Search Results (7,771)

Efficient simplification of 3D models is essential for mobile and other resource-constrained application scenarios. Industrial 3D assemblies, typically composed of numerous components and dense triangular meshes, often pose significant challenges in rendering and transmission due to their large scale and high complexity. The Quadric Error Metrics (QEM) algorithm offers a practical balance between simplification accuracy and computational efficiency. However, its application to large-scale industrial models remain limited by performance bottlenecks, especially when combined with curvature-based optimization techniques that improve fidelity at the cost of increased computation. Therefore, this paper presents a parallel implementation of the QEM algorithm and its curvature-optimized variant using the OpenMP framework. By identifying key bottlenecks in the serial workflow, this research parallelizes critical processes such as curvature estimation, error metric computation, and data structure manipulation. Experiments on large industrial assembly models at a simplification ratio of 0.3, 0.5, and 0.7 demonstrate that the proposed parallel algorithms achieve significant speedups, with a maximum observed speedup of 5.5×, while maintaining geometric quality and topological consistency. The proposed approach significantly improves model processing efficiency, particularly for medium- to large-scale industrial models, and provides a scalable and practical solution for real-time loading and interaction in engineering applications. Full article

The floating oil seal (FOS) is a critical component in coal mining machinery, where frictional wear and high stress on the O-ring can lead to oil leakage and eventual FOS failure, significantly impairing equipment performance. To address this issue, this study proposes a novel ceramic-coated floating oil seal (NCCFOS) composite structure that enhances wear resistance without modifying the existing sealing cavity configuration. A two-dimensional axisymmetric finite element model of the NCCFOS was developed based on the Mooney–Rivlin constitutive model, considering the O-ring assembly process for improved accuracy. The model was analyzed under oil pressure loading, with parametric studies examining the influence of oil pressure, assembly clearance, and material hardness on O-ring stress, contact pressure, and frictional stress distribution in the floating seal ring. The results demonstrate that accounting for the assembly process yielded more realistic stress predictions compared to conventional modeling approaches. The NCCFOS design effectively mitigated stress concentrations, reduced O-ring wear, and extended fatigue life, offering a practical solution for enhancing the reliability of coal mining machinery seals. Full article

Cell-mediated extracellular matrix (ECM) self-assembly provides a biologically relevant approach for developing near-physiological tissue-engineered constructs by utilizing stromal cells to secrete and assemble ECM components in the presence of ascorbic acid. Despite its unique advantages, this method often results in scaffolds with limited mechanical properties, depending on the cell type. This research aimed to enhance the mechanical properties of these constructs by culturing cells derived from various sources, including skin, bladder, urethra, vagina, and adipose tissue, on electrospun scaffolds composed of polycaprolactone and collagen (PCLCOL). The hybrid scaffolds were evaluated using various in vitro assays to assess their structural and functional properties. Results showed that different stromal cells could deposit ECM on the PCLCOL with distinct composition compared to the ECM that was self-assembled on tissue culture plates (TCP). Additionally, cells cultured on PCLCOL exhibited a different growth factor secretion profile compared to those on TCP. Mechanical testing demonstrated that the hybrid scaffolds exhibited high mechanical properties and superior manipulability. These findings suggest that PCLCOL could be a promising platform for developing biomimetic scaffolds that combine enhanced mechanical strength with integrated biological cues for tissue repair. Full article

β-Hydroxy-β-methylbutyrate (HMB), a natural metabolite derived from the essential amino acid leucine, is primarily recognised for its anabolic and anti-catabolic effects on skeletal muscle tissue. Recent studies indicate that HMB may also play a role in influencing the structural organisation of extracellular matrix (ECM) components, particularly collagen, which is crucial for maintaining the mechanical integrity of connective tissues. In this investigation, bovine type I collagen was polymerised in the presence of two concentrations of HMB (0.025 M and 0.25 M) to explore its potential function as a molecular modulator of fibrillogenesis. The morphology of the resulting collagen fibres and their molecular architecture were examined using atomic force microscopy (AFM) and Fourier-transform infrared (FTIR) spectroscopy. The findings demonstrated that lower levels of HMB facilitated the formation of more regular and well-organised fibrillar structures, exhibiting increased D-band periodicity and enhanced stabilisation of the native collagen triple helix, as indicated by Amide I and III band profiles. Conversely, higher concentrations of HMB led to significant disruption of fibril morphology and alterations in secondary structure, suggesting that HMB interferes with the self-assembly of collagen monomers. These structural changes are consistent with a non-covalent influence on interchain interactions and fibril organisation, to which hydrogen bonding and short-range electrostatics may contribute. Collectively, the results highlight the potential of HMB as a small-molecule regulator for soft-tissue matrix engineering, extending its consideration beyond metabolic supplementation towards controllable, materials-oriented modulation of ECM structure. Full article

The paper presents an innovative theoretical concept of a bio-inspired soft gripper system with two parallel jaws, a fixed and a mobile one. It is conceived for gripping fragile or soft objects with complex, irregular shapes that are easily deformable. This novel gripper is designed for handling small objects of masses up to 0.5 kg. The maximum gripping stroke of the mobile jaw is 13.5 mm. The driving motor is a pneumatic muscle, an actuator with inherently compliant, spring-like behavior. Compliance is the feature responsible for the soft character of the gripper system, ensuring its passive adaptability to the nature of the object to be gripped. The paper presents the structural, kinematic, static, and dynamic models of the novel gripper system and describes the compliant behavior of the entire assembly. The results of the dynamic simulation of the gripper have confirmed the attaining of the imposed motion-related performance. Full article

Shell-like housing structures for motors and compressors can be found in everyday products. Consumers significantly evaluate acoustic emissions during the first usage of products. Unpleasant sounds may raise concerns and cause complaints to be issued. A prevention strategy is a holistic acoustic design, which includes predicting the emitted sound power as part of end-of-line testing. The hybrid experimental-simulative sound power prediction based on laser scanning vibrometry (LSV) is ideal in acoustically harsh production environments. However, conducting vibroacoustic testing with laser scanning vibrometry is time-consuming, making it difficult to fit into the production cycle time. This contribution discusses how the time-consuming sampling process can be accelerated to estimate the radiated sound power, utilizing adaptive sampling. The goal is to predict the acoustic signature and its uncertainty from surface velocity data in seconds. Fulfilling this goal will enable integration into a product assembly unit and final acoustic quality control without the need for an acoustic chamber. The Gaussian process regression based on PyTorch 2.6.0 performed 60 times faster than the preliminary reference implementation, resulting in a regression estimation time of approximately one second for each frequency bin. In combination with the Equivalent Radiated Power prediction of the sound power, a statistical measure is available, indicating how the uncertainty of a limited number of surface velocity measurement points leads to predictions of the uncertainty inside the acoustical signal. An adaptive sampling algorithm reduces the prediction uncertainty in real-time during measurement. The method enables on-the-fly error analysis in production, assessing the risk of violating agreed-upon acoustic sound power thresholds, and thus provides valuable feedback to the product design units. Full article

With the continuous improvement of the prefabricated modular technology system, the prefabricated subway station structures are widely used in underground engineering projects. However, prefabricated subway stations in soft soil can suffer significant adverse effects under seismic action. In order to study the seismic performance of a prefabricated subway station, this work is based on an actual project of a subway station in soft soil. And the nonlinear static and dynamic coupling two-dimensional finite element models of cast-in-place structures (CIPs), assembly splicing structures (ASSs), and assembly monolithic structures (AMSs) are established, respectively. The soil-structure interaction is considered, and different peak ground accelerations (PGA) are selected for incremental dynamic analysis. The displacement response, internal force characteristics, and structural damage distribution for three structural forms are compared. The research results show that the inter-story displacement of the AMS is slightly greater than that of the CIP, while the inter-story displacement of the ASS is the largest. The CIP has the highest internal force in the middle column, the ASS has the lowest internal force in the middle column, and the AMS is between the two. The damage to the CIP is concentrated at the bottom of the middle column and sidewall. The AMS compression damage moves upward, but the tensile damage mode is similar to the CIP. The ASS can effectively reduce damage to the middle column and achieve redistribution of internal force. Further analysis shows that the joint splicing interface between cast-in-place and prefabricated components is the key to controlling the overall deformation and seismic performance of the structure. The research results can provide a theoretical basis for the seismic design optimization of subway stations in earthquake-prone areas. Full article

Karyotype analysis and the investigation of chromosomal variations in Populus are challenging due to its small and morphologically similar chromosomes. Despite its utility in chromosome identification and karyotype evolutionary research, satellite DNA (satDNA) remains underutilized in Populus. In the present study, 12 satDNAs were identified from P. trichocarpa, and the copy numbers and chromosomal distributions of each satDNA were analyzed bioinformatically in the reference genomes of P. trichocarpa, P. simonii, and P. nigra. Ten satDNA probes for fluorescence in situ hybridization (FISH) were successfully developed and validated on chromosomes of P. xiaohei (poplar hybrid P. simonii × P. nigra). By integrating bioinformatic genomic satDNA distribution patterns with experimental FISH signals, we constructed a molecular karyotype of P. xiaohei. Comparative analysis revealed errors in current poplar genome assemblies. Comparative karyotype analysis of P. xiaohei and its doubled haploid (DH) lines revealed chromosomal variations in the DH lines relative to the donor tree. The results demonstrate that the newly developed satDNA probes constitute robust cytogenetic tools for detecting structural variations in Populus, while molecular karyotyping provides new insights into the genetic mechanisms underlying chromosome variations in P. xiaohei and the DH plants derived. Full article

Elucidating amyloid formation inside biomolecular condensates requires models that resolve (i) local, chemistry specific contacts controlling β registry and (ii) mesoscale phase behavior and cluster coalescence on microsecond timescales—capabilities beyond single resolution models. We present a hybrid united atom/coarse grained (UA–CG) force field coupling a PACE UA peptide model with the MARTINI CG framework. Cross resolution nonbonded parameters are first optimized against all atom side chain potentials of mean force to balance the relative strength between different types of interactions and then refined through universal parameter scaling by matching radius of gyration distributions for specific systems using. We applied this approach to simulate a recently reported model system comprising the LVFFAR₉ peptide that can co-assemble into amyloid fibrils via liquid–liquid phase separation. Our ten-microsecond simulations reveal rapid droplet formation populated by micelle like nanostructures with its inner core composed of LVFF clusters. The nanostructures can further fuse but the fusion is reaction-limited due to an electrostatic coalescence barrier. β structures emerge once clusters exceed ~10 peptides, and the LVFFAR₉ fraction modulates amyloid polymorphism, reversing parallel versus antiparallel registry at lower LVFFAR₉. These detailed insights generated from long simulations highlight the promise of our hybrid UA–CG strategy in investigating the molecular mechanism of condensate aging. Full article

Timber structures and structural members have undergone rapid development in recent decades and are now fully competitive with traditional structures made of reinforced concrete or structural steel in many areas. Low self-weight, high durability, rapid construction assembly, and a favourable environmental footprint predispose timber structures for wider future use. A persisting drawback is the often-complicated joining of individual elements, especially when moment resistance is required. For CLT panels, this issue is more urgent due to their relatively small thickness and cross-laminated lay-up. This paper presents experimental research investigating parameters related to the actual behaviour of a moment-resisting embedded joint of CLT panels. The test programme consisted of four series (12 specimens) loaded in four-point bending to failure. The proposed and tested joint consists of high-strength steel rods glued into the two connected parts of the CLT panel. In addition to a detailed investigation of the resistance and stiffness of the joint, this research evaluates the effect of composite action with a reinforced-concrete slab on the performance of this type of joint. The experimental results and their detailed analysis are also extended to propose a framework concept for creating a theoretical (mechanical) model based on the component method. Full article

The microhylid frog Microhyla fissipes is a protected terrestrial wildlife species in China, recognized for its ecological, economic, and scientific value. However, its mitochondrial genome remains poorly characterized. To address this gap, we sequenced and annotated the complete mitogenome of M. fissipes to elucidate its structural organization and phylogenetic placement within Microhylidae. The assembled mitogenome is 16,723 bp in length and contains 37 genes, including 13 protein-coding genes, 2 rRNAs, and 22 tRNAs, along with one control region and the origin of heavy-strand replication. We also identified eight overlapping regions and eleven intergenic spacers. The overall base composition showed an A + T bias (59.91%) with negative AT-skew (−0.04) and GC-skew (−0.27). All tRNAs displayed typical cloverleaf secondary structures, except for trnS1, which lacked the D-arm. Phylogenetic reconstruction using both maximum likelihood and Bayesian inference strongly supported the monophyly of Microhylidae and revealed a sister-group relationship between Microhyla and Kaloula. Within Microhyla, M. fissipes was most closely related to M. heymonsi, with which it formed a well-supported clade that also included Microhyla okinavensis, Microhyla mixtura, and Microhyla beilunensis. Selection pressure analysis on protein-coding genes indicated widespread purifying selection (Ka/Ks < 1) across most genes, except for ATP8, COX2, and COX3, which may be under relaxed selective constraints. These findings offer valuable genomic resources for the conservation of M. fissipes and provide new insights into the phylogeny and evolution of microhylid frogs. Full article

This paper presents a novel mechanically beam-steered antenna system for 10 GHz applications, enabled by multi-material 3D-printing technology. The proposed design eliminates the need for complex electronic circuitry by integrating a mechanically rotatable, 3D-printed hemispherical lens with a conventional rectangular patch antenna. The system comprises three main components: a 10-GHz patch antenna, a precision-fabricated hemispherical dielectric lens produced via stereolithography (SLA), and a structurally robust rotation assembly fabricated using fused deposition modeling (FDM). The mechanical rotation of the lens enables discrete beam-steering from −45° to +45° in 5° steps. Experimental results demonstrate a gain improvement from 6.21 dBi (standalone patch) to 10.47 dBi with the integrated lens, with minimal degradation across steering angles (down to 9.59 dBi). Simulations and measurements show strong agreement, with the complete system achieving 94% accuracy in beam direction. This work confirms the feasibility of integrating additive manufacturing with passive beam-steering structures to deliver a low-cost, scalable, and high-performance alternative to electronically scanned arrays. Moreover, the design is readily adaptable for motorized actuation and closed-loop control via embedded systems, enabling future development of real-time, programmable beam-steering platforms. Full article

The global transition to a circular bioeconomy is accelerating the demand for sustainable, high-performance materials. Filamentous fungi represent a promising solution, as they function as living foundries that transform low-value biomass into advanced, self-assembling materials. While mycelium-based composites have proven potential, progress has been predominantly driven by empirical screening of fungal species and substrates. To unlock their full potential, a paradigm shift from empirical screening to rational design is required. This review introduces a conceptual framework centered on the biochemical programming of the fungal cell wall. Viewed through a materials science lens, the cell wall is a dynamic, hierarchical nanocomposite whose properties can be deliberately tuned. We analyze the contributions of its principal components—the chitin–glucan structural scaffold, the glycoprotein functional matrix, and surface-active hydrophobins—to the bulk characteristics of mycelium-derived materials. We then identify biochemical levers for controlling these properties. External factors such as substrate composition and environmental cues (e.g., pH) modulate cell wall architecture through conserved signaling pathways. Complementing these, an internal synthetic biology toolkit enables direct genetic and chemical intervention. Strategies include targeted engineering of biosynthetic and regulatory genes (e.g., CHS, AGS, GCN5), chemical genetics to dynamically adjust synthesis during growth, and modification of surface chemistry for specialized applications like tissue engineering. By integrating fungal cell wall biochemistry, materials science, and synthetic biology, this framework moves the field from incidental discovery toward the intentional creation of smart, functional, and sustainable mycelium-based materials—aligning material innovation with the imperatives of the circular bioeconomy. Full article

Polymeric vesicles, characterized by enhanced colloidal stability, excellent mechanical properties, controllable surface functionality, and adjustable membrane thickness, are extremely useful in nano- and bio-technology for potential applications as nanosized carriers for drugs and enzymes. However, a few preparative steps are necessary to achieve a unilamellar vesicle with a narrow size distribution. Herein, we report the spontaneous formation of unilamellar polymeric vesicles with nanometer sizes (<50 nm), fabricated by simply mixing diblock copolymers (P(EO-AGE)(2K-2K) and P(EO-AGE)(0.75K-2K)) with differing hydrophilic mass fractions in aqueous solutions. Depending on the mixing ratio of block copolymers and the temperature, the block copolymer mixtures self-assemble into various nanostructures, such as spherical and cylindrical micelles, or vesicles. The self-assembled structures of the block copolymer mixtures were characterized by small-angle neutron scattering, resulting in a phase diagram drawn as a function of temperature and the mixing condition. Notably, the critical temperature for the micelle-to-vesicle phase transition can be easily controlled by altering the mixing conditions; it decreases with an increase in the concentration of one of the block copolymers. Full article

Ensete ventricosum is a morphologically gigantic, monocot, diploid sister to the banana plant species. It is commercially cultivated as a starch source, only in Ethiopia, where it feeds twenty million people. Here, the complete chloroplast (CP) genomes of 15 diverse landraces of E. ventricosum were assembled and annotated, for comparative genomics, genetic diversity analysis, and molecular marker development. The assembled E. ventricosum CP genomes ranged between 168,388 and 168,806 bp. The sampled CP genomes were quadripartite in structure and had two single-copy regions, a large single-copy region (LSC, average length 88,657 bp), and a small single-copy region (SSC, average length 11,098 bp) separated by inverted repeat regions (IR, average length 34,437 bp). The total number of annotated genes varies between 135 and 138, including 89–92 protein-coding genes, 38 tRNA genes, and 4 rRNA genes. All CP genes, including non-functional ones and intergenic regions, were transcribed with the transcriptome, covering almost 92% of the E. ventricosum CP genome. Codon usage, amino acid frequency, GC contents, and repeat nucleotides were similar among the 15 landraces. Mono- and tetranucleotide simple sequence repeats (SSRs) were found more frequently than other SSRs. An average of 71% of these SSRs were located in the LSC region, and the majority of the SSR motifs were composed of A/T nucleotides. A phylogenetic analysis of the 15 Ensete landraces indicated a common evolutionary origin, while the China sample was positioned separately, suggesting notable genetic differences. This study presents a comparative analysis of the chloroplast genomes of 15 E. ventricosum landraces, providing valuable insights into their genetic diversity and evolution. The identified SSR markers and conserved genomic features offer essential resources for future research and an improvement in Ensete conservation and breeding. Full article