Hasil untuk "Engineering design"

Pradeep Raja C, G. Sridevi, Suman Pandipati et al.

Additive manufacturing using fused deposition modelling (FDM) has emerged as a versatile and resource-efficient route for producing complex polymer and composite structures. However, the quality and sustainability of FDM-printed components are strongly governed by process parameters, nozzle design, and post-processing methods. This review provides a systematic analysis of these factors and their combined influence on mechanical integrity, surface finish, and dimensional accuracy. The study highlights how optimized layer thickness, build orientation, and extrusion temperature enhance interlayer adhesion and structural performance, while advanced nozzle geometries improve melt flow and minimize material waste. Post-processing techniques such as annealing, chemical smoothing, and surface finishing are evaluated for their roles in extending product life cycles and enabling recycled or bio-based polymer feedstocks. By linking process optimization to energy efficiency and material utilization, this review positions FDM as a pathway for sustainable, waste-to-value additive manufacturing. The insights presented support the development of eco-efficient design frameworks for next-generation polymer and composite processing within circular engineering systems.

Zhang Bin, Feng Qian, Li Moxiao et al.

Abstract Predicting mining disaster risk levels is a critical component of intelligent mining systems. This study utilizes five common mining disaster datasets to predict various risk levels. By analyzing correlation coefficients and feature importance for each dataset, optimal evaluation indicators are identified. The Shapley Additive Explanations model is then applied to enhance interpretability. To address the presence of outliers and imbalanced data categories, the Mahalanobis Distance Discriminant Method and the Synthetic Minority Oversampling Technique algorithm based on Tomek Links are used for data preprocessing. Subsequently, Support Vector Machine, Random Forest, Extreme Gradient Boosting, one-dimensional Convolutional Neural Networks, and multi-Grained Cascade Forest algorithms are applied to the five mining disaster datasets. Comparative analysis reveals that the Deep Forest algorithm demonstrates superior performance and generalization in predicting stability levels of goaf, slope stability, rockburst intensity levels, pillar stability, and Hanging Wall stability, with prediction accuracies of 92.31%, 96.77%, 92.50%, 91.67%, and 95.00%, respectively. This research provides a systematic solution for mining disaster classification prediction, offering technical support and a scientific theoretical basis for intelligent mining development and mining safety operations.

Lijian Ouyang, Dongqiu Li, Shihao Cui et al.

Vertical slot fishways are a crucial measure to mitigate the blockage of fish migration caused by hydraulic engineering infrastructures, but their passage efficiency is often hindered by the complex interactions between fish behavior and hydrodynamic conditions. This study combines computational fluid dynamics (CFD) simulations with behavioral laboratory experiments to identify the hydrodynamic characteristics and swimming strategies of three types of fishways—Central Orifice Vertical Slot (COVS), Standard Vertical Slot (SVS), and L-shaped Vertical Slot (LVS)—using the endangered species <i>Schizothorax prenanti</i> from the upper Yangtze River as the study subject. The results revealed that (1) a symmetric and stable flow field was formed in the COVS structure, yet the passage ratio was the lowest (50%); in the SVS structure, high turbulent kinetic energy (peak of 0.03 m²/s²) was generated, leading to a significant increase in the fish’s tail-beat angle and amplitude (<i>p</i> < 0.01), with the passage time extending to 10.2 s. (2) The LVS structure induced a controlled vortex formation and created a reflux zone with low turbulent kinetic energy, facilitating a “wait-and-surge” strategy, which resulted in the highest passage ratio (70%) and the shortest passage time (6.1 s). (3) Correlation analysis revealed that flow velocity was significantly positively correlated with absolute swimming speed (<i>r</i> = 0.80), turbulent kinetic energy, and tail-beat parameters (<i>r</i> > 0.68). The LVS structure achieved the highest passage ratio and shortest transit time for <i>Schizothorax prenanti</i>, demonstrating its superior functionality for upstream migration. This design balances hydrodynamic complexity with low-turbulence refuge zones, providing a practical solution for eco-friendly fishways.

Xianglan Wei, Gaowang Cai, Naiwen Ke et al.

The vertical load-bearing performance of slab–column joints is significantly affected by bottom reinforcement and concealed beams, but existing studies remain insufficient in analyzing their influence mechanisms. To address this, the effects of bottom reinforcement, concealed beam width, and punch-to-span ratio on the mechanical properties of joints are systematically investigated in this study through finite element analysis. Validating 2 experimental models and establishing 13 parametric models, the results shows that adding bottom reinforcement can enhance the late-stage bearing capacity and ductility of joints; increasing the ratio of top-to-bottom reinforcement improves bearing capacity but reduces ductility; a wider concealed beam leads to better bearing capacity and ductility performance of the joint; and under the same concealed beam width, a larger punching–span ratio reduces bearing capacity but improves ductility. This study reveals the critical role of bottom reinforcement and concealed beams in joint performance, providing a theoretical basis for optimizing design.

Riana Magdalena Silitonga, Ferdian Aditya Pratama, Ronald Sukwadi

Due to the COVID-19 pandemic, most schools and colleges have adopted hybrid learning. Hybrid learning, also called “blended learning,” mixes online and classroom instruction. Blended learning may become permanent as face-to-face and internet-based education become more accepted. We examined how hybrid learning affects the understanding of Indonesian students majoring in Industrial Engineering at Atma Jaya Catholic University. In this study, understanding matched learning efficacy. An experimental design was used to measure component influence. In strategic planning, strengths, weaknesses, opportunities, and threats (SWOT) analysis was used as an effective tool to examine an organization’s internal and external variables with a learning methodology design. A questionnaire survey was conducted to measure the understanding of the SWOT analysis results and the related strategy. A total of 96 participants were involved in this study. The mixed learning method, using the weakness–opportunity or mini–maxi strategy with the divestment–investment principle, was found to be effective.

Pengna Wei, Tong Chen, Jinhua Zhang et al.

Studies using source localization results have shown that cortical involvement increased in treadmill walking with brain–computer interface (BCI) control. However, the reorganization of cortical functional connectivity in treadmill walking with BCI control is largely unknown. To investigate this, a public dataset, a mobile brain–body imaging dataset recorded during treadmill walking with a brain–computer interface, was used. The electroencephalography (EEG)-coupling strength of the between-region and within-region during the continuous self-determinant movements of lower limbs were analyzed. The time–frequency cross-mutual information (TFCMI) method was used to calculate the coupling strength. The results showed the frontal–occipital connection increased in the gamma and delta bands (the threshold of the edge was >0.05) during walking with BCI, which may be related to the effective communication when subjects adjust their gaits to control the avatar. In walking with BCI control, the results showed theta oscillation within the left-frontal, which may be related to error processing and decision making. We also found that between-region connectivity was suppressed in walking with and without BCI control compared with in standing states. These findings suggest that walking with BCI may accelerate the rehabilitation process for lower limb stroke.

Long Zhou, Shanshan Wang, Jizhe Zhang et al.

In the current recycling process of reclaimed asphalt pavement (RAP), due to the serious damage of aggregate gradation and the large amount of aged asphalt still wrapped around the surface of the treated aggregate, the low recycling rate and poor performance of the recycled asphalt mixture are the major problems of RAP. In view of the shortcomings of RAP recycling technology, it is urgent to research new treatment methods and design specialized asphalt-stripping equipment to solve the existing problems. In this paper, based on theoretical analysis and EDEM discrete element simulation, a principle prototype for efficient micro-damage fine stripping of asphalt on the RAP surface is developed and tested. The results demonstrate that the principle prototype has a satisfactory asphalt-stripping effect and achieves fine stripping of aged asphalt on the surface of aggregate without large-scale crushing. This principle prototype has significant engineering application values, which provides design solutions and data support for further equipment development.

Jure Ahtik

The goal of the study was to determine how close the eye-tracking results predicted by the AI model are to actual measurements and whether they can be used in scientific research or in real business cases. The study was based on a carefully prepared photo database of 30 photos of varying complexity and colour. The photos were shown to 110 participants (age and gender evenly distributed), and eye-tracking device (Tobii X120) was used to measure how the photos were viewed. In comparison, the same photos were tested using an AI-based application (Expoze.io). The final results show the comparison between the heatmaps and transparent gaze visualisations of the collected data with the two used measurement methods. Suggestions are made in which cases and how the two described methods should be used.

Mphatso Malota, Joshua Mchenga, Brighton Austin Chunga

Abstract The agricultural drainage engineering community is steadily shifting the design of subsurface drainage systems from the experience-based design approach to the simulation-based design approach. As with any design problem, two challenges are faced; firstly, how to determine all the input data required by the simulation model, and secondly to, a priori, anticipate what the performance of the designed system will be. This study sought to evaluate the performance of the WaSim model to simulate fluctuating water table depths (WTD), and drainage discharges (DD) in KwaZulu-Natal Province, South Africa. Saturated hydraulic conductivity (K sat), which is an input to the WaSim model, was estimated by the Rosetta computer program, based on soil particle size distribution data, bulk density, and soil water retention characteristics at pressure heads of – 33 and – 1500 kPa. performance of the WaSim model was statistically assessed using the coefficient of determination (R 2), coefficient of residual mass (CRM), mean absolute error (MAE), mean percent error (MPE), and the nash–sutcliffe efficiency (NSE). during the validation period, the WaSim model predicted WTDs with R 2, CRM, MAE, MPE, and NSE of 0.86, 0.003, 4.9 cm, 6.0%, and 0.98, respectively. In the same validation period, the model predicted DDs with R 2, CRM, MAE, MPE, and NSE of 0.57, 0.002, 0.30 mm day−1,11%, and 0.76, respectively. These results suggest that the use of Rosetta-estimated K sat data as inputs to the WaSim model compromised its accuracy and applicability as a subsurface drainage design tool. Owing to the relatively low R 2 value of 0.57, and that the WaSim model was empirically developed, we recommend further improvement on the calibration of the model for it to be suitable for application under the prevailing conditions. Also, in the absence of other means of determining K sat, we caution the use of Rosetta-estimated K sat data as inputs to the WaSim model for the design and analysis of subsurface drainage systems in KwaZulu-Natal Province, South Africa.

Nikolay Aniskin, Aleksey Shaytanov, Mikhail Shaytanov

In this paper, we consider the issue of assessing the degree of influence of the selected factors on the temperature regime and the thermally stressed state of a concrete gravity dam being built from low-cement concrete for several possible construction scenarios. The studies were carried out in relation to the design and conditions of the construction area of ​​the Pskem hydroelectric complex in the Republic of Uzbekistan. Variation factors were: cement consumption in the mixture, the initial temperature of the concrete mixture, the heat release of cement, the thickness of the laid concrete layer, the month of commencement of work. The environmental factors were the variable ambient temperature during the year by months and the influence of solar radiation. The calculations were carried out taking into account the seasonality of the moment the construction of the structure began. 2 options were considered: autumn-winter with concreting of the zone at the base of the dam from September to February inclusive; spring-summer with concreting of this zone from March to August inclusive. In addition, options were considered taking into account additional heating from exposure to solar radiation and without it. The studies were carried out using the methodology of experiment planning in the search for optimal solutions (method of factor analysis). The numerical experiment was carried out on the basis of the finite element method using the ANSYS software package. Using the method of factor analysis, the influence of the main acting factors on the temperature regime of a gravity dam made of rolled concrete was studied. A variant of a combination of factors is proposed to obtain the most favorable temperature regime. Regression equations are obtained for predicting the temperature regime of concrete gravity dams being built from low-cement content concrete. The results of studies using the factor analysis technique can be used in the design of concrete dams from rolled concrete.

Muhammad Asif, Sarmad Shams, Samreen Hussain et al.

This paper presents an adaptive control scheme for streetlights by optimizing the energy consumed using deep learning during late hours at night. A city’s infrastructure is not complete without a proper lightening system for streets and roads. The streetlight systems often consume up to 50% of the electricity utilized by the city. Due to this reason, it has a huge financial impact on the electricity generation of the city. Furthermore, continuous luminosity of the streetlights contributes to the environmental pollution as well. Economists and ecologists around the globe are working hard to reduce the global impact of continued utilization of streetlights at night. In regard to a developing country which is already struggling to produce enough electrical energy to fulfill its industry requirements, proposing a system to lessen the load of the energy utilization by the streetlights should be beneficial. Therefore, an innovative and novel energy efficient streetlight control system is presented based on embedded video processing. The proposed system uses deep learning for the optimization of energy consumption during the later hours. Conventional street lighting systems consume enormous amounts of electricity, even when there is no need for the light, i.e., during off-peak hours and late at night when there is reduced or no traffic on the roads. The proposed system was designed, and implemented and tested at two different sites in Karachi, Pakistan. The system is capable of detecting vehicles and pedestrians and is able to track their movements. The YOLOv5 deep-learning based algorithm was trained according to the local requirements and implemented on the NVIDIA standalone multimedia processing unit “Jetson Nano”. The output of the YOLOv5 is then used to control the intensity of the streetlights through intensity control unit. This intensity control unit also considers the area, object and time for the switching of streetlights. The experimental results are promising, and the proposed system significantly reduces the energy consumption of streetlights.

Reza Ebrahimi

Nanoresonators can be used in some engineering fields such as high quality factor filters for electronic signals and sensors. So, the main purpose of this paper is to analyze the nonlinear dynamic behavior of electrostatically actuated nanoresonators. In the framework of the Von Karman's theory and the Euler-Bernoulli beam model, the nonlinear governing equations of motion are developed using the Hamilton's principle. Also, the coupling of lateral and longitudinal vibrations is considered. The governing partial differential equations are discretized by means of the Galerkin’s method. The analytical and numerical solution are obtained using the multiple-scales method and Runge–Kutta method, respectively. The variation of natural frequencies and the response of the nanoresonator with the levels of the electrostatic load are investigated. The results show that the nonlinear frequency response curves are greatly affected by the gap distance and detuning frequency. A hardening behavior is observed in the nonlinear frequency responses of the nanoresonator. Also, through the comparison between the effect of gap distance and dc voltage, it is found that the natural frequencies of the nanoresonator are more sensitive to the variation of the dc voltage. So, this suggests a tunable resonator over a wide range of frequencies.

Amr A. Bekheet, Nahla M. AboulAtta, Neveen Y. Saad et al.

This study evaluates the effect of the piano key weir’s (PKW) shape and type on the flow efficiency for different inlet and outlet keys width ratios (Wi/Wo). The study is performed experimentally and numerically using a CFD model. Three PKW shapes are studied (rectangular, trapezoidal, and triangular). First, three Type-A shapes were studied experimentally considering Wi/Wo = 0.8. The trapezoidal shape had the highest efficiency, while the triangular had the least. The experimental results were used to verify the numerical model, then, the rectangular and trapezoidal shapes were studied numerically for Wi/Wo = 1.25. The trapezoidal Type-A PKW with Wi/Wo = 1.25 showed the highest flow efficiency of all shapes and Wi/Wo ratios. The rectangular and trapezoidal Type-B PKWs were also studied for Wi/Wo = 1.25 and compared to Type-A. The Type-B PKW showed higher efficiency. The ratio Wi/Wo is the most studied effective parameter on the PKW flow efficiency, followed by the weir’s shape, then its type.

Dmitry Merkushev, Olga Vodyanova, Felix Telegin et al.

The obtainment of new luminophores for molecular sensorics of biosystems is becoming one of the urgent tasks in the field of chemical synthesis. The solution to each practical problem imposes its own limitations in the design of new structures with practically useful properties. The relationship between the structure and spectral properties is still to be unveiled. Three aza-BODIPY complexes with substituents of different natures were studied using time-resolved and steady-state fluorescence and absorption spectroscopy. The solvatochromic properties of aza-BODIPYs were studied with the use of a combined polyparametric approach and analysis by chemoinformatics methods for the first time. It was found that red shift of aza-BODIPY dyes was due to the increase of their structural lability. Predictive and experimental methods showed that the investigated aza-BODIPYs exhibited a positive solvatochromic effect, in contrast to classic BODIPYs (bearing C in the <i>meso</i>-position of the dipyrromethene core), which represents the negative solvatochromic properties. Spectral maxima in the area of the therapeutic window, low and predictable solvatochromism, and the ability to fine-tune the spectral characteristics make the investigated aza-BODIPYs promising scaffolds for the construction of bioengineering devices. Generalizations on the aza-BODIPYs’ design patterns were made in accordance with further bioimaging applications.