Extension Mechanism Research Articles

Investigating the Effects of the Height-to-Diameter Ratio and Loading Rate on the Mechanical Properties and Crack Extension Mechanism of Sandstone-Like Materials

The causes of the size effect (SE) and loading rate effect (LR) for rocks remain unclear. Based on this, a gypsum-mixed material was used to simulate sandstone, where the dosing ratio was 7.5% river sand, 17.5% quartz, 58.3% α-high-strength gypsum, and 16.7% water. The specimens were designed to have a height-to-diameter ratio (HDR) of 0.6~2, and three strain rates (SRs)—static, quasi-dynamic, and dynamic—were used to perform single-factor rotational uniaxial compression experiments. PFC2D was used to numerically simulate the damage pattern of a sandstone-like specimen. The results showed that the physical parameters did not change monotonically, as was previously found. The main reason for this is that the end-face friction effect (EFE) is generated when the dynamic SR or the HDR is 0.6~1, with a damage pattern of “X”. Under mechanical analysis, the power consumed by the EFE was inversely proportional to the HDR and directly proportional to the LR, and it can reduce the actual amount of energy transferred inside the specimen. This paper may provide a foundation for the study of non-linear hazards in coal and rock.

Dungeons, Dragons, and Rogues: How Picaresque Literature Shaped the Thief Class in Dungeons & Dragons

This article advocates for a reevaluation of the thief class as a bridge linking literary narratives and tabletop role-playing games (TRPGs). It traces the roots of the Dungeons & Dragons (D&D) thief class in Picaresque Literature against the wider importance of literature in the early TRGP scene, by comparing the thief class to the Picaresque rogue. Through a thematic analysis of articles from eight key TRPG periodicals published between 1975 and 1986, the article illustrates how “extensibility mechanisms” facilitated creative exchanges between hobbyist game designers, Fantasy fiction, and Picaresque Literature via the rogue archetype. These exchanges demonstrate a turn towards nuanced narrative-supporting mechanics, complex player character development, and including vibrant fantasy cities as settings for adventures in D&D, and TRPGs more broadly, influenced by Picaresque Literature.

Calcineurin inhibition enhances Caenorhabditis elegans lifespan by defecation defects-mediated calorie restriction and nuclear hormone signaling.

Calcineurin is a highly conserved calcium/calmodulin-dependent serine/threonine protein phosphatase with diverse functions. Inhibition of calcineurin is known to enhance the lifespan of Caenorhabditis elegans through multiple signaling pathways. Aiming to study the role of calcineurin in regulating innate immunity, we discover that calcineurin is required for the rhythmic defecation motor program (DMP) in C. elegans. Calcineurin inhibition leads to defects in the DMP, resulting in intestinal bloating, rapid colonization of the gut by bacteria, and increased susceptibility to bacterial infection. We demonstrate that intestinal bloating caused by calcineurin inhibition mimics the effects of calorie restriction, resulting in enhanced lifespan. The TFEB ortholog, HLH-30, is required for lifespan extension mediated by calcineurin inhibition. Finally, we show that the nuclear hormone receptor, NHR-8, is upregulated by calcineurin inhibition and is necessary for the increased lifespan. Our studies uncover a role for calcineurin in the C. elegans DMP and provide a new mechanism for calcineurin inhibition-mediated longevity extension.

PilY1 regulates the dynamic architecture of the type IV pilus machine in Pseudomonas aeruginosa

Type IV pili (T4P) produced by the pathogen Pseudomonas aeruginosa play a pivotal role in adhesion, surface motility, biofilm formation, and infection in humans. Despite the significance of T4P as a potential therapeutic target, key details of their dynamic assembly and underlying molecular mechanisms of pilus extension and retraction remain elusive, primarily due to challenges in isolating intact T4P machines from the bacterial cell envelope. Here, we combine cryo-electron tomography with subtomogram averaging and integrative modelling to resolve in-situ architectural details of the dynamic T4P machine in P. aeruginosa cells. The T4P machine forms 7-fold symmetric cage-like structures anchored in the cell envelope, providing a molecular framework for the rapid exchange of major pilin subunits during pilus extension and retraction. Our data suggest that the T4P adhesin PilY1 forms a champagne-cork-shaped structure, effectively blocking the secretin channel in the outer membrane whereas the minor-pilin complex in the periplasm appears to contact PilY1 via the central pore of the secretin gate. These findings point to a hypothetical model where the interplay between the secretin protein PilQ and the PilY1-minor-pilin priming complex is important for optimizing conformations of the T4P machine in P. aeruginosa, suggesting a gate-keeping mechanism that regulates pilus dynamics.

Lower limb exoskeleton for gait rehabilitation with adaptive nonsingular sliding mode control

Abstract This paper introduces a lower limb exoskeleton for gait rehabilitation, which has been designed to be adjustable to a wide range of patients by incorporating an extension mechanism and series elastic actuators (SEAs). This configuration adapts better to the user’s anatomy and the natural movements of the user’s joints. However, the inclusion of SEAs increases actuator mass and size, while also introducing nonlinearities and changes in the dynamic response of the exoskeletons. To address the challenges related to the human–exoskeleton dynamic interaction, a nonsingular terminal sliding mode control that integrates an adaptive parameter adjustment strategy is proposed, offering a practical solution for trajectory tracking with uncertain exoskeleton dynamics. Simulation results demonstrate the algorithm’s ability to estimate unknown parameters. Experimental tests analyze the performance of the controller against uncertainties and external disturbances.

Activity History of the Gangga Graben in the Southern Segment of Kung Co Rift in Southern Tibet Constrained by ESR and U‐Series Dating

ABSTRACTCharacterising the spatial and temporal distribution of the S‐N‐trending rift in southern Tibet is crucial for elucidating the dynamics of E‐W extension within the Tibetan Plateau since the Miocene. The Kung Co–Tangra Yumco rift, located in the central part of the rift system, was initiated at the peak of rifting development. While the initiation of rifting has been ascertained through low‐temperature thermochronology, direct timing constraints remain absent for the Gangga Graben in the southernmost region. Utilising the quartz electron spin resonance (ESR) dating technique, we ascertained the onset age of the eastern boundary fault of the Gangga Graben to be 12.00 ± 1.80 Ma, with an accelerated activity phase at 9.17 ± 1.19 Ma, and an activity age for the western boundary fault at 2.22 ± 0.24 Ma. U‐series dating conducted on the western boundary disclosed a time span of 20–13 ka for hot spring fissure activity. Seismic evidence, inclusive of those from the Gongdapu Horst, indicates persistent activity of the Gangga Graben since the Pleistocene. Comparative analysis of age data from the Kung Co–Tangra Yumco rift suggests that it commenced almost synchronously along its strike at ~14.5–12 Ma. Considering the rifts trending from west to east in southern Tibet and the genetic mechanism of leucogranite, we propose an E‐W extension mechanism in southern Tibet. At ~26–14 Ma, the lithosphere experienced weakened delamination and asthenosphere upwelling, leading to a series of magmatic activities and onset of E‐W extension in southern Tibet. At ~17–7 Ma, as the basal shearing of the underthrusting Indian Plate increased, it marked the peak phase of rifting in southern Tibet.

Surgical Management for Boutonniere Disease

Boutonniere disease is a hand injury causing extension lag or restriction in the proximal interphalangeal joint and hyperextension in the distal interphalangeal joint. This condition often arises from direct laceration or closure damage to the central tendon, rheumatoid arthritis, osteoarthritis, Dupuytren contracture, pulley injury, burns, and other conditions. Surgical management for Boutonniere deformity relies on the expertise of the attending physician and involves both non-surgical and surgical options. In acute cases, conservative therapy should be pursued, while in chronic cases, conservative management may be advised. Surgical intervention is used to transform excessive extension force of the distal interphalangeal joint into extension force of the proximal interphalangeal joint. This is necessary to heal an open rupture of the central tendon. Surgical techniques for chronic deformity are complex due to variables and hand surgeons' expertise. There is no definitive surgical therapy for persistent buttonhole deformity, but several approaches have been documented in case studies. These include terminal tenotomy, collateral band surgery, central tendon surgery, tendon transfer and grafting, stepwise extension mechanism readjustment surgery, and arthrodesis. Central tendon surgery addresses the central tendon, where injured tissue transforms into scar tissue, resulting in delayed extension of the proximal interphalangeal joint. Tendon transfer or grafting have been documented for rotator cuff mechanism rehabilitation, but no definitive guidance exists for these techniques. Curtis treatment introduced a sequential therapy approach for traumatic buttonhole deformity, which involves splinting, excising the transverse reticular ligament, resecting and lengthening the collateral ligament, and repositioning the core tendon. Arthrodesis may be applicable in cases of advanced arthritis, coronal plane deformity, functional impairment, or elderly patients. There are no definitive indications for surgical interventions for persistent buttonhole deformity, and outcomes may be variable or inferior. Understanding the deformity, its progression, and patient's functional constraints is crucial for effective treatment

Analysis of criminal law on ecocide: A case study of war in Ukraine

While actions leading to environmental degradation already have global consequences threatening the very existence of humanity, the war in Ukraine has once again proved the effectiveness of existing international environmental protection mechanisms. The purpose of this study is to analyze existing international environmental protection mechanisms from the perspective of the possibility of criminalizing the crime of ecocide. Based on the analysis of the domestic law of countries that have incorporated ecocide as a crime, it follows that national approaches to addressing this issue depend on historical conditions and have significant differences. These differences hinder the prosecution of ecocide in the absence of appropriate international legal mechanisms, while the consequences of ecocide cause global damage. An analysis of the state of international regulations has shown that despite the existence of an extensive environmental protection mechanism, it remains imperfect, thus making it impossible to prosecute ecocide unless it is done in connection with war crimes. An assessment of the data presented in the reports on the war in Ukraine shows that participation in relevant international conventions does not in any way guarantee that the aggressor country will not violate its international obligations. It is shown that recognizing ecocide as a crime at the international level remains the only effective means to bring perpetrators to justice. The results of the study can be used to further improve the legal mechanisms for prosecuting ecocide, in teaching legal disciplines, and in further academic research.

Late Cambrian-early Ordovician extensional magmatism, uplift and sedimentation of the N Gondwana margin: new field, geochemical and geochronological data from the peri-Gondwanan Central Sakarya Terrane, Sakarya Zone, NW Turkey

ABSTRACT The timing and mechanism of the crustal extension that caused blocks of continental crust to rift and drift northwards from the northern Gondwana margin during the Early Palaeozoic are currently debated. Here, we present new field, geochemical and U-Pb zircon data from peri-Gondwanan Central Sakarya terrane in NW Turkey to shed light on the timing and petrogenesis of extensional magmatism and subsequent passive margin development of the northern Gondwana margin. Our 1/25.000 scale mapping of a selected area (250 km2) has revealed a south-vergent thrust stack comprising three slices. The Middle Slice of the thrust stack consists of a gneiss-amphibolite complex that has a basement-cover type stratigraphy (before regional metamorphism). The basement unit consists of meta-granitoids, intruded by meta-syenite and banded amphibolites, with geochemical characteristics reflecting I&S-type, A-type and within plate alkaline/transitional-type magmatism, respectively. The cover meta-clastic sediments have amphibolite lenses with MORB and back-arc basin-type geochemistry. Meta-granitoid bodies yielded zircon U-Pb ages of 507 ± 16 Ma, 503 ± 12 Ma, and 488 ± 2.6 Ma (Late Cambrian-Early Ordovician), whereas the meta-syenites gave ages of 473.9 ± 5.7 Ma and 471.4 ± 2.5 Ma (late Early Ordovician); also, age of the banded amphibolite was dated as 473.3 ± 4 Ma. The youngest detrital zircon population in the pebbly quartzite sample within cover meta-sediments (458 ± 3 Ma) constrains the maximum depositional age to around early Late Ordovician. The late Early Ordovician bimodal magmatism, a key focus of our study, is interpreted to have formed in response to the Rheic Ocean rifting along the northern margin of Gondwana. The Late Cambrian granitic magmatism, a precursor to bimodal magmatism, can be explained by lithospheric thinning and upwelling of the asthenosphere to form anatectic silicic melts. The unconformity between the basement and cover units may represent the initiation of a new phase of extension at the N Gondwana margin that culminated in the northward drifting of the Central Sakarya and the opening of Palaeotethys, associated with back-arc basic magmatism in Late Ordovician-Silurian.

Comprehensive study of the effect of Hf and Ta co-doped MCrAlY bond coat on the high-temperature properties of thermal barrier coating

The MCrAlY bond coat is modified by reactive element (RE) Hf and refractory element Ta, and the high-temperature oxidation resistance of the thermal barrier coating (TBC) before and after the modification are investigated by comparative experiments. The experiments use high-velocity oxygen-fuel (HVOF) to prepare NiCoCrAlY and NiCoCrAlYHfTa bond coats on the surface of GH4099 high-temperature alloy, and then yttrium stabilized zirconia (YSZ) ceramic layers are prepared on the surface of the bond coat by atmospheric plasma spraying (APS), and cyclic oxidation is carried out in air at 1050 °C until failure. It is shown that the oxidation lifetime of the modified TBC reached 1992 h, which is one time higher than that of the unmodified TBC. The doping of Hf and Ta elements reduces the growth rate of the oxide layer, and these diffuse externally and combine with the internally diffused O to form HfO2 and Ta2O5 in the thermally grown oxide (TGO) layer, thereby improving the adhesion and mechanical properties of the oxide layer. In addition, the bond strength and thermal shock resistance of the TBCs are significantly improved after doping with Hf and Ta elements, which prolongs the lifetimes of the TBCs. In this paper, the morphology, structure, and properties of the modified TBCs are characterized to investigate the mechanism of the oxidation lifetime extension.

Efficient property-oriented design of composite layups via controllable latent features using generative VAE

Fiber-reinforced composites provide substantial tailoring potential, while the extensive parameters and complex coupling mechanisms pose formidable challenges to layup designs. This paper presents an efficient inverse design framework for composite layups utilizing a variational autoencoder (VAE), which is applicable to non-conventional laminates. By leveraging the VAE's exceptional feature extraction and generative capabilities, the decoder rapidly produces layups with desired properties through controllable feature vectors. Based on the stacking characteristics of layups, multi-scale one-dimensional convolutions precisely extract sequence features relevant to mechanical properties and specific manufacturing constraints. A customized loss function is formulated to constrain the latent features, while addressing the non-uniqueness problem for layups with certain mechanical properties. The developed property-oriented VAE can generate 100,000 layups in seconds, achieving an average success rate of 66.9% under comprehensive in-plane and bending stiffness design, and remains effective for 100-ply thick laminate. For comparison, the VAE model outperforms the genetic algorithm and the logic-based method in reinforced panel designs, reducing the retrieval error by 46.4% and 38.1%, respectively. The proposed approach demonstrates flexible and efficient design advantages using generative machine learning models, and is easily extendable to other inverse design scenarios.

EDT demonstration for keeping low altitude orbit using carbon nanotube tether

This paper describes an electrodynamic tether system (EDT). Conductive tethers are used to overcome atmospheric resistance in low orbit and extend orbit life using EDT propulsion. First, based on the conceptual design, the feasibility of the EDT system has been evaluated through simulation. Especially, the induced electromotive force of the conductive tether has been clarified, the amount of current required to keep the orbital altitude, and the requirements for each device. Then, feasibilities of the key mission devices have been evaluated experimentally. Those are the conductive tether, the electron emission device, and the tether extension control mechanism. The conductive tether is planned to be made of carbon nanotubes, which are attracting attention as a new material, and its properties are evaluated. The electron-emitting device has been evaluated as a device that can be mounted on a micro/nano satellite. Tether extension mechanism was developed in our past project, then it should be evaluated with the purpose of adapting to conductive tether systems. Based on the evaluation, the orbital demonstration mission plan using a micro/nano satellite has been introduced. The mission is as follows. The conductive tether is extended and stabilized by the gravity gradient. By emitting electrons from an electron emitter mounted on a high-altitude satellite and collecting electrons on bare tether at low-altitude end, a current is generated from the high-altitude side to the low-altitude side. According to Fleming's law, the Lorentz force is generated in the direction of the orbiting accelerated, so it can be propelled in the upward direction of the orbit.

Study on the extension mechanism of fissures in expansive soil based on fracture mechanics test method

Expansive soil, characterized by widespread fissures, is a special type of soil prone to localized fissure propagation, leading to failure and instability, often resulting in landslides. Numerous studies have applied fracture mechanics theory to analyze soil failure along fissures, but no standardized testing method has been established. This paper reviews existing soil fracture toughness testing methods, designs an integrated system combining digital image correlation(DIC) technique and electrical resistance testing, and employs the Cracked Chevron-Notched Brazilian Disc (CCNBD) method to assess the fracture toughness of expansive soil. The deformation and internal damage accumulation processes of the specimens were monitored. The KΙc and KΙΙc of expansive soil were tested at moisture contents of 15 %, 20 %, and 25 % using specimens with three different crack length ratios (a/R). The role of water was explored by injecting water into the fissures. The results showed that KΙc of expansive soil ranged from 10 to 36 kPa·m0.5, with a linear negative correlation to moisture content and a proportional relationship to tensile strength, having a proportionality coefficient of 0.331. The KΙΙc ranged from 20 to 70 kPa·m0.5,and it is greater than KΙc under the same conditions. Based on the load, internal damage, strain, and fissure area during the tests, the failure process of expansive soil along fissures was divided into four stages: initial deformation stage(I), quasi-elastic deformation stage(II), fissure extension stage(III), and failure stage(IV). Water injection into the fissures reduced the soil's fracture toughness, with a more significant reduction as a/R increased and the failure showed progressive behavior. The CCNBD method, combined with DIC technique and electrical resistance testing, effectively measures the fracture toughness of soil, aiding in understanding the failure mechanism along fissures and providing a basis for preventing and controlling landslides and other hazards in expansive soils.

Damage and failure assessment of banana/ramie/epoxy composites using acoustic emission monitoring

In recent years, Composite materials that include natural fibers have played a significant role in aerospace, automotive industries, and other engineering applications. Due to its enhancing properties, the usage of composites has owing to an increase in day-to-day life. This research aims to develop a sustainable alternative material pronounced for environmental sustainability for surpassing synthetic fibers. Therefore, real-time monitoring and detection of the damage mechanisms in natural fiber composites are indispensable. In this regard, the acoustic emission (AE) technique lends itself to identifying the microscopic damage mechanisms in composite materials. Compression tests were performed in banana/ramie/epoxy composite specimens, and following consequences, the AE parameters (frequency, amplitude, counts, duration, energy rise time, etc.) were recorded. The novelty of this article is to detect the damage evolution and failure mechanisms of banana/ramie/epoxy composites under quasi-static compression with AE signal analysis for the first time. Findings showed that the stacking of hybrid reinforcing banana and ramie fiber improves the stress distribution, leading to enhanced load-carrying capacity (30.56 %), energy absorption (26.78 %), and stiffness (35.24 the compressive strength reached the maximum strength of the banana/ramie/epoxy composites%).This increase represents a substantial 30 % increase in AE energy absorption prior to failure, suggesting that the composite specimens experienced significant damage or extensive failure mechanisms Further, the AE parameters also showed that the AE energy under compression is relatively low and that frequency disperses between 70 and 150 kHz.

Degree of Crystal Structure Distortion-Induced Tunable LiGaO2 Long Persistent Luminescence for Optical Information Encryption.

Tunable long persistent luminescence (LPL) phosphor materials have great potential for optoelectronic cryptographic applications. However, the mainstream techniques of modulating LPL generally have the characteristics of complex preparation processes, demanding crystal field environments, or expensive dopant ions, which restrict large-scale commercial application. Herein, we develop a simple, high-efficiency, and low-cost strategy to optimize the LPL of LiGaO2(LGO):Cu2+ by changing the sintering time to regulate the degree of crystal structure distortion. The Cu2+ as charge compensation will substantially enhance the emission intensity of LGO by a factor of 11.02 originating from the appropriate ionic size and coordination mode. Besides, the LPL time of LGO:Cu2+ can be extended effectively to 2 h by adjusting the sintering temperature and time (900 °C@24 h). The extension mechanism is that Li and Ga can be substituted for each other more easily and induce crystal structure distortion due to the special crystal structure of LGO, resulting in an optimal trap concentration in LGO:Cu2+. Thus, our findings provide a simple way to modulate long persistent luminescence and further consider their potential impact on optical information encryption.

Mechanism of Fatigue-Life Extension Due to Dynamic Strain Aging in Low-Carbon Steel at High Temperature.

An enhancement in fatigue life for ferrite-pearlite low-carbon steel (LCS) at high temperature (HT) has been discovered, where it increased from 190,873 cycles at room temperature (RT) to 10,000,000 cycles at 400 °C under the same stress conditions. To understand the mechanism behind this phenomenon, the evolution of microstructure and dislocation density during fatigue tests was comprehensively investigated. High-power X-ray diffraction (XRD) was employed to analyze the evolution of total dislocation density, while Electron Backscatter Diffraction (EBSD) and High-Resolution EBSD (HR-EBSD) were conducted to reveal the evolutions of kernel average misorientation (KAM), geometrically necessary dislocations (GND) and elastic strains. Results indicate that the enhancement was attributed to the dynamic strain aging (DSA) effect above the upper temperature limit, where serration and jerky flow disappeared but hindrance of dislocations persisted. Due to the DSA effect, periods of increase and decrease in the total dislocations were observed during HT fatigue tests, and the fraction of screw dislocations increased continuously, caused by viscous movement of the screw dislocations. Furthermore, the increased fraction of screw dislocations resulted in a lower energy configuration, reducing slip traces on sample surfaces and preventing fatigue-crack initiation.

Dynamic Fault Tree Generation and Quantitative Analysis of System Reliability for Embedded Systems Based on SysML Models.

As embedded systems become increasingly complex, traditional reliability analysis methods based on text alone are no longer adequate for meeting the requirements of rapid and accurate quantitative analysis of system reliability. This article proposes a method for automatically generating and quantitatively analyzing dynamic fault trees based on an improved system model with consideration for temporal characteristics and redundancy. Firstly, an "anti-semantic" approach is employed to automatically explore the generation of fault modes and effects analysis (FMEA) from SysML models. The evaluation results are used to promptly modify the system design to meet requirements. Secondly, the Profile extension mechanism is used to expand the SysML block definition diagram, enabling it to describe fault semantics. This is combined with SysML activity diagrams to generate dynamic fault trees using traversal algorithms. Subsequently, parametric diagrams are employed to represent the operational rules of logic gates in the fault tree. The quantitative analysis of dynamic fault trees based on probabilistic models is conducted within the internal block diagram of SysML. Finally, through the design and simulation of the power battery management system, the failure probability of the top event was obtained to be 0.11981. This verifies that the design of the battery management system meets safety requirements and demonstrates the feasibility of the method.

CT imaging‐enhanced numerical simulation of microscopic structure and resilient safety of asphalt concrete

AbstractAsphalt concrete is a foundational material in water conservancy projects, serving a critical function in the construction of impermeable structures such as dams. The seismic response characteristics and resilient safety of concrete dams are heavily influenced by the arrangement and evolution of the microscopic structure of the dam material. In this study, a high‐precision computed tomography (CT) scanning technique, in conjunction with advanced numerical simulations, was employed to analyze the internal damage and crack extension mechanism of asphalt concrete. Microstructural images of the asphalt concrete specimen were accurately captured by CT scanning, followed by the construction of corresponding numerical models. Presented simulation results show that the displacement deformation of asphalt concrete reaches its maximum value in the top region of the model and subsequently decreases with depth. Material damage was first observed at the interface between aggregate and asphalt matrix, where microcracks emerge and extend to the entire asphalt matrix, resulting in a gradual deterioration of the model performance. The simulation results indicate that the overall strength of asphalt concrete is primarily influenced by the strength characteristics of its aggregates. The stress–strain curves obtained from the numerical simulations exhibit a hyperbolic relationship, which is in high agreement with the physical test results. This study not only enhances our comprehension of the mechanical behavior of concrete but also contributes to the analysis of seismic response and risk assessment in dam engineering through dynamic experimental testing and numerical simulation.

Multidisciplinary Reliability Design Optimization Modeling Based on SysML

Model-Based Systems Engineering (MBSE) supports the system-level design of complex products effectively. Currently, system design and optimization for complex products are two distinct processes that must be executed using different software or platforms, involving intricate data conversion processes. Applying multidisciplinary optimization to validate system optimization often necessitates remodeling the optimization objects, which is time-consuming, labor-intensive, and highly error-prone. A critical activity in systems engineering is identifying the optimal design solution for the entire system. Multidisciplinary Design Optimization (MDO) and reliability analysis are essential methods for achieving this. This paper proposes a SysML-based multidisciplinary reliability design optimization modeling method. First, by analyzing the definitions and mathematical models of multidisciplinary reliability design optimization, the SysML extension mechanism is employed to represent the optimization model based on SysML. Next, model transformation techniques are used to convert the SysML optimization model generated in the first stage into an XML description model readable by optimization solvers. Finally, the proposed method’s effectiveness is validated through an engineering case study of an in-vehicle environmental control integration system. The results demonstrate that this method fully utilizes SysML to express MDO problems, enhancing the efficiency of design optimization for complex systems. Engineers and system designers working on complex, multidisciplinary projects can particularly benefit from these advancements, as they simplify the integration of design and optimization processes, facilitating more reliable and efficient product development.

The Potential of Composite Cements for Wound Healing in Rats.

Recent developments in biomaterials have resulted in the creation of cement composites with potential wound treatment properties, even though they are currently mainly employed for bone regeneration. Their ability to improve skin restoration after surgery is worth noting. The main purpose of this research is to evaluate the ability of composite cement to promote wound healing in a rat experimental model. Full-thickness 5 mm skin defects were created, and the biomaterials were applied as wound dressings. The hybrid light-cured cement composites possess an organic matrix (Bis-GMA, TEGDMA, UDMA, and HEMA) and an inorganic phase (bioglasses, silica, and hydroxyapatite). The organic phase also contains γ-methacryloxypropyl-trimethoxysilane, which is produced by distributing bioactive silanized inorganic filler particles. The repair of the defect is assessed using a selection of macroscopic and microscopic protocols, including wound closure rate, histopathological analysis, cytotoxicity, and biocompatibility. Both composites exerted a favorable influence on cells, although the C1 product demonstrated a more extensive healing mechanism. Histological examination of the kidney and liver tissues revealed no evidence of toxicity. There were no notable negative outcomes in the treated groups, demonstrating the biocompatibility and efficacy of these bioproducts. By day 15, the skin of both groups had healed completely. This research introduces a pioneering strategy by utilizing composite cements, traditionally used in dentistry, in the context of skin wound healing.