Composite Design Research Articles

Development of inulin nanocarrier for effective oral delivery of insulin: synthesize, optimization, characterization, and biophysical study

The susceptibility of insulin against gastric acid degradation presents a major challenge for oral insulin delivery. The potential of biopolymer-based nanocarriers was investigated in order to address this issue. Inulin, a biopolymer produced by the halophilic bacterium Salinivibrio sp. GM01, has been evaluated for its effectiveness as an insulin nanocarrier. Using central composite design (CCD) method, the optimum condition of inulin-encapsulated insulin (I-In) was achieved at 53 mg of inulin stirred at 17,800 rpm for 10 min, resulting in spherical I-In nanoparticles (I-In NPs) with an average diameter of 416 ± 32 nm and encapsulation efficiency of 87.04 ± 3.01%. The insulin release profile of I-In NPs in simulated gastric fluid follows a burst pattern. Biophysical analysis revealed that insulin in I-In NPs had higher conformational stability than the free state (FS) insulin, as evidenced by an increase in denaturation half-life up to 60 min and the transition enthalpy by 0.29 and 1.53 kcal/mol for secondary and tertiary structures, respectively. Furthermore, preliminary in vivo studies showed that I-In NPs showed significant effect compared to FS insulin for up to 15% in blood glucose level reduction. This study demonstrates the potential of I-In NPs as a promising candidate for antidiabetic therapy and an effective oral delivery system.

Design of experiments and artificial neural networks as useful tools in the optimization of analytical procedure.

Developing the analytical procedure requires estimating what independent variables will be tested and at what levels. There are statistical models that enable the optimization of the process. They involve statistical analysis, which indicates the crucial factors for the process and the potential interactions between the analyzed variables. Analysis of variance (ANOVA) is applied in the evaluation of the significance of the independent variables and their interactions. The most commonly used chemometric models are Box-Behnken Design, Central Composite Design and Doehlert Design, which are second-order fractional models. The alternative may be the artificial neural networks (ANN), whose structure is based on the connection of neurons in the human brain. They consist of the input, hidden and output layer. In such analysis, the activation functions must be defined. Both approaches might be useful in planning the analytical procedure, as well as in predicting the response prior to performance the measurements. The proposed procedures may be applied for polymeric systems.

A multivariate study on the effect of 3D printing parameters on the printability of gluten-free composite dough.

The advancement of three-dimensional (3D) food printing technology is significantly influencing the food processing industry. The present study utilized extrusion 3D printing to create a gluten-free dough composed of little millet flour (LMF), amaranth seed flour (ASF) and curry leaf flour (CLF). The primary objective was to elucidate the effects of various extrusion-based 3D printing conditions, including extruder nozzle diameter (ND), extrusion rate (ER), print speed (PS) and layer height (LH) on the printability parameters of the dough. In this study, three formulations of composite dough were prepared (i.e., S1, S2 and S3) by varying LMF, ASF and CLF compositions; among which S1 composite (LMF:ASF:CLF::30:60:10 w/w) was found to have comparable viscoelastic properties with the wheat dough. Central composite design (CCD) was selected with 30 experimental runs and 3D dough samples were printed using S1 composite by varying ND, ER, PS and LH. Principal component analysis of the printed samples accounted for 82.75% of variability and classified the samples into three confidence ellipses. From the results of the CCD model, four solution parameters in terms of ND:ER:PS:LH::mm: pulse μL-1:mm s-1:%, namely, P1 (1.8:115:8:70), P2 (1.6:115:7.8:65), P3 (2:100:7.8:55) and P4 (2:105:6.2:75), with high desirability value (> 0.85) were selected for sample 3D printing and post-baking analysis. The P1 sample was found to have least print deformations, highest print fidelity (85.66%), and lowest hardness (55.95 N) and fracturability (39.66 N) values, and hence was selected as optimized product. The present study provides parametric solutions for efficient 3D printing of gluten-free composite dough, aligning with the increasing dietary preferences and demand of novel functional customized foods. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Assessment of the Biocontrol Efficacy of Silver Nanoparticles Synthesized by Trichoderma asperellum Against Infected Hordeum vulgare L. Germination

This study investigated the biosynthesis, statistical optimization, characterization, and biocontrol activity of silver nanoparticles (AgNPs) produced by newly isolated Trichoderma sp. The Trichoderma asperellum strain TA-3N was identified based on the ITS gene sequence, together with its phenotypic characteristics (GenBank accession number: OM321439). The color change from light yellow to brown after the incubation period indicates AgNPs biosynthesis. The UV spectrum revealed a single peak with the maximum absorption at 453 nm, indicating that T. asperellum produces AgNPs effectively. A Rotatable Central Composite Design (RCCD) was used to optimize the biosynthesis of AgNPs using the aqueous mycelial-free filtrate of T. asperellum. The optimal conditions for maximum AgNPs biosynthesis (156.02 µg/mL) were predicted theoretically using the desirability function tool and verified experimentally. The highest biosynthetic produced AgNPs by T. asperellum reached 160.3 µg/mL using AgNO3 concentration of 2 mM/mL, initial pH level of 6, incubation time of 60 h, and biomass weight of 6 g/100 mL water. SEM and TEM imaging revealed uniform spherical shape particles that varied in size between 8.17 and 17.74 nm. The synthesized AgNPs have a Zeta potential value of −9.51 mV. FTIR analysis provided insights into the surface composition of AgNPs, identifying various functional groups such as N–H, -OH, C-H, C=O, and the amide I bond in proteins. Cytotoxicity and genotoxicity assays demonstrated that AgNPs in combination with T. asperellum can mitigate the toxic effects of Fusarium oxysporum on barley. This intervention markedly enhanced cell division rates and decreased chromosomal irregularities. The results indicate that AgNPs synthesized by T. asperellum show the potential as an eco-friendly and efficient method for controlling plant diseases. Further studies are necessary to investigate their possible use in the agricultural sector.

Composite Command Pattern for Managing Spherical Geometry Constructions

Spherical Easel (https://easelgeo.app) is a free web application for researching, teaching, and learning spherical geometry written in Typescript. The authors have created an open-source code base in VueJS v3 that combines several design patterns, global data structures, and cloud-based storage for storing and retrieving spherical constructions. Spherical constructions are made up of interdependent geometric objects (like lines and circles). Interdependencies means that while being moved, updates to a single object must propagate to other dependent objects. The application stores the dependency structure using a directed acyclic graph to allow these updates to propagate correctly. In this paper, we describe how Spherical Easel employs the Command and Composite design patterns (fully integrated with various VueJS supporting libraries) to maintain a history of construction edits, allowing users to undo and redo edits, and to store a final construction script in a cloud database. To guarantee correct rendering of the spherical objects when loading a construction, the stored script also preserves the structure of the directed acyclic graph. The construction script parser built is also designed to take advantage of the (Composite) Command design pattern. Using this innovative design, adding new object types does not require a major redesign of the script parser. Keywords: Spherical geometry, software design patterns, web application

Ingredient Selection and Product Design Optimization Using D-D Optimal Design

ABSTRACT To achieve the desired sensory qualities in food product design, the proper combination of ingredients and processing conditions must be chosen. Conventional experimental designs, such as factorial or Central Composite Design, frequently result in combinations that are not feasible or necessitate an extensive amount of testing. The D-optimal design eliminates non-viable combinations while maintaining variable independence, offering a flexible and effective substitute. The efficacy of D-optimal design in optimizing food processes and improving product quality is demonstrated through case studies, such as optimizing the osmotic drying of zucchini and upgrading bread recipes.

Red, green, and blue model assessment and AQbD approach to HPTLC method for concomitant analysis of metformin, pioglitazone, and teneligliptin

BackgroundThe CDSCO of India has authorized a combination of metformin hydrochloride, teneligliptin hydrochloride, and pioglitazone hydrochloride for the treatment of insulin-independent diabetes. For the purpose of estimating metformin, teneligliptin, and pioglitazone combinations as well as individual commercial formulations, there are a plethora of publicly accessible chromatographic techniques. More importantly, the development of these chromatographic procedures has included the use of chemical solvents that are dangerous to both animals and the environment.ObjectivesHowever, to date, there has been no documented chromatographic technique that can concomitantly estimate various commercial formulations of drugs under study employing a uniform chromatographic condition and environmentally friendly solvents. In order to concomitantly estimate drugs under study utilizing unified chromatographic conditions, a green HPTLC method was developed.MethodThe AQbD approach was used to carry out the method development. To determine the most important method parameters and response variables, the analytical risk assessment was conducted using the risk priority number ranking and screening approach. Critical method parameters and response variables were modeled using the response surface modeling approach, which relies on the central composite design. Optimal ranges for the intended method operable design region were determined, and control strategy was framed. The chromatographic separation was carried out on preparative TLC plate precoated with silica gel G-60 F254 using 1.0%W/V ammonium acetate in ethanol: water: triethylamine (6.5:0.4:0.6, V/V) as mobile phase. The detection of the anti-diabetic drugs under study was carried out at 267 nm wavelength.ResultsThe linearity of metformin, teneligliptin, and pioglitazone was found to be 5000–25000 ng/band, 200–1000 ng/band, and 150–750 ng/band, respectively. The %RSD for robustness and precision study was found to be less than 2.0%. The %recovery of method was found to be 98–102%. The assay results were shown to be in compliance with respective labeled claims of anti-diabetic medications when the suggested method was used for concurrent analysis of several formulations and combinations of drugs under study.ConclusionThe suggested technique was evaluated utilizing red–green–blue model scoring tools. The suggested technique was determined to be precise, accurate, rapid, cost-effective, and easy to apply for the estimation of drugs under study.

Impact Resistance of Aluminum Foam Composites with Filler and Coating Materials

The main objective of this study is to analyze the impact resistance of aluminum foam composites containing fillers and coatings and to investigate the effect of different thickness ratios of the composites on this capability. We prepared composites using aluminum foam and polyurea and performed impact tests and numerical simulations. A comparison of the results shows that the Abaqus simulation results are in general agreement with the test results. The results show that the polyurea filler material and polyurea coating can significantly improve the impact resistance of the aluminum foam, and the best impact resistance of the aluminum foam composite with polyurea coating on the back. An extended study of the composites was carried out using a numerical model validated by the test results. For the energy absorption effect of the aluminum foam composites in the impact resistance process, there is an optimum value for the thickness ratio of the aluminum foam/polyurea composite, which is 3:1. The remaining kinetic energy of cylindrical fragments in the 3-1-1-2 composite material decreased by 13.26%, in the 4-1-1-2 composite material decreased by 11.91%, in the 2-1-1-2 composite material decreased by 11.78%, and in the 1-1-1-2 composite material increased by 2.7% when compared to the remaining kinetic energy of cylindrical fragments in the control group. The energy absorption efficiency of the aluminum foam composite increases as the residual kinetic energy of the cylindrical fragments decreases. The 3-1-1-2 composite can significantly improve the energy absorption effect, which can be used as a reference for the design of impact-resistant composites in the future.

Investigation of compound fault in the Rotor Bearing System with the integration of Central Composite Rotatable Design (CCRD)

Investigation of compound fault in the Rotor Bearing System with the integration of Central Composite Rotatable Design (CCRD)

Impact resistance of biomimetic gradient sinusoidal composites by 3D printing: Tunable structural stiffness and damage tolerance

Taking inspiration from the remarkable impact resistance of the dactyl club of Odontodactylus scyllarus and utilizing the material extrusion-based 3D printing process for continuous fiber reinforced composites (CFRCs), the biomimetic gradient sinusoidal CFRCs (BGS-CFRCs) was designed and manufactured. This material combines the bidirectional sinusoidal structure with a gradient layering configuration, mimicking the natural design found in the dactyl club. Experimental tests revealed that BGS-CFRCs achieved a Charpy impact strength of up to 63.24 kJ/m2, surpassing flat-layered polylactic acid (PLA) and continuous carbon fiber reinforced PLA (CCF/PLA) specimens by 143 % and 80 %, respectively. Moreover, BGS-CFRCs exhibited tunable structural stiffness and damage tolerance. This can be attributed to the innovative in-plane fiber architecture and out-of-plane material gradient, revealing the synergistic effects of composite materials, bidirectional sinusoidal structure, and gradient layering configuration. Overall, this study combines multi-degree-of-freedom 3D printing of CFRCs with biomimetic structural design, providing new dimensions of design space. This breakthrough surpasses the limitations of traditional additive manufacturing techniques and structural design of composites, opening new possibilities for developing next-generation high-performance structural materials.

Optimizing extrusion processes and understanding conformational changes in itraconazole amorphous solid dispersions using in-line UV–Vis spectroscopy and QbD principles

This paper presents a comprehensive investigation of the manufacturing of itraconazole (ITZ) amorphous solid dispersions (ASDs) with Kolllidon® VA64 (KVA64) using hot-melt extrusion (HME) and in-line process monitoring, employing a Quality by Design (QbD) approach. A sequential Design of Experiments (DoE) strategy was utilized to optimize the manufacturing process, with in-line UV–Vis spectroscopy providing real-time monitoring. The first DoE used a fractional factorial screening design to evaluate critical process parameters (CPPs), revealing that ITZ concentration had the most significant impact on the product quality attributes. The second DoE, employing a central composite design, explored the interactions between feed rate and screw speed, using torque and absorbance at 370 nm as responses to develop a design space. Validation studies confirmed process robustness across multiple days, with stable in-line UV–Vis spectra and consistent product quality using 30 % ITZ, 300 rpm, 150 °C and 7 g/min as the optimized process conditions. Theoretical and experimental analyses indicated that shifts in UV–Vis spectra at different ITZ concentrations were due to conformational changes in ITZ, which were confirmed through density functional theory (DFT) calculations and infrared spectroscopy. This work offers novel insights into the production and monitoring of ITZ-KVA64-ASDs, demonstrating that in-line UV–Vis spectroscopy is a powerful tool for real-time process monitoring and/or control.

Nanosecond laser ablation of micro-pits in Ni60/WC coatings with coupled thermal-stress simulation and parameter optimization

In order to solve the problem of crack sprouting inside the micro-pit caused by improper design of laser ablation process parameters, this study establishes a thermal-stress coupling simulation model of nanosecond laser ablation of micro-pits on Ni60/WC coated surfaces. It researches the influence of laser process parameters (laser power, scanning speed, processing times) on the index parameters of micro-pit diameter, depth, and maximum residual stress. The weighting of diameter, depth and maximum residual stress sub-objectives in the comprehensive evaluation objectives of micro-pits are calculated. The response surface method of Central Composite Design (CCD) and regression analysis are used to fit the response surface functions of micro-pit diameter, depth, and maximum residual stress as a function of the variation of laser ablation process parameters. The Genetic Algorithm (GA) is used to minimize value of the maximum residual stress sub-objective function and to optimize the process parameters of laser ablation of micro-pits, using the values interval of the micro-pit diameter and depth functions as nonlinear constraints. The results show that the maximum residual stress varies quadratically with laser power and scanning speed, increases linearly with the processing times, and is coupled with the ablation process parameters. A design method for optimizing the parameters of nanosecond laser ablation by maximum residual stress is established, and the process parameters are optimized to meet the design parameters and quality requirements of micro-pits: laser power of 12 W, scanning speed of 276 mm/s, and 4 times of processing. The optimized process is provided for the parameter tuning nanosecond laser ablation of micro-pits on Ni60/WC coating surfaces.

Tailoring N and S Heteroatoms Through Rational Design in Carbon Nanotubes-Graphene Composites for Enhanced Zn-Air Battery Performance.

Cathodic materials significantly influence the performance, durability, and sustainability of primary zinc-air batteries (ZABs). This study focuses on the rational design of highly active metal-free composites by tailoring the content of N and S heteroatoms in carbon nanotube-graphene (CNTG) composites. The oxygen reduction reaction (ORR) tests showed onset potentials (Eo) of 0.88 V (N-CNT) and 0.89 V (N-graphene) for individual materials and 0.92 V for the N-CNTG composite. The N content varied with dicyandiamide and urea, showing changes in the surface area and N content (7.09 vs. 5.30 at. %), and in pyridinic and quaternary N species. The abundance of pyridinic-N species in N-CNTG using urea enabled a higher ORR activity (Eo=0.92 V). The S incorporation through thiourea improved the Eo to 0.94 V (Pt/C= 1.03 V). And, the combination of urea and thiourea resulted in a highly active and durable N,S-CNTG material, displaying a Eo of 0.96 V, and an activity loss of 8.7% (Pt/C= 25.4%) after 2000 cycles. In ZAB mode, this material displayed a voltage of 1.35 V, a power density of 107 mW cm-2, and a specific capacity of 1060 mA‧h g-1.

Efficient and Accurate Calibration of Discrete Element Method Parameters for Black Beans

Discrete element parameters of the black bean (BLB) are key to developing high-performance BLB machineries (e.g., seeders and shellers), which are still lacking in previous literature. In this study, the effects of the radius and lifting speed of cylinder-in-cylinder lifting method (CLM) simulations were investigated to efficiently and accurately obtain the repose angle. Discrete element method (DEM) parameters of the BLB were determined by combining the Plackett–Burman Design test, the steepest ascent design test, and the central composite design test. The results show that the measurement moment (i.e., 12 s) of repose angles should be determined when kinetic energy reaches the minimal threshold (1 × 10−6 J) to efficiently and accurately obtain repose angles; too early or too late a measurement can result in inaccurate repose angles or excessive computation time of the computer, respectively. The lifting speed and cylinder radius affected the lateral displacements of BLBs and came at the cost of higher computation time and memory usage. A lifting speed of 0.015 m s−1 and a radius of 40 mm of the cylinder were determined in CLM simulations. The static friction coefficient and rolling friction coefficient between BLBs significantly affected the repose angles. A static friction coefficient of 0.202 and rolling friction coefficient of 0.0104 between BLBs were obtained based on the optimization results. A low relative error (0.74%) and insignificant difference (p > 0.05) between the simulated and measured repose angles were found. The suggested method can be potentially used to calibrate the DEM parameters of BLBs with good accuracy. The results from this study can provide implications for investigating interactions of BLBs and various BLB processing machines and for the efficient and accurate determination of DEM parameters of crop grains.

Revalorisation of brewer’s spent grain for biotechnological production of hydrogen with Escherichia coli

IntroductionAgro-industrial wastes are generated in huge amounts triggering damages to the environment and human health. Therefore, there is an urgent necessity for its revalorisation into high-value compounds, including biofuels. One such wastes is the brewer's spent grain (BSG), a by-product of the beer industry, which is produced in vast quantities worldwide. The rich-fibre and protein content of BSG makes this waste a valuable resource for biotechnological applications, although the main challenge of this approach is to make the carbohydrates and proteins available for bacterial metabolisation into high-value products. This work aims to optimise a thermal-hydrolysis process to revalorise BSG by bacterial conversion into hydrogen (H2), as a clean energy that can replace fossil fuels.MethodsA 2k full factorial design method was employed hydrolysation of BSG and showed that temperature and acid concentration are significant factors that affect the extraction of reducing sugars (RS) and proteins. Subsequently, steepest ascent and central composite design (CCD) statistical methods were applied to determine the optimal conditions for hydrolysis.ResultsThe optimised hydrolysis condition were 0.047 M H2SO4, 150°C, 30 min and 15% BSG, leading to the theoretical concentrations of 54.8 g RS/L and 20 g/L proteins. However, 5'-hydroxymethylfurfural (HMF) was generated in thermal-hydrolysis conditions at higher temperatures exceeding 132°C. Therefore, a screening of HBSGs fermentation using Escherichia coli was conducted in order to identify the most suitable conditions for maximizing H2, as well as the production of volatile fatty acids (succinate and acetate) and ethanol. Among the tested conditions, HBSG A17 (117°C, 20 min, and 0.1 M H2SO4) yielded the highest H2 production of 48 mmol/L in this work.ConclusionThis study provides valuable insights into the optimisation of BSG pre-treatment for biotechnological applications, which may help in the selection of the most appropriate hydrolysis conditions based on the desired end product.

Optimized production of a truncated form of the recombinant neuraminidase of influenza virus in Escherichia coli as host with suitable functional activity

BackgroundTo discover effective drugs for treating Influenza (a disease with high annual mortality), large amounts of recombinant neuraminidase (NA) with suitable catalytic activity are needed. However, the functional activity of the full-length form of this enzyme in the bacterial host (as producing cells with a low cost) in a soluble form is limited. Thus, in the present study, a truncated form of the neuraminidase (derived from California H1N1 influenza strain) was designed, then biosynthesized in Escherichia coli BL21 (DE3), Shuffle T7, and SILEX systems. E. coli BL21 (DE3) was selected as a best host for statistical optimization. Using central composite design methodology, neuraminidase expression level was measured at 20 different runs considering most effective factors including; concentration of isopropyl-β-D-thiogalactopyranoside (IPTG), temperature, and induction time.ResultThe recombinant neuraminidase was purified using Ni-affinity chromatography in soluble form. The neuraminidase expression was confirmed by western blot technique with a molecular mass of 48 kDa. The optimum expression condition was at temperature (30°C), induction time (3 h), and concentration of IPTG (0.6 mM) resulting in maximum neuraminidase expression (7.6 µg/mL) with P < 0.05. The analysis of variance with the significant value of R2 (0.97) indicated that the quadratic model utilized for this prediction was highly significant (p < 0.0001). Applying the optimized condition led to a ~ 2.2-fold increase in NA expression level (from 3.4 to 7.6 µg/ml). The kinetic parameters were also confirmed by fluorescent signals (by 2’-(4-Methylumbelliferyl)-α-D-N acetyl neuraminic acid substrate) with specific activity; ~3.5 IU/mg and Km: 86.49 ± 0.1 µ, close to the Vibrio Cholera neuraminidase with specific activity; 4 IU/mg. The neuraminidase inhibition test confirmed the inhibition of the neuraminidase activity by the drug inhibitor (Oseltamivir) compared to the control sample.ConclusionThe high quality and proper functional activity of the truncated neuraminidase described in this research show that E. coli can be a suitable host for a wide range of applications with less cost and risk compared to eukaryotic expression systems.

Mathematical Modeling and Optimization of Seed Distribution Uniformity in Planting of Sage Seeds Using a Micro-Granular Applicator

The objective of this study was to determine the seed flow characteristics and in-row seed distribution uniformity under different operating conditions to develop mathematical models and to optimize the seed distribution uniformity in the seeding of sage seeds by a micro-granule applicator equipped with a conveyor belt seed-metering unit. In this study, weighing tests were used to determine the seed flow characteristics, while sticky belt tests were used to determine the in-row seed distribution uniformity. While the evaluations of flow uniformity were carried out depending on the coefficient of variation values (CVs), in-row seed distribution uniformity evaluations were carried out using the values of the variation factor (Vf) and goodness criterion (λ). Central Composite Design (CCD) was used as the experimental design. Based on the analysis of data obtained from the experiments, the polynomial functions were developed for Vf and λ values and the models were optimized. The forward speed was determined as 2.14 m s−1, the seed rate was 13.9 kg ha−1, and the seed falling angle was 42.73° for the Vf model, while these values were determined as 2.43 m s−1, 14.7 kg ha−1, and 33.11°, respectively, for the λ model. All these findings reveal that the metering unit equipped with conveyor belt could be used for the seeding of sage seeds successfully. Data and information found in this work would have great potential to be used as a guide for farmers, manufacturers, and scientists who work in such areas.

High impact resistance and energy absorption composite reinforced via shear thickening gel/angle interlocking for flexible wearable protective

The study reveals the combination of shear thickening gel (STG) with angle interlocking fabrics with different thickness direction binding modes to prepare flexible composites. The effect of thickness direction binding modes on flexible composites' ballistic performance and failure mechanisms are systematically investigated. The results reveal that the bullet penetrates STG and yarn simultaneously during the impact phase, causing STG to produce the shear thickening effect. Flexible composites produce synergistic energy absorption. The layer-to-layer structure has a 4.49 % higher ballistic limit than the through-thickness structure, proving superior impact resistance. This investigation aims to enhance the design of lightweight ballistic composites by examining the failure mechanisms of flexible composites in response to ballistic impacts.

Multiscale study on the synergistic effect of interface heat transfer and filler structure on enhancing the thermal conductivity of boron nitride/alumina/polyurethane composites

The design and preparation of polymer composites for microelectronic package with high thermal conductivity is an important route to solve the thermal problem of electronic devices. The synergistic effect of interface heat transfer and hybrid filler structure on the enhancement of thermal conductivity in polyurethane composites was analyzed using a multiscale approach. Firstly, the interface heat transfer characteristics and strengthening mechanism of BN-TPU and Al2O3-TPU regulated by functionalization were analyzed by atomic scale calculation. Then, the thermal conductivity of BN/Al2O3/TPU composites under different interface thermal resistance, filler distribution, filler ratio and contents were studied through representative volume elements with interface layer structure. The results indicate that, due to the functionalized molecules increasing the phonon vibration overlap between the filler and matrix and thereby reducing the interface thermal resistance, the thermal conductivity of the composite materials shows an increasing trend with interface functionalization. Moreover, under the combined effects of constructing oriented BN structures, optimizing the ratio between BN and Al2O3, and regulating interface functionalization, the composites showed excellent thermal conductivity at low filler content. The research can provide important guidance for the preparation of highly thermal conductive polymer composites.

Measurement and analysis of residual stress of multilayer carbon fiber laminate based on incremental drilling method

In the automotive and aerospace industries, carbon fiber is widely used in structures such as chassis and wings due to its lightweight and excellent mechanical properties, and the residual stresses are crucial for product design. In this paper, six kinds of carbon fiber laminates with different layup directions are investigated by using the integral method, and the calibration coefficient matrix is numerically solved by using ABAQUS finite element software, and the effects of laminate direction and incremental step on the three-direction residual stresses are experimentally analyzed. The residual stresses in different oriented layers were predicted by classical lamination theory (CLT), and the longitudinal, transverse and in-plane shear stresses were compared by combining incremental drilling experiments with calibration factors. The results showed that the ply with [45/90/−45/0/45/90/−45/0] laminate had the best performance,the difference between theoretical and experimental values for σx was 0.421MPa. The maximum τxy measurement was 1.7103MPa, with a maximum percentage error of 25.3%. The maximum difference for σy was 0.7306MPa. These findings indicate that the method is more accurate in predicting the residual stresses in the first four layers of composite material. This provides important theoretical and experimental support for the optimal design of composites.