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Accurate wind speed measurement in low-pressure conditions is crucial for the thermal performance validation and attitude control of stratospheric aircraft. As air density decreases, traditional wind speed measurement systems based on principles such as dynamic pressure, heat transfer, ultrasound, and particle velocimetry face significant challenges when applied in low-pressure environments, often failing to achieve the required measurement accuracy. This paper presents the development of a wind speed simulation system based on a rotation method designed to operate in low-pressure conditions, utilizing a space environment simulation chamber in conjunction with a high-precision turntable. The system was employed to conduct response tests on a constant heat flow thermal sphere anemometer within a stratospheric pressure range of 1 kPa to 30 kPa. The experimental results revealed that at extremely low Reynolds numbers, the probe signal exhibited increasing nonlinearity, significantly affecting the response curve at pressures below 15 kPa. While the sensitivity of the hot-sphere probe remained relatively stable at wind speeds above 5 m/s, it decreased nonlinearly as the pressure dropped when wind speeds fell below 5 m/s. Furthermore, this paper analyzes the impact of various interpolation methods on wind speed conversion errors, providing valuable data to support the future development and validation of stratospheric aircraft. [ABSTRACT FROM AUTHOR]

Molecular dynamics (MD) simulations were first employed to achieve the optimal sintering temperature of carboxyl-functionalized graphene (GNS-COOH)-modified polyether ether ketone (PEEK)/polytetrafluoroethylene (PTFE) composites. A model of GNS-COOH/PEEK/PTFE composites was constructed to simulate the effects of different sintering temperatures on the mechanical and tribological properties, as well as their underlying atomic mechanisms. Samples of PTFE composites were prepared and characterized through experimental methods. Results revealed that the sintering temperature significantly affects the intermolecular forces, mechanical properties, and tribological characteristics of the composites. The agglomeration of the PEEK/PTFE composite matrix was effectively mitigated by introducing GNS-COOH. When the sintering temperature was controlled at 360 °C, the compressive strength of GNS-COOH/PEEK/PTFE composites was improved compared to GNS/PEEK/PTFE composites, albeit with a slight reduction in wear resistance. This study provides a theoretical reference for the preparation process and performance evaluation of new materials. [ABSTRACT FROM AUTHOR]

The paper presents an interdisciplinary study based on an experimental model for investigating clay sources to identify prehistoric human behavior regarding resources. The study focuses on the Middle Bronze Age (1955/1773–1739/1614 cal. BC) settlement of Siliştea-Pe Cetățuie in eastern Romania, where archaeological materials from the Costișa and Monteoru cultures were discovered. Standard criteria for macroscopic analysis and analytical techniques, such as optical microscopy (OM), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX), Micro-Fourier Transform Infrared Spectroscopy (µ-FTIR), and thermal analysis (DTA and TG), were used to investigate the ceramic material from multiple points of view. The results showed that there were no significant differences between the ceramics of the two communities. Putting together the data obtained from macroscopic and physico-chemical analyses helped in partially reconstructing ancient human behaviors related to the production and use of ceramic vessels. [ABSTRACT FROM AUTHOR]

The authors focus on innovating the research tool Urban's Test of Creativity to enhance the evaluation and efficiency of the educational process. This paper presents the possibility of measuring creativity and spatial imagination in the SketchUp virtual environment. Teachers and HR professionals in modern companies require an overview of the key competencies of students and graduates, essential for the transformation towards Industry 5.0. The authors utilize the proven concept of Urban's Test, modify it into a digital format, and integrate new elements that assess spatial visualization and functional creativity. Teachers and HR professionals gain an efficient tool that is easy to evaluate, time-efficient, and requires minimal infrastructure. The modified research tool is suitable for conducting action research and allows for comparing respondents' results using quantitative methods. This pilot study aimed to validate the modified test and its properties. A total of one hundred respondents, divided into five groups based on age and education (approximately 10 to 25 years old), were tested. The results confirmed that the concept of Urban's Test of Creativity can be successfully adapted for commonly available 3D modeling environments. Moreover, it was confirmed that within the target group, the level of spatial visualization improves gradually with age. [ABSTRACT FROM AUTHOR]

The German Aerospace Center designed, aero-mechanically optimized and experimentally investigated its own counter-rotating shrouded fan stage in the frame of the project CRISPmulti. Their target and the motivation of this work was, on the one hand, the generation of a highly accurate experimental database for the validation of the modern numerical design and optimization processes, and on the other hand, the development of a new innovative technology for the manufacturing of 3D fan blades made of a lightweight CFRP material. The original CRISP-1m test rig designed by the MTU Aero Engines in the 1980s was reused with the new blading for experimental investigation in the Multistage Two-Shaft Compressor Test Facility (M2VP) of the DLR in Cologne. The evaluation of the steady measurement results and the validation of the numerical simulation based on the pressure and temperature measurement are presented in this paper. [ABSTRACT FROM AUTHOR]

To gain a better understanding of the complex flow dynamics and stealth characteristics of submarines under maneuvering conditions, flow field experiments were conducted on the SUBOFF submarine model in the large low-speed wind tunnel at the China Ship Scientific Research Center (CSSRC). The three-dimensional velocity field above the hull at 6° and 9° yaw angles was captured using the stereo particle image velocimetry (SPIV) system. The experimental Reynolds numbers were selected as ReL = 0.46 × 107 and ReL = 1.08 × 107. The wake of the sail and the junction between the sail root and the hull were analyzed in detail, focusing on the core flow of the sail-tip vortex. The results revealed that at a larger yaw angle, the vorticity magnitude and turbulent kinetic energy (TKE) of the wake increased, and the downwash effect of the sail-tip vortex center became more pronounced. Furthermore, a higher Reynolds number resulted in an even more significant downwash of the vortex center, accompanied by a slight deviation towards the suction side. These experimental findings can contribute to the enrichment of the benchmark database for validating and improving numerical simulations of submarine wakes. [ABSTRACT FROM AUTHOR]

Freak waves have caused numerous accidents resulting in the collapse of ship structures due to structural plasticity, buckling, and instability, leading to the loss of life and property. Consequently, there is a growing academic interest in understanding ship structural collapsed responses induced by freak waves. This paper presents both numerical and experimental investigations on the structural collapse response of a ship model caused by freak waves. The study uses the Peregrine breather solution theory based on the Nonlinear Schrödinger (NLS) equation to generate a theoretical freak wave, and the nonlinear time-domain wave elevation and velocity field are obtained. The theoretical history of wave elevation is transferred into the wave maker of the wave tank to create experimental freak waves, and the velocity field of the freak wave is defined in a Computational Fluid Dynamics (CFD) solver to generate 3D numerical freak waves. A similar hydroelasto-plastic model is designed, and a hydroelasto-plastic experiment is conducted to observe experimental freak waves and large rotational deformations. The theoretical velocity field from the Peregrine breather solution theory, based on the NLS equation, is defined in a CFD platform to generate 3D numerical freak waves. A two-way Fluid-Structure Interaction (FSI) numerical hydroelasto-plastic approach coupling of CFD with a nonlinear Finite Element Method (FEM) solver is applied. Co-simulation of wave pressures and the structural collapsed response of the ship model caused by freak waves is performed. The wave elevation of experimental and numerical freak waves and the large rotational deformation of the buckling hinge are analyzed and compared, revealing a good agreement between the experiment and calculation. The maximum simulation rotational angle is 38.9°, while the maximum experimental rotational angle is equal to 42.3° for a typical wave case H2, which means numerical model accuracy and performance are acceptable for the simulating hydroelasto-plastic problem. The findings demonstrate that the numerical approach proposed in this study can effectively solve the hydroelasto-plastic response of ship structures in freak waves, offering a valuable tool for evaluating ship strength in these conditions and guiding future ship structural design. [ABSTRACT FROM AUTHOR]

The purpose of this work is a comparative analysis of the workpiece shape, and parameters of the stress-strain state during deformation on two radial-shear rolling mills with different roll configurations to determine the most suitable scheme for obtaining a screw reinforcement profile. During the FEM simulation of the radial-shear rolling process in the DEFORM program, a comparison of the workpiece shape change after rolling, equivalent strain, damage index, and Lode–Nadai index was carried out. Steel 10 (analogue of AISI 1010) was chosen as material workpiece. The analysis of the obtained data revealed that the most rational choice for the implementation of the reinforcement profile production process is the radial-shear rolling mill RSR 10-30. Subsequent modeling of the combined process of radial-shear rolling and twisting in a screw matrix showed that when using rolls of RSR 10-30 mill, the screw profile of the workpiece is formed successfully, whereas using rolls of the SVP-08 mill, the formation of a screw profile is impossible due to jamming due to an irregular cross-section shape. A laboratory experiment confirmed the possibility of forming a screw reinforcement profile at RSR 10-30 mill, and an assessment of the geometric parameters of the final workpiece showed full compliance with the dimensions of the profiles obtained during modeling and experiment. [ABSTRACT FROM AUTHOR]

Epoxy resin concrete, characterized by its superior mechanical properties, is frequently utilized for structural reinforcement and strengthening. However, its application in structural members remains limited. In this paper, the bond–slip behavior between steel reinforcement and epoxy resin concrete was investigated using a combination of experimental research and finite element analysis, with the objective of providing data support for substantiating the expanded use of epoxy resin concrete in structural members. The research methodology included 18 center-pullout tests and 14 finite element model calculations, focusing on the effects of variables such as epoxy resin concrete strength, steel reinforcement strength, steel reinforcement diameter and protective layer thickness on bond performance. The results reveal that the bond strength between epoxy resin concrete and steel reinforcement significantly surpasses that of ordinary concrete, being approximately 3.23 times higher given the equivalent strength level of the material; the improvement in the strength of both the epoxy resin concrete and steel reinforcement are observed to marginally increase the bond stress. Conversely, an increase in the diameter of the steel reinforcement and a reduction in the thickness of the protective layer of the concrete can lead to diminished bond stress and peak slip. Particularly, when the steel reinforcement strength is below 500 MPa, it tends to reach its yield strength and may even detach during the drawing process, indicating that the yielding of the steel reinforcement occurs before the loss of bond stress. In contrast, for a steel reinforcement strength exceeding 500 MPa, yielding does not precede bond stress loss, resulting in a distinct form of failure described as scraping plough type destruction. Compared to ordinary concrete, the peak of the epoxy resin concrete and steel reinforcement bond stress–slip curve is more pointed, indicating a rapid degradation to maximum bond stress and exhibiting a brittle nature. Overall, these peaks are sharper than those of ordinary concrete, indicating a rapid decline in bond stress post-peak, reflective of its brittle characteristics. [ABSTRACT FROM AUTHOR]

The interface of fresh-aged concrete represents a critical vulnerability within monolithic assembled monolithic concrete structures. In this paper, the shear performance of the interface between post-cast epoxy resin concrete and standard concrete is studied using experimental methods and finite element analysis. The objective is to furnish empirical data that support the broader adoption of epoxy resin concrete in assembled structures. A direct shear experiment of 19 Z-shaped samples and a computation of 20 finite element models were completed. The results from both experimental and computational analyses provided insights into several factors influencing the shear performance at the interface. These factors include the pre-cast part of concrete strength, the friction coefficient of the interface, the longitudinal reinforcement ratio at the interface, the compressive strength of concrete in the post-cast part, and confining stress. The findings indicate that utilizing epoxy resin concrete for post-cast material, roughing the interface, and setting keyways can enhance the shear performance of the interface so that it equals or even exceeds the cast-in situ sample. Optimal shear results are obtained when the compressive strength of the post-cast epoxy resin concrete closely matches that of the pre-cast conventional cement. Moreover, increasing the depth of the keyways rather than their width is more effective in improving the shear capacity of the sample. It is recommended that the depth of the keyway should be at least 30 mm, and its width should be no less than three times the depth. As the longitudinal reinforcement ratio at the interface increases, there is an enhancement in shear capacity coupled with a reduction in deformative performance. It is advisable to maintain this ratio below 1.0% to balance the strength and ductility effectively. [ABSTRACT FROM AUTHOR]

This study introduces a novel direct expansion air conditioning (DX AC) system with three evaporators (DX-TE) to enhance indoor temperature and humidity control. Operating in two modes, the DX-TE system provides variable cooling output, adapting to fluctuating indoor cooling loads while maintaining uniform air supply. Experimental and simulation studies were conducted to investigate the system's operational characteristics. An experimental setup was established to obtain preliminary steady-state data, followed by the development and validation of a steady-state mathematical model. Simulation studies were then performed to optimize the evaporator sizes. The results indicate that the DX-TE system delivers variable cooling capacities at a constant compressor speed and airflow rate, outperforming conventional variable frequency DX AC systems in cooling and dehumidification. The evaporator area ratio significantly impacts the system's performance, with smaller ratios yielding a larger output range. As the area ratio increases from 1:1 to 1:3, the cooling capacity range in Modes 1 and 2 increases by 33.6% and 14.3%, respectively, while the dehumidification range expands by 58.6% and 51.69%. [ABSTRACT FROM AUTHOR]

Extrusion-based printing of cementitious materials represents an innovative technology in civil engineering. The additive manufacturing process significantly influences the material properties in the hardened state, leading to anisotropic behaviour in terms of stiffness and strength compared to conventionally cast concrete. This experimental study aims to deepen the understanding of the mechanical behaviour of hardened printed concrete. Beam-like specimens with varying printing patterns, loading orientations and lengths are investigated within three-point bending tests (3PBT) and uniaxial compression tests (UCT). Homogenized material parameters such as Young's modulus, compressive and flexural tensile strength and density are statistically evaluated using optically measured displacement and strain fields on the specimen surface. The qualitative and quantitative results demonstrate a strong dependency of material properties and failure mechanisms on the printing pattern. The interfilamental and interlayer areas with weak adhesion are identified as the main reason for anisotropy. [ABSTRACT FROM AUTHOR]

The presented experimental program focuses on the design of high-performance dry concrete mixtures, which could find application in advanced manufacturing technologies, for example, additive solutions. The combination of high-performance concrete (HPC) with advanced or additive technologies provides new possibilities for constructing architecturally attractive buildings with high material requirements. The purpose of this study was to develop a dry mixture made from high-performance concrete that could be distributed directly in advanced or additive technologies of solutions in pre-prepared condition with all input materials (except for water) in order to reduce both financial and labor costs. This research specifically aimed to improve the basic strength characteristics—including mechanical (assessed using compressive strength, tensile splitting strength, and flexural strength tests) and durability properties (assessed using tests of resistance to frost, water, and defrosting chemicals)—of hardened mixtures, with partial insight into the rheology of fresh mixtures (consistency as assessed using the slump-flow test). Additionally, the load-bearing capacity of the selected mixtures in the form of specimens with concrete reinforcement was tested using a three-point bending test. A reference mixture with two liquid plasticizers—the first based on polycarboxylate and polyphosphonate and the second based on polyether carboxylate—was modified using a powdered plasticizer based on the polymerization product Glycol to create a dry mixture; the reference mixture was compared with the developed mixtures with respect to the above-mentioned properties. In general, the results show that the replacement of the aforementioned liquid plasticizers by a powdered plasticizer based on the polymerization product Glycol in the given mixtures is effective up to 5% (of the cement content) with regard to the mechanical and durability properties. The presented work provides an overview of the compared characteristics, which will serve as a basis for future research into the development of additive manufacturing technologies in the conditions of the Czech Republic while respecting the principles of sustainable construction. [ABSTRACT FROM AUTHOR]

To overcome the issue of unstable speed output encountered by cotton pickers operating in harsh environments and subject to frequent external load fluctuations, a hydraulic–mechanical transmission (HMT) for cotton pickers is proposed in this study. By analyzing the driving system of the cotton picker, a Lavira-based HMT scheme is developed. The matching characteristics of the HMT speed ratio are analyzed, a continuity and smoothness test of the speed ratio of the changing segment is carried out, and the influence law of smoothness of the HMT changing segment is discussed. The results show that the HMT system effectively satisfies the driving speed requirements for both field harvesting and road transportation of cotton pickers. The HMT speed ratio is continuously controllable and the design is reasonable. The HMT load torque and the oil pressure in the main oil circuit have a significant impact on the smoothness indicators of speed reduction and dynamic load. Additionally, the flow rate of the governor valve has a notable effect on the smoothness indicator of sliding friction power. However, the engine's output speed has no significant influence on the HMT's smoothness. This research can provide theoretical support for the development and design of cotton picker gearboxes and the transmission characteristics and experimental research of off-road vehicle gearboxes. [ABSTRACT FROM AUTHOR]

Due to the extensive utilization of liquid nature gas (abbreviated as LNG) resources and a multitude of considerations, LNG storage tanks are gradually transitioning towards smaller footprints and heightened safety standards. Consequently, underground LNG storage tanks are being designed and constructed. However, underground LNG storage tanks release a considerable quantity of cold into the ground under both accidental and normal conditions. The influence of cold results in the ground freezing, which further compromises the safety of the structure. Existing research has neglected to consider the effects of this. This oversight could potentially lead to serious safety accidents. In this work, a complete set of experiments using a novel LNG underground storage tank fluid-solid-thermal coupled cryogenic leakage scale model were conducted for the first time to simulate the effect of the tank on the soil temperature field, stress field, and displacement field and to analyze the development of the three fields and the results of the effect. This research helps the related personnel to better design, construct, and evaluate the LNG underground storage tanks to avoid the catastrophic engineering risks associated with cryogenic leakage and helps to improve the design process of LNG underground storage tanks. [ABSTRACT FROM AUTHOR]

Indirect evaporative coolers (IECs) use the latent heat of water evaporation to cool air. This system has the advantage of operating at low power without a compressor and does not increase the absolute humidity of the air. However, an IEC is difficult to use on its own because its cooling capacity is limited by the theoretical constraint of the wet-bulb temperature of the ambient air. Therefore, an air conditioning unit (ACU) was integrated with an IEC and experimentally evaluated in this study. The dry and wet channels of the IEC were integrated with an ACU evaporator and a condenser, unlike previous studies where IECs were integrated solely with either an evaporator or a condenser. This reduced the cooling load on the evaporator and helped the condenser to dissipate heat to improve the performance of the existing ACU. In addition, the IEC was equipped with baffles to improve its performance. To assess the extent of the performance improvement due to integration with the IEC, comparisons were also performed under the same experimental conditions with an ACU only. The results showed that under conditions with an indoor temperature of 32 °C, integrating the IEC with the ACU increased the average cooling capacity by 13.1% and decreased the average power consumption by 8.60% during the test period, compared to using only the ACU. Consequently, the average coefficient of performance (COP) increased by 19.5% compared to using only the ACU under the same conditions. [ABSTRACT FROM AUTHOR]

This study examined whether public opinion on drug addiction, perceived culpability/responsibility, and punishment were impacted by statements from medical associations that drug addiction is a disease and not a choice. We utilized an experimental information provision survey distributed via Qualtrics to heads of household in South Carolina with an associated email address. The randomized treatment variable had two conditions. The first condition presented participants with a statement from several noteworthy medical associations/institutions noting that drug addiction is a disease. The second condition provided no statement (control condition). Results from our sample of over 5000 indicated that a large majority of respondents felt that individuals who have been diagnosed with a drug addiction should be fully responsible for any crimes that they commit. The presentation of official statements that addiction was a disease did not produce meaningful differences from the control group. Additionally, a large majority of respondents did not agree that addiction should relieve a defendant from punishment for drug crimes, theft crimes, or violent crimes. Here again, the presentation of official statements that addiction was a disease did not produce meaningful differences from the control groups. Finally, our results indicated that a majority of respondents viewed addiction as both a choice and disease, and the presentation of official statements that addiction was a disease did not meaningfully alter any responses. [ABSTRACT FROM AUTHOR]

Augmented reality (AR) improves science education by facilitating teaching and experiments in schools and universities. Studies show positive effects, like increased motivation and improved concept connections, but there is a lack of consistency in the implementation and investigation of AR in science experiments. This review examines AR usage, criteria, design parameters for the development of AR applications and the validation methods, taking into account the PRISMA guidelines. A Web of Science database search using "Publish or Perish" software (version 23.4.0) identified 247 potentially relevant articles from 2000 to March 2024 in international, peer-reviewed journals. After removing duplicates, inaccessible abstracts, and applying inclusion and exclusion criteria, 40 studies were selected for in-depth analysis. Physics had the most AR applications, primarily for visualizing invisible properties. Most studies used quantitative or qualitative methods, only a few used both or did not conduct empirical research. Research questions varied, but common drawbacks included small sample sizes and low use of AR design parameters such as interactivity, adaptivity, realistic representation and use of game elements. This review identifies opportunities for improvement in the implementation and investigation of AR in science education experiments and emphasizes consistent and rigorous approaches to fully exploit the benefits of AR in science education. [ABSTRACT FROM AUTHOR]

Drawing upon advancements in profiling technology, this paper presents an innovative lateral profiling mechanism for the header to improve mowing efficiency and the ability to adapt to terrain for river dike mowers. It delves into the imitation principle and forced situations. Furthermore, a novel lawn protection boot design has been introduced, capable of adjusting mowing heights with swift transitions. The structural integrity of this boot has been optimized through rigorous finite element analysis. Meanwhile, the rolling shaft and cutter have been carefully selected and designed, with a mechanical model of the cutter established to examine its motion and force characteristics. In addition, hydraulic circuits tailored to fulfill the required functions of the header have been devised, and key hydraulic components have been appropriately selected. Key components are subjected to finite element analysis by using ANSYS to verify and optimize their structural strength. Prototype testing and field trials are subsequently conducted, revealing that the mower can achieve a mowing speed of 0.85 m/s on flat ground and a 25-degree slope, thereby fulfilling the design requirements for mowing speed. The imitation mechanism adapts to different embankment terrains. Notably, the lawn protection boots offer adjustable mowing heights of 10.4 cm, 12 cm, and 14 cm, respectively, with a height adjustment range of approximately 2 cm for each position, meeting the requirement for adjusting mowing heights. In addition, the transition time between different positions of the lawn protection boots is less than 5 min, achieving rapid switching and operational efficiency. Furthermore, a mowing uniformity test is conducted by using a header equipped with profiling functionality. The results reveal that the mowing effect of the profiling header meets design requirements, demonstrating its effectiveness and reliability in agricultural applications. [ABSTRACT FROM AUTHOR]

In this study, we proposed and experimentally investigated a novel solar-assisted heat pump (SAHP) system integrated with a dual-purpose solar collector (DPSC). The DPSC is a solar collector designed to produce both heated air and hot water, and the proposed configuration of the SAHP utilizes both heated air and water simultaneously to improve the performance of the heat pump. The experiment was conducted under natural weather conditions on a clear day. The performance of the proposed system was evaluated and compared to that of a conventional air-type SAHP system. The results showed that the coefficient of performance (COP) of the proposed system, which takes into account the performance of the DPSC, heat pump, and the power consumption of both the blower and pump, was 3.14. In contrast, the system COP of the SAHP operated as conventional air-type SAHP was 2.33. This finding clearly demonstrated that the proposed SAHP performed better than the traditional SAHP mode. Additionally, the results of this research are useful as fundamental data related to SAHP combined with DPSC. [ABSTRACT FROM AUTHOR]

The paper presents a static analysis of the buckling and post-buckling state of thin-walled cold-formed steel (TWCFS) lipped channel section beam-columns subjected to eccentric compression. Eccentricity is taken into consideration relative to both major and minor principal axes. An analytical–numerical solution to the buckling and post-buckling problems is described. The solution is based on the theory of thin plates. Equations of equilibrium of section walls are derived from the principle of stationary energy. Then, to solve the problem, the finite difference (FDM) and Newton–Raphson methods are applied. Linear (buckling) and nonlinear (post-buckling) analyses are performed. As a result, pre- and post-buckling equilibrium paths are determined. Comparisons of the obtained numerical results, FE simulation results, and experimental test results are carried out and presented in comparative load-shortening diagrams. Additionally, a comparison of the buckling forces and buckling modes obtained from theoretical analysis and experiments is presented. [ABSTRACT FROM AUTHOR]

This article describes a transport planning model which applies a simulation to support decision-making in quarry operations. The analysis of the transport system was used as input for creating the model and the subsequent research. There are five loading points in the quarry from which, according to the plan, the quarry stone is transported to the crusher, where it proceeds for further processing. The required daily capacity of the downstream technological line is 3800 t/day. Based on the analysis, it was found that it was impossible to fulfill this requirement from the two loading points which were the furthest from the unloading point. For this reason, two simulation models of the transport system were created. The first simulation model is a transport system (loading, removal and dumping of quarry stone) from one loading point. Simulation experiments were performed on this model for all loading points. The findings from the analysis confirmed the results of the simulation experiments. Subsequently, a model of the combined quarry stone removal from two loading points was proposed. The model was designed for two variants of dividing the work shift into two work sections. In the model, which had a tabular form, the combinations of loading points and values of the minimum number of unloaded cars for stone removal were suitable to ensure its necessary daily capacity. The last part of this research was expanding the original model with an additional loading point. Several experiments were performed on this model. The aim of these experiments was to verify the combinations of loading points presented in the proposed model and the combinations of unsatisfactory loading points. Based on the research results, the transport planning model and simulation models are suitable additional tools for the decision-making process in removing quarry stone. [ABSTRACT FROM AUTHOR]

This research aimed to analyze the possibility of installing an ultrasonic emitter in an already manufactured car and to prove the possibility of cleaning the exhaust gases of an internal combustion engine through the action of an ultrasonic wave due to coagulation and examining the optimal regimes of its work. The existing theoretical solution to describe the proposed process was analyzed. A Mercedes-Benz M-Class ML 270 CDI MT car with the OM 612 DE 27 LA Diesel engine was used for the experiment. An ultrasound generator and an ultrasound emitter were connected to the muffler. The stand was connected to the car via the inlet with a rubber hose that directs the exhaust gases out of the car. The crankshaft speed of the engine was changed in the range of 750 to 1250 rpm, which corresponds to urban conditions when cars are moving in heavy traffic jams. The content of CH, CO, CO2, and O2 in the exhaust gas of the vehicle was determined as a function of the crankshaft speed without ultrasonic exposure and with ultrasonic exposure at an ultrasound frequency of 25, 28, and 40 kHz. The results of the experiment showed that the introduction of an ultrasonic emitter into the muffler reduced the smoke content of the gas, increased the oxygen content, and reduced the amount of carbon dioxide in the exhaust gases. With an increase in the ratio between the ultrasonic frequency and the angular velocity of the engine crankshaft (f/ω), the smoke content of the gas also decreased. At the maximum values of ultrasonic frequency and angular velocity of the engine crankshaft selected in the experimental studies, the minimum value of the ratio of gas smoke indicators was achieved, and the degree of purification was 10–13%. Such results correspond to the condition of optimal operation of the ultrasonic muffler, where the ratio of gas to smoke values should tend to a minimum. These results confirm the potential of using ultrasound as a method for cleaning exhaust gases and underline the need for further research in this area. [ABSTRACT FROM AUTHOR]

An air-based photovoltaic thermal collector (PVTC) is a system that generates both electricity and heat using air flowing over a photovoltaic (PV) module. This system offers the advantage of easy maintenance; however, it suffers from lower thermal efficiency compared to other PVTCs, mostly owing to the low heat capacity of air. Thus, this study introduces a novel PVTC incorporating dual ducts and semicircular turbulators, which were experimentally evaluated under actual weather conditions in the Republic of Korea. The proposed PVTC was compared with two other types of PVTC: one is a single-duct PVTC with semicircular turbulators, and the other is a dual-duct PVTC without turbulators. The results showed that the thermal efficiency of the proposed PVTC increased by approximately 88.7% compared to the single-duct PVTC with a turbulator and by 9.3% compared to the dual-duct PVTC without a turbulator. The electrical efficiency showed a slight decrease of about 7.2% compared to the single-duct PVTC but an increase of 1.4% compared to the dual-duct PVTC without a turbulator. Overall, the total efficiency of the proposed PVTC increased by 54.2% and 7.7% compared to the single-duct PVTC and the dual-duct PVTC without a turbulator, respectively. These experimental results demonstrate that attaching dual ducts and semicircular turbulators to an existing PVTC increases the daily thermal energy output, which ultimately enhances the total daily energy output. [ABSTRACT FROM AUTHOR]

A series of experiments were carried out to investigate the performance of a WEC rotor with platform motion. To achieve platform motion, a forced motion device with a rotor was installed in the Ocean Engineering Basin. In this study, the rotor's performance was examined at various phase stages between incoming waves at three wave heights, and compared to a rotor without a PTO system. The phase stage where the rotor exhibited the largest pitch motion was identified, and the efficiencies of the rotor with the PTO system were analyzed during this stage. Without the PTO system, the rotor experienced its largest pitch motion when the rotating center was positioned at the zero-up crossing point of the incoming waves at three different wave heights. Furthermore, it was observed that in the optimal phase, the rotor's efficiency increased with relatively large platform motion. These findings provide fundamental data for rotor design. [ABSTRACT FROM AUTHOR]

In response to the significant challenge posed by the trade-off between the efficiency of separating potato soil and minimizing potato peel damage in the 4SW-170 potato excavator, this study focused on enhancing the design of the swing separation sieve. The objective was to develop a novel separation sieve comprising three distinct orders of sieve surfaces. Building upon this foundation, the EDEM-Adams coupled simulation method was employed to explore the fragmentation and separation attributes of potato–soil aggregates. This investigation aimed to elucidate the behavior of potato–soil aggregates within the operational scope of the novel swing separation sieve. Subsequently, the optimized parameters were validated through field tests. The findings indicate a direct correlation between the fracture ratio of the cohesive bond and the crank speed, illustrating an increase in the former with higher crank speeds. Conversely, an inverse relationship exists between the fracture ratio and the sieve inclination angle, demonstrating a decrease in the ratio as the sieve inclination increases. At a machine speed of 1.9 km/h, the fracture ratio of the cohesive bond attains its peak value. The force exerted on potatoes at their maximum point escalates with rising crank speed but diminishes with increasing machine speed. Conversely, the effect of sieve inclination on the peak force applied to the potatoes is deemed inconsequential. The most effective parameter configuration for the separation sieve comprises a crank speed of 180 revolutions per minute (r/min), a machine speed of 1.9 km per hour (km/h), and a sieve inclination of 14.4°. Field trials have confirmed that the parameter combination yielded a potato detection rate of 98.01% and a mere 0.68% rate of potato skin breakage, meeting the stipulated technical specifications of the potato harvester. [ABSTRACT FROM AUTHOR]

This contribution gives basic information about the mechanical behavior of the facial part of the human skull cranium, i.e., the splanchnocranium, associated with external loads and injuries caused mainly by brachial violence. The main areas suffering from such violence include the orbit, frontal, and zygomatic bones. In this paper, as a first approach, brachial violence was simulated via quasi-static compression laboratory tests, in which cadaveric skulls were subjected to a load in a testing machine, increasing till fractures occurred. The test skulls were also used for research into the dynamic behavior, in which experimental and numerical analyses were performed. A relatively high variability in forces inducing the fractures has been observed (143–1403 N). The results lay the basis for applications mainly in forensic science, surgery, and ophthalmology. [ABSTRACT FROM AUTHOR]

Does it matter whether charitable organizations address potential donors with an informal or formal second-person pronoun in their appeal to donate money? This study shows that it does indeed make a difference. Using an informal pronoun of address can have a positive effect on intentions to donate money. An online experiment (n = 220) found that a charitable appeal to potential donors was more effective when an informal rather than a formal second-person pronoun was used in Dutch, particularly for altruistic people. We discuss the potential explanations of this effect, concentrating on the association between the informal pronoun of address and perceived closeness, and the generic versus deictic reference of informal pronouns of address in Dutch. [ABSTRACT FROM AUTHOR]

This article outlines the relevance of building online telemetry systems for online monitoring of the technical conditions of rolling mill equipment. Electromechanical systems of the horizontal stand of the plate Mill 5000 are described, when operating in harsh conditions caused by the shock loading when workpieces enter the stand. It is noted that dynamic torque overloads, exceeding the rated motor torque by many-fold, cause the fatigue failure of spindle joints and breakage of rolls. In this regard, the development and implementation of systems for monitoring the elastic torque on spindles are extremely urgent. This issue has long been studied, but the references provide no information on the building principles and hardware composition of such systems. The use of strain gauges connected according to a balanced bridge circuit to measure the elastic torque is justified. This paper's contribution is the proposed modular principle for building a telemetry monitoring system based on the analysis of known techniques for measuring and transmitting diagnostic data. The developed system structure is provided and the concept of data transfer and processing are explained. This article suggests the inductive power supply of a measuring unit mounted on a shaft without the use of batteries. A hardware structure was developed to be applied in a system for measuring, transmitting, and visualizing signals proportional to the elastic torque, manufactured on the basis of data measuring instruments by leading companies. The specifics of placement and connection of strain gauges are considered. The hardware providing a wireless power supply to the signal encoder and digital data transfer between the transmitter and receiver is described. The results of implementing the system on Mill 5000 are provided. The installation of a telemetry ring and a receiving head for the inductive power supply and data reception is shown. An experimental assessment of the elastic torques occurring when workpieces enter the cage was obtained by implementing a drive control algorithm which provided biting in the drive acceleration mode. The reliability of measuring the elastic torque with an error not exceeding ±5% and the reduction of dynamic loads on the spindle by 1.3–1.5 times due to the elimination of impacts from closing angular gaps in spindle joints was confirmed. This increases the service life of mechanical equipment and reduces the cost of eliminating the accident aftermath. The prospect of modifying the developed system into a cyber-physical system for monitoring the rolling mill's mechatronic equipment conditions is shown. [ABSTRACT FROM AUTHOR]

An experiment was conducted on a prestressed concrete (PC) composite girder bridge with steel truss webs to investigate its flexural performance. The mechanical characteristics and failure modes of a PC composite girder bridge with steel truss webs was clarified. Finite element (FE) analysis was carried out, and the influence of the girder height-to-span ratio and eccentric loading effect on the flexural performance of a composite beam bridge with a steel truss web was discussed. The method for calculating the cracking bending moment, the bending moment at the rebar yield stage, and the ultimate bending moment of a PC composite girder with steel truss webs was proposed. Key findings include that, in both the elastic and cracking elastic stages, the strain of the bottom and top conforms to the plane-section assumption. Throughout the loading process, there was no occurrence of joint failure or local buckling failure in the steel truss webs; the composite girder ultimately fails due to excessive deformation, indicating that the overall mechanical performance of the composite beam is good. The deflection and stress in the mid-span section decrease with an increasing height-to-span ratio, and there are significant impacts of eccentric loading on deflection and stress. Compared with the results of the FE analysis and test, the calculation methods of the cracking moment, reinforcement yield moment, and ultimate moment of PC composite girders with steel truss webs presented in this paper have a high accuracy. [ABSTRACT FROM AUTHOR]

The firmware developed for the readout and trigger processing of the information emerging from the BIS78-RPC Muon Spectrometer chambers in the ATLAS experiment at CERN is presented here, together with data processing techniques, data acquisition software, and tests of the readout chain system, which represent efforts to make these chambers operational in the ATLAS experiment. This work is performed in the context of the BIS78-RPC project, which deals with the pilot deployment of a new generation of sMDT+RPCs in the experiment. Such chambers are planned to be fully deployed in the whole barrel inner layer of the Muon Spectrometer during the Phase II upgrade of the ATLAS experiment. On-chamber front-ends include an amplifier, a discriminator ASIC, and an LVDS transmitter. The signal is digitized by CERN HPTDC chips and then processed by an FPGA, which is the heart of the readout and trigger processing, using various techniques. [ABSTRACT FROM AUTHOR]

The long-term challenges of climate change are becoming increasingly evident. Considering the ever-increasing need for energy in parallel with population growth and the impact of greenhouse gases, the built environment is among the issues that should be addressed as a priority. As international agreements, the EU, and national legislation become institutionalized, the need to decarbonize the built environment increases. For this reason, there is a need for an understanding that enables the transition to a more sustainable society. In line with this understanding, a transition to zero-energy buildings is required. In this article, the evaluation framework is created by combining the Transition Management (TM) approach, which is a framework developed to understand long-term changes in culture, structure, and practices for sustainable development solutions, and the Strategic Niche Management (SNM) approach, which encourages technological and social change to initiate sustainable innovations at the niche level. Applications regarding energy efficiency and niche formation for the built environment in Türkiye (Gaziantep) were discussed. When the applications and theories are evaluated together, it can be seen that the applications carried out in Gaziantep regarding Nearly Zero Energy Buildings may be starter experiments. However, these projects are insufficient to create a niche, and the developments are progressing very slowly. [ABSTRACT FROM AUTHOR]

The new technique of filming in autumn and planting directly through the plastic film in spring is an effective method for water-saving and drought-resistant commercial potato production. However, there are currently no supporting film-drilling seeders available. To address this, a new potato seeder machine has been specifically designed for planting potatoes in the dryland, hilly, and mountainous areas of northwest China. This machine can perform top mulching and hole planting in both the autumn and spring seasons. This innovative potato seeder accomplishes several tasks simultaneously: seeding, inoculation (if desired), hole punching through the mulch film, seed placement, and soil covering. The machine features an optimized spoon-chain seeder with an eccentric coupling mechanism that ensures the hole-punching device stays perpendicular to the ground throughout planting, minimizing damage to the mulch film. Additionally, a dedicated seeding valve opening and closing mechanism was designed to extend the opening time of the hole-forming device's movable mouth beyond the potato's falling time, guaranteeing successful seed placement. Furthermore, a soil-covering device specifically designed for use with mulch film ensures proper soil retention after seeding. Through computer-aided design (RecurDyn V9R5 software) analysis, the hole-punching device's penetrating angle was optimized to minimize the tearing of the mulch film during entry into and exit from the soil. Rigorous field testing demonstrated the machine's effectiveness. The seeder achieved a 92% success rate for proper planting depth, an 88% success rate for accurate seed potato spacing, a 98% success rate for avoiding overplanting, and a 99% success rate for eliminating missed planting spots. These field test results meet or exceed national and industry standards, validating the machine's design goals. In essence, this innovative potato seeder, with its eccentric coupling mechanism, offers a one-pass solution for potato seeding, inoculation (optional), planting, and soil covering, significantly improving efficiency. [ABSTRACT FROM AUTHOR]

To address the inefficiency and instability of automatic transplanting machines, a dual-row seedling pick-up device and its corresponding control system were developed. Existing seedling end-effectors are primarily mechanically controlled, and the seedling needles can easily cause damage to the interior of the bowl. In order to reduce the damage inflicted by the end-effectors to the bowl, this paper conducted a mechanical analysis of the end-effector. At the same time, a buffer optimization analysis was conducted on the operation of the end-effector, and a flexible pneumatic end-effector for seedling picking was designed. The control system combined the detection of multiple sensors to monitor the process of seedling picking and throwing. By coordinating the lifting cylinder and clamping cylinder, the system effectively reduced seedling pot damage while improving seedling picking efficiency. By setting the operating parameters of the servo motor, the goal of low-speed and high-efficiency seedling picking was achieved. To evaluate the performance of the control system, the linear displacement sensors and acceleration testing systems were used to analyze the performance of the seedling throwing. The results showed that the seedling picking efficiency could reach 180 plants min−1, with no significant difference between the actual measured moving distance and the theoretical setting distance. The positioning error remained stable between 0.5 and 0.9 mm, which met the requirements for seedling picking accuracy. The buffer optimization design reduced the peak acceleration of the end-effector from −22.1 m/s2 to −13.4 m/s2, and the peak value was reduced by 39.4%, which proved the significant effectiveness of the buffer design. A performance test was conducted using 128-hole seed trays and 33-day-old cabbage seedlings for seedling picking and throwing. When the planting frequency reached 90 plants/row·min−1, the average success rate of picking and throwing seedlings was 97.3%. This indicates that the various components of the designed seedling pick-up device work in good coordination during operation, and the control system operates stably. Technical requirements for the automatic mechanical transplanting of tray seedlings were achieved, which can provide reference for research on automatic transplanting machines. [ABSTRACT FROM AUTHOR]

In order to address the issues of poor stability in vehicle speed and deteriorated spraying quality caused by changes in road slope and the decrease in overall mass due to liquid spraying, this study focuses on analyzing the structure and longitudinal dynamic characteristics of a 4WID high ground clearance self-propelled electric sprayer. By utilizing MATLAB/Simulink software, three subsystems, namely, the inverse longitudinal dynamics model, torque distribution model, and motor model, are established. The model takes into account the effects of longitudinal driving resistance, slope, and vehicle roll angle on the distribution of loads among the four wheels during slope driving. A seven-degrees-of-freedom dynamic model is developed. A hierarchical control structure is designed, incorporating an upper-level PID controller and a lower-level fuzzy PID controller, to control the overall system. The control algorithms are tailored to the specific characteristics of the sprayer's operation, and simulation experiments are conducted under the corresponding operating conditions. Building upon this, a sensor-equipped experimental platform is set up in the self-propelled sprayer manufactured by the team in the preliminary stage. Real vehicle tests are conducted in two scenarios: transition transportation and field operations, with the evaluation of the overall vehicle speed serving as the performance metric to validate the correctness of the model and the control theory. [ABSTRACT FROM AUTHOR]

In order to further exploit the production advantages of rice throwing, this paper proposes a systematically designed throwing device suitable for integration with unmanned aerial vehicles (UAVs). The device primarily comprises a seedling carrying and connection system, a seedling pushing mechanism, and a seedling guiding device. The operational principles and workflow of the device are initially elucidated. Subsequently, an analysis of factors influencing rice throwing effectiveness is conducted, with throwing height, working speed, and the bottom diameter of the seedling guide tube identified as key factors. Seedling spacing uniformity and seedling uprightness are designated as performance indicators. A three-factor, three-level response surface experiment is conducted, yielding regression models for the experimental indicators. Through an analysis of the response surface, the optimal parameter combination is determined to be a throwing height of 142.79 cm, a working speed of 55.38 r/min, and a bottom diameter of the seedling guide tube of 43.51 mm. At these parameters, the model predicts a seedling spacing uniformity of 88.43% and a seedling uprightness of 88.12%. Field experiments validate the accuracy of the optimized model results. Experimental data indicate that under the optimal operational parameters calculated by the regression model, the seedling spacing uniformity is 86.7%, and the seedling uprightness is 84.2%. The experimental results meet the design requirements, providing valuable insights for UAV rice-throwing operations. [ABSTRACT FROM AUTHOR]

The erosive wear encountered in some industrial processes results in economic loss and even disastrous consequences. Hitherto, the mechanism of the erosive wear is not clear, especially when the erosive wear is caused by large particles (>3.0 mm) carried by a flowing liquid. Current approaches of predicting erosive wear need improvement, and the optimization of relevant equipment and systems lacks a sound guidance. It is of significance to further explore such a subject based on the relevant literature. The present review commences with a theoretical analysis of the dynamics of large particles and the fundamental mechanism of erosion. Then the characteristics of the erosion of various equipment are explicated. Effects of influential factors such as particle size and properties of the target material are analyzed. Subsequently, commonly used erosion models, measurement techniques, and numerical methods are described and discussed. Based on established knowledge and the studies reported, some expectations for future work are proposed. [ABSTRACT FROM AUTHOR]

This paper takes a low-energy building in Changchun, China, as an object to test and study the characteristics of two heating modes, AC/DC (Alternative current/Direct current) switching and AC/DC synthesis, from the perspectives of temperature change, irradiation intensity, power generation, electricity consumption, etc. Firstly, the experimental research was conducted under two heating cable modes by establishing mathematical models and a test rig, and it was found that the photoelectric conversion efficiency on sunny, cloudy, and overcast days was 18%, 14.5%, and 12%, respectively. A simulation model was established by TRNSYS to run an ultra-low-energy building throughout the year. It was found that the highest and lowest monthly power generation occurred in February and July, respectively. The annual power generation of the system was 6614 kWh, and the heating season power generation was 3293.42 kWh. In the current research, the DC electricity consumption was slightly higher than the AC electricity consumption. Under conditions of similar radiation intensity and power generation, the indoor temperature of the AC/DC synthesis cable heating mode were 1.38% higher than the AC/DC switching heating able mode, and the electricity consumption were 10.9% and 4.76% higher, respectively, than those of the AC switching heating cable mode. This is of great significance for clean-energy heating, energy savings, and emissions reduction in northern China. [ABSTRACT FROM AUTHOR]

In Japan, the heavy rain disaster that occurred in July 2018 revealed that about 70% of the streams affected by debris flows that resulted in human casualties were small, steep mountain streams with a catchment area < 0.05 km2. Generally, many streams that are close to residential houses or roads do not have a constant flow of water and are known to pose a high risk of human fatalities when a debris flow occurs. This study aimed to promote sediment control as debris flow countermeasures in non-flowing mountain streams, utilizing secondary manufactured products (permeable debris flow barriers) with excellent constructability, focusing on the mechanism of sediment outflow from the gaps between a permeable debris flow barrier and mountain stream side banks. The necessity and effectiveness of preventative measures based on preliminary experimental results are presented. When impermeable structures were installed at both ends of the permeable debris flow barrier side, compared to using only a permeable debris flow barrier (covering the entire width with permeable debris flow barriers), we found that the capture function improved significantly, achieving a 200% increase in effectiveness. [ABSTRACT FROM AUTHOR]

This study investigates the impact of applying digital learning through the use of augmented reality technology in university education on student learning outcomes. The research strategy and design were developed with the aim of answering the following research questions: Do different forms of active learning using augmented reality (AR) influence student knowledge?; Is it possible to assess the impact of AR implementation in teaching on the quality of learning outcomes? The main goal of his research is to identify the information objects Situated, Games, and Research within the Active Learning information package and, based on them, examine and determine the existence, relationship, and intensity of connections of the created information construct Knowledge. The research was conducted through the application of an experimental technique with incorporated survey and knowledge test methods on a sample of 270 participants, in 3 groups of 90 students each. Knowledge was examined through initial tests and final tests for each form of the conducted experiment: Situated, Games, and Research. The obtained results were processed using statistical methods of calculating correlation coefficients and factor analysis. The results indicate that students taught through all forms of AR active learning achieve a statistically significantly higher level of knowledge, thus confirming the hypothesis. In conclusion, the obtained research results provide a basis for further research using the described methodology and the further development of educational application solutions based on new AR technologies. [ABSTRACT FROM AUTHOR]

Identifying bridge damage using a movable test vehicle is highly regarded for its mobility, cost-effectiveness, and broad monitoring coverage. Previous studies have shown that the residual contact-point (CP) response between connected vehicles is free of the impact of vehicle self-vibrations and road roughness, making it particularly suitable for the indirect extraction of bridge modal properties. However, most experimental campaigns regarding contact-point (CP) responses focus on a single-axle testing vehicle within a non-moving state. This study aims to theoretically and experimentally identify bridge damage using the instantaneous amplitude squared (IAS) extracted from the residual CP response of a two-axle passing vehicle. First, the closed-form solution of the residual CP acceleration was derived for a two-axle vehicle interacting with a simply supported beam. The IAS index was constructed from the driving frequency of the residual CP acceleration. Then, numerical investigations using finite element simulation were conducted to validate using the IAS index for indirect bridge damage identification. The application scope of the approach under various vehicle speeds and road roughness grades was examined. Finally, a laboratory vehicle–bridge interaction system was tested to validate the approach. Numerical studies demonstrated that bridge damage could be directly determined by observing the IAS abnormalities, which were baseline-free. The IAS from the residual CP response outperformed the IAS from CP responses in identifying bridge damage. However, it was better to use the IAS when the vehicle speed was no greater than 2 m/s and the grade of the road surface roughness was not high. Laboratory tests showed that it was possible to identify bridge damage using the IAS extracted from the residual CP acceleration under perfect road surfaces. However, it fell short under rough road surfaces. Hence, further experiments are required to fully examine the capacity of the IAS for bridge damage identification in practical applications. [ABSTRACT FROM AUTHOR]

To explore the law of load-carrying performance enhancement of concrete beams reinforced with corrugated steel plates (CSPs), three groups of controlled bending tests were conducted on five beam specimens. The load-bearing capacity of concrete members commensurately increased with the thickness of reinforcing flat and corrugated steel plates. Additionally, for the same amount of steel, the load-bearing capacity of concrete beams improved more with CSP reinforcement than with reinforcement with flat steel plates. Accordingly, a theoretical formula for the moment of inertia of the combined section of a CSP-reinforced concrete beam was derived. Comparison verification showed that the calculation results for the beams reinforced with CSPs of different thicknesses were highly accurate. Finally, based on the damage mode of the CSP-reinforced concrete beam specimens, a formula for calculating the flexural bearing capacity of the positive cross-section of the beam with corrugated steel reinforcement was established. The calculated values agreed with the experimental values, which validated the flexural load capacity theory pertaining to positive sections and the flexural capacity model for reinforced beams. [ABSTRACT FROM AUTHOR]

The recent availability of commercial platforms for behavioral analyses in zebrafish larvae based on video-tracking technologies has exponentially increased the number of studies analyzing different behaviors in this model organism to assess neurotoxicity. Among the most commonly used assays in zebrafish larvae are basal locomotor activity (BLA) and visual motor responses (VMRs). However, the effect of different intrinsic and extrinsic factors that can significantly alter the outcome of these assays is still not well understood. In this work, we have analyzed the influence of age (5–8 days post-fertilization), time of day (8:00, 10:00, 12:00, 14:00; 16:00, 18:00, and 20:00 h), and experiment (three experiments performed at different days) on BLA and VMR results (4004 analyses for each behavior) in 143 larvae. The results from both behaviors were adjusted to a random-effects linear regression model using generalized least squares (GLSs), including in the model the effect of the three variables, the second-way interactions between them, and the three-way interaction. The results presented in this manuscript show a specific effect of all three intrinsic factors and their interactions on both behaviors, supporting the view that the most stable time period for performing these behavioral assays is from 10:00 am to 04:00 pm, with some differences depending on the age of the larva and the behavioral test. [ABSTRACT FROM AUTHOR]

This paper discusses an approach to estimating the parameters of the cohesive zone model (CZM) by mode II by extruding the bushing along the lug axis. This method of evaluation requires small samples, which is particularly relevant when investigating short fiber-reinforced polymers (SFRPs) with additively manufactured embedded elements. Adhesion is investigated on the example of 30% carbon fiber-reinforced polyamide-6 molded to Ti-6Al-4V (VT6) selective laser-melted (SLM) alloy bushing in cases of a roughness Ra = 2.66 μm (vibratory finishing), Ra = 8.79 μm (sandblasting), and Ra = 10.02 (directly from SLM). The values of the maximum equivalent tangential contact stress were in a range from 1.1 MPa to 9.5 MPa, while the critical fracture energy for tangential slip was estimated at 15 N/mm for all cases. Experimental validation of the obtained CZM mode II was carried out by evaluating the load-carrying capacity of the lugs with different bushings. In both the experiment and the calculation, greater bushing roughness provides greater lug load-bearing capacity. The ribbed bushings added significant strength in the experiments, which confirmed the importance of considering the tangential mode in the contact model. The presented models can be used for the preliminary evaluation of short fiber-reinforced polyamide-6 parts with titanium-embedded elements bearing capacity. [ABSTRACT FROM AUTHOR]

Tire recycling is becoming an increasingly important problem due to the growing number of end-of-life tires (ELTs). World-wide, ELTs account for more than 80 million tons. ELTs contribute to environmental pollution in the long term. They are flammable, toxic and non-biodegradable. At the same time, ELTs contain rubber, metal and textile cord, which are valuable raw materials. ELTs are buried in landfills, burned, crushed and restored. Most of these methods have a negative impact on the environment. From an environmental point of view, the most preferred ways to recycle tires are retreading and shredding. Rubber powder (RP) or crumb is mainly used for rubber pavers production, waterproofing, curbs, road slabs and various surfaces. An alternative method for RP processing, eliminating the disadvantages of the above approaches, is plasma gasification and pyrolysis. The paper presents a thermodynamic and kinetic analysis and an experiment on plasma processing of RP from worn tires to produce flammable gas. At a mass-average temperature of 1750 K, the yield of synthesis gas from plasma-air gasification of RP was 44.6% (hydrogen—19.1, carbon monoxide—25.5), and 95.6% of carbon was gasified. The experimental and calculated results satisfactorily agreed. It was found that plasma products from RP did not contain harmful impurities, either in calculations or experiments. Plasma gasification allows for recycling ELTs in an environmentally friendly way while also generating flammable gases that are valuable commodities. In this research, plasma technology was demonstrated to be effective for gasifying RP to produce flammable gas. [ABSTRACT FROM AUTHOR]

This paper concerns the effects of electrodynamic forces that act on current paths that are part of high-grade industrial distribution switchgear. This work is composed of experimental and simulation sections. In the experimental section, the short-circuit tests are presented and the occurrence of electrodynamic forces are shown in a visible way. The formation of electrodynamic forces in the current circuits of electrical energy distribution systems is related to the flow of high currents, but mostly it is related to short-circuit currents. In order to highlight these phenomena, the detailed specification of the parameters during tests is displayed. In the simulation section, the physical phenomenon of electrodynamic forces is being captured by employing a detailed real-scale model of switchgear and current paths. Therefore, the authors proposed employment of the FEM (finite element method) in order to obtain values of electrodynamic forces acting on the current paths by executing the detailed 3D coupled simulation. The analysis of the results and aftermath effects of their interactions provided interesting conclusions that concerned the operation of such power distribution layouts in critical short-circuit conditions. [ABSTRACT FROM AUTHOR]

Compared to sensible heat storage, latent heat storage provides higher energy density due to the enthalpy difference of the storage medium undergoing a phase change. However, the heat storage capability of phase change materials is opposed by low thermal conductivity. To enable sufficient heat transfer within a latent heat storage unit, phase change materials can be used in combination with a metallic matrix. One approach is the infiltration of phase change materials into additively manufactured metallic lattice structures. In this work, the fabrication of aluminum lattice structures through laser powder bed fusion is described. During fabrication, the cell size and the strut diameter were varied to obtain specimens of different geometries. To obtain the thermal conductivity of the fabricated lattices, measurements were conducted based on the transient plane source method. Additionally, finite element simulations were carried out to evaluate the effect of fabrication and measurement uncertainties. The thermal conductivity of the fabricated lattices was found to be between 3 W/(m·K) and 130 W/(m·K). The numerically and analytically performed calculations provide good estimations of the experimentally obtained data. [ABSTRACT FROM AUTHOR]

This study aims to investigate the influence of wheel configurations on hydrodynamic resistance of an amphibious vessel through experiments and simulations. To evaluate the resistance performance associated with wheel attachments, three configurations were examined: vessel without attachments, with caterpillars, and with both caterpillars and shoe−paddles. A comprehensive series of computational fluid dynamics (CFD) simulations were conducted for these attachment types, complemented by experimental validations. The Volume-of-Fluid (VOF) model was employed in CFD simulations to capture the free surface movement, and the Dynamic Fluid–Body Interaction (DFBI) model was adopted to represent the two-degree-of-freedom motion of the vessel, specifically trim and sinkage. The total resistance derived from CFD simulations was calculated across a range of Froude numbers (Fns), including the design speed of the target vessel, and validated through model tests conducted in a wave basin equipped with a towing facility. The analysis indicated a general increase in resistance when attachments were added to the amphibious vessel. Remarkably, at the design speed (Fn = 0.27), the total resistance with both caterpillars and shoe−paddles exceeded that of the configuration without any attachments by more than 75.7%. These results provide crucial insights for the preliminary design stage of amphibious vessels, particularly those intended for marine debris collection in hard-to-reach areas. [ABSTRACT FROM AUTHOR]

The tangential adhesive contact (friction) between a rigid steel indenter and a soft elastomer at shallow indentation depths, where the contact exists mainly due to adhesion, is investigated experimentally. The dependencies of friction force, contact area, average tangential stresses, and the coordinates of the front and back edges of the contact boundary on the indenter displacement are studied. It is found that first a stick–slip mode of friction is established, which is then replaced by another, more complex mode where the phase of a global slip of the elastomer on the indenter surface is absent. In both regimes, the evolutions of friction force and contact area are analyzed in detail. [ABSTRACT FROM AUTHOR]

To satisfy the demand for efficient heat transfer, a novel three-dimensional overall jagged internal finned tube (3D-OJIFT) was fabricated, using the rolling–ploughing/extruding method. The thermal performance of the 3D-OJIFT were studied and compared in experiments and three-dimensional numerical simulations. The RNG k-ε turbulence model is well verified with the experimental results. By analyzing the distributions of velocity, temperature, and turbulence kinetic energy, it was found that the 3D-OJIFT destroyed the development of the velocity and thermal boundary layers, increased the turbulence disturbance, and reduced the temperature gradient, thus improving the heat transfer. The influences of the jagged height and jagged spiral angle of the 3D-OJIFT are discussed. The Nu and f increased as the jagged height of the 3D-OJIFT increased. The Nusselt number of the 3D-OJIFT was 1.67–2.04 times the value for the smooth tube. In addition, the comprehensive heat transfer performance of the 3D-OJIFT improved after increasing the jagged spiral angle. Compared with conventional internal helical-finned tubes and other reinforcement structures reported in the literature, the 3D-OJIFT demonstrated better comprehensive heat transfer performance. Finally, empirical correlations of the 3D-OJIFT were obtained. [ABSTRACT FROM AUTHOR]