Composite Element Research Articles

АНАЛІЗ РОЗПОДІЛУ КОНТАКТНИХ НАПРУЖЕНЬ У ДВОЗРІЗНОМУ БОЛТОВОМУ З'ЄДНАННІ КОМПОЗИТНИХ ТА МЕТАЛЕВИХ ЕЛЕМЕНТІВ

Bolted joining technique is the dominant joining method for CFRP load-carrying structures in aircraft. However, the weak point of such structures are the areas located in the vicinity of the fastener holes, which are the areas of increased stress concentration. In addition, drilling the holes results in structural discontinuities due to cutting material fibers. Among all failure modes of composite bolted joint, bearing failure is one of the most common type of damage. This failure is caused by the local compressive stresses acting normal to the contact surface, that leads to delamination of material due to insufficient strength of matrix. Therefore, it is extremely important to optimize the design of composite bolted joints in order to enhance the entire composite structure. To increase the load-carrying capacity of the composite joint structural parts and protect the hole walls from damage, a method for installing titanium bushing with glue into the holes of composite plate is proposed. The paper presents the results of numerical analysis of the impact of stacking sequence on the distribution of contact stresses in a double-shear bolted joint of composite plate to steel cover plates. Using the finite element method and ANSYS Workbench 2019 R3 software, a three-dimensional finite element model of a double-shear bolted joint was created, which enables to analyze the impact of the stacking sequence on the distribution of contact stresses at the bolts to titanium bushings interface in the case of uniaxial tension of the middle composite plate at the level of tensile stresses in the gross section of 100 MPa. The obtained result explains the fundamental difference in the behavior of composite and metal materials: due to the change in the orientation and sequence stacking, the stiffness of the composite element of the joint changes, which affects the ovalization of the holes and the level of local deformations of the bushings, which in turn leads to a change in the maximum contact stresses and their concentration. By optimizing stacking sequence, it was possible to reduce the level of maximum contact stresses by 1.1 times. At the same time, the degree of unevenness of the distribution of contact stresses decreased by 1.21 times. The optimal stacking sequence was one in which 37.5% of the fibers oriented at an angle of 0°, 50% of the fibers oriented at angles of ±45°, and 12.5% of the fibers oriented at an angle of 90°

A Simple Method to Evaluate the Bearing Capacity of Concrete-Filled Steel Tubes with Rectangular and Circular Sections: Beams, Columns, and Beam–Columns

This study investigates the behavior and capacity of concrete-filled steel tubes (CFTs) with rectangular and circular sections under various loading conditions: axial loads, pure-bending, and combined axial load-bending moments. A finite element-based numerical model is developed and validated against existing experimental data. Using an extensive databank generated from finite element analysis, this research proposes analytical empirical relations for determining the bearing capacity of rectangular and circular composite beams, columns, and beam–columns. These relations provide a direct, concise, and efficient method for calculating the ultimate strength of CFT members, making them valuable for engineering design. Comparisons between the proposed analytical results and previous experimental studies demonstrate the high accuracy of this method in analyzing rectangular and circular CFT member behavior. The findings contribute to a better understanding of CFT structural performance and offer practical tools for designers working with these composite elements.

8774 An Uncommon Presentation Of A Large Silent Pheochromocytoma

Abstract Disclosure: M. Lozano: None. A. Pinero-Pilona: None. Background: The reported estimated incidence of pheochromocytoma is approximately 2-8 cases per 1 million people per year. Of those, silent pheochromocytomas will make up about 8%. Thus, biochemically silent and non-secreting pheochromocytomas are a very rare phenomenon. Clinical Case: A 74-year-old Caucasian female with significant past medical history of primary hypothyroidism, hypercholesterolemia, and nasal sinus carcinoma s/p surgery (in remission) presented to the clinic for endocrine evaluation of a right adrenal mass. The patient was asymptomatic and denied headaches, tachycardia, sweating, severe hypertension, diabetes, muscle weakness, easy bruising, or striae. The mass was initially diagnosed as an incidental finding after a contrast CT scan of the abdomen was performed for diverticulitis. The right adrenal enhancing mass was 2.3 x 3.9 x 4.1 cm in diameter. Subsequent MRI abdomen with and without contrast ordered by the referring physician showed that the adrenal mass had grown to 4.9 x 3.8 x 5.4 cm and was hyperenhancing in nature with central T2 hyperintense signal. Notably, multiple “parasitized and arborealized” vessels were detected within the mass. Such findings led us to suspect metastatic versus primary adrenal neoplasm such as cortical carcinoma as a working diagnosis. Other laboratory studies including plasma free metanephrines (<10 pg/mL, normal 0-88 pg/mL), plasma normetanephrines (29.2 pg/mL, normal 0-285.2 pg/mL) and 24-hour urine collections (24 hr urine epinephrine - 3 ug/24 hr [normal 0-20 ug/24 hr]; 24 hr urine norepinephrine - 75 ug/24 hr [normal 0-135 ug/24 hr]; 24 hr urine VMA - 3 mg/24 hr [normal 0-7.5 mg/24 hr]) were negative for pheochromocytoma. As her mass was greater than 4 cm in diameter, surgical referral was then recommended to the patient. Right adrenalectomy was performed. Pathology report was consistent with pheochromocytoma as supported by immunohistochemistry. Ki-67 proliferation index was 0-10% (average 3-4%, rare hotspots 10%). Atrophy and vascular ectasia were present in residual non-neoplastic adrenal cortex and medulla. Histology showed a nested growth pattern, absence of composite tumor elements, absence of necrosis, and no atypical mitoses. The incidence of non-secreting pheochromocytomas has been quoted to be 0.000064% (1). Conclusion: The case illustrates an uncommon presentation of a large, silent pheochromocytoma with negative plasma metanephrines accompanied by negative urine studies, which have a negative predictive value close to 100% in ruling out a pheochromocytoma. Our case emphasizes the importance of considering pheochromocytoma on the differential of adrenal masses with high attenuation or high enhancement even when biochemical studies suggest otherwise. Reference: (1) Radojkovic, D., et al. "CLINICALLY" SILENT GIANT PHEOCHROMOCYTOMA. CASE REPORT." Acta Endocrinologica (1841-0987) 9.1 (2013). Presentation: 6/1/2024

DESIGN AND MANUFACTURE OF BENT AND VARIABLE SECTION TUBES MADE OF FRP COMPOSITE

Manufacturing of bent composite tubes with variable cross-section is a challenge. The traditional process in composite materials uses retractable mandrels that in case of inflated or bent tubes cannot be applied. The tubular composite elements are often used in high performance bicycles, in the manufacturing of frames, handlebars, saddle pipe supports, etc. This paper presents research on the design of a Mountain Bike (MTB) riser handlebar made of Fiber Reinforced Polymer (FRP). The handlebar is numerically analyzed to estimate the most suitable stacking sequence of Carbon Fiber Reinforced Polymer (CFRP) layers. Depending on the safety standard of bicycle handlebars, a case of longitudinal bending tests was numerically evaluated. Comparing the weight of the CFRP handlebar with the steel handlebar of the same shape, the mass reduction is 5.2 times. The obtained results indicate a two-fold reduction in the weight of the handlebar if it is compared to a handlebar made of aluminum alloys. The research also presents the manufacturing process of the composite mold, and CFRP tubular element. Prepreg CFRP materials are used to manufacture the handlebar, the employed technology being the vacuum bag forming and autoclave curing process.

Exploring the effect of Cr and Mn on the intrinsic strength of the tensile properties of FeCoNi, FeCoNiMn, FeCoNiCr, and FeCoNiCrMn multi-principal element alloys using in-situ EBSD

As the composition elements in multi-principal element alloys increase, it can bring excellent mechanical properties. However, the strengthening mechanism of the additional element is still unclear. In this work, we establish a method based on the in-situ EBSD technology to explore the possible effect of additional elements on the intrinsic strength of tensile properties. We prepared four different multi-principal element alloys, including FeCoNi, FeCoNiMn, FeCoNiCr, and FeCoNiCrMn with similar initial status. We systematically investigated the evolution of the microstructure, dislocation density, twin boundary, grain size, and element distribution during the tensile process by in-situ EBSD and EDS. By carefully analyzing the results of four different multi-principal element alloys, the strength effects of the solid-solution hardening, grain-boundary hardening, twin boundary hardening, precipitate hardening, and dislocation hardening were peeled. The effect of the Cr and Mn element addition on the intrinsic strength can be explored. It is found that the element addition indeed increases the intrinsic strength from quaternary to quinary but not very clear from ternary to quaternary no matter Cr or Mn, which indicated that the intrinsic strength was more related to the number of elements in the alloy than to which element was present. This can be explained using the mixing entropy theory, which states that the intrinsic strength is enhanced when the mixing entropy is over a threshold between the MEA and HEA. This paper presents a method to study the individual factors affecting the tensile properties, which can help other researchers to better investigate HEA.

Quality Assessment of Aluminum Alloys for Automotive Rims

Abstract This paper presents experimental research conducted at a factory specializing in the development of aluminum alloys and the semi-continuous production of bars intended for rim manufacturing. The semi-finished products are made of 6082 aluminum alloy and undergo forging processes to obtain rims. The charge load consists of various types of aluminum waste and primary aluminum in different proportions, depending on the quality of the waste in the experimental recipes. The elaboration of the aluminum alloy takes place in melting furnaces with a capacity of 80 tons, equipped with two chambers. The casting is performed using a semi-continuous casting installation, and the cast semi-finished products undergo further heat treatment. The casting process involves the addition of alloying elements, in the form of wire, which serve to refine the structure. Experimental data were processed, and correlations between the qualitative characteristics of the alloy and the elements in the chemical composition, as well as grain size, were analyzed. From the obtained correlation analysis, it is observed that the alloying elements refine the grain size, while the grain size and quality of the resulting product are of interest for industrial practice.

Aesthetic image cropping meets VLP: Enhancing good while reducing bad

Aesthetic Image Cropping (AIC) enhances the visual appeal of an image by adjusting its composition and aesthetic elements. People make these adjustments based on these elements, aiming to enhance appealing aspects while minimizing detrimental factors. Motivated by these observations, we propose a novel approach called CLIPCropping, which simulates the human decision-making process in AIC. CLIPCropping leverages Contrastive Language-Image Pre-training (CLIP) to align visual perception with textual description. It consists of three branches: composition embedding, aesthetic embedding, and image cropping. The composition embedding branch learns principles based on Composition Knowledge Embedding (CKE), while the aesthetic embedding branch learns principles based on Aesthetic Knowledge Embedding (AKE). The image cropping branch evaluates the quality of candidate crops by aggregating knowledge from CKE and AKE; an MLP produces the best result. Extensive experiments on three benchmark datasets—GAICD-1236, GAICD-3336, and FCDB—show that CLIPCropping outperforms state-of-the-art methods and provides insightful interpretations.

Effects of Core and Surface Materials on the Flexural Behavior of Lightweight Composites Sandwich Beams

Sandwich composite elements are used in many sectors thanks to their low weight/strength ratios, high bending strength, good thermal insulation properties, and low costs. It is widely used in the machinery and construction industry, especially in land, sea, and air vehicles. The main objective of this research is to design and produce lightweight, durable, insulated, and low-cost, sustainable building elements that will meet emergency shelter needs after disasters. For housing purposes, 24 sandwich beams were prepared, eight designs with different surface coatings and core materials, and three in each design group. The effects of surface coating and core material on behavior were investigated with four-point bending experiments. Load-displacement relationships were determined from the experiments, and the beams' load-carrying capacities and failure patterns under the effects of bending and shearing were determined. In addition, theoretical methods determined maximum load values and compared them with the results of the experiments. As a result of the experiments, it was concluded that the best-performing design under bending effects was sandwich beams with plywood surface and XPS core.

PID controller design for manipulating electrorheological valves with mesh electrodes using in 2D matrix display

Abstract The electrorheological (ER) valve with parallel electrodes structure has an inherent characteristic. The electrodes gap is the same as its flow channel gap, which causes a strong coupling relationship between the applied voltages and the flow rates of the ER valve. If flow rates of ER valves in the condition of turn on operational mode were increased, their applied voltages were increased necessarily for keeping their shutdown operational mode, which brings a bunch of problems of product costs and dimensions, especially when multiple ER valves with different operational modes work together, such as application of ER valves matrix used in 2D matrix displays. The mesh electrodes structure can decouple the relationship between the electrodes gap and the flow channel gap of parallel electrodes structure. However, due to the complexity of mesh electrodes structure, a mathematic model is difficult to be established theoretically. And, a mathematic model of ER valve with mesh electrodes plays a vital role in designing its controller. By analyzing the composition elements of an ER valve with mesh electrodes, a semi experimental model was established using the parametric identification toolbox of MATLAB. The consistency between the output of recognition model and the output of validation data reaches 93.46%. Subsequently the PID controller for ER valves with mesh electrodes was designed to meet the operational demands of a 2D matrix display using Simulink. The constrain of simulation was that the pressures of flow channel inlets of ER valves, the dynamic responses of ER valves with mesh electrodes kept stable and within its operational range. The results will be helpful for applications of ER valves with mesh electrodes.

Аналіз розподілу температури у двошаровій композитній циліндричній оболонці зумовленої конвективним теплообміном на її зовнішній поверхні

A non-stationary thermal conductivity problem for a two-layer cylindrical shell is formulated. The materials of the constituent layers of the shell are assumed to be homogeneous and isotropic. This shell is convectively heated by the external environment. The system of linear two-dimensional equations for the integral temperature characteristics summed over the component layers of the shell was used as the initial system of equations of the problem under consideration. When obtaining this system, the hypothesis of a linear distribution of temperature along the thickness of the entire shell was applied. On the basis of the developed two-dimensional mathematical model of thermal conductivity for layered cylindrical shells, a general solution to the thermal conductivity problem for a two-layered cylindrical shell was obtained. A temperature distribution was found for such a shell, which is locally convectively heated by the external environment in a rectangular region on the outer surface. For the numerical analysis, a metal-ceramic cylindrical shell was considered, the inner layer of which is made of tungsten, and the outer layer is made of ceramics. Under such a structure and conditions of heat exchange with the external environment for the considered shell, the effect of its geometric parameters and thermophysical characteristics of the materials of its component layers on the temperature field on the outer surface of the shell was investigated. The revealed new qualitative and quantitative regularities can be used to estimate temperature fields in composite elements of layered structures and in structures with one-sided coatings. The dependences of temperature distributions on geometric parameters and thermophysical characteristics obtained in this work are the basis of the theoretical basis for the analysis of temperature regimes of metal-ceramic cylindrical shells. In particular, metal-ceramic dental crowns to predict their temperature regimes are modeled by the two-layer metal-ceramic cylindrical shells described above, which are locally convectively heated by the external environment

Systematization of the application of polymer composite materials in the design of bridge structures

Background. This study systematizes the principles of using polymer composite materials in bridge structure design, outlining the fundamental principles for calculating load-bearing structures of bridge spans featuring these materials. Aim. The goal is to enhance the strength and durability of bridge spans during construction and maintenance, while optimizing costs through the use of polymer composite materials. Materials and Methods. The research employs a modern approach to bridge structure design, utilizing mathematical statistics for experimental data analysis and numerical methods for calculating bridge structures using nonlinear deformation models of anisotropic materials. Results. Developed principles for designing bridge spans with polymer composite elements include methods for strengthening and reinforcing concrete bridge structures. These methods account for operational factors such as long-term constant and temporary loads, low and elevated temperatures, as well as methods for designing all-composite spans pedestrian and road bridges Conclusion. The principles of designing bridge spans with elements made of polymer composite materials have been introduced into the practice of transport construction in the Russian Federation. The technical and economic efficiency of using polymer composite materials in bridge structures of transport infrastructure has been confirmed.

Dynamics for rigid–flexible coupled solar panel multibody system composed of composite laminated plates

Composite laminates are widely employed in the fabrication of solar panels in modern spacecraft engineering because of their superior durability, mechanical qualities, and cost-effectiveness. This research is dedicated to multibody system dynamics modeling of composite laminate solar panels, specifically the coupling system between the rigid main body and the flexible solar panels. In this study, the rigid body is modeled using the natural coordinate formulation (NCF), and for the flexible solar panel, the absolute nodal coordinate formulation (ANCF) with a 36-DOF reduced-order composite thin shell element is used to accurately capture the coupling effect of the solar panel under large motion and deformation. Compared to a 48-DOF fully parameterized thick plate element, this method efficiently avoids shear locking and improves numerical solution convergence efficiency. Based on the Kirchhoff theory and the constitutive relationship of composite laminates, a dynamic model of the multibody system is developed, taking into account the rigid-flexible coupling effect and the kinematic constraints. This work thoroughly discusses the dynamic behavior of solar panel deployment using a comparative analysis of numerical simulation and virtual prototype simulation, and the accuracy is verified. The findings indicate that the flexible characteristics and fiber orientation of composite laminates have a significant impact on the dynamic response of solar panels during deployment. Furthermore, the bang-bang attitude controller is designed, and the difference in dynamic response between the two modeling methods in controlled and uncontrolled states is studied, providing an important theoretical foundation and technical support for solar panel design and analysis.

Enhancing structural protection of reinforced concrete structures against high dynamic loads using post-installed UHPFRC/UHPFRSC

Recently there has been an observed change in security policy across the globe which implies that humanity must prepare for hybrid and asymmetric acts of war. This security situation will result in spontaneous attacks from non-military groups. The threats include ballistic attacks from commercially available weapons, detonation of explosives, and impact of vehicles. These attacks are focused on critical infrastructures. Reinforced concrete (RC) elements with ballistic and explosion protection are of huge relevance. This requires new concepts and innovative solutions for the protection of new buildings and/or for the strengthening of existing structures. In this paper a method for the increase of structural safety is shown using Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) or sprayed UHPFRC, so called UHPFRSC, as a surface layer for reinforced concrete structures. The UHPFRC/UHPFRSC is applied in thin layers of 30 - 80 mm on the protection side. The interaction of the two different cementitious materials results in increased resistance to high dynamic loads. The traditional reinforced concrete on the impact side absorbs a major fraction of the energy of impact. On the back side (protection side), tensile forces are generated by the impact, which can excellently be handled by the UHPFRC/UHPFRSC. For proof of concept of the hybrid strengthening method, tests were carried out on UHPFRC - RC composite elements. In the test campaign, ballistic tests were performed using test specimens with dimensions of 500 × 500 mm. The layer thicknesses were 120 mm reinforced concrete and 40 mm UHPFRC. Additional steel rebars in the UHPFRC layer were applied for half of the specimens. The investigation demonstrated the effectiveness of the strengthening method, showing high resistance to high-dynamic loads. This behavior is attributed to the absorption and transfer of tensile stresses by the UHPFRC, that reduces penetration depth and damage, ensuring remaining load-bearing capacity after gunfire.

A two-level semi-hybrid-mixed model for Stokes–Brinkman flows with divergence-compatible velocity–pressure elements

A two-level version for a recent semi-hybrid-mixed finite element approach for modeling Stokes and Brinkman flows is proposed. In the context of a domain decomposition of the flow region Ω, composite divergence-compatible finite elements pairs in H(div,Ω)×L2(Ω) are utilized for discretizing velocity and pressure fields, using the same approach previously adopted for two-level mixed Darcy and stress mixed elasticity models. The two-level finite element pairs of spaces in the subregions may have richer internal resolution than the boundary normal trace. Hybridization occurs by the introduction of an unknown (traction) defined over element boundaries, playing the role of a Lagrange multiplier to weakly enforce tangential velocity continuity and Dirichlet boundary condition. The well-posedness of the method requires a proper choice of the finite element space for the traction multiplier, which can be achieved after a proper velocity FE space enrichment with higher order bubble fields. The method is strongly locally conservative, yielding exact divergence-free velocity fields, demonstrating pressure robustness, and facilitating parallel implementations by limiting the communication of local common data to at most two elements. Easier coupling strategies of finite elements regarding different polynomial degree or mesh widths are permitted, provided that mild mesh and normal trace consistency properties are satisfied. Significant improvement in computational performance is achieved by the application of static condensation, where the global system is solved for coarse primary variables. The coarse primary variables are a piecewise constant pressure variable over the subregions, velocity normal trace and tangential traction over subdomain interfaces, as well as a real number used as a multiplier ensuring global zero-mean pressure. Refined details of the solutions are represented by secondary variables, which are post-processed by local solvers. Numerical results are presented for the verification of convergence histories of the method.

Celtic music, Shakespeare and fandom

Abstract Why would Celtic women performers invoke a dead colonialist English poet in their airs and dance sets? This article provides close readings of Shakespearean elements in the musical compositions of gold- and platinum-selling artists Loreena McKennitt, Ensemble Galilei, and Méav. It assesses the archaicising musical language, structural reshapings, and ekphrastic elements as signals of ‘restitutional creativity’ and trans-temporal collaboration. It also analyses the reception of these works by fans and critics, responses replete with invocations of tradition and of timelessness. Like the fanfic-producing enthusiasts of Johnathan Pope's Shakespeare's Fans, the fans for Celtic music capitalise on their awareness of Shakespearean elements in this music to display personal expertise. In so doing, they enhance their own belonging within the Celtic music community.

Vilyui and Priverkhoyansk Composite Tectono-Sedimentary Elements, Northeastern East Siberia

A vast region of the Northeastern Siberia west of the Verkhoyansk Range includes two large sedimentary basins, Vilyui and Priverkhoyansk. Combined, these basins constitute the Lena-Vilyui Petroleum Province, which contains the largest gas reserves in the northeastern Asia. Both basins have a long and complex geological history that resulted in the accumulation of over 14 km-thick succession of Upper Proterozoic, Paleozoic, Mesozoic and Cenozoic sedimentary rocks. According to the volume's terminology, we subdivide this sedimentary body into two composite tectono-sedimentary elements (CTSE), the Vilyui and Priverkhoyansk (VI CTSE and PV CTSE), which closely correspond to the same-named basins. The CTSEs consist of ten distinct tectono-sedimentary elements (TSEs), each representing a distinct tectonic setting. This region has been studied very irregularly. In total, more than 400 deep wells have been drilled, mostly within the VI CTSE and only a few tens - in the PV CTSE. Eleven gas and gas condensate accumulations have been discovered in the VI CTSE. The PV CTSE remains poorly explored with only two commercial discoveries made as of the present-day.

Experimental and Numerical Study of Steel-Concrete Composite Beams Strengthened under Load.

This study analysed the strengthening process of a classical steel-concrete composite beam. The beam consisted of a reinforced concrete slab connected by shear studs to an IPE steel profile. The key idea was that the composite beam was strengthened under load. This process simulated an actual reinforced structure that is always subjected to dead loads, with possible service loads. This study assumed that strengthening was implemented to increase the load-carrying capacity and stiffness, not as a way for simulation a repair. The strengthening consisted of expanding the steel part of the beam by welding an additional plate to the bottom flange of the IPE profile. This study included the results of numerical analyses conducted in Abaqus software and lab results. A three-dimensional numerical model was created, taking into account the non-linear behaviour of concrete and steel, the susceptibility of the composite at the joint plane, and the residual stresses created during welding. A full-scale strengthening of the composite beams under load was carried out. Comparison of the results obtained in the experimental tests and numerical analyses showed a very high convergence of the results, as well as in terms of the non-linear operation of steel and concrete. This confirmed the validity of the created numerical model, which can be the basis for further research into the process of optimal strengthening of composite elements.

Kureika–Tunguska Composite Tectono-Sedimentary Element, northern East Siberia

The Kureika–Tunguska Composite Tectono-Sedimentary Element (KT CTSE) is located in East Siberia. Geologically, it is confined to the homonymic basin in the northwestern part of the Siberian Craton. The basement of the basin is composed of Archean–Early Proterozoic metamorphic rocks. The sedimentary cover is composed of Mesoproterozoic, Neoproterosoic and Early Paleozoic predominantly carbonate rocks capped with a succession of Pennsylvanian–Permian coal-bearing sediments overlain by thick section of Early Triassic tuffs and lavas. The entire sedimentary cover, especially its upper part, is saturated with mafic intrusive bodies. The maximum depth to the top basement can exceed 10 km. The KT CTSE is characterized by a very low degree of exploration. The rather scarce prospecting work carried out on oil and gas in the CTSE has not yet yielded positive results. However, indirect data such as, for example, numerous bitumen fields and evidence of the source rocks are promising for potential discoveries including large hydrocarbon accumulations.

Compositional Elements of Photographic Coverage of the Westgate Mall Terrorist Attack

Purpose: Terrorism is a global threat that has prompted extensive research, with mass media playing a crucial role in reporting such events. This study investigated the compositional elements of photographic coverage of the Westgate Mall terrorist attack in Nairobi, Kenya, on September 21, 2013. Methodology: Photographs from the Daily Nation, Standard, and New York Times were analysed. Using qualitative descriptive research and content analysis through MaxQDA software, the study identified patterns and themes in the images, focusing on denotative, stylistic-semiotic, connotative, and ideological representations. Findings: It was found that camera angles, shot proximity, and image sizes were strategically used by photojournalists to convey messages and emotions. Large images on front pages provided visual appeal, while medium and small images added content and facilitated sensationalized storytelling. Shot proximity varied to deliver specific messages, with few close-ups used to avoid evoking sombre emotions or aiding terrorist propaganda. Unique Contribution to Theory, Practice and Policy: The study contributes to the existing mass media research by highlighting the importance of thoughtful image selection and composition in responsible photojournalism to balance accurate reporting with mitigating potential harm.

NIR-II light-encoded 4D-printed magnetic shape memory composite for real-time reprogrammable soft actuator

For the intelligent 4D-printed actuators, the excellent performance, including quickly reversible spatial-shape transformation and locking, digital and precise shape manipulation in real-time, and remote actuation in special spaces or harsh environments, is significantly desirable but still challenging. Here, using a UV-curable system containing the shape memory polymer (SMP) and NdFeB particles, namely the magSMP composite, we fabricate a real-time reprogrammable soft actuator via high-resolution Digital Light Processing (DLP)-based 4D printing. The printed structure is composed of an array of physical binary magSMP composite elements (m-bits), analogous to digital bits. Owing to the NdFeB's photothermal effect, each m-bit can be independently and reversibly switched between unlocking or locking states (allowing or prohibiting responsive shape-morphing) in response to the on/off state of NIR-II light. Through projecting NIR-II light patterns for encoding a set of binary instructions onto 4D-printed actuators, the real-time light-programmed deformations are induced precisely under an actuation magnetic field due to the NdFeB's huge coercivity. Thus, the synergistic magnetic and light field-manipulated multimodal deformations of actuators, including mimosa shape changing, grasping, and wire guiding, are achieved. This study shines lights on the fabrication of soft structures of arbitrary sizes and provides their future perspectives in soft robot design.