Honeycomb sandwich structures are widely used in lightweight ***,these structures are subjected to extreme loading conditions,leading to potential failures due to delamination and debonding between the face sheet and ...
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Honeycomb sandwich structures are widely used in lightweight ***,these structures are subjected to extreme loading conditions,leading to potential failures due to delamination and debonding between the face sheet and the honeycomb ***,the present study is focused on the mechanical characterisation of honeycomb sandwich structures fabricated using advanced 3D printing *** continuous carbon fibres and ONYX-FR matrix materials have been used as raw materials for 3D printing of the specimens needed for various mechanical characterization testing;ONYX-FR is a commercial trade name for flame retardant short carbon fibre filled nylon filaments,used as a reinforcing material in Morkforged 3D *** and flatwise compression tests have been conducted for different configurations of honeycomb sandwich structures,fabricated by varying the face sheet thickness and core cell size,while keeping the core cell thickness and core height *** on these tests,the proposed structure with face sheet thickness of 3.2 mm and a core cell size of 12.7 mm exhibited the highest energy absorption and prevented delamination and debonding ***,3D printing technology can also be considered as an alternative method for sandwich structure ***,detailed parametric studies still need to be conducted to meet various other structural integrity criteria related to the lightweight applications.
It is widely recognized that civil engineering practice,including underground construction,is lagging the fast pace digital transformation taking place in many *** key reason for this revolution is the emergence and c...
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It is widely recognized that civil engineering practice,including underground construction,is lagging the fast pace digital transformation taking place in many *** key reason for this revolution is the emergence and convergence of digital technologies that include machine learning,artificial intelligence(AI),blockchain,cloud/edge computing,Internet of Things,5G communication,automation,digital twin,and *** parallel,Industry 4.0 is now complemented by Industry 5.0 that advocates a shift from economic value to societal value(sustainability,well-being,etc.).This means a shift from enterprises benefiting shareholders(profits)to stakeholders(people).
The total thermal resistance of bedding systems can be affected by environmental variables.A computational fluid dynamics(CFD)model of child manikin and duvet bedding system was developed to investigate the effects of...
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The total thermal resistance of bedding systems can be affected by environmental variables.A computational fluid dynamics(CFD)model of child manikin and duvet bedding system was developed to investigate the effects of air temperature(T_(air),5–25°C)and air velocity(V_(air),0.2–1.0 m/s)on the total thermal resistance(R_(t))of children’s bedding systems composed of duvet with different total filling weights(w,350–1000 g)in three sleep postures(P1,P2,and P3).Heat flux experiments were conducted to validate the CFD *** from the simulations indicated that a 1℃rise in T_(air)led to a reduction in R_(t)by 0.09–0.11 ***,R_(t)decreases with the increase in V_(air),and the reduction in R_(t)slows down as V_(air)*** in T_(air)and V_(air)had the most significant impact on R_(t)in the P2 sleep position and the least effect in the P3 sleep *** on the simulation results,a prediction equation for the R_(t)of the children’s bedding systems was *** research findings offer valuable insights into the scientific selection and design of children’s bedding systems,which are crucial for improving children’s sleep quality.
The development of modern mathematical theory, especially two-dimensional fractal graph algorithm, provides a possibility for large-scale landscape data processing. Landscape digital identification technology is an in...
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The development of modern mathematical theory, especially two-dimensional fractal graph algorithm, provides a possibility for large-scale landscape data processing. Landscape digital identification technology is an innovative technology based on digital landscape technology and computer identification of experimental data. It is an important artificial intelligence technology, which includes three steps: landscape acquisition, landscape processing and landscape identification. The characteristics of the scene in the landscape picture can be collected by special instruments, such as cameras, etc., and then the collected data can be processed by two-dimensional fractal graph algorithm, and finally realice the automatic identification of the landscape. For images with significant boundary characteristics, we can extract the boundary of the región quickly and accurately, so as to realice the segmentation of the region. However, when the edge features of the image are not good enough, there is little color difference between the background and the region, or there is some interference, the result will be very bad. In this paper, based on the two-dimensional fractal graph generation algorithm, a series of optimization of landscape architecture planning and design. The accuracy of landscape prime number can reflect whether specific types of landscape pictures can be correctly identified and divided. 200 Pictures are divided into six categories, namely Water scene, landscape scene, living scene, sky scene, architecture and transportation then exact ratios of two-dimensional fractal graph network -8s, two-dimensional fractal graph network - 16s, two-dimensional fractal graph network -32s and two-dimensional fractal graph network -32s. It reached the best level in pixel accuracy, average accuracy, average IU, etc., and the pixel accuracy has reached as high as 100%, average accuracy has reached 100%, average accuracy has reached 100%. When compared to the recommended algorith
Solid rocket motors have important applications in the propulsion of trans-media vehicles and underwater launched *** this paper,the ignition start-up process of an underwater solid rocket motor across a wide depth ra...
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Solid rocket motors have important applications in the propulsion of trans-media vehicles and underwater launched *** this paper,the ignition start-up process of an underwater solid rocket motor across a wide depth range has been numerically studied.A novel multi-domain integrated model has been developed by combining the solid propellant ignition and combustion model with the volume of fluid multiphase *** integrated model enables the coupled simulation of the propellant combustion and gas flow inside the motor,along with the gas jet evolution in the external water *** detailed flow field developments in the combustion chamber,nozzle,and wake field are carefully *** variation rules of the internal ballistics and thrust performance are also *** effects of environmental medium and operating depth on the ignition start-up process are systematically *** results show that the influence of the operating environment on the internal ballistic characteristics is primarily reflected in the initial period after the nozzle closure *** development of the gas jet in water lags significantly compared with that in *** the water depth increases,the ignition delay time of the motor is shortened,and the morphology evolution of the gas jet is significantly compressed and ***,the necking and bulging of the jet boundary near the nozzle outlet and the consequent shock oscillations are intensified,resulting in stronger fluctuations in the wake pressure field and motor thrust.
Anticipating the imminent surge of retired lithium-ion batteries(R-LIBs)from electric vehicles,the need for safe,cost-effective and environmentally friendly disposal technologies has *** paper seeks to offer a compreh...
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Anticipating the imminent surge of retired lithium-ion batteries(R-LIBs)from electric vehicles,the need for safe,cost-effective and environmentally friendly disposal technologies has *** paper seeks to offer a comprehensive overview of the entire disposal framework for R-LIBs,encompassing a broad spectrum of activities,including screening,repurposing and ***,we delve deeply into a thorough examination of current screening technologies,shifting the focus from a mere enumeration of screening methods to the exploration of the strategies for enhancing screening ***,we outline battery repurposing with associated key factors,summarizing stationary applications and sizing methods for R-LIBs in their second life.A particular light is shed on available reconditioning solutions,demonstrating their great potential in facilitating battery safety and lifetime in repurposing scenarios and identifying their techno-economic *** the realm of battery recycling,we present an extensive survey of pre-treatment options and subsequent material recovery ***,we introduce several global leading recyclers to illustrate their industrial processes and technical ***,relevant challenges and evolving trends are investigated in pursuit of a sustainable end-of-life management and disposal *** hope that this study can serve as a valuable resource for researchers,industry professionals and policymakers in this field,ultimately facilitating the adoption of proper disposal practices.
Herein,a novel MoS_(2)-stainless steel composite material was first synthetized via a 3D printing method(3DP MoS_(2)-SS)for peroxymonosulfate(PMS)activation and organics *** with MoS_(2)-SS powder/PMS system(0.37 g/(m...
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Herein,a novel MoS_(2)-stainless steel composite material was first synthetized via a 3D printing method(3DP MoS_(2)-SS)for peroxymonosulfate(PMS)activation and organics *** with MoS_(2)-SS powder/PMS system(0.37 g/(m^(2)/min)),4.3-fold higher k_(FLO)/S_(BET)value was obtained in 3DP MoS_(2)-SS/PMS system(1.60 g/(m^(2)/min),resulting from the superior utilization of active *** observed that 3DP MoS_(2)-SS significantly outperformed the 3DP SS due to the enhanced electron transfer rate and increased active ***,Mo^(4+)facilitated the Fe^(2+)/Fe^(3+)cycle,resulting in the rapid degradation of florfenicol(FLO).Quenching experiments and electron paramagnetic resonance spectra indicated that·OH,SO_(4)·^(-),O_(2)·^(-)and^(1)O_(2)were involved in the degradation of *** effect of influencing factors on the degradation of FLO were evaluated,and the optimized degradation efficiency of 98.69%was achieved at 1 mM PMS and pH of *** degradation products were detected by UPLC/MS analyses and several possible degradation pathways were proposed to be the cleavage of C-N bonds,dechlorination,hydrolysis,defluorination and *** addition,3DP MoS_(2)-SS/PMS system also demonstrated superior degradation performance for 2-chlorophenol,acetaminophen,ibuprofen and *** study provided deep insights into the MoS_(2)-SS catalyst prepared by 3DP technology for PMS activation and FLO-polluted water treatment.
This paper presents a comprehensive review of the latest advancements in fabric defect detection leveraging machine learning techniques. It introduces the characteristics of textile defects and public datasets, and en...
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As an aerial base station (BS), unmanned aerial vehicle (UAV) has been considered as a promising platform to provide wireless data service in future networks due to its flexible, swift and low cost features. However, ...
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As an aerial base station (BS), unmanned aerial vehicle (UAV) has been considered as a promising platform to provide wireless data service in future networks due to its flexible, swift and low cost features. However, since the suddenness and randomness of ground users’ (GUs’) data requirements, it is challenging for the UAV BSs to dynamically make decisions to provide real-time data services to GUs. In a multi-mode UAV-assisted wireless network, we formulate a multi-objective optimization problem to minimize the average peak age of information (APAoI) and energy consumption of UAVs, and to maximize the accumulated service data (ASD) for GUs. Therefore, this paper proposes the multi-agent hybrid twin delayed deep deterministic policy gradient (MAHTDDDPG) algorithm with hybrid action space design, which is empowered by centralized training and distributed execution (CTDE) framework. In the proposed algorithm, the UAVs can cooperatively make decisions by sharing the GU status information, in a result of jointly optimizing the UAV trajectory, mode selection and transmit power. Simulation results demonstrate that our proposed approach achieves 79.6% and 120.4% higher reward than MADDPG algorithm and HTD-DDPG algorithm respectively. IEEE
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