Search Results (128)

The study reconsiders the architectural production associated with Russian Suprematism (which was speaking of “the supremacy of pure artistic sensation” rather than the veritable figurative depiction of real-life subjects) in the early Soviet period as a coherent and conceptually rigorous mode of speculative world-making rather than as a marginal or unrealized appendix to avant-garde art history and theory. By examining the architectural propositions articulated by Kazimir Malevich and then elaborated by his younger colleagues Lazar Khidekel, Ilya Chashnik, and Nikolai Suetin, the study advances the claim that Russian Suprematist architecture constituted an epistemic experiment aimed at redefining the very ontological premises of architecture. Far from functioning as a mere transposition of abstract pictorial language into three-dimensional form, Suprematist planits, architectons, and aerocentric projects operated as instruments for thinking spatiality beyond terrestrial gravity, anthropocentric utility, and historical typology. Situating these projects within the intellectual horizon of Russian cosmism and early aerospace thought, the article demonstrates how Suprematist architecture intersected with contemporary philosophical, scientific, and technological discourses that envisioned humanity’s active participation in the reorganization of cosmic space. The architectural imagination of Suprematism emerges here as inseparable from broader debates on excitation, non-objectivity, transformation of matter, and the reconfiguration of human corporeality. Through close analysis of formal strategies, pedagogical frameworks, and theoretical writings, the paper reveals the internal plurality of avant-garde Suprematist architectural inquiry, ranging from ecological proto-urbanism and hovering settlements to magnetic and cruciform spatial systems. Ultimately, the paper argues that the historical non-realization of these projects should not be interpreted as a failure but as an intrinsic feature of their speculative methodology. Suprematist architecture is thus redefined as an anticipatory practice whose unresolved propositions continue to resonate with contemporary discussions on space habitation, planetary design, ecological responsibility, and post-human architectural thought, challenging inherited assumptions about the scope and function of architecture as such. Full article

Longitudinal shuttle-shaped concrete-filled steel column with cruciform sections (LSS-CFST-CS) is highly valued by architects and structural engineers for its distinctive appearance and significant architectural impact in spatial steel structures. However, there are currently no available studies addressing the buckling behavior, load-carrying capacity, and strength design methods of such structures. This study numerically investigates the elastic buckling behavior, load-carrying capacity, and design methods of LSS-CFST-CS under axial compression, as well as under combined axial compression and bending moment. First, closed-form solutions for the elastic buckling load under axial compression are derived for a pinned–pinned tapered concrete-filled steel column (TCFST) with cruciform sections and standard LSS-CFST-CS, respectively. The resulting solutions are validated against finite element (FE) numerical results from a wide range of LSS-CFST-CS examples, and the corresponding buckling modes are examined. Next, a unified expression for the elastic buckling load under axial compression is established for both types of TCFST and standard LSS-CFST-CS. Finally, a parametric study incorporating initial geometric imperfections is conducted to investigate the load-carrying capacity of LSS-CFST-CS and to quantify the influence of key parameters on stability capacity. On this basis, design recommendations for the stability capacity are proposed for axial compression and combined axial compression and bending moment of LSS-CFST-CS, respectively. Full article

This study presents a hybrid experimental–numerical methodology for the preliminary design and optimization of a CFRP crash box intended for high-performance automotive applications. An initial experimental campaign was conducted on frustum-shaped crash boxes manufactured by Pagani Automobili S.p.A., comparing constant and variable thickness configurations through drop tower impact tests to evaluate energy absorption, crushing stability, and failure mechanisms. A lightweight finite element model was developed in Abaqus/Explicit using shell elements and Hashin-based damage criteria, achieving calibration errors below 10% for most parameters and under 15% for peak forces. Geometric enhancements, including continuous flanges, removal of the top surface, and an internal cruciform reinforcement, significantly improved energy absorption (up to 110%) but introduced trade-offs in stroke efficiency and mean force levels. To mitigate these effects, a genetic algorithm was employed to optimize laminate layup by varying ply orientations, resulting in improved stroke efficiency and reduced peak and average forces while maintaining crushing stability. The proposed approach demonstrates that integrating experimental validation with efficient numerical modeling and optimization accelerates the development of lightweight, high-performance crash absorbers, offering a robust framework for motorsport and automotive applications that balances safety, efficiency, and manufacturability. Full article

The performance upgrading of stratospheric airships hinges on breakthroughs in the mechanical properties of envelope materials. As a multi-layer composite, the envelope’s load-bearing layer exhibits orthotropic and nonlinear mechanical behaviors owing to its unique structure and manufacturing process. To overcome the limitations of traditional testing methods and classical strength criteria in characterizing envelope materials, this paper presents a systematic investigation of typical airship envelope materials. The classical cruciform biaxial specimen was modified with a double-layer heat-sealed loading arm design to ensure preferential failure of the core region. Combined with digital image correlation (DIC) equipment, tensile tests were conducted under seven warp–weft stress ratios to acquire full-range stress–strain data. A three-dimensional stress–strain response surface was fitted based on the experimental results, and biaxial tensile constitutive models with varying precisions were established. Furthermore, a five-parameter implicit quadratic strength criterion was adopted to characterize the failure envelope of the envelope material. The model was calibrated using five biaxial failure points and independently validated against uniaxial tensile strengths, achieving a prediction error of less than 4%. The criterion’s generalization capability was enhanced through systematic parameterization based on the present test data. This work provides experimental evidence and reliable support for the engineering design and strength prediction of envelope materials. Full article

To address the technical bottlenecks commonly encountered with real-time quantitative PCR instruments, such as insufficient ramp rates and uneven chamber temperature distribution, this study proposes an innovative design scheme for a temperature control system that incorporates key hot air circulation and temperature field regulation technologies. By combining the PCR instruments’ working principles and structural characteristics, the failure mechanisms associated with the temperature control system are systematically analyzed, and a reliability-oriented thermodynamic analysis model is constructed to clarify the functional positioning of core components and to systematically test the airflow uniformity, temperature dynamics, and nucleic acid amplification efficiency. An integrated fixture for airflow rectifier and cruciform frames is designed, which enables precise quantitative characterization of the system temperature uniformity, ramp rates, and amplification efficiency on a multi-condition comparison platform. Through modeling analysis combined with experimental validation, the thermal performance differences among various heating chamber structures are compared, leading to a multidimensional optimization of the temperature control system. The test results demonstrate outstanding core performance metrics for the optimized system: the up ramp reaches 7.5 ± 0.1 °C/s, the down ramp reaches 13.5 ± 0.1 °C/s, and the steady-state temperature deviation is only ±0.1 °C. The total duration for 35 PCR cycles is recorded at 16.3 ± 0.6 min, with a nucleic acid amplification efficiency of 98.9 ± 0.2%. The core performance metrics comprehensively surpass those of mainstream global counterparts. The developed temperature control system is well-suited for practical applications such as rapid detection, providing critical technological support for the iterative upgrade of nucleic acid amplification techniques while laying a solid foundation for the engineering development of high-performance PCR instruments. Full article

To improve the computational efficiency of complex fatigue assessments, this study proposes a framework that integrates high-fidelity finite element analysis (FEA)with ensemble learning for evaluating the fatigue performance of weathering steel welded joints. First, a three-dimensional crack propagation model for cruciform fillet welds was developed on the ABAQUS-FRANC3D platform, with a validation error of less than 20%. Subsequently, a large-scale parametric analysis was conducted. The results indicate that as the stress amplitude increases from 67.5 MPa to 99 MPa, the fatigue life decreases to 40.29% of the baseline value. When the stress amplitude reaches 180 MPa, the fatigue life drops sharply to 14.28% of the baseline. Within the stress ratio range of 0.1 to 0.7, increasing the initial crack size from 0.075 mm to 0.5 mm reduces the fatigue life to between 85.78% and 86.48% of the baseline. Edge cracks, influenced by stress concentration, exhibit approximately 15.2% shorter fatigue life compared to central cracks, while the maximum variation in fatigue life due to crack geometry is only 10.25%. Second, an Extremely Randomized Trees surrogate model constructed based on the simulation data demonstrates excellent performance. Finally, by integrating this model with Paris’s law, the developed prediction framework achieves high consistency with numerical simulation results, with all predicted values falling within the two-standard-deviation interval. This data-driven approach can effectively replace computationally intensive finite element analysis, enabling efficient structural safety assessments. Full article

In-plane shear is the dominant deformation mode during thermoforming of fiber-reinforced composites, and accurate characterization of shear behavior is essential for reliable forming simulations. The present work investigates the shear response of a unidirectional cross-ply UHMWPE material system (DSM Dyneema^® HB210) using the picture-frame test, with emphasis on sample configuration, normalization methods, and shear rate effects. Three cruciform sample sizes were tested at 120 °C, along with a configuration in which cross-arm material was removed to isolate the gage region. Finite element analyses using LS-DYNA^® were performed to evaluate the shear rate distribution during forming and to validate the experimental characterization. To maintain a constant shear rate during testing, a decreasing crosshead speed profile was implemented in the test software. Results showed that normalizing by the full specimen area yielded consistent shear stiffness curves across sample sizes, indicating that the arm region contributes equally to the load. Samples with cross-arm material removed exhibited greater scatter than those specimens without cross-arm material removed, confirming that preparation of cross-arm removal complicates repeatability. Rate dependence was observed at room temperature but not at elevated processing temperatures, suggesting that rate-dependent shear models are unnecessary for forming simulations of this material system. These findings provide a practical methodology for shear characterization of UHMWPE cross-ply laminates suitable for thermoforming analyses. Full article

Soft robotics represents a rapidly advancing and significant subfield within modern robotics. However, existing soft actuators often face challenges including unwanted deformation modes, limited functional diversity, and a lack of versatility. This paper presents a four-chamber multimodal soft actuator with a centrally symmetric layout and independent pneumatic control. While building on existing multi-chamber concepts, the design incorporates a cruciform constraint layer and inter-chamber gaps to improve directional bending and reduce passive chamber deformation. An empirical model based on the vector superposition of single- and dual-chamber inflations is developed to describe the bending behavior. Experimental results show that the actuator can achieve omnidirectional bending with errors below 5% compared to model predictions. To demonstrate versatility, the actuator is implemented in two distinct applications: a three-finger soft gripper that can grasp objects of various shapes and perform in-hand twisting maneuvers, and a steerable crawling robot that mimics inchworm locomotion. These results highlight the actuator’s potential as a reusable and adaptable driving unit for diverse soft robotic tasks. Full article

Isolating the mechanical properties of an FDM joint by performing a direct tensile test on it is something that has yet to be achieved. Developing a methodology for isolating the properties of a single joint could help to inform simulations and achieve a better understanding of the mechanisms affecting the bond strength between FDM-printed materials. In this work, a cruciform single-joint test (CSJT) of a cross-shaped specimen and a fast mechanical clamping protocol are introduced to evaluate the apparent tensile strength and fracture mechanisms of a single FDM-printed joint between two PLA filaments. First, a discussion of different approaches for obtaining a fast, reproducible, and reliable test of the samples is presented. Then, nozzle temperature (180–215 °C) and bed temperature (30–120 °C) were systematically varied, producing a minimum of n = 12 samples per condition. Samples were classified after failure, depending on the fracture mechanism (type 1 = joint failure; type 2 = filament failure), and the apparent tensile strength (ATS) of the joint was computed from the tensile tests and optical micrographs. The detachment probability of the joints decreased sharply above 210 °C, while the ATS increased, approaching a plateau near ~50 MPa. The influence of bed temperature was smoother, with a stable decrease in the detachment ratio as the ATS increased, indicating that nozzle temperature is the main factor contributing to the joint strength. These results map a temperature-driven transition from joint-controlled to filament-controlled failure. The method proposed also provides a minimal-material, high-throughput route to quantify FDM interlayer bonding and inform process simulations. Additional tests are performed to contextualize the results presented. Full article

An atypical course of male meiosis in Littorina saxatilis from zygotene to early anaphase I has been established, which includes non-canonical stages—diffuse and karyosomal. In diakinesis, a structural stepwise transition of bivalents from a single-thread, homogeneously colored form to a double-thread and banded form was discovered. In early diakinesis, in addition to bivalents without pronounced chiasmata, which constitute the majority, rare cruciform short bivalents with one chiasma are revealed. In mid-diakinesis, two or three types of bivalents with one or two chiasmata and several achiasmatic bivalents are identified. In late diakinesis—metaphase I—seven types of bivalents were distinguished, bearing from one to three chiasmata. Some bivalents of the set showed noticeable chiasmata only in early anaphase I. Therefore, the course of diakinesis in L. saxatilis male meiosis is rather atypical. In pachytene, mid- and late diakinesis, and partly in metaphase I, individual bivalents of the L. saxatilis set are reliably identified because they exhibit chromomeric patterns similar to those of the G-banded prometaphase chromosomes of early embryos and spermatogonial mitotic cells. Our research provides a cytological basis for further studies of conservation/variability and evolution of male meiosis. Full article

Recent advances in sequencing methods have led to major progress in the gapless assemblies of the human genome. However, until mid-2023, the complete sequence of the Y chromosome remained elusive. While only a small percentage of autosomal chromosomes were without complete sequences in the broadly used reference assembly of the human genome (GRCh38), around 50% of the chromosome Y DNA sequence was unknown. Using a sophisticated computational approach, we analyzed the presence of short inverted repeats in the current human reference genome (GRCh38) and in the Telomere-to-Telomere (T2T) assembly of chromosome Y. This analysis identified the location of the repeats in chromosome Y and highlighted their association with functionally annotated sequences. The comparison revealed notably more inverted repeats in the T2T assembly compared to GRCh38. These are located abundantly around exons and mobile elements, and, unexpectedly, also within gene annotations. The remarkable abundance of short inverted repeats around exons points to their importance in gene regulation, and their presence in regions associated with recombination suggests crucial roles in recombination processes. Interestingly, the most underestimated sequences in the T2T assembly are inverted repeats with a repeat length of 12–14, which are more than 20 times as frequent as those in the human reference genome GRCh38. These findings indicate that the number of short inverted repeats was significantly underestimated in the current human reference genome (GRCh38). These previously unidentified sites are of great bio-medicinal potential, as inverted repeats are precursors for the formation of cruciform DNA functional epitopes. Full article

Background/Objectives: Short inverted repeats (SIRs) are abundant DNA motifs capable of forming secondary structures, such as hairpins and cruciforms, that can induce genome instability. However, their mutational consequences in cancer, particularly in osteosarcoma (OS), remain largely unexplored. Methods: In this study, we systematically identified over 5.2 million SIRs in the human genome and analyzed their mutational patterns across six common cancer types. Results: We found that increased small insertion and deletion (INDEL) density within SIR spacer regions represents a consistent feature across cancers, whereas elevated single nucleotide variant (SNV) and structural breakpoint density is cancer-type specific. Integrating whole-genome sequencing data from 13 OS patients, we found that both SNVs and INDELs are significantly enriched within SIR spacer regions in OS. Notably, genomic regions with higher SIR density tend to accumulate more somatic mutations, suggesting a link between SIR abundance and local genome instability. SIR-associated mutations frequently occur in oncogenes and tumor suppressor genes, including TP53, NFATC2, MECOM, LRP1B, RB1, CNTNAP2, and PTPRD, as well as in long non-coding RNAs. Mutational signature analysis further suggests that defective DNA mismatch repair and homologous recombination may act in concert with SIR-induced DNA structural instability to drive OS development. Conclusions: Our findings highlight SIRs as mutational hotspots and potential drivers of osteosarcoma pathogenesis. Full article

Floating vertical−axis wind turbines present unique advantages for deep−water offshore deployments, but their basin model testing encounters significant challenges in aerodynamic load simulation due to Reynolds scaling effects. While Froude−scaled experiments accurately replicate hydrodynamic behaviors, the drastic reduction in Reynolds numbers at the model scale leads to substantial discrepancies in aerodynamic forces compared to full−scale conditions. This study proposed two methodologies to address these challenges. Fully physical model tests adopt a “physical wind field + rotor model + floating foundation” approach, realistically simulating aerodynamic loads during rotor rotation. Semi−physical model tests employ a “numerical wind field + rotor model + physical floating foundation” configuration, where theoretical aerodynamic loads are obtained through numerical calculations and then reproduced using controllable actuator structures. For fully physical model tests, a blade reconstruction framework integrated airfoil optimization, chord length adjustments, and twist angle modifications through Taylor expansion−based sensitivity analysis. The method achieved thrust coefficient similarity across the operational tip−speed ratio range. For semi−physical tests, a cruciform−arranged rotor system with eight dynamically controlled rotors and constrained thrust allocation algorithms enabled the simultaneous reproduction of periodic streamwise/crosswind thrusts and vertical−axis torque. Numerical case studies demonstrated that the system effectively simulates six−degree−of−freedom aerodynamic loads under turbulent conditions while maintaining thrust variation rates below 9.3% between adjacent time steps. These solutions addressed VAWTs’ distinct aerodynamic complexities, including azimuth−dependent Reynolds number fluctuations and multidirectional force coupling, which conventional methods fail to accommodate. The developed techniques enhanced the fidelity of floating VAWT basin tests, providing critical experimental validation tools for emerging offshore wind technologies. Full article

One new species of Laboulbeniaceae, Peyritschiella styngeti, is described and illustrated. It is characterized by appendages with a black constriction at the base, perithecia with four papillae on the apical zone, cruciform bilateral symmetry, and an extremely melanized receptacle. This species was observed on the stylus of the staphylinid Styngetus deyrollei, which is distributed in tropical montane cloud forests in Mexico. Currently, the Laboulbeniales mycobiota in Mexico comprises 82 species, with 11 described growing on species of the Staphylinidae family. Additionally, a compilation of the Laboulbeniales species reported for Mexico and for Staphylinidae species is presented. Full article

Several experimental and numerical studies have been conducted on the towing behavior of floating offshore wind turbines (FOWTs); however, these studies mainly focus on tension-leg platform (TLP) and semi-submersible designs with cylindrical features. The University of Maine’s VolturnUS+ concept is a cruciform-shaped barge-type FOWT with distinctive hydrodynamic properties that have not been characterized in previous research. This study presents basin-scale experiments that characterize the hydrodynamic drag properties of the VolturnUS+ platform, as well as observing the motion behavior of the platform and added resistance during towing in calm water and waves. The towing experiments are conducted in two towing configurations, with differing platform orientations and towline designs. The basin experiments are supplemented with a numerical study using computational fluid dynamic (CFD) simulations to explore flow-induced motion (FIM) on the platform during towing. In both the experiments and the CFD simulations, it was determined that the towing configuration significantly impacted the drag and motion characteristics of the platform, with the cruciform shape producing FIM phenomena. Observations from the towing tests confirmed the feasibility of towing the VolturnUS+ platform in the two orientations. The results and observations developed from the experimental and numerical towing studies will be used to inform numerical models for planning towing operations, as well as develop informed recommendations for towing similar cruciform-shaped structures in the future. Full article