Engineering Insights Research Articles

Improving early strength and durability of eco-friendly mortars: Investigating the influence of limestone filler fineness and blast furnace slag combination

This research investigates the application of Life Cycle Cost (LCC) analysis in the construction industry, focusing on reinforced concrete structures. LCC analysis goes beyond initial building costs, encompassing all expenses throughout a structure's service life. Among various service life prediction models, Life-365 and DURACON are noteworthy. Life-365, a specialized computer program, predicts the life cycle cost of reinforced concrete exposed to chlorides. This paper presents a case study using Life-365 to compare the LCC of two concrete mixes, TM1 and TM2, in Mumbai, a location with conditions conducive to chloride exposure. The study uses average monthly temperatures and location-specific input parameters to evaluate the LCC of M70-grade concrete mixes with different compositions, including Fly Ash, GGBS, and Micro Silica as partial cement replacements. Results indicate that quaternary blended M70 grade concrete, incorporating supplementary cementitious materials (SCMs), not only enhance durability but also offers economic benefits, reducing overall life cycle costs. These findings provide valuable insights for engineers and decision-makers, promoting durable, cost-effective, and sustainable concrete structures.

Analysis of performance for the various types of controllers used in the Automatic Voltage Regulator System (AVR)

The paper will present a performance analysis of various types of controllers used in the Automatic Voltage Regulator (AVR) system. The AVR is a crucial component of power systems, responsible for regulating the voltage levels of generators to ensure a stable and reliable power supply. Different types of controllers, such as proportional integral derivative (PID), Z-N tuning, and LQR controllers, are evaluated and compared based on their performance metrics, including setting time, overshoot, and steady state error. Simulation findings show that each controller has its own strengths and weaknesses in terms of regulating voltage. Moreover, the selection of a controller is contingent upon the particular needs as well as the features of the power system. This analysis can provide valuable insights for engineers and researchers in selecting and designing appropriate controllers for AVR systems.

A theoretical investigation on the structural stability, superconductivity, and optical and thermodynamic properties of Ir2P under pressure.

The potential applications of Ir2P are promising due to its desirable hardness, but its fundamental properties are still not fully understood. In this study, we present a systematic investigation of Ir2P's structural, electronic, superconducting, optical, and thermodynamic properties of Ir2P under pressure. Our calculations show that Ir2P has a Fm3̄m structure at ambient pressure, which matches well with experimental data obtained from high-pressure synchrotron X-ray diffraction. As pressure increases, a transition from the Fm3̄m to the I4/mmm phase occurs at 103.4 GPa. The electronic structure and electron-phonon coupling reveal that the Fm3̄m and I4/mmm phases of Ir2P are superconducting materials with superconducting transition temperatures of 2.51 and 0.89 K at 0 and 200 GPa, respectively. The optical properties of Ir2P indicate that it has optical conductivity in the infrared, visible, and ultraviolet regions. Additionally, we observed that the reflectivity R(ω) of Ir2P is higher than 76% in the 25-35 eV energy range at different pressures, which suggests that it could be used as a reflective coating. We also explored the finite-temperature thermodynamic properties of Ir2P, including the Debye temperature, the first and second pressure derivatives of the isothermal bulk modulus, and the thermal expansion coefficient up to 2000 K using the quasi-harmonic Debye model. Our findings offer valuable insights for engineers to design better devices.

A Study on Failure Rate, Reliability, and Collection Efficiency Trend of Bag Filters in a Cement Plant

This thesis presents a comprehensive study on the failure rate, reliability, and collection efficiency trends of bag filters in a cement plant over 15 years. Bag filters are vital pollution control equipment used in various industries, including cement plants, to maintain environmental compliance. Understanding their performance and failure patterns is crucial to ensure efficient and reliable operation while adhering to stringent pollution control standards. The research findings reveal that the failure rate trend of bag filters closely follows the bathtub curve, with an initial high failure rate, a period of lower failures, and a subsequent increase in failures as the equipment nears the end of its life cycle. Reliability trends align with Madhab's Hat curve, exhibiting higher reliability during the first 10 to 12 years of operation, followed by a decline in reliability. The collection efficiency of bag filters declines as the equipment ages, with the efficiency decreasing from 99.998% in the early years to 95.05% in the 15th year. This emphasizes the importance of maintenance and retrofitting for older dust collection equipment to maintain high collection efficiency. The study concludes that the typical life span of bag filters ranges from 10 to 15 years, after which major maintenance interventions are necessary to minimize failure rates. The research provides valuable insights for maintenance engineers, design engineers, and reliability engineers, enabling them to improve the performance of pollution control equipment, such as bag filters, reverse air bag houses (RABH), and electrostatic precipitators (ESP), to meet the pollution control standards set by regulatory authorities.

An Overview of Mathematical Methods Applied in the Biomechanics of Foot and Ankle–Foot Orthosis Models

Ankle–foot orthoses (AFOs) constitute medical instruments designed for patients exhibiting pathological gait patterns, notably stemming from conditions such as stroke, with the primary objective of providing support and facilitating rehabilitation. The present research endeavors to conduct a comprehensive review of extant scholarly literature focusing on mathematical techniques employed for the examination of AFO models. The overarching aim is to gain deeper insights into the biomechanical intricacies underlying these ankle–foot orthosis models from a mathematical perspective, while concurrently aiming to advance novel models within the domain. Utilizing a specified set of keywords and their configurations, a systematic search was conducted across notable academic databases, including ISI Web of Knowledge, Google Scholar, Scopus, and PubMed. Subsequently, a total of 23 articles were meticulously selected for in-depth review. These scholarly contributions collectively shed light on the utilization of nonlinear optimization techniques within the context of ankle–foot orthoses (AFOs), specifically within the framework of fully Cartesian coordinates, encompassing both kinematic and dynamic dimensions. Furthermore, an exploration of a two-degree-of-freedom AFO design tailored for robotic rehabilitation, which takes into account the interplay between foot and orthosis models, is delineated. Notably, the review article underscores the incorporation of shape memory alloy (SMA) elements in AFOs and overviews the constitutive elastic, viscoelastic, and hyperelastic models. This comprehensive synthesis of research findings stands to provide valuable insights for orthotists and engineers, enabling them to gain a mathematical understanding of the biomechanical principles underpinning AFO models and fostering the development of innovative AFO designs.

Design optimization of a domestic centrifugal pump using Taguchi Method

This study focuses on optimizing the design of a domestic centrifugal pump through the Taguchi method, aiming to enhance its performance. Experimental data on pump performance, including total head, efficiency, and suction specific speed, were collected and analyzed. The effects of three design parameters—impeller diameter, blade angle, and volute tongue angle—were investigated using ANOVA. The analysis revealed that impeller diameter had the most significant influence on pump performance, followed by volute tongue angle and blade angle. Optimal performance was achieved with a 55 mm impeller diameter, 25° blade angle, and 20° volute tongue angle. These findings provide valuable insights for engineers seeking to improve centrifugal pump performance, highlighting the importance of impeller diameter in particular. By optimizing design parameters, significant enhancements in pump performance can be achieved, leading to more efficient and effective domestic centrifugal pumps.

AC POWER REGULATION TECHNIQUES FOR RENEWABLE ENERGY SOURCES

This article explores different AC power regulation techniques that can be employed to optimize the output of renewable energy sources, such as solar and wind power systems. The article provides an overview of the challenges associated with regulating AC power output from renewable sources and examines various techniques that can be used to improve the performance of power regulation systems. These techniques include voltage control, phase control, reactive power compensation, and power factor correction. The article also discusses the benefits and limitations of each technique, as well as their potential applications in renewable energy systems. Overall, this article provides valuable insights for engineers and researchers working to optimize power auto consumption in renewable energy systems.

Application of Neural Network Feedforward in Fuzzy PI Controller for Electric Vehicle Thermal Management System: Modeling and Simulation Studies

The electric vehicle thermal management system (EVTMS) plays a crucial role in ensuring battery efficiency, driving range, and passenger comfort. However, EVTMSs still face unresolved challenges, such as accurate modeling, compensating for temperature variations, and achieving efficient control strategies. Addressing these issues is crucial for enhancing the performance, reliability, and energy efficiency of electric vehicles. Therefore, this study presents a cooling EVTMS model, considering both the battery pack temperature and the cabin comfort, and utilizes the prediction of neural network as a feedforward in a fuzzy PI controller to compensate for the model temperature variations. The simulation results reveal that, compared with PI controller and MPC, the neural network fuzzy PI (NN-Fuzzy PI) controller can well predict and compensate for the system’s nonlinear characteristics as well as the time-delay caused by heat transfer, achieving superior control performance and reducing energy consumption. The battery pack temperature and PMV fluctuations are effectively constrained within [−0.5, 0.5] and [−0.1, 0.1], reducing up to 150% and 164%, and the energy consumption of the pump and compressor are reduced by up to 0.23 and 100.1 KJ, with ranges of 18% and 2.68%. Meanwhile, the neural network feedforward also works effectively in different controllers. The findings of this research can provide valuable insights for TMS engineers to select advanced control strategies.

Project EngiBot: Engineering Insights through NLP- driven Chatbot

Abstract: A chatbot is an automated system designed to engage with users, offering human-like conversations and promptly responding to their queries based on the input provided. This technology creates a seamless illusion of interacting with a human interlocutor. This chatbot empowers students with the ability to access information about college activities from anywhere with an internet connection. Furthermore, it extends its capabilities to guide engineering students on various aspects, including identifying colleges with the highest salary packages, exploring trending domains within the field, and providing a roadmap for mastering these domains. The development of the college inquiry chatbot involved the utilization of a Natural Language Processing (NLP) system that assesses and understands user questions and messages. Understanding that people interact with varying emotional states and attitudes, chatbots adhere to defined rules, ensuring polite and accurate communication with customers, mirroring human interaction. Additionally, the chatbot offers invaluable insights on the technologies essential for achieving expertise in a specific engineering domain, serving as a comprehensive resource for students in their educational journey. They significantly reduce response times, allowing students to receive prompt and accurate answers.

Opportunities and challenges in machining of aluminium metal matrix composites using electrical discharge machining

The machining of aluminium metal matrix composites (aluminium MMCs) presents a dynamic landscape of opportunities and challenges, with electrical discharge machining (EDM) emerging as a promising technique. This review article systematically navigates the intricate interplay between AMMCs’ unique characteristics and the EDM process. Through a comprehensive analysis of existing literature, we uncover the underlying mechanisms that govern the machining dynamics of AMMCs, exploring their compositional variations, reinforcement distribution and thermal properties. The article delves into the opportunities offered by EDM, such as precision machining of intricate geometries, inherent thermal control and the ability to navigate the varying hardness levels in AMMCs. Furthermore, the review addresses the challenges that arise, including electrode wear, surface integrity preservation and the influence of reinforcement particles on material removal rates. The authors highlight the role of parameter optimisation in achieving desirable machining outcomes, underlining the need to strike a balance between material removal efficiency and surface finish quality. Additionally, environmental considerations in EDM of AMMCs are discussed, emphasising sustainable machining strategies in line with contemporary ecological concerns. As the field of advanced materials and manufacturing continues to evolve, this review article provides valuable insights for researchers, engineers and industries seeking to harness the potential of EDM in machining AMMCs. By navigating the intricate landscape of opportunities and challenges, this article contributes to a holistic understanding of the nuanced relationship between EDM and AMMCs, laying the foundation for future advancements in precision machining of these composite materials.

Analysis of the influence of fillet geometry on stress concentration in keyway by the finite element method

Machines play a pivotal role in the modern world, as they streamline various activities by virtue of their capacity to convert energy, such as transforming electrical energy into mechanical energy. In this context, the mechanical shaft assumes significant importance, as it enables the transmission of power to a wide range of applications. Being a solid component, the shaft is subjected to mechanical stresses, and the keyway groove, present in the shaft, is a feature that exacerbates stress concentrations in its geometry, which is undesirable as it increases the risk of failure due to rupture. Therefore, this research aimed to investigate the influence of the keyway groove geometry on stress concentration in shafts under bending loads, using simulations based on the finite element method. The study compares elliptical keyways with circular keyways and assesses how variations in parameters impact stress concentration, employing the Ansys tool for the analysis. The results demonstrate that slight modifications in the keyway groove geometry can significantly reduce stress concentrations, thereby contributing to the optimized design of mechanical components and providing valuable insights for engineers working in this field.

Numerical Study on Hydrodynamic Performance of a New Semi-Submersible Aquaculture Platform

To address the limitations of traditional aquaculture cages, such as poor performance in offshore environments, challenges in energy supply, and the inability to integrate modern farming facilities, a new semi-submersible aquaculture platform has been developed and put into operation. The hydrodynamic performance of the platform is analyzed using a fully coupled numerical model. The numerical model incorporates the main structure of the platform, the net system, and the mooring system, and is based on the linear potential flow theory and the Morison equation. The natural period of the platform is found to be far away from the common wave period. The mooring system for the platform in a specific sea area is proven to be safe. The net system significantly affects the hydrodynamic performance and alleviates the dynamic response of the platform. This study provides valuable insights for researchers and engineers in the design and optimization of this type of semi-submersible aquaculture platform in the future.

Unraveling Debris-Enhanced Local Scour Patterns around Non-Cylindrical Bridge Piers: Experimental Insights and Innovative Modeling

Bridge structures face a critical threat from localized scour-induced damage, prompting urgent attention to civil infrastructure resilience. Prior research has primarily focused on the influence of pier shapes on scour patterns. However, the exploration of the combined effects of various debris shapes, each possessing distinct properties, on predictive scour depth models around the non-cylindrical pier has hitherto remained less researched. This study explored the complex dynamics governing local scour around bridge piers, focusing on the influence of surface and near-surface debris. This research shed light on changes in scour depth by investigating factors like pier geometries, debris arrangements, and submersion depths. The experiments and analysis revealed the effects of various pier shapes—cylindrical, square, rectangular, oblong, oval, and lenticular—on scour patterns. Different geometries influenced primary scour zones and affected areas, with square piers causing the deepest scour and lenticular ones showing shallower instances. Scour depths typically peaked upstream across geometries, but ogival and lenticular shapes exhibited unique patterns. The research also introduced a formula that integrated debris attributes into predictive scour depth modeling, validated with favorable accuracy. Ultimately, this predictive model advances scour prediction, particularly in debris-laden flows, offering valuable insights for engineering and management practices in understanding real-world scour mechanisms and hydraulic dynamics.

Earthquake wonders: High school investigation in mortise tenon structures

Frequent global earthquakes lead to catastrophic property damage and casualties due to building collapses. However, the 1976 Tangshan Earthquake showcased an exception: the Forbidden City, constructed with wooden materials and featuring mortise-tenon structures, remained unscathed among surrounding destruction. This study investigates the earthquake-resilient attributes of wooden mortise-tenon joints utilizing economical high school equipment. An innovative low-cost sensor system, featuring custom instrumented hammer, is developed and validated. Calibration of the hammer's impact force employs correlation with acceleration data from a standardized scale weight during impact. The system's reliability is tested by comparing resonance frequencies from Finite Element modal analysis and experimental data for a cantilever beam. Impact hammer tests assess frequency response and damping across buildings with various joint configurations. Mortise-tenon joints display augmented frictional damping due to internal displacement. Through simulated vibration acceleration responses, a crucial finding emerges---integration of mortise-tenon joints translates to an impressive 11.0% reduction in earthquake vibrations. This research underscores the potential of accessible high school devices in advancing seismic engineering insights.

Suppression of carbody hunting for a locomotive caused by low wheel–rail contact conicity by optimising yaw damper location

This study addresses the issue of carbody hunting in an electric locomotive induced by low wheel-rail contact conicity. The main objective is to mitigate this unstable motion by optimising the location of yaw dampers while ensuring bogie stability under high conicity conditions. A field test was first conducted to observe the carbody hunting behaviour, and a detailed locomotive dynamics model was then developed and validated using experimental data. The impact of yaw damper locations on locomotive stability was investigated, taking into consideration different carbody modes. The findings reveal the mechanism behind the deterioration of carbody stability due to the yaw damper installation angle and two installation layouts were proposed to enhance the carbody stability. Comparisons were then made with traditional solutions using both linear and nonlinear analysis, and experimental validation confirmed the effectiveness of the optimised yaw damper locations in improving carbody stability. This research highlights the importance of optimising the yaw damper's location to suppress carbody hunting, providing valuable insights for railway engineers and offering a promising solution for enhancing stability in high-speed train.

Investigating the consumption behavior of young adults using online food delivery platforms during the COVID-19 pandemic

PurposeOnline food delivery has been prevalent in recent years worldwide, especially during the COVID-19 pandemic, and people's consumption behaviors have changed significantly. This study aims to investigate the consumption behavior of young adults using online food delivery platforms during the COVID-19 pandemic and focuses on the dominant factors influencing their decision to use online food delivery platforms.Design/methodology/approachSemi-structured interviews including 14 young adults aged 18–25 living in Hong Kong were conducted to collect data about their perspectives on online food delivery platforms in five areas. This research adopted the stimulus-organism-response model (S-O-R model) to analyze how the factors influence young adult users' loyalty and satisfaction with online food delivery platforms.FindingsThematic analyses revealed that young adults were attracted to online food delivery platforms for their numerous benefits. They had a high frequency of usage and significant spending. Usability, usefulness, satisfaction and loyalty influenced young adults' behaviors on online food delivery platforms. Participants were overall satisfied with their experiences, but platforms still had room for improvement.Originality/valueFew prior studies investigated the factors affecting the consumer experience and behavioral intention of online food delivery for young adults in Asia. This study contributes to understanding young adults' experiences and problems with online food delivery platforms. It provides practical insights for system engineers and designers to improve the current services and for the governments to enhance the existing regulatory loopholes.

Soft robotics informs how an early echinoderm moved.

The transition from sessile suspension to active mobile detritus feeding in early echinoderms (c.a. 500 Mya) required sophisticated locomotion strategies. However, understanding locomotion adopted by extinct animals in the absence of trace fossils and modern analogues is extremely challenging. Here, we develop a biomimetic soft robot testbed with accompanying computational simulation to understand fundamental principles of locomotion in one of the most enigmatic mobile groups of early stalked echinoderms-pleurocystitids. We show that these Paleozoic echinoderms were likely able to move over the sea bottom by means of a muscular stem that pushed the animal forward (anteriorly). We also demonstrate that wide, sweeping gaits could have been the most effective for these echinoderms and that increasing stem length might have significantly increased velocity with minimal additional energy cost. The overall approach followed here, which we call "Paleobionics," is a nascent but rapidly developing research agenda in which robots are designed based on extinct organisms to generate insights in engineering and evolution.

Investigating the influence of outdoor temperature variations on fire-induced smoke behavior in an atrium-type underground metro station using hybrid ventilation systems

Underground metro systems are expanding rapidly worldwide, necessitating research on energy-efficient ventilation systems, fire safety, and smoke control. This study investigates the optimisation of hybrid mechanical-natural ventilation for smoke control in complex metro stations. Full-scale winter/summer experiments and numerical simulations examined a double-deck atrium-type station. Results demonstrate the atrium fires are more significantly impacted by outdoor temperature variations versus concourse/platform fires, with a 70 K versus 30 K temperature rise above the fire respectively. The heat of the gathered high-temperature smoke inside the atrium can reach up to 900 K under a 5 MW train fire energy release. The dimensionless Archimedes number (Ar) defines the ratio of thermal buoyancy to gravitational forces. Cold exterior winter air (Ar<1) entering via the atrium ceiling openings restricted vertical smoke diffusion, enabling enhanced lateral propagation. With rising outdoor temperatures from −20 °C to 10 °C (Ar<1), the natural smoke extraction efficiency increased from 0 to 18 %, coupled with vertical airflow velocities accelerating from −3.5 m/s to 1.5 m/s. When outdoor temperatures were between 10 °C and 40 °C (Ar>1), airflow velocity only changed slightly. Empirical models predict internal temperature profiles as a function of external meteorology. The findings provide crucial engineering insights into integrating weather data and adaptable ventilation protocols for scenario-based smoke prevention/mitigation. Further work should examine seasonal variations beyond the tested -20‒40 °C range. Overall, considering outdoor climate effects allows 30 % optimisation of hybrid ventilation systems for fire safety in underground metro stations. This study promotes technological advances in energy-efficient transport infrastructure resilience.

USE OF STEEL FIBER AND COPPER SLAG IN CONCRETE PAVEMENT

This study explores the utilization of steel fiber as a reinforcement material in concrete pavement construction. The investigation delves into the mechanical and structural properties of steel fiber-reinforced concrete (SFRC) and its impact on the performance of pavement structures. Various proportions of steel fibers are incorporated into the concrete mix, and the resulting mixtures are subjected to comprehensive testing, including compressive strength, flexural strength, and fatigue resistance. The study aims to assess the potential enhancement in the durability and load-bearing capacity of concrete pavements through the incorporation of steel fibers. The findings indicate that the addition of steel fibers contributes to increased tensile strength and crack resistance, addressing common issues such as reflective cracking and fatigue failure in concrete pavements. Moreover, the study investigates the economic viability and sustainability aspects associated with the use of steel fiber in concrete pavements, considering its influence on lifecycle costs and environmental impact. The outcomes provide valuable insights for engineers and practitioners seeking optimized solutions for durable and resilient concrete pavement construction. Keywords: Steel fibers, Concrete pavement, Reinforcement, Mechanical Properties, Durability,Structural Performance, Compressive strength, Flexural Strength,Fatigue resistance, Reflective Cracking,Sustainability.

A Review on the Non-Linear Optical Performance of Picric Acid based Crystals

This review delves into the nonlinear optical characteristics of crystals derived from picric acid, providing a comprehensive analysis of their unique properties and potential applications in the realm of nonlinear optics. Picric acid, with its distinctive molecular structure, has been widely explored for its nonlinear optical behaviour, making it a fascinating subject for research and development. The review begins by elucidating the fundamental need and significance of crystal growth. The summary of preparation, spectral analysis and nonlinear optical characteristics and the significance of picric acid as a promising material in this domain is also discussed. The interpretation of nonlinear behaviour in optical properties of various compounds of picric acid is reviewed and discussed. The structural data of aminoacidic picrate crystals in the field of non-linear applications are reviewed. The conceptual background of nonlinear optical properties is well deliberated and used in order to have a better knowledge of the optical behaviour of the picrate crystals. UV-VIS spectroscopy and Second harmonic efficiency of picric acid compounds are also briefly discussed. In conclusion, this review provides a comprehensive overview of the nonlinear optical performance of picric acid-based crystals, offering valuable insights for researchers, scientists, and engineers working in the field of nonlinear optics.