Matrix Degradation Research Articles

Seabuckthorn pulp extract alleviates UV-B-induced skin photo-damage by significantly reducing oxidative stress-mediated endoplasmic reticulum stress and DNA Damage in human primary skin fibroblasts and Balb/c mice skin.

Skin homeostasis is predominantly compromised by exposure to UV-B irradiation, leading to several physiopathological processes at cellular and tissue levels that deteriorate skin function and integrity. The current study investigated the photo-protective role of seabuckthorn fruit pulp (SBT) extract against UV-B-induced damage in primary human skin fibroblasts (HDFs) and Balb/C mice skin. We subjected HDFs and Balb/C mice to UV-B irradiation and measured multiple cellular damage indicators. We found that UV-B-irradiated HDFs treated with SBT had a considerably greater survival rate than cells exposed to UV-B radiation alone. The UV-B irradiation-induced ROS generation led to the degradation of the extracellular matrix, inflammation, DNA damage, endoplasmic reticulum (ER) stress, and apoptosis. SBT treatment significantly reduced these manifestations. Topical application of SBT alleviated UV-B-induced epidermal thickening, leukocyte infiltration, and degradation of extracellular matrix in Balb/c mice skin. Based on our results, we conclude that SBT has the potential to be developed as a therapeutic/cosmetic remedy for the prevention of skin photo-damage.

A Zn-Ca-Based Metallic Glass Composite Material for Rapid Degradation of Azo Dyes

The catalytic capabilities of metals in degrading azo dyes have garnered extensive interest; however, selecting highly efficient metals remains a significant challenge. We have developed a Zn-Ca-based metallic glass composite which shows outstanding degradation efficiency for Direct Blue 6. This alloy comprises a Zn2Ca crystalline phase and an amorphous matrix, allowing for the degradation of azo dyes within minutes in a wide temperature range of 0–60 °C. Kinetic calculations reveal an exceptionally low activation energy of 8.99 kJ/mol. The rapid degradation is attributed to the active element Ca and the unique amorphous structure of the matrix, which not only facilitates abundant redox conditions but also minimizes the hydrolysis of the active element. The newly developed metallic glass composite exhibits a notably higher azo dye degradation rate compared to those of general metallic glasses, offering a new avenue for the rapid degradation of azo dyes. This paper holds significant importance for the development of novel azo dye wastewater treatment agents.

Tumor biomechanics as a novel imaging biomarker to assess response to immunotherapy in a murine glioma model

Glioblastoma is the most common and aggressive primary malignant brain tumor with poor prognosis. Novel immunotherapeutic approaches are currently under investigation. Even though magnetic resonance imaging (MRI) is the most important imaging tool for treatment monitoring, response assessment is often hampered by therapy-related tissue changes. As tumor and therapy-associated tissue reactions differ structurally, we hypothesize that biomechanics could be a pertinent imaging proxy for differentiation. Longitudinal MRI and magnetic resonance elastography (MRE) were performed to monitor response to immunotherapy with a toll-like receptor 7/8 agonist in orthotopic syngeneic experimental glioma. Imaging results were correlated to histology and light sheet microscopy data. Here, we identify MRE as a promising non-invasive imaging method for immunotherapy-monitoring by quantifying changes in response-related tumor mechanics. Specifically, we show that a relative softening of treated compared to untreated tumors is linked to the inflammatory processes following therapy-induced re-education of tumor-associated myeloid cells. Mechanistically, combined effects of myeloid influx and inflammation including extracellular matrix degradation following immunotherapy form the basis of treated tumors being softer than untreated glioma. This is a very early indicator of therapy response outperforming established imaging metrics such as tumor volume. The overall anti-tumor inflammatory processes likely have similar effects on human brain tissue biomechanics, making MRE a promising tool for gauging response to immunotherapy in glioma patients early, thereby strongly impacting patient pathway.

First evidence of plastics in coypu (Myocastor coypus)'s platforms.

Platforms are structures built by coypus for various purposes, such as reproduction, resting, and thermoregulation. In a coastal wetland of central Italy, during a study aimed at investigating the characteristics of coypu's platforms, it was recorded, for the first time worldwide, the presence of plastic in these structures. Through a transect survey, we censused 83 platforms, among which three (3.61%) were found with presence of macro- and megaplastics (polystyrene, polypropylene, and low-density polyethylene in film form; polyester, polyamide, and expanded polystyrene in fragments). Through the FTIR spectra, it was possible to highlight the degradation of the polymeric materials. To stimulate possible in-depth investigations at the level of the food chain (e.g., coypu predators, including canids) in wet habitats, we discussed possible causes and implications of plastic presence in coypus' nest structures.

First-principles study of the effect of oxygen vacancy and iridium doping on formaldehyde adsorption on the La2O3(001) surface.

Formaldehyde adsorption on intrinsic La2O3 surface, four-fold coordinated oxygen vacancy (VO4c), six-fold coordinated oxygen vacancy (VO6c), and iridium-doped La2O3(001) surface was studied by the first-principles method. The results show that formaldehyde adsorption on the Ir-doped La2O3(001) surface with VO6c is the strongest because of the directional movement of electrons caused by the interaction of the Ir-5d orbitals and internal oxygen vacancy, wherein the adsorption energy is 3.23 eV. This model showed a significant increase in adsorption energy, indicating that Ir doping improves the formaldehyde adsorption capacity of the La2O3(001) surface. The energy band analysis shows that iridium doping introduces impurity energy levels into the intrinsic La2O3 energy band, which enhances the interaction between the La2O3(001) surface and formaldehyde molecules. Density of state analysis indicated that the adsorption of formaldehyde molecules on the La2O3(001) surface is mainly due to the interaction between the O-2p, C-2p orbitals of formaldehyde and the Ir-5d orbital of iridium atoms. Furthermore, the existence of VO4c and VO6c defects has no effect on the position and shape of the valence and conduction bands. The effects of oxygen vacancy and iridium doping on the optical properties mainly appeared in the low-energy infrared and visible regions, making the O-2p, C-2p orbitals of formaldehyde and the Ir-5d, O-2p orbitals of the La2O3(001) surface become hybridized near the Fermi level and the electronic transition from the valence band to conduction band more likely to occur. The La2O3 material can be used as an ideal photocatalytic material for formaldehyde degradation.

SnS2: A piezocatalytic material for efficient degradation of ciprofloxacin

Tin disulfide (SnS2), as a two-dimensional transition metal sulfide with similar electronic or structural properties, has been calculated to have the possibility of piezoelectricity. SnS2 was prepared by different methods, the structure of materials were characterized by XRD and FT-IR. Then the morphology and surface elements of materials were characterized by SEM and XPS. Through the detection of PFM and electrochemical transient currents, the results show that the SnS2 samples prepared by coprecipitation method have piezoelectric characteristics and current can be generated by applying mechanical stirring force. Comparing the materials that prepared by coprecipitation method, hydrothermal method and commercially purchased SnS2, it was found that the degradation rate of ciprofloxacin by the material prepared by the coprecipitation method could reach 93 % after 1 h. Through characterization, it is speculated that the piezocatalytic activity of the coprecipitation material is due to sodium ion doping. It is found that the preparation method and the introduction of heteroatoms have a great influence on the piezocatalytic activity. It provides a way for subsequent researchers to improve the performance of materials from material design.

Performance of Iron Ore Tailings/Cement Composite at High Temperatures: Inconbustibility

Objective: This study aims to evaluate the performance of an iron ore tailings/cement composite at high temperatures, used in brick manufacturing. Specifically, it investigates the non-combustibility of the material and its structural integrity after exposure to intense heat, with an emphasis on compressive strength and the economic and sustainable viability of this composite. Theoretical Framework: The research is based on concepts of sustainability in civil construction and the reuse of industrial waste. The literature highlights the synergy between iron ore tailings and Portland cement, resulting in materials with good durability and non-combustibility. Previous studies indicate a reduction in environmental impact and the economic feasibility of using these composites as substitutes for traditional materials, in addition to the importance of maintaining structural strength under extreme conditions. Method: The adopted methodology involves the manufacture of test specimens using CP V-ARI cement and iron ore tailings, molded and cured according to Brazilian standards. Non-combustibility tests are conducted in a muffle furnace at 750°C, measuring temperature variation, smoke emission, and mass loss. Additionally, compressive strength tests are conducted before and after heat exposure to assess material degradation. Results and Discussion: The results indicate that the composite exhibits satisfactory non-combustibility properties, with an average mass loss of 3.1%, well below the permissible limit of 50%. However, a significant loss of 67.5% in compressive strength was observed after exposure to high temperatures. The discussion contextualizes these results, highlighting the need to optimize the composition to minimize strength loss, although non-combustibility remains a positive aspect. Research Implications: Practical implications include the potential use of the composite in environments subject to high temperatures, as a passive fire protection measure. Theoretically, the research contributes to the understanding of the behavior of cementitious composites with industrial waste under extreme conditions, suggesting directions for future studies and applications in civil engineering and sustainable construction. Originality/Value: This study makes an original contribution by exploring the specific combination of iron ore tailings with cement at high temperatures, providing new insights into its applicability and limitations. The relevance of the research lies in the potential reduction of environmental impact and the promotion of sustainable practices in civil construction, as well as enhancing fire safety in buildings.

The application of poly(dimethyldiallylammonium chloride) in poly(butylene adipate‐co‐terephthalate)/starch composites

AbstractAntimicrobial degradable materials are pivotal in enhancing food safety, mitigating plastic pollution, and advancing sustainable development. In this study, poly(diallyldimethylammonium chloride) (PDMDAAC) was initially anchored to the starch surface (PMS) and utilized as a filler. Subsequently, poly(butylene adipate‐co‐terephthalate) (PBAT)/PMS composites with antimicrobial properties were successfully prepared by melt blending. The results showed that the introduction of PMS filler can improve the mechanical and antimicrobial properties of PBAT. Compared with pure PBAT, the tensile strength and modulus of PBAT/10PMS composites were enhanced by 25% and 29%, respectively. In addition, the prepared PBAT/PMS composites exhibited excellent antimicrobial activity against Escherichia coli when the PMS filler content reached 10 wt% or even higher. Therefore, an antimicrobial biodegradable composite was successfully prepared using a facile blending method in this study.

Multiphysics modeling of 3D traction force microscopy with application to cancer cell-induced degradation of the extracellular matrix

Abstract3D Traction Force Microscopy (3DTFM) constitutes a powerful methodology that enables the computation of realistic forces exerted by cells on the surrounding extracellular matrix (ECM). The ECM is characterized by its highly dynamic structure, which is constantly remodeled in order to regulate most basic cellular functions and processes. Certain pathological processes, such as cancer and metastasis, alter the way the ECM is remodeled. In particular, cancer cells are able to invade its surrounding tissue by the secretion of metalloproteinases that degrade the extracellular matrix to move and migrate towards different tissues, inducing ECM heterogeneity. Typically, 3DTFM studies neglect such heterogeneity and assume homogeneous ECM properties, which can lead to inaccuracies in traction reconstruction. Some studies have implemented ECM degradation models into 3DTFM, but the associated degradation maps are defined in an ad hoc manner. In this paper, we present a novel multiphysics approach to 3DTFM with evolving mechanical properties of the ECM. Our modeling considers a system of partial differential equations based on the mechanisms of activation of diffusive metalloproteinase MMP2 by membrane-bound metalloproteinase MT1-MMP. The obtained ECM density maps in an ECM-mimicking hydrogel are then used to compute the heterogeneous mechanical properties of the hydrogel through a multiscale approach. We perform forward and inverse TFM simulations both accounting for and omitting degradation, and results are compared to ground truth reference solutions in which degradation is considered. The main conclusions resulting from the study are: (i) the inverse methodology yields results that are significantly more accurate than those provided by the forward methodology; (ii) ignoring ECM degradation results in a considerable overestimation of tractions and non negligible errors in all analyzed cases.

C-Src-induced vascular malformations require localised matrix degradation at focal adhesions.

Endothelial cells lining the blood vessel wall communicate intricately with the surrounding extracellular matrix, translating mechanical cues into biochemical signals. Moreover, vessels require the capability to enzymatically degrade the matrix surrounding them, to facilitate vascular expansion. c-Src plays a key role in blood vessel growth, with its loss in the endothelium reducing vessel sprouting and focal adhesion signalling. Here, we show that constitutive activation of c-Src in endothelial cells results in rapid vascular expansion, operating independently of growth factor stimulation or fluid shear stress forces. This is driven by an increase in focal adhesion signalling and size, with enhancement of localised secretion of matrix metalloproteinases responsible for extracellular matrix remodelling. Inhibition of matrix metalloproteinase activity results in a robust rescue of the vascular expansion elicited by heightened c-Src activity. This supports the premise that moderating focal adhesion-related events and matrix degradation can counteract abnormal vascular expansion, with implications for pathologies driven by unusual vascular morphologies.

DSCR1–1 attenuates osteoarthritis-associated chondrocyte injury by regulating the CREB1/ALDH2/Wnt/β-catenin axis: An in vitro and in vivo study

The progression of osteoarthritis (OA) includes the initial inflammation, subsequent degradation of the extracellular matrix (ECM), and chondrocyte apoptosis. Down syndrome candidate region 1 (DSCR1) is a stress-responsive gene and expresses in varied types of cells, including chondrocytes. Bioinformatics analysis of GSE103416 and GSE104739 datasets showed higher DSCR1 expression in the inflamed cartilage tissues and chondrocytes of OA. DSCR1 had two major isoforms, isoform 1 (DSCR1–1) and isoform 4 (DSCR1–4). We found that DSCR1–1 had a faster (in vitro) and higher expression (in vivo) response to OA compared to DSCR1–4. IL-1β-induced apoptosis, inflammation, and ECM degradation in chondrocytes were attenuated by DSCR1–1 overexpression. DSCR1–1 triggered the phosphorylation of cAMP response element-binding 1 (CREB1) at 133 serine sites by decreasing calcineurin activity. Moreover, activated CREB1 moved into the cell nucleus and combined in the promoter regions of aldehyde dehydrogenase 2 (ALDH2), thus enhancing its gene transcription. ALDH2 could recover Wnt/β-catenin signaling transduction by enhancing phosphorylation of β-catenin at 33/37 serine sites and inhibiting the migration of β-catenin protein from the cellular matrix to the nucleus. In vivo, adenoviruses (1 × 108 PFU) overexpressing DSCR1–1 were injected into the articular cavity of C57BL/6 mice with medial meniscus surgery-induced OA, and it showed that DSCR1–1 overexpression ameliorated cartilage injury. Collectively, our study demonstrates that DSCR1–1 may be a potential therapeutic target of OA.

Mitigating chain degradation of lithium-rich manganese-based cathode material by surface engineering

Due to offering joint cationic and anionic redox, lithium-rich manganese-based layered oxides (LMLOs) allow high energy density in lithium-ion batteries. However, the oxygen loss, electrode-electrolyte interface side reactions and the structural degradation have resulted in continuous performance decay, hindering the scale-up application of LMLOs. Here, Li1.3V0.94(BO3)2 (LVB) is uniformly coated on the Li1.2Mn0.54Co0.13Ni0.13O2 (LMNCO) surface by using a sol-gel method combined with a high-temperature calcination. By applying multiple characterizations including in-situ XRD, DEMS, HRTEM, AFM and electrochemical test, we prove that the LVB layer provides a physical barrier, which effectively inhibits the surface reactivity and blocks the chain degradation from the source, improves the reversibility of O2- redox and prevents the phase transition and structural degradation propagating from the surface to the bulk. Moreover, the kinetic investigations and calculations reveal that the LVB modification not only improves the electron conductivity by the strong bond of V-O and B-O to decrease the surface work function and increase the electron density near the Fermi energy level, but also provides expanded pathways with lower impedance to facilitate the Li+ transfer and diffusion. Impressively, the modified cathode exhibits the higher rate performance (151 mAh g-1 at 5C) and improved cycle stability under high cutoff voltage (217.7 mAh g-1 after 200 cycles at 0.2C in 2.0–4.8 V, 92.5% capacity retention; even in 2.0–5 V, 93.9% after 100 cycles). This work systematically investigates the inhibiting degradation mechanism and establishes the correlation between the intrinsic structure and surface engineering, and offers valuable insight into the development of high-performance LMLOs.

Inter-crosslinked Spirocyclic Mixed Matrix Membranes Exhibiting Enhanced Gas Permeability, Selectivity, and Plasticization Resistance

Poor interfacial compatibility is the most common issue inhibiting performance enhancement in mixed matrix membranes (MMM) for gas and liquid separations. To address this issue, we fabricated highly selective and permeable inter-crosslinked mixed matrix membranes (IcMMMs) based on carboxylic-acid functionalized polymer of intrinsic microporosity-1 (CPIM) containing up to 30 wt. % triptycene-isatin polymer porous network (PPN) particles. Polymer-filler inter-crosslinking is accomplished via thermal decarboxylation at 200°C, which is the lowest temperature this reaction has been found to occur in the literature. This low temperature circumvents potential issues with degradation of porous supports or gutter layer materials, and thus enables these materials to be integrated into traditional membrane processes. The resulting IcMMMs exhibit gel fractions above 90%. Beyond IcMMMs, membranes based on neat CPIM, thermally crosslinked CPIM, as well as non-crosslinked CPIM-PPN mixed matrix membranes were fabricated to elucidate the individual and synergistic effects of filler inclusion and thermal treatment. In addition to showing upper bound permeability-selectivity performance, IcMMMs also exhibit an almost unprecedented stability against plasticization upon extended exposure to CO2 up to 50 atm or above. This study shows that crosslinking across the polymer-filler interface is the key feature to achieve simultaneous enhancement in permeability, selectivity, and stability. To elucidate the molecular mechanism of these enhancements in the IcMMMs with respect to the baseline materials, permeability was broken into its sorption and diffusion contributions and an energetic analysis of sorption was performed. The low cost of PPNs coupled with the mild crosslinking temperature make this approach highly scalable, resulting in materials exhibiting high rigidity and structural stability with the potential to excel in aggressive separations, such as organic solvent separations or high-CO2 content, high-pressure natural gas sweetening.

Mitigating chain degradation of lithium-rich manganese-based cathode material by surface engineering

Due to offering joint cationic and anionic redox, lithium-rich manganese-based layered oxides (LMLOs) allow high energy density in lithium-ion batteries. However, the oxygen loss, electrode-electrolyte interface side reactions and the structural degradation have resulted in continuous performance decay, hindering the scale-up application of LMLOs. Here, Li1.3V0.94(BO3)2 (LVB) is uniformly coated on the Li1.2Mn0.54Co0.13Ni0.13O2 (LMNCO) surface by using a sol-gel method combined with a high-temperature calcination. By applying multiple characterizations including in-situ XRD, DEMS, HRTEM, AFM and electrochemical test, we prove that the LVB layer provides a physical barrier, which effectively inhibits the surface reactivity and blocks the chain degradation from the source, improves the reversibility of O2- redox and prevents the phase transition and structural degradation propagating from the surface to the bulk. Moreover, the kinetic investigations and calculations reveal that the LVB modification not only improves the electron conductivity by the strong bond of V-O and B-O to decrease the surface work function and increase the electron density near the Fermi energy level, but also provides expanded pathways with lower impedance to facilitate the Li+ transfer and diffusion. Impressively, the modified cathode exhibits the higher rate performance (151 mAh g-1 at 5C) and improved cycle stability under high cutoff voltage (217.7 mAh g-1 after 200 cycles at 0.2C in 2.0–4.8 V, 92.5% capacity retention; even in 2.0–5 V, 93.9% after 100 cycles). This work systematically investigates the inhibiting degradation mechanism and establishes the correlation between the intrinsic structure and surface engineering, and offers valuable insight into the development of high-performance LMLOs.

Enhanced visible light utilization of BiOI/BiOBr/Bi composite catalytic materials for photocatalytic degradation of TC and reduction of Cr(Ⅵ)

The rational design and construction of semiconductor photocatalytic materials are important significance for efficient utilization of solar energy and enhancement of photocatalytic activity. In this study, composite photocatalytic materials modified with Bi0 on the surface of BiOI/BiOBr heterojunction were successfully constructed based on the current mature electrostatic spinning technology by using solvothermal and in-situ reduction methods. The successful preparation of BiOI/BiOBr/Bi composites was confirmed by a series of characterization methods. The composite photocatalyst was applied to the degradation of pollutants, and by adjusting the addition ratio of different substances, it was found that the photocatalytic composites prepared with the addition of 0.125 mmol NaBH4 and the ratio of I/Br of 3:1 showed the best performance. The degradation efficiency of the catalyst for tetracycline hydrochloride (TC) at 10 mg/L reached 98.4 % after 180 min of visible light irradiation, and the high degradation performance of the material was maintained after five cycles. Meanwhile, the reduction efficiency of the material for Cr(VI) was 98.2 % after 100 min of visible light irradiation. Free radical trapping experiments demonstrated that photogenerated holes (h+) and superoxide radicals (•O2-) are the main active substances for photocatalytic degradation of TC. Due to the partial reduction of Bi0, the absorption of the catalyst in the near-infrared region was enlarged, which enhanced the photothermal effect of the whole material and further improved the catalyst activity.

Degradable, self-healing, humidity-driven poly(urethane-urea) film

Humidity-driven materials are widely used in actuators, soft robots, sensors, and other fields. The extensive use of these materials increases the demand for degradable, highly durable, and self-healing materials. However, the preparation of such ideal materials still faces serious challenges. Herein, a novel poly(urethane-urea) film material (PUU-DHA-Cu4) with synergetic quadruple dynamic bonds (acylhydrazone bonds, boron-oxygen bonds, coordination bonds, and hydrogen bonds) is developed. The prepared PUU-DHA-Cu4 film material exhibited a tensile strength of 23.2 MPa, an elongation at break of 1142 %, and a healing efficiency of 90.1 % after 48 h of self-healing at room temperature. Meanwhile, the reversibility of the boron-oxygen bond imparts degradability to the material. Finally, a humidity-driven poly(urethane-urea) material that not only has self-healing ability but can also be degraded easily was successfully developed. This work will make a valuable addition to the field of environment-friendly humidity-driven materials.

Distinct transcriptional and prognostic impacts of TERT promoter mutations C228T and C250T in papillary thyroid carcinoma.

TERT promoter mutations C228T and C250T are associated with disease aggressiveness and poor clinical outcomes in patients with papillary thyroid carcinomas. However, very little is known about the transcriptional consequences of these mutations and whether they both carry similar oncogenic potential. Here we characterized the transcriptional disturbances and clinical outcomes associated with the presence of each of these two mutations using data derived from The Cancer Genome Atlas. We observed that tumors harboring the C228T mutation (n=27) exhibited a 16-fold increase in TERT mRNA levels (P=5.3x10-42), whereas C250T tumors (n=8) showed only a 2-fold increase in expression (P=0.034). The C228T mutation was associated with the activation of signaling pathways controlling the cell cycle, cellular division, and extracellular matrix degradation. Univariate analysis demonstrated that the C228T mutation was associated with older age at diagnosis, large tumor size, lymph node invasion, and distant metastases at diagnosis. The C228T mutation was also associated with worse progression-free interval (PFI) in comparison to WT tumors (HR=5,04; P<0.001). This association remained significant in a multivariate analyses (HR=3.74, P=0.003) adjusting for BRAF-V600E status and ATA risk group. Our data indicate that TERT promoter mutations C228T and C250T have distinct transcriptional consequences in PTC, suggesting a greater oncogenic potential for the C228T mutation. TERT promoter mutation C228T may be a useful prognostic marker to identify patients at high risk of distant recurrence. Clinical data for the C250T mutation is still limited, with no evidence up to date to confirm its prognostic significance.

Simple double shooting approach with bisection for FRCM reinforced curved masonry prisms subjected to shear

In this study, curved masonry pillars reinforced with FRCM subjected to standard shear tests are analyzed through a novel mono-dimensional model, where failure is governed by Mode II. Three approaches with different accuracy are proposed: i) the first, where the outer matrix is neglected; ii) the second, where the inner matrix is assumed rigid; and iii) the third which considers both matrix layers. Matrix and fiber are assumed subjected to a monoaxial state of stress and exchange tangential stresses at the interfaces. The load is applied by incrementing the displacement at the free fiber edge. Material properties of matrix, fiber and interfaces are assumed constant on small portions of the bonded length. Non-linearity is considered penalizing the elastic modulus using the results of the previous time step. The substrate is assumed rigid. The substrate curvature influence is manifested through interface normal stresses, incorporated into the bond-slip constitutive behavior via the Mohr-Coulomb law. The normal stresses can be determined by enforcing radial equilibrium. For the first two models, the field problem is constituted by a system of two 2nd order differential equations into two variables, namely the displacement of the inner (or outer) layer of mortar and of the fiber textile. A 1D shooting is employed, after having converted the boundary value problem (BVP) into an initial value one (IVP), being the latter fully explicit. For the third model, the field problem is constituted by a system of three 2nd order differential equations, and an additional displacement variable is introduced, necessitating a 2D shooting. The validation is carried out through comparisons with existing experimental data. Good predictions of the load-slip curves, for different strengthening configurations (extrados and intrados with two curvature radii), are observed. In addition, an insight into local stress distributions and material degradation for matrix layers and interfaces is obtained.

Optimization of liquid cooled heat dissipation structure for vehicle energy storage batteries based on NSGA-II

Introduction: With the development of the new energy vehicle industry, the research aims to improve the energy utilization efficiency of electric vehicles by optimizing their composite power supply parameters.Methods: An optimization model based on non-dominated sorting genetic algorithm II was designed to optimize the parameters of liquid cooling structure of vehicle energy storage battery. The objective function and constraint conditions in the optimization process were defined to maximize the heat dissipation performance of the battery by establishing the heat transfer and hydrodynamic model of the electrolyzer.Results: The results showed that the optimization method had excellent performance on multiple evaluation indicators, the material degradation rate after optimization was reduced by 42%, the corrosion rate was reduced by 36%, and the battery life was increased by 17%. The optimization method ensured the maximum temperature control for the safe operation of the lithium-ion battery pack. The temperature of the battery pack was effectively controlled. The temperature difference was kept within 5°C, preventing the battery from overheating and extending its service life.Discussion: The proposed liquid cooling structure design can effectively manage and disperse the heat generated by the battery. This method provides a new idea for the optimization of the energy efficiency of the hybrid power system. This paper provides a new way for the efficient thermal management of the automotive power battery.

FORMULATION OF A MODE I CRACK PROPAGATION MODEL BY ANALYZING THE STRESS FIELD AT THE CRACK TIP

One of the phases in the development of materials is knowledge of their possible degradation. At this stage, taking into account the influence of temperature variation remains essential for certain materials. The objective of this work is to take this aspect into account by formulating a mode I crack propagation model by studying the stress field in the vicinity of the crack tip. To do this, starting from Hookes law generalized in linear elasticity, we use the asymptotic expressions in displacements of the crack tip of Moes et Al. in order to obtain the stress field model. To validate the model, a comparison is made with data from the literature. The observations show a very high agreement of results. The advantage of this model is to take into account the role of temperature in the degradation of materials by analyzing crack propagation. It will be used in our future work.