Addition Of Solution Research Articles

Application on power system economic dispatch of marine predator algorithm improved by asymmetric information exchange

The solution to the economic dispatch (ED) problem for power systems allows the power sector to reduce operating costs. However, the ED problem is a complex nonlinear and nonconvex optimization problem whose solution requires powerful algorithms. We propose a new version of the Marine Predator Algorithm (MPA), called IMPA, for solving complex ED problems. The algorithm introduces an asymmetric information exchange (AIE) mechanism, which not only accelerates to escape of local optima but also enriches the diversity of search. In this work, 12 benchmark functions were used to test the performance of the proposed algorithm IMPA. Then, the IMPA was used to solve the ED engineering problem of power system containing of 6, 13, 40, and complex 140 units. The minimum and average costs searched by IMPA are 1657962.7265$/h and 1657962.7265$/h, and they are much lower than the results of the MPA and NMPA, which means that our proposed improved IMPA improves the performance of MPA for solving the economic dispatch problem of large-scale power systems. The results show that the solutions obtained by IMPA are more competitive than those of MPA and NMPA, which provides an additional solution for cost reduction of the power system.

UAV Wing leading edge crashworthiness behaviour under bird strike events: The added value of CF/PA additive solutions versus traditional metallic wing structures

In recent years, an increasing interest in innovative solutions design of aircraft structural components has been raised through both research and industrial fields, aimed at optimising weight and enhancing the ability to withstand both static and dynamic loads. This study compares the structural response to a bird strike phenomenon of a vertical tail of a UAV in standard metallic configuration with the one obtained from an innovative solution, equal in volume but with an internally designed architecture for an additive approach and manufactured by employing a carbon fibre reinforced filament engineered for metal replacement applications (carbon fibre, CF/polyamide, PA). The additive solution proposes the use of a 10 % infill and a lattice structure that completely replaces the traditional aircraft structure concept. This approach leads to a significant weight reduction, approximately 45 % compared to the traditional metallic configuration. The investigation was conducted through explicit numerical simulations considering different impact angles. The numerical model of the bird strike has been assessed by numerical-experimental comparison, simulating the impact of a bird with a flat plate. For this study, the Coupled Eulerian-Lagrangian (CEL) approach has been adopted to perform the simulation. The results were compared in terms of stress distribution, failure analysis, displacements, and energy-time and force-time diagrams. The work demonstrated that using innovative manufacturing processes, such as additive manufacturing, can significantly improve the bird strike resistance of aerospace structures. This improvement is achieved though the production of lighter, structurally collaborative geometries, by reducing the load transferred to the rest of the UAV by about 47 % and decreasing the displacement on the impact area by 53 %.

Problems and Solutions in Vertical Addition of Adults Mental Disorders

This study discusses the problems of adult students (30-40 years old) with mental disabilities in vertical addition learning and proposes several tailored solutions. Through the specific analysis of three students that participated in the study, the difficulties in the process of their mathematical operation ability acquisition are found, such as being influenced by others, and forgetting to carry numbers. In response to these problems, concrete measures have been taken, such as improving students’ self-confidence, using auxiliary tools, and concretizing mathematical concepts. Through the implementation of these measures, a noticeable difference in mathematical ability was achieved. The research summarized some teaching experiences, including the rational use of tools, and attention to students’ psychology and behavior norms.

Pertanggungjawaban Pidana bagi Pelaku Pencemaran Lingkungan Perspektif Fikih Jinayah

This study aims to identify and analyze the strengths and weaknesses of the criminal liability system in environmental law and evaluate how Islamic jurisprudence can offer alternative or additional solutions to address environmental pollution problems. This study uses an empirical legal research method with qualitative procedures. The results of the study indicate that the act is considered to violate Islamic jurisprudence and environmental regulations in Indonesia, as shown in the findings. However, law enforcement still has obstacles related to evidence collection and time constraints that must be overcome in order to effectively pursue individuals or groups responsible for environmental damage. Therefore, to ensure environmental sustainability, it is important for the government to actively participate, for law enforcement to achieve effectiveness, and for business entities and the community to be aware of their obligations and be responsible for their behavior.

Closing the gap in access to child mental health care: provider feedback from the Wisconsin Child Psychiatry Consultation Program

BackgroundMental illnesses are common among children and negatively impact wellbeing during childhood as well as later in life. However, many children with these conditions are not able to access needed mental health care. The Wisconsin Child Psychiatry Consultation Program (WI CPCP) was created to reduce gaps in access to care by providing primary care providers with referral resources, access to behavioral health consultations, and training on mental health topics.ObjectivesThe purpose of this study was 1) to assess the effectiveness of the WI CPCP in Milwaukee County, providing specific insights into provider’s ability to care for child mental health, and 2) identify challenges Milwaukee PCPs faced in providing mental health care to child patients and contextualize these challenges in a conceptual framework of access to health care.MethodsA cross-sectional mixed-methods secondary data analysis was conducted using data collected from online baseline and nine-month follow-up surveys completed by providers participating in the program practicing in Milwaukee County from 2014 to 2022. Provider confidence and skill in providing mental health care was analyzed quantitatively using Two-sample Wilcoxon rank-sum (Mann–Whitney) tests (baseline vs. follow-up survey responses) and descriptive statistics (follow-up survey only). Provider challenges to providing mental health care were analyzed qualitatively using a thematic analysis research approach.ResultsResults from quantitative analyses showed that provider confidence and skill in treating childhood anxiety and depression improved from baseline to follow-up. Results from qualitative analyses were categorized by factors within and beyond the scope of WI CPCP. Within the scope of WI CPCP, providers reported a lack of knowledge of referral options and a lack of training in mental health care as well as a lack of knowledge in assessing and treating mental disorders. Still, many barriers to mental healthcare access persist that are beyond the scope of WI CPCP, such as long wait times and a lack of insurance coverage.ConclusionsThis study supports the effectiveness of the program to improve access to care for children. However, there is a need for additional solutions such as better reimbursement for mental health professionals and expanded insurance coverage.

Comparative Study of Base Transceiver Stations Infrastructure Planning Using Machine Learning for Under Construction Area: A Case Study of Ibu Kota Nusantara

Communication is a fundamental human need that occurs directly or through technologies like telephones and signal transmitters such as BTS and satellites. Satellites, including Starlink, serve as additional solutions for internet access needs, particularly in remote areas, albeit higher costs remain a factor necessitating conventional BTS infrastructure development. Telecommunication operators face challenges in constructing BTS in areas with limited access and complex financial considerations due to low demand in rural areas, requiring careful planning. This study utilizes several supporting variables with the aid of machine learning techniques such as Linear Regression, SVR, Random Forest, and Gradient Boosting to forecast BTS requirements. Comparative analysis shows that the random forest machine learning method provides the best modeling results compared to linear regression, Gradient Boosting, and SVR methods. Despite the superior performance of the random forest method, further fine-tuning is still needed through parameter adjustments and evaluation of variables used to achieve an even better model. The modeling results can be utilized to predict the BTS infrastructure needs in IKN, estimated at 61,135 units. In BTS development planning, mobile operators can collaborate both among themselves and with Internet Service Providers (ISPs) utilizing satellite media. Utilizing shared towers can be an option for cost-efficient BTS infrastructure development.

Oxidative modulations in platelets stored in SSP+, PAS-G and Tyrode's buffer: a comparative analysis

BackgroundPlatelet additive solutions (PASs) improve the efficacy of stored platelets. Oxidative stress causes storage lesions and platelet functions deteriorate. Studies assessing the influence of oxidative stress on platelets stored in PASs are limited. This study compares variations in platelets in different storage solutions (SSP+, PAS-G and Tyrode's buffer). MethodsPlatelets isolated from the blood of Wistar rats were resuspended in SSP+, PAS-G and Tyrode's buffer and stored for seven days at 22°C. The markers of platelet metabolism, function, oxidative stress, antioxidant status and viability were analyzed on Days 1, 3, 5 and 7 of storage. Main resultsSSP+ is associated with platelet function, viability and antioxidant defenses (SOD, CAT and GSH); it decreased primary lipid peroxidation products and maintained the susceptible protein groups in reduced state. Platelet function, antioxidant defenses such as SOD and GSH improved, and lipids and thiols were protected from oxidation in PAS-G. SOD and GSH increased, and lipids and thiols were preserved in Tyrode's buffer. ConclusionSSP+ and PAS-G are more effective in maintaining platelet efficacy till Day 7 compared to Tyrode's buffer. Thus, PAS-G and ∼SSP+ are better than Tyrode's buffer in terms of platelet responses to oxidative stress during storage. This is the first comparative account on the influence of PASs (SSP+, PAS-G and Tyrode's buffer) on platelets in altering oxidative stress. It provides a comprehensive view of the differential responses of platelets in PASs.

Fourier-Based Function Generation of Four-Bar Linkages With an Improved Sampling Points Adjustment and Sylvester's Dialytic Elimination Method

Abstract Four-bar linkages are critical fundamental elements of many mechanical systems, and their design synthesis is often mathematically complicated with iterative numerical solutions. Analytical methods based on Fourier coefficients can circumvent these difficulties but have difficulties with sampling points adjustment and solutions of the design equations in previous studies. In this paper, an improved Fourier-based analytical synthesis method is presented, which transforms the function generation synthesis of planar four-bar linkages into a problem of solving design equations. Calculation of the Fourier coefficients is discussed, including the discretization of the prescribed function and an improved sampling points adjustment method. It is shown that the Fourier coefficients can be computed efficiently and accurately by discretizing the prescribed function with a small number of sampling points. The proposed sampling adjustment method overcomes the difficulty of easily resulting in non-Grashof solutions by considering the complete period of the prescribed function. An improved Sylvester's dialytic elimination method is presented to solve design equations. The method reduces the computation time and avoids cumbersome procedures without generating additional invalid solutions. Several examples are presented to demonstrate the advantages of the proposed synthesis method, which is easy-understanding and efficient, and yields more accurate solutions than available synthesis methods.

Assessment of metabolic and hemostatic profile of apheresis platelet concentrates: does the storage medium play a role?

The impact of pathogen reduction technology (PRT) on metabolic and haemostatic profile of treated platelets remains a subject of debate. Platelets Additive Solutions (PASs) are suggested as more appropriate storage medium compared to plasma. To investigate this in terms of zero heterogeneity PRT-treated and control apheresis platelet concentrates (PCs), collected from the same donors and stored in PAS and plasma respectively, were analyzed. In the first arm of the study six double dose-apheresis PCs were produced, split and stored in plasma, while in the second arm six split double dose-apheresis PCs from the same donors, were produced and stored in PAS. Control and PRT-treated PCs resulted in both arms. Metabolic and haemostatic markers were evaluated in all the examined groups on days 1, 3 and 5. A time dependent increased metabolism both in PAS and plasma-stored PCs was evident in PRT-treated PCs. However, the metabolic profile was better preserved in PCs stored in PAS, as higher pH (6.8 vs 6.5, p=0.007) and lower lactate levels (12.6 vs 17.8 mmol/L, p=0.009) were documented in PRT-treated PAS-PCs compared to plasma-PCs, on day 5. A time dependent decreased hemostatic capacity regardless the storage medium was evident in PRT-treated PCs, (PAS-PCs MCF, p=0.004 and plasma-PCs MCF, p=0.007). Similar results were obtained in control PCs. The use of PAS preserves the metabolic profile of PCs more adequately compared to plasma but has no effect on the haemostatic profile. The clinical relevance of these findings needs further investigation.

Metabolomic and Proteomic Analyses to Reveal the Role of Plant-Derived Smoke Solution on Wheat under Salt Stress.

Salt stress is a serious problem, because it reduces the plant growth and seed yield of wheat. To investigate the salt-tolerant mechanism of wheat caused by plant-derived smoke (PDS) solution, metabolomic and proteomic techniques were used. PDS solution, which repairs the growth inhibition of wheat under salt stress, contains metabolites related to flavonoid biosynthesis. Wheat was treated with PDS solution under salt stress and proteins were analyzed using a gel-free/label-free proteomic technique. Oppositely changed proteins were associated with protein metabolism and signal transduction in biological processes, as well as mitochondrion, endoplasmic reticulum/Golgi, and plasma membrane in cellular components with PDS solution under salt stress compared to control. Using immuno-blot analysis, proteomic results confirmed that ascorbate peroxidase increased with salt stress and decreased with additional PDS solution; however, H+-ATPase displayed opposite effects. Ubiquitin increased with salt stress and decreased with additional PDS solution; nevertheless, genomic DNA did not change. As part of mitochondrion-related events, the contents of ATP increased with salt stress and recovered with additional PDS solution. These results suggest that PDS solution enhances wheat growth suppressed by salt stress through the regulation of energy metabolism and the ubiquitin-proteasome system related to flavonoid metabolism.

Add-on effect of using 0.05% atropine in fast progressors of orthokeratology: A preliminary retrospective study

PurposeTo investigate the potential benefit of combining orthokeratology (OK) lenses with 0.05% atropine ophthalmic solution on the efficacy of myopia control in the fast progressors of OK. MethodsAverage axial length (AL) elongation of both eyes in 70 participants using OK lenses alone or OK lenses combined with 0.05 % atropine ophthalmic solution was retrospectively reviewed. During the observation period (phase 1), all participants exhibited an AL elongation that exceeded 0.15 mm over a 6-month period or 0.3 mm over a 12-month period. Subsequently, the participants were divided into two groups: one group received nightly 0.05 % atropine ophthalmic solution in addition to OK lenses for another 1 year (OKA), while the other group continued using OK lenses alone (phase 2). The changes in AL elongation over time and the differences in AL elongation between the two groups were then compared. ResultsThe baseline and phase 1 demographics and characteristics of the participants was similar between the two groups (all p > 0.05). when considering a one-year timeframe, the OKA group displayed a significantly less AL elongation compared to the OK group (0.14 ± 0.13 mm vs 0.27 ± 0.12 mm, p < 0.001). Within the OKA group, the AL elongation in the second half of the year was significantly faster than in the first half (0.12 ± 0.11 mm vs 0.02 ± 0.14 mm, p = 0.01). Conversely, there was no significant difference in AL elongation between the OK group in the first and second half of the year (0.12 ± 0.07 mm vs 0.15 ± 0.08 mm, p = 0.71). The combination of 0.05 % atropine ophthalmic solution had a significant effect on 1-year AL elongation (p < 0.001). ConclusionsThis study provided preliminary evidence that the combination of OK lenses and 0.05% atropine ophthalmic solution can significantly enhance the effectiveness of myopia control.

Predicting Weld Quality in Duplex Stainless Steel Butt Joints During Laser Beam Welding: A Hybrid DNN-HEVA Approach

Duplex stainless steel (DSS) welding is critical for producing structures and components in a variety of industries. Because traditional optimization approaches cannot manage the complexity of welding, additional solutions must be investigated. This study addresses the need for a systematic exploration of the welding parameters affecting the quality and performance of DSS butt joints, specifically employing fiber laser welding. This study focuses on butt joints in UNS S32304 and 304L using a fiber laser. Welding process parameters were systematically varied, including laser power, scanning speed, beam diameter, and focal position. To efficiently examine the parameters in the design space, the response surface methodology (RSM) with Box–Behnken design (BBD) was used. The combination of the specific parameter values used in the 7th run (Laser Power: 1600 W, Scanning Speed: 2000 mm/min, Beam Diameter: 1.5 [Formula: see text]m, Focal Position: 30 mm) led to better yield point stress (YPS), maximum tensile stress (MTS), break stress (BS) and reduction in area (RA). ANOVA and lack of fit analysis confirmed the significance of the experiment. In particular, the selected welding parameters significantly influenced all responses. A hybrid machine learning method of deep neural network (DNN) and human eye vision algorithm (HEVA) was used for predicting weld quality during laser beam welding (LBW). The hybrid DNN-HEVA consistently outperformed other optimization methods (RSM-BBD, FNN, CNN, and RNN) across key welding quality parameters. High [Formula: see text]2 values (0.9922, 0.9962, 0.9983, and 0.9907) indicated a strong correlation between predicted and actual values for all calculated responses. Lower RMSE, MSE, and MAE values were also highlighted in the precision of predicted values to the experimental data.

Utilization of High-Performance Concrete Mixtures for Advanced Manufacturing Technologies

The presented experimental program focuses on the design of high-performance dry concrete mixtures, which could find application in advanced manufacturing technologies, for example, additive solutions. The combination of high-performance concrete (HPC) with advanced or additive technologies provides new possibilities for constructing architecturally attractive buildings with high material requirements. The purpose of this study was to develop a dry mixture made from high-performance concrete that could be distributed directly in advanced or additive technologies of solutions in pre-prepared condition with all input materials (except for water) in order to reduce both financial and labor costs. This research specifically aimed to improve the basic strength characteristics—including mechanical (assessed using compressive strength, tensile splitting strength, and flexural strength tests) and durability properties (assessed using tests of resistance to frost, water, and defrosting chemicals)—of hardened mixtures, with partial insight into the rheology of fresh mixtures (consistency as assessed using the slump-flow test). Additionally, the load-bearing capacity of the selected mixtures in the form of specimens with concrete reinforcement was tested using a three-point bending test. A reference mixture with two liquid plasticizers—the first based on polycarboxylate and polyphosphonate and the second based on polyether carboxylate—was modified using a powdered plasticizer based on the polymerization product Glycol to create a dry mixture; the reference mixture was compared with the developed mixtures with respect to the above-mentioned properties. In general, the results show that the replacement of the aforementioned liquid plasticizers by a powdered plasticizer based on the polymerization product Glycol in the given mixtures is effective up to 5% (of the cement content) with regard to the mechanical and durability properties. The presented work provides an overview of the compared characteristics, which will serve as a basis for future research into the development of additive manufacturing technologies in the conditions of the Czech Republic while respecting the principles of sustainable construction.

Cumulative donor-specific antibody threshold predicts platelet transfusion response in HLA-alloimmunized patients

AbstractUp to a third of patients with hemato-oncologic conditions who have received multiply transfusions develop immune-mediated platelet transfusion refractoriness. Yet factors that influence posttransfusion platelet corrected count increments (CCI) in patients with HLA-alloimmune platelet transfusion refractoriness remain less well elucidated. Recent advances in HLA antibody characterization using fluorescent bead-based platforms enable the study of donor-specific antibody (DSA) avidity (as measured by mean fluorescence intensity [MFI]) and its impact on HLA-alloimmune platelet transfusion refractoriness. In this large retrospective study of 2012 platelet transfusions among 73 HLA-alloimmunized patients, we evaluated the impact of cumulative HLA DSA-MFI alongside other donor, platelet component, and patient characteristics on CCI at 2 and 24 hours after transfusion. As part of a quality improvement initiative, we also developed and tested a computerized algorithm to optimize donor–recipient histocompatibility based on cumulative DSA-MFI and sought other actionable predictors of CCI. In multivariate analyses, cumulative HLA DSA-MFI of ≥10 000, major/bidirectional ABO-mismatch, splenomegaly, transfusion reactions, and platelet storage in additive solution negatively affected 2-hour but not 24-hour posttransfusion CCI. The DSA-MFI threshold of 10 000 was corroborated by greater antibody-mediated complement activation and significantly more CCI failures above this threshold, suggesting the usefulness of this value to inform “permissive platelet mismatching” and to optimize CCI. Furthermore, DSA-MFI decreases were deemed feasible by the computer-based algorithm for HLA-platelet selection in a pilot cohort of 8 patients (122 transfusions) evaluated before and after algorithm implementation. When HLA-selected platelets are unavailable, ABO-identical/minor-mismatched platelet concentrates may enhance 2-hour CCI in heavily HLA-alloimmunized patients with platelet transfusion refractoriness.

Enthalpies of formation of RCoO3-δ (R = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y) perovskite cobaltites

Standard enthalpies of formation at 298.15 K, ΔfH298.15∘, for RCoO3-δ (R = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y) perovskite-type rare-earth cobaltites were obtained from the combined results of drop and reduction calorimetry. The relationship between the oxygen nonstoichiometry, δ, and thermodynamics of RCoO3-δ was discussed. The fact that RCoO3-δ with smaller ionic radius of R3+ tend to be less stable, having more positive enthalpy of formation from binary oxides (CoO and R2O3), Δf,oxH298.15∘, was confirmed for all the studied RCoO3-δ. Drop calorimetry results were also used in discussing, comparing and assessing the literature heat capacity, CpT, data for RCoO3-δ (R ≠ Y). For YCoO3-δ, both ΔfH298.15∘ and CpT were obtained for the first time solely from the drop calorimetric results; ΔfH298.15∘ values determined by two different methods perfectly agree with each other. The reference data and CpT of RCoO3-δ were used to calculate ΔfH298.15∘ from the published EMF measurement results so as to compare the available Δf,oxH298.15∘(RCoO3-δ) values. An unusual dependence of ΔfH298.15∘(LaCoO3-δ) on its heat treatment history was identified and supported by the additional isoperibolic solution calorimetry measurements.

Platelet Storage-Problems, Improvements, and New Perspectives.

Platelet transfusions are routine procedures in clinical treatment aimed at preventing bleeding in critically ill patients, including those with cancer, undergoing surgery, or experiencing trauma. However, platelets are susceptible blood cells that require specific storage conditions. The availability of platelet concentrates is limited to five days due to various factors, including the risk of bacterial contamination and the occurrence of physical and functional changes known as platelet storage lesions. In this article, the problems related to platelet storage lesions are categorized into four groups depending on research areas: storage conditions, additive solutions, new testing methods for platelets (proteomic and metabolomic analysis), and extensive data modeling of platelet production (mathematical modeling, statistical analysis, and artificial intelligence). This article provides extensive information on the challenges, potential improvements, and novel perspectives regarding platelet storage.

Dynamics of novel soliton and periodic solutions to the coupled fractional nonlinear model

This study secures the soliton solutions of the (2+1)-dimensional Davey–Stewartson equation (DSE) incorporating the properties of the truncated M-fractional derivative. The DSE and its coupling with other systems have extensive applications in many fields, including physics, applied mathematics, engineering, hydrodynamics, plasma physics, and nonlinear optics. Various solutions, such as dark, singular, bright-dark, bright, complex, and combined solitons, are derived. In addition, exponential, periodic, and hyperbolic solutions are also generated. The newly designed integration method, known as the modified Sardar subequation method (MSSEM), has been applied in this study for extracting the solutions. The approach is efficient in explaining fractional nonlinear partial differential equations (FNLPDEs) by confirming pre-existing solutions and producing new ones. Furthermore, we plot the density, 2D, and 3D graphs with the associated parameter values to visualize the solutions. The outcomes of this work indicate the effectiveness of the method utilized to improve nonlinear dynamical behavior. We anticipate that our work will be helpful for a large number of engineering models and other related problems.

Impact of Different Red Blood Cell Storage Solutions and Conditions on Cell Function and Viability: A Systematic Review.

Red blood cell (RBC) storage solutions have evolved significantly over the past decades to optimize the preservation of cell viability and functionality during hypothermic storage. This comprehensive review provides an in-depth analysis of the effects of various storage solutions and conditions on critical RBC parameters during refrigerated preservation. A wide range of solutions, from basic formulations such as phosphate-buffered saline (PBS), to advanced additive solutions (ASs), like AS-7 and phosphate, adenine, glucose, guanosine, saline, and mannitol (PAGGSM), are systematically compared in terms of their ability to maintain key indicators of RBC integrity, including adenosine triphosphate (ATP) levels, morphology, and hemolysis. Optimal RBC storage requires a delicate balance of pH buffering, metabolic support, oxidative damage prevention, and osmotic regulation. While the latest alkaline solutions enable up to 8 weeks of storage, some degree of metabolic and morphological deterioration remains inevitable. The impacts of critical storage conditions, such as the holding temperature, oxygenation, anticoagulants, irradiation, and processing methods, on the accumulation of storage lesions are also thoroughly investigated. Personalized RBC storage solutions, tailored to individual donor characteristics, represent a promising avenue for minimizing storage lesions and enhancing transfusion outcomes. Further research integrating omics profiling with customized preservation media is necessary to maximize post-transfusion RBC survival and functions. The continued optimization of RBC storage practices will not only enhance transfusion efficacy but also enable blood banking to better meet evolving clinical needs.

Achieving Homogeneous Microstructure and Superior Properties in High-N Austenitic Stainless Steel via a Novel Atmosphere-Switching Method

Powder metallurgy is widely used to fabricate high-nitrogen, nickel-free austenitic stainless steel. However, after sintering and nitriding, additional solution treatment is typically required to achieve uniform nitrogen distribution and a homogeneous austenite phase. This work proposes a novel method to eliminate the need for lengthy and high-temperature solution treatment by switching the nitrogen atmosphere to argon during the cooling process. The effects of different N2-Ar atmosphere-switching temperatures (750–1320 °C) on the phase composition, element distribution, microstructure, mechanical properties, and corrosion resistance of the studied steels were systematically investigated. Results show that cooling in the N2 atmosphere initially transforms the matrix to a fully austenitic structure enriched with nitrogen. Excessive nitrogen infiltration leads to Cr2N precipitation, inducing partial austenite decomposition and forming a multiphase structure comprising austenite, α-Fe, and Cr2N. Strategic switching from N2 to Ar reverses this reaction, yielding a high-nitrogen, chemically uniform austenitic structure. Specifically, switching at 1150 °C, the steel exhibits excellent mechanical properties and corrosion resistance, with a yield strength of 749 MPa, an ultimate tensile strength of 1030 MPa, an elongation of 38.7%, and a corrosion current of 0.06 mA/cm2, outperforming the steels cooled solely in N2 and subsequently solution-treated. This novel method offers advantages in cost reduction, energy saving, and operational effectiveness, highlighting its potential for broad industrial application.

Unsteady Magnetohydrodynamics PDE of Monge–Ampère Type: Symmetries, Closed-Form Solutions, and Reductions

The paper studies an unsteady equation with quadratic nonlinearity in second derivatives, that occurs in electron magnetohydrodynamics. In mathematics, such PDEs are referred to as parabolic Monge–Ampère equations. An overview of the Monge–Ampère type equations is given, in which their unusual qualitative features are noted. For the first time, the Lie group analysis of the considered highly nonlinear PDE with three independent variables is carried out. An eleven-parameter transformation is found that preserves the form of the equation. Some one-dimensional reductions allowing to obtain self-similar and other invariant solutions that satisfy ordinary differential equations are described. A large number of new additive, multiplicative, generalized, and functional separable solutions are obtained. Special attention is paid to the construction of exact closed-form solutions, including solutions in elementary functions (in total, more than 30 solutions in elementary functions were obtained). Two-dimensional symmetry and non-symmetry reductions leading to simpler partial differential equations with two independent variables are considered (including stationary Monge–Ampère type equations, linear and nonlinear heat type equations, and nonlinear filtration equations). The obtained results and exact solutions can be used to evaluate the accuracy and analyze the adequacy of numerical methods for solving initial boundary value problems described by highly nonlinear partial differential equations.