Search Results (26,840)

This study developed a novel 3D-printable poly(vinylidene fluoride) (PVDF)-based nanocomposite incorporating 6 wt% graphene nanoplatelets (GNPs) with programmable characteristics for resistive heating applications. The results highlighted the significant effect of a controlled printing direction (longitudinal, diagonal, and transverse) on the electrical, thermal, Joule heating, and thermo-resistive properties of the printed structures. The 6 wt% GNP/PVDF nanocomposite exhibited a high electrical conductivity of 112 S·m⁻¹ when printed in a longitudinal direction, which decreased significantly in other directions. The Joule heating tests confirmed the material’s efficiency in resistive heating, with the maximum temperature reaching up to 65 °C under an applied low voltage of 2 V at a raster angle of printing of 0°, while the heating T_max decreased stepwise with 10 °C at the 45° and the 90° printing directions. The repeatability of the Joule heating performance was verified through multiple heating and cooling cycles, demonstrating consistent maximum temperatures across several tests. The effect of sample thickness, controlled by the number of printed layers, was investigated, and the results underscore the advantages of programmable 3D printing orientation in thin layers for enhanced thermal stability, tailored electrical conductivity, and efficient Joule heating capabilities of 6 wt% GNP/PVDF composites, positioning them as promising candidates for next-generation 3D-printed electronic devices and self-heating applications. Full article

Microstructures in high-purity tantalum (Ta) were analyzed in three directions, focusing on the evolution of stored energy during rolling and heating processes. Results indicated significant fluctuation in the transaction direction (TD) surface, which was observed in both deformed and annealed states. This phenomenon is attributed to the alternately arranged {111}<uvw>(<111>//normal direction (ND)) and {100}<uvw>(<100>//ND) oriented grains, coupled with the substantial energy difference between them, even after 12 passes. Additionally, through the estimation and calculation of stored energy based on band contrast from electron backscatter diffraction and X-ray line profile analyses, the recovery kinetics for different directions and grain types were quantitatively assessed. Findings revealed that the dislocation density of {111} grains decreased significantly more than that of {100} grains when annealed at 1073 K. The degree of recovery was closely related to temperature, dislocation density, and dislocation type. Full article

The exploration and advancement of feminism are vital for addressing critical issues such as social progress, equitable education, and healthcare access. This paper comprehensively examines the feminist movement’s impact on architecture over the past century, identifying key trends and significant areas to establish an academic foundation for feminist architecture. A literature review on feminism in urban planning, architecture, landscape design, and urban safety highlights the current research focus on feminist architectural development. Furthermore, this paper traces the evolution of feminist architecture through both purpose-driven and process-oriented approaches, exploring the interplay between feminist and modern architectural practices. It specifically examines the development of feminist architecture within the Chinese context from two perspectives: the influence of feminist thought on architecture and the evolution of gendered spaces within the “Residence and Courtyard” model. By comparing the internal logic of feminist architectural development in China and the West, this study investigates how geopolitical culture and regional differences shape the future trajectory of this field. Unlike traditional feminist architectural research, which often emphasizes women’s practices within specific feminist ideologies or focuses on visual culture and psychological interpretations of gendered spaces, this paper redefines the scope of feminist architectural studies through a comparative analysis of historical and contemporary contexts, and Eastern and Western perspectives, employing a systematic genealogical approach. Full article

Optimizing composite materials, particularly in rotating structures, offers several practical benefits in the mechanical engineering and aerospace engineering industries. Improved material configurations, such as optimal fiber orientations, enhance the structural performance by maximizing stiffness-to-weight ratios and reducing vibrations. This study optimized the fundamental frequencies of rotating laminated cylindrical shells using the golden section method with respect to fiber orientations. The investigation explored the impact of various factors such as end conditions, shell length, axial compressive force, rotating speed, and the size of the cutout on the maximum fundamental frequencies. Additionally, the associated vibration modes and optimal fiber orientations were demonstrated in relation to these influencing parameters. Generally, it was observed that the optimal frequency decreased with increasing length-to-radius ratio and compressive force. Full article

Detecting sub-surface objects poses significant challenges, partly due to attenuation of the ground medium and cluttered environments. The acquisition polarisation and antenna orientation can also yield significant variation of detection performance. These challenges can be mitigated by developing more versatile systems and algorithms to enhance detection and identification. In this study, a novel application of a 3D SAR inverse algorithm and polarisation synthesis was applied to ultra-wideband polarimetric data of buried objects. The principle of polarisation synthesis facilitates an adaptable technique which can be used to match the target’s polarisation characteristics, and the application of this revealed hidden structures, enhanced detection, and increased received power when compared to single polarisation results. This study emphasises the significance of polarimetry in ground-penetrating radar (GPR), particularly for target discrimination in high-lift-off applications. The findings offer valuable insights that could drive future research and enhance the performance of these sensing systems. Full article

The plasma immersion nitriding system was utilized to make massive nitrogen supersaturation (MNS) to CoCrMo disc and die substrates at 723 K for 21.6 ks. The top layer thickness in the multi-layered MNSed layer was 20 μm. Its nitrogen solute content reached 5 mass% on average after SEM-EDX analysis. The surface hardness was 1300 HV_1N (HV_0.1), which was much higher than the bare CoCrMo with 450 HV_1N. The original polycrystalline structure was modified to be a multi-layered microstructure, which consisted of the nanograined MNSed top layer, the buffer layer with a thickness of 5 μm, and the column–granular structured layer with their textured crystallographic orientations. The BOD (ball-on-disc) testing was employed to describe the frictional sliding behavior under the applied loads of 5 N and 10 N and the sliding velocity of 0.1 m/s against the AISI316 ball. The friction coefficient was held constant by 0.68 on average. The CNC (Computer Numerical Control) stamping system was employed to upset the fine-grained 1.0 mm thick AISI316 wire up to 70% in reduction in thickness. The friction coefficient at RT was estimated to be 0.05. A round, fine-grained AISI316 wire was shaped into a thin plate with a thickness of 0.3 mm in cold and dry. Full article

Magnetic fields influence the deposition process and its current efficiency. They have a remarkable influence on thin films’ surface characteristics and catalytic properties. Here, we study the correlation between the magnetic flux density and the current efficiency of the deposition process in the presence of a magnetic field with different intensities in different directions: the directions parallel and perpendicular to the electrode surface. We also show how the magnetic field direction impacts the surface roughness. Furthermore, we also analyze the impact of these synthesized films on the hydrogen evolution reaction (HER) when using them as electrocatalysts and how the application of a magnetic field in two dissimilar orientations influences the surface roughness and wettability. The synthesized Ni films are characterized using a scanning electron microscope (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM). Full article

Restaurant segmentation is an effective tool for decision-making when developing business strategies. The objective of this research is to classify restaurant groups according to the level of employee training in sustainable practices and food waste, and to contrast the differences in the degree of sustainability-oriented service innovation and brand equity, as well as in the implementation of various sustainable practices. A cluster analysis was conducted with 300 restaurants in Guayaquil, Manta, and Portoviejo in Ecuador, based on face-to-face interviews with their managers, and then confirmed with discriminant analysis. Two groups were identified: (1) restaurants with less training in green practices, higher level of food waste, lower level of sustainability-oriented service innovation, and higher brand equity; (2) restaurants with more training in green practices, lower level of food waste, higher level of sustainability-oriented service innovation, and lower brand equity. The most sustainable restaurants claim to have less brand equity, which demonstrates that the Ecuadorian consumer does not particularly value sustainability. Full article

Considering global plastic waste pollution, current production and consumption patterns must be changed. Various measures address this challenge, which can be divided into efficiency, consistency, and sufficiency. Sufficiency has become more critical as research on sustainable consumption and packaging-related behavior has shown that efficiency and consistency strategies alone cannot solve environmental challenges. A deeper understanding of consumers’ packaging-related behavior is necessary to promote sufficiency-oriented consumption patterns and support consumers in everyday implementation. This study aims to investigate consumers’ packaging-saving practices in the fast-moving consumer goods (FMCG) sector and to explore to what extent the practices differ in their actual feasibility in everyday life. For this purpose, we conducted an online survey in Germany with open-ended questions (n = 299). We evaluated the open-ended questions using qualitative content analysis. Overall, the results show that reducing plastic packaging plays a significant role in the participants’ everyday lives. However, the extent to which plastic packaging is avoided or reduced varies by consumption sector. This study extends research on plastic packaging avoidance and reduction to non-food consumption sectors. It also provides essential impulses for actors from science, politics, and industry regarding how consumers can be more strongly supported in their packaging-related behavior in the future, through targeted measures. Full article

The review summarizes the results of previous and the latest studies on aromaticity and related concepts. The electron counting rule for 3D-aromatic systems 2(n + 1)² is shown to be a generalization of the 4n + 2 rule for planar molecules, and, vice versa, the latter can be derived from the former. The relative stability of the push–pull and captodative aromatic systems is shown to depend on the nature of the groups separated by the C=C bond in geminal or vicinal positions. The fully symmetrical molecules of hexamethylbenzene and hexacyanobenzene were studied using structural, energetic, and NMR criteria, and the donor substituents were shown to increase the aromaticity. Taking into account the coincidence of the number of π-electrons in aromatic systems with the number of electrons on the filled electron subshells (s, p, d, and f) and considering electrons as objects in a space of states allowed to conclude that no g-elements can exist and that the extension of the Periodic Table is possible only by filling 6f, 7d, or 8s subshells. The dimensionality of space also affects the chirality of molecules, making planar or even linear molecules chiral on oriented surfaces, which can be used for the preparation of enantiomerically pure drugs, resolution of prochiral compounds, etc. Full article

This work presents a novel infill method for additive manufacturing, specifically designed to optimize material use and enhance stiffness in fused filament fabrication (FFF) parts through a geometry-aware, corrugated design inspired by sandwich structures. Unlike standard infill patterns, which typically employ uniform, space-filling grids that often disregard load-specific requirements, this method generates a cavity inside the component to be printed and fill the space between inner and outer contours with continuous, adaptable extrusion paths. This design enables consistent support and improved load distribution, making it particularly effective for parts under bending stresses, as it enhances structural resilience without requiring additional material. Simulations performed on a 10 cm³ test part using this method showed potential reductions in material consumption by up to 77% and a decrease in print time by 78%, while maintaining stiffness comparable to parts using conventional 100% grid infill. Additionally, simulations demonstrated that the new corrugated infill pattern provides near-isotropic stiffness, addressing the anisotropic limitations often seen in traditional infill designs that are sensitive to load orientation. This geometry-aware infill strategy thus contributes to balanced stiffness across complex geometries, enhancing reliability under mechanical loads. By integrating directly with slicer software, this approach simplifies advanced stiffness optimization without the necessity of finite element analysis-based topology optimization. Full article

The 2024 Report on the Work of the Chinese Government promotes trade in consumer goods and green consumption. Therefore, better understanding is needed of consumer attitudes and behaviors toward environmental protection and sustainable development. The relationships among future orientation, construal level, and green consumption were explored using a delayed-effect design to conduct two surveys at one-month intervals with 160 participants (100 women and 60 men). The results showed that (1) future orientation positively predicted green consumption intention and green consumption behavior, and (2) the construal level significantly moderated the influence of future orientation on green consumption. Specifically, a high construal level and high future orientation predicted the greatest green consumption intention, green consumption behavior, and green consumption decisions, while at a high construal level, future orientation positively predicted green consumption intention and behavior, with a greater tendency to purchase environmentally friendly rather than hedonic products. At a low construal level, future orientation had no significant effect on green consumption intention, behavior, and intention to purchase environmentally friendly products. This study is important for promoting public awareness of the importance of green consumption and encouraging green consumption behaviors to achieve the goals of sustainable development and protect the environment and social well-being. Full article

With the increasing severity of environmental problems and energy scarcity, fuel cell electric vehicles (FCEVs), as a sustainable and efficient means of transportation, are attracting more attention. The ageing of fuel cells (FCs) has become an urgent problem with the development of FCEV. In order to prolong the lifetime of FCs, this paper builds a model of a vehicle driven by two power sources, FC and lithium battery (Lib) using AVL Cruise. A rule-based energy management strategy (EMS) is developed in Simulink to explore the optimal control strategy for the vehicle in terms of the durability of the FC. An FC ageing model is used to quantify the degradation voltage of different duty cycles. The results show that the FC engagement levels, OCV operations, and start/stop operations can affect the lifetime of the FC significantly. By optimising the EMS, the lifetime of the FC is improved by 9.47%. Full article

Ultra violet (UV) solar energy can cause several negative effects to the skin and eyes in case of overexposure. To protect people from erythemal damage, personal erythemal exposure must be carefully assessed when outdoor activities are carried out. The direct measure with scientific instruments is impracticable to common people, and indirect methods assess the exposure only on the horizontal plane: this work developed a mathematical model to assess erythemal exposure to all the body districts. UVA irradiance and erythemal irradiance were measured on several inclined planes, oriented to the four cardinal directions, in seven environments with multiple sky conditions. The UV erythemal (UVE) ratio between erythemal irradiance on an inclined plane (Iery°) and UVA irradiance on a horizontal plane (IUVAh) was calculated. The results indicate that the UVE = Iery°/IUVAh is variable across the day and depends on the plane orientation, its degree of inclination, and sky conditions. Mathematical models to calculate erythemal exposure in clear, intermediate and overcast sky conditions on planes with different inclinations and orientations were derived from the daily trends of the UVE = Iery°/IUVAh. The application procedure of the mathematical model to the vertical plane oriented to the south is provided as an example. Full article

This paper designs and fabricates a small-type permanent-magnet linear motor and driver for automation applications. It covers structural design, magnetic circuit analysis, control strategies, and hardware development. Magnetic circuit analysis software JMAG is used for flux density distribution, back electromotive force (back-EMF), and electromagnetic force analysis. To address the lack of a complete closed magnetic circuit path at the ends of the linear motor, which causes magnetic field asymmetry, a phenomenon known as end effects, auxiliary core structures are proposed to compensate for the magnetic field at the ends. It successfully utilizes auxiliary cores to achieve the phase voltages of each phase, which are balanced at a phase voltage error of 0.02 V. To address the cogging force caused by variations in the magnetic reluctance of the core, this paper analyzes the relationship between electromagnetic force and mover position, conducting harmonic content analysis to obtain parameters. These parameters are applied to the designed cogging force control compensation strategy. It successfully achieves q-axis current compensation of around 1.05 A based on the mover’s position, ensuring that no jerking caused by cogging force occurs during closed-loop electromagnetic force control. The S-curve motion trajectory control is proposed to replace the traditional trapezoidal acceleration and deceleration, resulting in smoother position control of the linear motor. Simulations using JMAG-RT models in MATLAB/Simulink verified these control strategies. After verification, practical test results showed a maximum position error of approximately 5.0 μm. Practical tests show that the designed small-type permanent-magnet linear motor and its driver provide efficient, stable, and high-precision solutions for automation applications. Full article