Optimal Reinforcement Research Articles

Graphene Oxide and Natural Silk as Reinforcements for Epoxy Resin Matrix: Fabrication, Sample Preparation, and Testing

The integration of graphene oxide (GO) and natural silk into epoxy matrices offers a promising approach to developing high-performance composites for structural applications. This study examines the fabrication processes, focusing on sample preparation and testing of GO and natural silk-reinforced epoxy composites. A comprehensive literature review spanning 1990 to 2024 provides insights into the necessity of Vacuum-Assisted Resin Transfer Molding (VARTM) at 30 PSI, the role of ultrasonication in achieving homogeneous GO dispersion, strategies to prevent agglomeration, optimal reinforcement proportions, and challenges encountered during hybridization. Key findings, including the impact of high silk volume fractions (60–70%) on mechanical properties, are incorporated, offering a comprehensive guide for composite fabrication. The findings underscore the critical parameters for successful composite fabrication and performance enhancement. Key Words: Graphene Oxide, Natural Silk, Epoxy Composites, VARTM, Ultrasonication, Hybrid Reinforcements, Structural Applications

Bearing capacity of strip footings in unsaturated soils reinforced with layered geogrid sheets using upper bound method

A frequently overlooked aspect in previous research on bearing capacity of reinforced foundations is the prevalent unsaturated properties of soils. This paper provides an analytical framework for evaluating the bearing capacity of strip footings with single-layer and double-layer reinforcement in unsaturated soils. Four classical nonlinear expressions are used to determine the additional cohesion induced by matric suction. Solutions for the reinforcement layer undergoing tensile failure and sliding failure are provided separately. In the former case, where the bearing capacity depends on the reinforcement's tensile strength, the Prandtl mechanism is employed. In the latter case, where the bearing capacity is influenced by the characteristics of the reinforcement-soil interface, a multi-block mechanism is adopted. Additionally, sliding failure exhibits different mechanisms depending on the reinforcement's embedded depth. By comparing the results of different failure mechanisms, accurate upper bound solutions for bearing capacity are obtained. In the case of sliding failure, the optimal reinforcement depths that maximize the bearing capacity are identified for both single-layer and double-layer reinforcement. To facilitate engineering use, the optimum depths and corresponding bearing capacity factors are given in tabular form. The effectiveness of the framework is demonstrated through comparisons with previous theories, experiments, and finite element simulation results.

Effect of expandable graphite content on the physical, thermal and mechanical properties of novolac matrix composites: Halogen-free flame-retardant polymer composites

Flame-retardant properties are particularly important for materials used in high-temperature applications. This study focuses on novolac matrix composites reinforced with expandable graphite (EG) particles, produced through a hot pressing process using powders prepared by mechanical milling. The research examines the particle size of both the matrix and the reinforcing particles used in composite production. Additionally, the morphology of the powders, the microstructural properties of the composites, and the fracture surfaces after tensile testing were analyzed using scanning electron microscopy (SEM). Phase analysis of the samples was performed using X-ray diffraction (XRD). Hardness and tensile tests were conducted to evaluate the mechanical properties. The effect of EG particles on the thermal stability of the composites was assessed using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and thermal conductivity tests. Furthermore, flammability was evaluated by determining the Limit Oxygen Index (LOI) values. The experimental results identified the optimum reinforcement ratio as 20 wt% EG. TGA results showed residue values of approximately 37.39 % for pure novolac and 57.87 % for novolac matrix composites reinforced with 20 wt% EG. The highest thermal conductivity (0.72 W/mK) and LOI values (40.64 %) were achieved with 20 wt% EG reinforcement, resulting in an LOI value approximately 1.25 times greater than that of the pure novolac sample (32.45 %). Additionally, tensile strength increased by approximately 2.7 times compared to the pure novolac sample. This research highlights the potential of the novolac/EG composites for advanced high-temperature applications where enhanced flame retardancy and structural integrity are essential.

Development and characterization of sustainable epoxy resin composites reinforced with palm kernel shell particulate and sisal fiber

This study explores the development and characterization of epoxy resin composites reinforced with palm kernel shell (PKS) particulate and sisal fibers, aiming to create sustainable and high-performance materials. Elemental composition analysis using energy dispersive X-ray revealed significant increases in carbon and oxygen content with higher PKS particulate content, indicating successful reinforcement integration. The mechanical properties were evaluated through Brinell hardness, impact energy, impact strength, tensile stress, and wear resistance tests. The Brinell hardness increased from 31.8 kg/mm2 in the control sample to a peak of 60.6 kg/mm2 in sample SP4, demonstrating enhanced hardness with PKS particulate addition. Impact tests identified an optimal reinforcement level in sample SP3, which achieved the highest impact energy (83 J) and impact strength (47.43 kJ/m2). Tensile stress analysis showed a maximum tensile stress of 28.7991 MPa for SP3, while excessive PKS content in SP4 reduced this to 20.4612 MPa. Wear tests indicated a trade-off between mechanical reinforcement and wear resistance, with the control sample exhibiting the lowest wear rates and SP4 the highest having a 91.9% increase. Based on the obtained results, SP3 with 0.8 g PKS particulate, 0.2 g sisal fiber in epoxy resin matrix seems the optimized composite with enhance mechanical properties without compromising wear resistance.

Unveiling the untapped potential of Hibiscus Rosa-sinensis lignocellulosic fiber: A multifaceted characterization for advancing sustainable biocomposite applications

In the pursuit of sustainable advancements in bio-inspired fiber reinforced polymer composite materials, the exploration of novel natural fibers has become a focal point of research. This experimental study aims to elucidate the unexplored potential of Hibiscus Rosa-sinensis fiber (HRF) as a versatile reinforcement material for high-performance composites. Through an integrated approach, this research offers a meticulous analysis of the HRF's physico-chemical properties, and single fiber tensile strength. The crystalline structure are revealed by X-ray diffraction (XRD), thermal behavior are characterized through thermo-gravimetric analysis (TGA), and surface morphology has been visualized using field emission scanning electron microscopy (FESEM) studies. From the results, it is found that the HRF contains a cellulose content of 79.50 %, positioning it as a prime bast fiber among its counterparts. This composition is complemented by hemicellulose (10.36 %), lignin (4.62 %), wax (0.84 %), and ash (2.96 %). The Fourier-transform infrared spectroscopy (FTIR) spectra unveils the intricate functional groups present in the fibers. XRD analysis highlights a crystallinity index (CI) of 66.93 %, confirming a well-organized and structured crystalline arrangement. The thermal stability established through TGA underscores HRF's resilience up to 284 °C, presenting it is an optimal reinforcement material for bio-inspired green composites operating within 280 °C. The surface morphology of HRF is examined through FESEM and three-dimensional profiling, showcasing its inherent morphological intricacies. The multidimensional characterization provided herein contributes significantly to the evolving landscape of biocomposite research, fostering a platform for future advancements and innovations in HRF-based composite materials.

The Structural Behavior of Lightweight Self-Compacting Concrete Slabs Using Different Types of Reinforcement

The purpose of this study is to examine how the type of reinforcement used in self-compacting concrete (SCC) and lightweight self-compacting concrete (LWSCC) affects their structural behavior. There were three forms of reinforcement used: wire mesh, glass fiber-reinforced rebars, and regular steel rebars. To evaluate the mechanical characteristics of reinforced concrete slabs with various types of reinforcement, extensive experiments were carried out. The tensile strength, stiffness, and crack resistance of the concrete were studied in each case. The finite element program Abaqus was utilized in addition to the experimental investigations to create the numerical simulation of the test. The experimental results revealed that the reinforcement type significantly affects the structural behavior of SCC and LWSCC slabs. Conventional steel rebars provided high tensile strength and excellent crack resistance, while glass fiber-reinforced rebars contributed to enhanced flexibility and reduced overall weight of the concrete. On the other hand, the wire mesh exhibited average mechanical and structural properties. These findings emphasize the importance of selecting the appropriate reinforcement type based on specific applications and desired performance requirements. This research provides valuable guidance for architects and civil engineers in choosing optimal reinforcement for SCC and LWSCC. Furthermore, it can contribute to the advancement of techniques and potential improvements in these materials to achieve better performance and enhance sustainability in infrastructure and building construction. From the practical results, it was found that in the case of using lightweight self-compacting concrete and self-compacting concrete, it is preferable to reinforce it with ordinary reinforcement steel, as it gives the best results in terms of maximum load capacity at failure. Although the use of steel reinforcement in self-compacting concrete also gives the best results, but from the laboratory results it is possible to improve the performance of self-compacting concrete by reinforcing it with GFRP or welded wire mesh.

Kinematic bearing capacity analysis of strip footings on reinforced soils using discretisation technique

The kinematic discretisation technique of upper bound limit analysis is adopted in this study to evaluate the limit load of a strip footing located on the soils reinforced with different geosynthetic layers. The reinforcement is assumed to withstand the tension but not bending moment. The failure model of the reinforced foundation soil is generated using the discretisation method, a ‘point by point’ technique. Two failure modes of the reinforcement, the tensile rupture and sliding, are considered in the analysis. This article proposed the formulas for the first time to evaluate the effect of soil friction angle φ on the ultimate bearing capacity and on the failure mechanism of foundation. The calculation results are given considering different reinforcement layers, which describe the impact of different reinforcement depth and length on the ultimate bearing capacity. The optimum positions of different reinforcement layers and the optimum reinforcement length are obtained. The bearing capacity ratios are also presented in figures combing impact of reinforcement depths, soil cohesion and friction angle. The present method was verified by the results reported in literature. The present method can provide a reference for the footing design on the reinforced soils.

Mechanical performance and reinforcing mechanisms of foamed concrete strengthened by carbon fibers

Foamed concrete (FC) is a lightweight and environmentally friendly building material that offers versatile applications in civil engineering. However, FC is inherently weak in withstanding tensile and compressive loads. While incorporating fibers into FC has been shown to resist crack propagation and enhance its mechanical properties, the specific mechanisms through which carbon fibers affect FC's tensile and compressive behaviors remain unclear. This study aims to address this gap by incorporating short-cut carbon fibers into FC to achieve a micro-reinforcement effect and enhance its compressive and tensile performance. The mechanical properties, failure modes, and microstructure evolution of carbon fiber-reinforced FC at different density levels, carbon fiber lengths, and contents were comprehensively explored. Digital Image Correlation (DIC) was utilized to analyze crack propagation, and an optimal mix ratio experiment was conducted. The results demonstrate that incorporating carbon fibers effectively enhances the mechanical performance of FC, with a more significant impact on specimens with a density of 500 kg/m3. Furthermore, the maximum improvements in tensile and compressive strengths reached 250 % and 88.5 %, respectively. This study suggests that optimal reinforcement ratio can be achieved through mix ratio adjustments and curve fitting formulas, thereby optimizing the tensile and compressive performance of the specimens.

Mechanical and tribological performance of NaOH-Treated bamboo fiber-reinforced recycled HDPE composites under fretting wear conditions

ABSTRACT The study investigates the impact of bamboo fiber reinforcement on the mechanical and tribological properties of recycled high-density polyethylene (rHDPE) composites. Bamboo fibers extracted from locally sourced Bambusa Balcooa were subjected to a comprehensive alkali treatment to enhance their properties, including increased crystallinity, thermal stability, and altered morphology. The treated bamboo fibers were incorporated into rHDPE using a compression molding technique at varying weight percentages (0.5–2.0 wt-%). The results revealed that optimal mechanical performance, particularly tensile strength (155.7 MPa) and modulus (6.6 GPa), was achieved at 1.5 wt-% fiber content, attributed to effective load transfer between the matrix and fibers. Beyond this content, performance declined due to fiber agglomeration and poor dispersion. Flexural properties mirrored these findings, with the highest strength (207.5 MPa) and modulus (11.7 GPa) observed at 1.5 wt-%. Thermogravimetric analysis (TGA) and X-ray diffraction confirmed enhanced thermal stability and crystallinity in treated fibers. Fretting wear tests indicated a reduction in the coefficient of friction with increased fiber content, particularly at lower loads, while wear loss was minimized at 1.5 wt-% BF, suggesting optimal reinforcement. SEM analysis highlighted microstructural changes, including fiber pull-out, debonding, and void formation, correlating with the observed mechanical degradation at higher fiber contents. .

A strategy for the improvement of the bonding performance of 3D-printed concrete interlayer interfaces

3D-printed concrete, as an intelligent building technology, has enormous potential in construction. However, the weak bond interfaces between two adjacent layers of concrete are still a well-known problem affecting the mechanical properties of printed structures, with reduced interlayer shear and tensile properties. The reinforcement method of inserting steel bars in vertically printed layers is crucial and requires research and exploration of suitable methods, as well as finding the optimal reinforcement scheme that satisfies the interlayer interface when facing different loads. This study proposes a method of interlayer reinforcement by vertically laying steel fibers between layers, and investigates the effects of steel fiber offset, deployment density, and cross-sectional area on interlayer bonding strength. The strengthening effect of steel fiber on interlayer shear and tensile strength was tested through shear and splitting tests. Microscopic numerical models are used to study the evolution process of interlayer cracking. The correlation between different steel fiber variables and interlayer bonding strength was studied using a Generalized Grey Relational Analysis (GGRA). The results showed that the shear strength and tensile strength of the interlayer interface could be improved by 256.32 % and 353.61 %, respectively, through a reasonable fiber layout scheme. It is recommended to lay steel fibers with small offsets. When the interlayer interface is subjected to shear loads, priority should be given to increasing the cross-sectional area. When the interlayer interface is subjected to tensile loads, the deployment density should be increased first to achieve the best improvement in interlayer strength.

Experimental and Analytical Study on Non-Damaged Reinforcement Method for Pipe Rack Steel Structures

Pipe racks are steel structures that support various pipes transporting materials in industrial complexes. The pipes on pipe racks may transport hazardous substances, which imposes limitations on their structural reinforcement. Therefore, this study aimed to propose methods for reinforcing the joints of pipe rack structures through non-welding and non-drilling techniques. The joints of pipe rack structures were connected by end plates. Initially, this study evaluated the capacity of existing end plates in a real-world experiment and conducted cyclic loading tests with two additional reinforcement methods to validate their performance. Finally, finite element analysis was conducted to explore additional variables that were not covered in the experiments, and the optimal reinforcement method that demonstrated the best performance was proposed.

Optimization of structural reinforcement assessment for architectural heritage digital twins based on LiDAR and multi-source remote sensing

This study investigates the geometric modelling of architectural heritage digital twins constructed based on multi-source point cloud data and its effectiveness in structural reinforcement assessment. Particular emphasis has been placed on the use of static stiffness rules to identify areas of structural weakness in the geometric models of digital twins and the need for their reinforcement, in order to prevent potential structural problems and to ensure the long-term preservation of the built heritage. Taking Yingxian wooden pagoda as a study case, based on the collection of multi-source point cloud data, the digital twin geometric model is constructed through fine modelling, decoupling of digital models, and geometric transformation. This enhances the true reflection of the column-architrave structure morphology, providing a more accurate model for structural stress analysis. Based on verifying the accuracy of the digital twin geometric model, the instability conditions are identified through static stiffness rules and the deformation values at multiple points are analyzed, enabling precise identification of weak areas in the column-architrave structure. Two types of reinforcement measures are designed and simulated for the structural weak areas identified through the geometric modelling, and the optimal reinforcement scheme is obtained after detailed analysis, according to which specific adjustments and optimization strategies are proposed to enhance the overall stability and durability of the structure. The results showed that the maximum deformation value of 4.65 mm existed in column M2W23, which required reinforcement. Aluminum reinforcement reduced the deformation to 3.5 mm (24.7% reduction), while CFRP fabric reinforcement was more effective, reducing the deformation to 2.8 mm (39.7% reduction), showing high stability. The research results demonstrate the potential application of digital twin technology in architectural heritage preservation and restoration, providing methodological and empirical guidance for heritage preservation research.

Reinforcement of Insufficient Transverse Connectivity in Prestressed Concrete Box Girder Bridges Using Concrete-Filled Steel Tube Trusses and Diaphragms: A Comparative Study

To address the issue of insufficient transverse connectivity in prestressed concrete box girder (PCB) bridges, this study investigates two transverse strengthening methods—installing diaphragms and utilizing concrete-filled steel tube trusses (CFSTTs). A finite element model was developed for a typical 30 m PCB bridge and was validated by on-site load test results for reliability. Based on the deflection and load distribution of PCB bridges before and after reinforcement, as well as the maximum stress and strain of the diaphragms and the CFSTTs, comparative analyses were conducted on diaphragms of different thicknesses and materials, as well as on CFSTTs of various strength grades. The results show that the addition of a transverse partition and CFSTTs can effectively improve the load distribution of the PCB bridge and reduce the maximum deflection of the girder, especially when using the CFSTT reinforcement method. The unique structural design improves the reinforcement effect of the material in the post-elastic stage. When using CFSTTs, increasing the steel tube wall strength significantly reduces the maximum deflection of the main girder. For example, using steel tubes with yield strengths of 235 MPa and 420 MPa filled with concrete of 50 MPa compressive strength reduced the maximum deflections by 15.32% and 24.55%, respectively, and improved the load distribution coefficients by up to 7.31% and 11.57%. Additionally, steel diaphragms demonstrated better reinforcement effects compared with concrete diaphragms. The load transverse distribution coefficients for the CFSTT-reinforced PCB bridge were calculated using the hinge plate (beam) and the rigid plate (beam) methods, showing minimal differences between the two approaches. The findings of this study provide valuable insights into the design of diaphragm and CFSTT reinforcement in PCB bridges, aiding in the selection of optimal reinforcement strategies.

Reinforced protection of fragile bronze cultural relics based on nano-cuprammonium fiber material

Bronze artifacts often suffer from “bronze disease” due to the presence of chloride ions, which result from copper chlorides forming on their surfaces during storage. Therefore, reinforced protection is essential for these unearthed cultural artifacts, and new materials for the reinforced protection of fragile bronzes are urgently needed. In this study, cuprammonium solvent and nanocellulose (CNC) were utilized as reinforcement materials to protect fragile bronzes. The chemical and aesthetic properties before and after reinforcement were analyzed using ultra-depth field microscopes, SEM-EDX, XRD, and Raman spectroscopy. The results indicated that at a nano-cuprammonium reinforcer concentration of 2.5 mol/L, the optimal reinforcement effect on simulated bronze powdery rust samples was achieved.Mechanical strength increased by an average of 77.59%. The mass growth rate reached 84.8%, while the color difference ΔE\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta E$$\\end{document} remained below 4.0. Additionally, aging resistance significantly improved, aligning with cultural artifact protection standards.Meanwhile, a compact and stable protective membrane formed on the surface of the bronzes, isolating the bronze matrix from direct contact with the external environment, which delayed bronze corrosion and contributed to long-term stable preservation.Graphical

Importance of duodenal stump reinforcement to prevent stump leakage after gastrectomy: a large-scale multicenter retrospective study (KSCC DELICATE study).

The significance of reinforcement of the duodenal stump with seromuscular sutures and the effectiveness of reinforced staplers in preventing duodenal stump leakage remain unclear. We aimed to explore the importance of duodenal stump reinforcement and determine the optimal reinforcement method for preventing duodenal stump leakage. This retrospective cohort study was conducted between January 1, 2012 and December 31, 2021, with data analyzed between December 1, 2022 and September 30, 2023. This multicenter study across 57 institutes in Japan included 16,475 patients with gastric cancer who underwent radical gastrectomies. Elective open or minimally invasive (laparoscopic or robotic) gastrectomy was performed in patients with gastric cancer. Duodenal stump leakage occurred in 153 (0.93%) of 16,475 patients. The proportions of males, patients aged ≥ 75years, and ≥ pN1 were higher in patients with duodenal stump leakage than in those without duodenal stump leakage. The incidence of duodenal stump leakage was significantly lower in the group treated with reinforcement by seromuscular sutures or using reinforced stapler than in the group without reinforcement (0.72% vs. 1.19%, p = 0.002). Duodenal stump leakage incidence was also significantly lower in high-volume institutions than in low-volume institutions (0.70% vs. 1.65%, p = 0.047). The rate of duodenal stump leakage-related mortality was 7.8% (12/153). In the multivariate analysis, preoperative asthma and duodenal invasion were identified as independent preoperative risk factors for duodenal stump leakage-related mortality. The duodenal stump should be reinforced to prevent duodenal stump leakage after radical gastrectomy in patients with gastric cancer.

Seismic vulnerability analysis of palace-style timber structures base on lumped mass model considering column rocking effect

To investigate the influence of joint reinforcement on the vulnerability of palace-style ancient timber structures, a spring-rigid rod analysis model was established, considering the mechanical behavior of tenon-mortise joints, column base joints, and bracket set joints. A lumped mass model was proposed using the centroid method and stiffness equivalent method and the accuracy of the simplified model is verified through shake table tests. Additionally, the influence of reinforcement on tenon-mortise joints and bracket set joint on the seismic displacement response was investigated, the optimal reinforcement range for joints was determined. Finally, incremental dynamic analysis was conducted on the model considering joint reinforcement, and the influence of optimal joint reinforcement on the seismic vulnerability of timber structures was researched. The study found that the optimal stiffness enhancement of column frame mortise-tenon joints range from 4 to 6 times and the stiffness of bracket set joints by 2.9 times. The probability of structural collapse of reinforced both mortise-tenon joints and bracket set joints was reduced by 15.56 %. However, individually reinforcing either tenon-mortise joints or bracket set joints only slightly decreases the probability of collapse.

Highly Water‐Rich Robust Coating for Separating Immiscible Liquids Mixtures of Wide Range of Surface Tension Differences

AbstractDeveloping mechanically robust and chemically tolerant coatings that maintain a high water content remains an extremely challenging task to pursue to date. Here, an optimum reinforcement of a hollow nano‐clay i.e., halloysite in a dual crosslinked and interpenetrating polymeric network is introduced to yield a high (≈95 wt%) water content coating with an ability to improve toughness (9.9 ± 0.6 MJm−3 Vs. 0.5 ± 0.03 MJ m−3) of a deformable fibrous substrate. The association of covalent and physical crosslinking chemistries provides essential tolerance against exposures to diverse severe chemically complex conditions, including extremes of pH, seawater, river water, and organic solvents. High water content in the prepared hydrogel network endows a robust bio‐inspired underwater nonadhesive superoleophobicity with oil contact angle of 160.7 ± 0.2° and force of oil‐droplet adhesion of 8.7 ± 0.3 µN. This approach provides a liquid selective filtrating membrane with ultrahigh crude oil/water separation efficiency (99.7%), superior intrusion pressure (3.5 ± 0.4 kPa), relatively high separation flux (11,162 Lm−2 h−1), and the ability to perform even when the surface tension of aqueous phase is brought down to similar of oily phase. Moreover, a mixture of immiscible, non‐aqueous liquids having differences in surface tension below 2.5 mN m−1 is successfully separated.

Optimal selection of cable reinforcement for concrete 3D printed lattice beam

This paper presents the optimal selection of cable reinforcement for concrete 3D-printed lattice beam. It also addresses key challenges associated with interlayer bonding and flexural strength of 3D printed elements. Three different types of reinforcement including 1.6 mm and 2 mm diameter rebar, (R1.6 & R2) and 1.5 mm wire (W1.5) with seven strings were evaluated with different stand-off distances of 10–20 mm. The interlayer bonding and flexural strength were investigated to determine the most effective reinforcement configuration. Results show that W1.5 reinforcement exhibited higher interlayer bonding and flexural strength as compared with R1.6 and R2. Subsequently, the optimal reinforcement configuration (W1.5) was embedded in a concrete 3D-printed lattice beam. The lattice beam was structurally evaluated using four-point testing, demonstrating an ultimate load-carrying capacity of 49.01 kN with a mid-span displacement of 2.99 mm. Moreover, it exhibited flexural failure with no premature failures such as inter-layer delamination.

An efficient approach to manufacturing carbon nanosheets from lignite and their impact on the mechanical performance of semi-crystalline thermoplastic composites with comprehensive benchmarking

Lignite-derived carbon nanosheets (CNS) offer a novel approach to producing carbon-based nanomaterials with unique advantages over other precursors. The primary mechanism successfully demonstrated the transformation of lignite into CNS by thermo-chemical treatment process through acid treatment (HNO3), catalyst impregnation (FeCl3), and carbonization (1000 °C, 5 min) steps resulting in the enrichment in the carbon content by maintaining the desired efficiency to be used as a filler in compounding process. Moreover, the produced CNS had superior characteristics in terms of carbon content reached 70 % and thermal stability even at 1000 °C compared to lignite. Subsequently, a comprehensive benchmarking study was conducted to achieve high compatibility and uniform dispersion between semi-crystalline thermoplastics such as HomoPP, CopoPP, PA6 and PA6,6 with CNS using a high-speed thermokinetic shear mixer. CNS exhibited enhanced compatibility with thermoplastics, leading to improved mechanical properties such as tensile and flexural modulus inpolymer composites. The benchmark studies revealed that a loading ratio of 0.5 wt% of CNS exhibited optimal reinforcement efficiency. Notably, PA6 matrix demonstrated the most significant improvement in yield strength, increasing by 12 %, while PA6,6 showed the highest increase in tensile modulus at 25 %. Similarly, PA6,6 exhibited the most notable improvement in flexural modulus with a substantial increase of 17 %. Conversely, HomoPP matrix displayed the highest improvement in flexural strength, increasing by 13 %. Furthermore, the incorporation of CNS into the polymer leads to an increase in the crystallization temperature from 182 °C to 194 °C for PA6-0.5 % CNS. These findings highlight the potential of CNS as versatile materials with promising polymer applications such as automotive and aviation.

Adaptive dynamic programming for the optimal liver regeneration control

Every living organism interacts with an environment and uses that interaction for an improvement of its own adaptability, and, as a result, one’s survival and overall development. The process of evolution shows us that different species change methods of interaction with an environment with passage of time, which leads to natural selection and survival of the most adaptive ones. This learning, which based on actions, or reinforcement learning may embrace the idea of optimal behavior occurring in environmental systems. We describe mathematical formulas for reinforcement learning and the practical integration method also known as adaptive dynamic programming. That gives us the overall concept of controllers for artificial biological systems that both learn and show the optimal behavior. This paper reviews the formulation of the upper optimality problem, for which the optimal regulation strategy is guaranteed to be better or equivalent to objective regulation rules that can be observed in natural biological systems. In cases of optimal reinforcement learning algorithms the learning process itself moves from the analysis of the item take on system dynamics to the much higher level. The object of interest now is not the details of the system dynamics, but the quantity efficiency index, which clearly represents how optimally the control system works. Such scheme of reinforcement learning is learning technique of optimal behavior in order to monitor the response to non-optimal control strategies. The purpose of this article is to show the possibility of using of reinforcement learning methods, the adaptive dynamic programming (ADP) in particular, to control biological systems using feedback. This article shows the on-line methods for solving the problem of searching the upper optimality estimate with adaptive dynamic programming.