifying particles that remain in the weld in the form of non-metallic inclusions are stress concentrators and can become centers of cracking

This paper is focused on horizontal, vertical, and temperature-dependent distributions, size composition of bottom and mid-water trawl catches, and biomass estimations of smooth lumpsucker Aptocyclus ventricosus (Pallas) (Cyclopteridae) within the Russian Exclusive Economic Zone (EEZ) of the northwestern Sea of Japan. This species is distributed very widely throughout the study area inhabiting both near-bottom layers and water column. It is less abundant in small bays and in the northern Tatar Strait (north to 50°N). Despite wide bathymetric (0 to 940 m) and temperature (-1.1 to +12.2 °C) ranges this species occurred mainly within the lower mesopelagic zone of 400-800 m depths and cold temperatures of -0.5-1°C. In the near-bottom layer catches of smooth lumpsucker were represented by fish with TL 5-45 cm (mean 28.1 cm, dominant lengths 29-37 cm) while in water column its TL varied 4 to 41 cm with mean 17.9 cm, most abundant were fish with TL 8-15 and 24-31 cm; the difference is associated with specific life history aspects of the species considered. Recent increase of smooth lumpsucker biomass in the study area was observed with estimated value of 3000 t in the northern Primorye.

ObjectiveWe aimed to describe pediatric program directors' perceptions of existing mentorship programs in pediatric residencies, to assess whether characteristics used for mentor-mentee assignments impact mentoring outcomes, and to identify barriers to success in mentorship programs.MethodsWith the support of the Association of Pediatric Program Directors (APPD) Research Task Force, we conducted a cross-sectional survey study of all associate pediatric program directors in the United States in March 2022.ResultsNearly half (82 of 197, 41.6%) of programs responded. Most (87.8%) report having a formal mentoring program. Half of programs (51.4%) do not provide training to residents on how to be a mentee, and only slightly more than half (62.5%) provide training to faculty mentors. Most programs (80.6%) do not provide protected time for faculty mentors. There were no meaningful associations with characteristics used for mentorship matches and perceived successful mentorship. Top barriers from the program leadership perspective included faculty and residents lacking time, residents lacking skills to be proactive mentees, and inadequate funding.ConclusionsWhile a majority of programs have formal mentorship programs, many do not provide training to mentors or mentees. Barriers to mentorship include a lack of funding and time. National organizations, such as APPD and the Accreditation Council for Graduate Medical Education, have an opportunity to provide guidance and support for protected time, funding, and training for mentors and mentees.

The chemical analysis of metal seam showed that introduction of titanium dioxide with MCA intensifies transition of Al2O3 from slag into metal pool and provides double concentration of titanium in the seam compared to the one which appears in the interaction of bathtub with melted flux AH-47 without TiO2 additives. The presence of oxides of titanium and aluminium of endogenous origin in the melt leads to formation of refractory particles with the center of TiO2 and Al2O3 in it. These particles are the centers of crystallization in the tail part of the molten pool and they remain in seam metal in the form of evenly distributed fine nonmetallic inclusions, which have crystallographic affinity with a matrix (α-iron). That provides the fine-grained seam structure with the raised and stable strength characteristics. This article compares the existing and developed technologies for production of MCA. The granulometric analysis of the powder TiO2 has demonstrated that when MCA is processed in the planetary mill, particles of titanium dioxide are crushed to a nanodimensional order. It is shown that the preparation of MCA in high-energy planetary mill (due to double increase of durability in coupling of the modifier with granulate) provides its stable structure, increases the cold resistance (20–25%) and stability of strength characteristics along the length of welded seam. Metalgraphic researches determined that the fine-grained structure which linear size of grain is twice smaller than the one obtained in the old technology welding is formed in a seam. However the direct introduction of nanomodifiers in a molten pool through the flux or an electrode wire is not efficient because of their deactivation and high temperature in welding zone. Therefore it was offered to use modifiers in the mix with the cooling macroparticles in case of automatic welding of a bridge metalware under flux using metalchemical additive (MCA). The MCA consists of a chopped welding wire (granulate), the powdering modifying chemical additive TiO2 in the mixer with the displaced rotation axis «piyanay bochka» accorfint to the existing technology. However this MCA's technology doesn't provide the stable durability of modifier's coupling with the granulate's surface and it is not able to control its structure under production conditions that, certainly, negatively affects on stability of welded connections' properties. Therefore one of the main task in this research was to improve the existing technology to increase durability of the modifier' coupling with granulate. Welding is one of the main technological methods to connect details and nodes in production process. However 70–80% of metalware destruction occuring in operational process are related to welded connections. These destructions are mainly fragile. The increased firmness of welded connections against the fragile destruction is needed due to development of northern and east regions in Russia. The most perspective method to increase cold resistance of welded connections is the crush of seam metal grain by means of nanomodification.