Engineering Point Research Articles

ELECTRICAL ENGINEERING IN RENEWABLE ENERGY SYSTEMS: A REVIEW OF DESIGN AND INTEGRATION CHALLENGES

As the global pursuit of sustainable energy intensifies, the integration of renewable energy sources into existing power systems has become a critical focal point for electrical engineers. This review explores the challenges and advancements in the field of Electrical Engineering concerning the design and integration of renewable energy systems. The transition from traditional fossil fuels to renewable sources, such as solar, wind, and hydroelectric power, necessitates a comprehensive understanding of the intricate engineering aspects involved. The first section of the review delves into the design challenges faced by electrical engineers when developing efficient and reliable renewable energy systems. This encompasses the optimization of power generation from intermittent sources, the enhancement of energy conversion technologies, and the development of energy storage solutions to mitigate the inherent variability of renewables. Cutting-edge design methodologies and innovative materials are discussed to highlight the ongoing efforts to improve the performance and reliability of renewable energy systems. The second section focuses on the integration challenges encountered during the incorporation of renewable energy into existing power grids. Grid stability, power quality, and the management of decentralized energy sources pose significant hurdles. Electrical engineers are addressing these challenges through the implementation of advanced control systems, smart grid technologies, and energy management strategies. The review also explores the role of energy storage systems and the potential of emerging technologies like microgrids in facilitating seamless integration. Furthermore, the review examines the interdisciplinary nature of electrical engineering in the context of renewable energy, emphasizing the collaboration between electrical engineers, environmental scientists, and policymakers. The synergy between these disciplines is crucial for developing holistic solutions that address not only technical challenges but also environmental and regulatory considerations. This review provides a comprehensive overview of the design and integration challenges faced by electrical engineers in the realm of renewable energy systems. By understanding and overcoming these challenges, the global community can accelerate the transition towards a sustainable and resilient energy future.
 Keywords: Renewable energy, Energy Integration, Challenges, Electrical, Engineering, Review.

Aging Effect of Plasma-Treated Carbon Fiber Surface: From an Engineering Point

Dielectric barrier discharge (DBD) plasma surface modification has certain aging effect. This article studies the aging effect of plasma (DBD) on the surface modification of carbon fibers. The test results show that plasma (DBD) treatment reduces the impurity particles on the surface of carbon fibers and makes the surface texture coarser. In addition, there is no significant change. After plasma (DBD) treatment, the content of C–O–C, C–O and C=O on the surface of carbon fibers increased from 3.20%, 7.76% and 1.64% to 7.06%, 21.50 and 6.08%, respectively. This is due to the high-energy particle bombardment of the fiber surface, which forms activated carbon atoms on the surface. The free electrons of these activated carbon atoms combine with ionized oxygen in the air. However, with the passage of time, the content of C–O–C, C–O and C=O gradually decreases to 3.31%, 8.57% and 1.77%, respectively. This is because some functional groups formed on the treated carbon fiber surface are not firmly bound, and some of these functional groups containing O2 groups will combine with surrounding substances through irreversible chemical oxidation reactions to produce CO2, which leaves the carbon fiber surface as a gas. The treated carbon fibers will immediately become hydrophilic, and the water contact angle decreases from 148.71° to 0°. With the passage of time, the water contact angle gradually increases to 118.16°, and the hydrophobicity recovers.

Energy, exergy, sustainability, thermoeconomic, exergoeconomic, environmental and environmental-economic effects of novel boron-containing open cell geopolymer filter of a diesel engine on exhaust emissions

In this study, the energy, exergy, sustainability, thermoeconomic, exergoeconomic, environmental and environmental-economic based analyses are applied to the experimentally developed (3 % boric acid based) boron-doped geopolymer filter used for the diesel engine to assess it in a large engineering point of view. In this context, novel boron-doped filter exhaust after treatment system (BDF EAS) is compared with catalytic exhaust after treatment system (catalytic EAS) and unfiltered option (filterless) with engine loads of 50 Nm, 75 Nm and 100 Nm, while engine speeds are 1500 rpm, 1700 rpm, and 1900 rpm. The utilization of the newly developed BDF EAS has a significant effect on the exhaust emission particles. It effectively filters the particles compared to the original catalytic EAS of the engine. On the other hand, the developed BDF EAS has effective oxidation process for the emissions. So, the newly developed boron-doped filter can be used as a single device that has both of the Diesel Oxidation Catalyst (DOC) and Diesel Particulate Filter (DPF) specifications together. Hence, the new product of BDF EAS is environmentally benign system for the diesel engines and boron-doped geopolymer material can be used as an innovative material in the automotive industry's exhaust emission control system.

Lab-on-a-chip models of the blood-brain barrier: evolution, problems, perspectives.

A great progress has been made in the development and use of lab-on-a-chip devices to model and study the blood-brain barrier (BBB) in the last decade. We present the main types of BBB-on-chip models and their use for the investigation of BBB physiology, drug and nanoparticle transport, toxicology and pathology. The selection of the appropriate cell types to be integrated into BBB-on-chip devices is discussed, as this greatly impacts the physiological relevance and translatability of findings. We identify knowledge gaps, neglected engineering and cell biological aspects and point out problems and contradictions in the literature of BBB-on-chip models, and suggest areas for further studies to progress this highly interdisciplinary field. BBB-on-chip models have an exceptional potential as predictive tools and alternatives of animal experiments in basic and preclinical research. To exploit the full potential of this technique expertise from materials science, bioengineering as well as stem cell and vascular/BBB biology is necessary. There is a need for better integration of these diverse disciplines that can only be achieved by setting clear parameters for characterizing both the chip and the BBB model parts technically and functionally.

(Invited) Exploring New ALD Processes for Coinage and Transition Metals through Molecularly Engineered Precursors

Atomic layer deposition (ALD) of functional materials has gained significant interest during the recent years and a range of new materials has been introduced into semiconducting manufacturing since ‘materials-limited device scaling’ has replaced the days of ‘happy geometric scaling’. The ability to integrate very thin layers into silicon structures has opened the way for a variety of novel applications which enhances the functionality and flexibility for future nanotechnologies. For ALD, precursors are indispensable and there are continuous efforts to develop new or precursors with improved physico-chemical properties.From the precursor engineering point of view, the concept is not only to synthesize one or more arbitrary members of a particular family of ligands, rather rationally introduce distinct changes in the ligand sphere in a systematic manner. This approach provides knowledge on the relationship between the molecular structure of the precursors, their thermal characteristics and reactivity. This presentation reveals how key precursor design parameters strongly influence the efficacy of ALD by comparing representative precursors possessing the same metal centre but different ligands or same ligand structure but different metal centres. Representative cases with coinage and transition metals will be illustrated. Alternative approaches to grow metal films and proof-of-concept applications will be demonstrated.

Elastoplastic solutions for deep-buried twin tunnels with arbitrary shapes and various arrangements under biaxial in-situ stress field based on Mohr-Coulomb and generalized Hoek-Brown criteria

Theoretical solutions for elastoplastic analysis of deep-buried twin tunnels with arbitrary shapes and various arrangements are developed under biaxial in-situ stress field based on Mohr-coulomb (M–C) and generalized Hoek-Brown (G-H-B) criteria. The boundary stress transformation formulas adapted for arbitrary stress conditions on non-circular tunnel wall are provided in terms of conformal transformations. Regarding the plastic analysis, analytical expressions for stress characteristic relationships along slip lines under generalized Hoek-Brown criterion are derived. Subsequently, the semi-analytical solutions for plastic stresses of rock surrounding arbitrary-shaped tunnels are constructed based on Mohr-Coulomb and generalized Hoek-Brown criteria applying conformal mapping technique, slip-line method and finite difference-numerical iterative approach. On the basis of the discrete plastic stresses, interpolation functions are generated according to three-dimensional linear interpolation technique. And then, solutions for elastic stress function and plastic radius of twin tunnels with various arrangements are developed with improved mapping functions and newly defined fitness functions through differential evolution method. The accuracy of the semi-analytical solutions is verified by the numerical simulation. Meanwhile, the proposed solutions have the advantages of meshless characteristic, better convergence and higher computing efficiency comparing with the numerical simulation. From the point of engineering, the developed elastoplastic solutions can provide theoretical supports for the stress analysis, plastic radius estimation, safety clearances optimizations of deep-buried twin tunnels.

TABASCO—Topology Algorithm That Benefits from Adaptation of Sorted Compliances Optimization

Although structural topology optimization has been developing for decades, it still plays a leading role within the area of engineering design. Solving contemporary design problems coming from industry requires the implementation of efficient methods and approaches. This stimulates research progress in the development of novel and versatile topology optimization algorithms. To follow these modern trends, an original topology generator has been elaborated and finally built as a Cellular Automaton with original update rules. The motivation for building the algorithm in this way came from the idea of utilizing the benefits of local compliances sorting. This is conducted on two levels: on the global level, the monotonic function mapping local compliances distribution is defined based on their sorted values; on the local level, for each cell, the compliances are sorted within the cell neighborhood. The three largest absolute values are selected, and these are the basis from which to formulate Cellular Automata update rules. These original rules can efficiently control the generation of structural topologies. This technique is somewhat inspired by the grey wolf optimizer strategy, wherein the process of updating design variables refers to the positions of the three best fitted wolves. It is proposed that we refer to the topology algorithm that benefits from the adaptation of sorted compliances optimization as TABASCO. The developed algorithm is a modified version of the flexible Cellular Automata one presented previously. The implemented extension, regarding the local level cell sorting, allows us to improve the resulting compliance values. The advantages of the algorithm, both from numerical and practical engineering points of view, as compared to the others developed within the field, may be gathered as follows: the algorithm works based on simple update rules, i.e., its numerical implementation is not complicated; it does not require gradient computations; filtering techniques are not needed; and it can easily be combined with professional structural analysis programs which allow engineering applications. The developed topology generator has been linked with ANSYS to show that it can be incorporated into a commercial structural analysis package. This is especially important with respect to the engineering implementations.

Sustainable colonization of Mars using shape optimized structures and in situ concrete

The major obstacle to Martian colonization is the mission cost which requires significant reduction. From the structural engineering point of view, importing materials and structural elements from Earth or massive excavations on the surface of Mars require an enormous amount of energy; thus, inflatable and under-surface structures as the main options for Martian colonization seem unrealistically expensive. Construction of affordable buildings onsite using only in situ sources may represent an ideal solution for Martian colonization. On the other hand, solar energy, at the early stage of colonization, would be the only available, practical, and low-cost energy source on Mars. Though, for sustainable and broad colonization, the energy required for construction and the construction cost should be minimized. Here, we propose three types of simple (relatively optimized), perforated, and algorithmic shape-optimized Martian structures to minimize the material and energy required for construction as well as the construction cost using only in situ resources. These structural forms can be considered remarkable steps towards sustainable structural construction and colonization on Mars. Also, these innovative structures were designed to minimize the tensile stress (maximize the compressive stress) and enable the use of in situ concrete. Our data indicate that compared to our previous study, the material and energy required for construction as well as the construction cost can be reduced by more than 50%. Acceptance criteria and limitations appropriate to the Martian environment, and desirable structural and material behaviors were defined to evaluate whether or not the behavior of a structure under the applied loads and conditions will be acceptable. To detect potential issues for onsite construction and evaluate the geometry of the models, a 1:200 3D model of the best structural form was printed.

Semiconductor piezoresistance prediction model for mechanical sensor design

AbstractThis paper addresses semiconductor piezoresistive materials selection in MEMS engineering design. From the practical engineering point of view, it is important to understand piezoresistance properties of semiconductors even if less accuracy under feasibility design phase. However, piezoresistance is frequently analyzed based on first principle electronic band structure simulations by sophisticate physicists. Practical engineers not familiar with this simulation cannot directly apply useful information derived from the result of simulation. This paper provides practical prediction method for piezoresistance based on electronic band parameters obtained from the state‐of‐the‐art solid‐state physics. It is demonstrated that the crucial parameters which control the p‐type shear piezoresistance coefficient π44 in diamond and zinc‐blend single crystals are the inverse of square of bond length in unit cell atom, the square root of valence light hole mass, and the shear elastic compliance coefficient S44.

Energy management strategy and simulation analysis of a hybrid train based on a comprehensive efficiency optimization

Since trains usually have long travel mileage requirements, designing an optimal energy management strategy has great potential for reducing energy consumption. First, a hybrid train power component model was developed, and the train operating efficiency, as well as a map of the optimal integrated efficiency of the entire vehicle operation, was derived for each mode from simulation calculations by analyzing the power flows in different operating modes. Next, the overall optimal efficiency of the entire vehicle was used to determine the mode division rules, and proportional integral control was used to ensure that the engine and motor operated at the target speed under the target torque. Finally, with the optimization objectives of reducing the fuel consumption of the entire vehicle and maintaining a balanced battery state of charge, a forward simulation model for the overall efficiency optimization of the entire vehicle was built in the MATLAB/Simulink software. Then, the trajectories of the engine and motor operating points, the fuel consumption, and the battery SOC were obtained for certain operating conditions. The effectiveness of the energy management strategy based on integrated efficiency optimization was verified by comparing the simulation results for the hybrid train with those of a conventional internal combustion engine train.

Causes and Remedies of High Jet Pipe Temperature in Turbo Shaft Engines : Case Studies

Jet Pipe Temperature (JPT) is a representation of Turbine Entry Temperature (TET) and is one of the most critical parameters in a gas turbine engine. Excessive turbine temperatures result in decreased life or catastrophic failure of the engine. This paper presents some case studies analyzing the causes of such high JPT in a turbo shaft engine in association with helicopter operation, effect of high JPT on engine performance and life and highlights the precautions and preventions to be adopted from engine point of view.

Structural design and engineering of Striatus, an unreinforced 3D-concrete-printed masonry arch bridge

This paper describes the structural design and engineering of “Striatus”, a 3D-concrete-printed unreinforced masonry pedestrian bridge built in Venice in 2021 as part of the Time Space Existence exhibition organised by the European Cultural Centre. The project combines the latest developments in 3D concrete printing with the structural principles of historic unreinforced masonry. Typically, the structural applications of 3D concrete printing are limited to elements such as columns and walls loaded vertically, perpendicularly to the horizontal printing layers, to formwork elements or secondary structural elements. Indeed, fabrication constraints, delamination issues and the low tensile strength of the concrete have been seen as limiting factors to 3D concrete printing for structural applications demanding resistance to bending or predominant loading directions not perpendicular to the printing layers. By using unreinforced-masonry structural principles, this paper shows that structural elements spanning space horizontally, such as a pedestrian bridge, can be built by using the 3D concrete printing components as the main structure, working only in compression, loaded perpendicularly to the printed layers. Furthermore, as a compression-only structure following masonry principles, Striatus enabled the use of unreinforced concrete without any mechanical or chemical connections between the elements and the separation of concrete and steel, only used for the supports and to equilibrate the horizontal thrust of the arch effect through the tension ties. This work shows how the application of unreinforced masonry principles to 3D concrete printing offers new opportunities in terms of structural design and represents a strategy to increase sustainability by reducing material consumption and allowing reusability and recyclability of the structure. Finally, this paper discusses the critical aspects related to the design of Striatus from an engineering and construction point of view.

Review of Structural Health Monitoring by using Sensors Technology

Abstract: The rapid technical development of technology in the fields of sensors, data acquisition and communication, signal analysis and data processing has prepared SHM with great benefits. SHM often provides reliable data on the real conditions of a structure. Bridges, wind farms, nuclear power plants, geotechnical structures, historical buildings and monuments, dams, offshore platforms, pipelines, ocean structures, airplanes, turbine blades etc. may be objects for monitoring, just to mention some. The monitoring can be periodic or continuous, short-term or long term, local or global and the monitoring system can consist of a few sensors up to hundreds or even thousands of them depending on the demands of the monitoring object. As the area of the subject is numerous, this thesis principally brings up and discusses the subject from a civil engineering point of view. Cracking concrete, collapsing and deteriorating constructions are a not only phenomena that occurs in old structures.

An Approach to Determine of the Formation Stages of Volcanism Using Natural Gamma-Ray Spectrometer from Geophysical Methods (Example of Gölcük Volcanism)

Gölcük Caldera is in the Isparta Angle, which is an interesting tectonic structure in Southwest Anatolia. This caldera is formed as a result of back-arc volcanism associated with the northward subduction zone of the African plate under the Eurasian Plate during the Tertiary. It attracts the attention of many researchers with its tectonic and volcanic structure. In this article, the results of in situ natural gamma radiation measurements made in the caldera are evaluated. In the study, radioactive element (Potassium (%K), Uranium (eU), and Thorium (eTh)) contents of volcanics were measured in situ with the portable gamma-ray spectrometer, which is effectively used in Geophysical Engineering. The changes in natural gamma radiation of alkaline volcanic are presented with maps. When these maps are examined, it is understood that K%, U-ppm and Th-ppm concentrations of Gölcük volcanic are higher than the world average values. The high potassium concentration draws even more attention. The high potassium content indicates that the local volcanic are ultrapotassic and contain lithospheric materials. In addition, since the radioactive element concentration will reflect the magmatic development, the volcanic stages in the region have been tried to be determined. The number of these stages was determined from the curves of the radioactive data from a purely geophysical engineering (numerical) point of view, and the study area was interpreted as consisting of three different phases. This finding is supported by the results of the articles on the aging studies of the samples taken as a result of observations. In addition to these, the ranges of radioactive elements belonging to these stages were determined.

Large‐scale system identification using self‐adaptive penguin search algorithm

AbstractFrom an engineering point of view, non‐linear systems are essential to the operation of control systems, because all systems actually have a non‐linear state in nature. In reality, there are many different kinds of non‐linear systems hidden by this negative definition. For successful analysis and control, the identification of non‐linear systems using unknown models is typically necessary. Till now, numerous approaches are developed for identifying non‐linear systems, but it cannot be employed with a large number of components. Moreover, system identification is typically restricted to output and input signals alone, also such systems are rarely used in reality. This is the primary justification for using non‐linear systems in this research. So, this research proposed a non‐linear model of system identification for large‐scale systems under the consideration of two systems: bilinear system and Volterra system. Therefore, a novel algorithm named Self Adaptive Penguin Search Optimization (SAPeSO) is introduced to attain the system characteristics properly and minimize the output variation. Finally, the effectiveness of the proposed work is compared with existing works in terms of various error measures. This research mainly focuses on the application‐oriented engineering problems. In particular, the Mean Absolute Error (MAE) of the proposed work for the Volterra system at 4000 samples is 18.83%, 14.05%, 8.88%, 29.72%, 19.91%, and 6.70% which is better than the existing bald eagle search (BES), arithmetic optimization algorithm (AOA), whale optimization algorithm (WOA), nonlinear autoregressive moving average with exogenous inputs‐ frequency response function + principal component analysis (NARMAX‐FRF+PCA), Global Gravitational Search Algorithm‐Assisted Kalman Filter (CGS‐KF), and sparse regression and separable least squares method (SR‐SLSM) methods, respectively. Finally, the error is minimum for the proposed model when compared with the other traditional approaches.

Semiconductor Piezoresistance Prediction Model for Mechanical Sensor Design

This paper addresses semiconductor piezoresistive materials selection in MEMS engineering design. From the practical engineering point of view, it is important to understand piezoresistance properties of semiconductors even if less accuracy under feasibility design phase. However, piezoresistance is frequently analyzed based on first principle electronic band structure simulations by sophisticate physicists. Practical engineers not familiar with this simulation cannot directly apply useful information derived from the result of simulation. This paper provides practical prediction method for piezoresistance based on electronic band parameters obtained from the state-of-the-art solid-state physics. It is demonstrated that the crucial parameters which control the p-type shear piezoresistance coefficient π44 in diamond and zinc-blend single crystals are the inverse of square of bond length in unit cell atom, the square root of valence light hole mass, and the shear elastic compliance coefficient S44.

Analysis and Design of G + 1 RCC Building

Due to advancement of technology humans are creating software to make things easier and time saving. As a result in the civil engineering point of view the manual design of buildings has lost its importance. It is true that design using a software is easy and time saving and mostly results are accurate. On the other hand manual design is a cumbersome job and a time consuming process, but for a beginner manual design helps to understand the basic fundamentals that are involved in designing a building. Once a person gains knowledge in manual design he will be knowing the elements involved in designing and can easily understand the usage of software. The main objective of the project is to use the knowledge that we have learn during our graduation and learn to deal with practical cases. We wish this project will fulfil our purpose.

Evaluation of Mechanical Properties and HPM Pulse Shielding Effectiveness of Cement-Based Composites

In today’s world, protection against electromagnetic waves, including high-power microwave (HPM) pulses, is becoming increasingly important. Hence, the aim of this research was to select an absorbing admixture, which, when used in an appropriate quantity, improves the effectiveness of shielding against electromagnetic waves and, at the same time, satisfies the requirements that are important from a construction engineering point of view. Altogether, eighteen admixtures (including two types of fibers), added in different quantities, and three types of aggregate have been tested. The compressive and flexural strength test results show that the greatest improvement in the tested mechanical properties was achieved in the case of admixtures such as steel fibers, carbon black P803, ferrite, and fly ash. Regarding the effect of the admixtures on shielding effectiveness, the best results were obtained for graphite in the form of flakes, graphite in the form of powder, carbon black N990 and P803, polypropylene and steel fibers, and hybrid admixtures, i.e., ashporite aggregate with carbon black and ashporite aggregate with graphite flakes. Regarding both mechanical properties and HPM pulse shielding effectiveness, the best effects were achieved in the case of the specimens with a high steel fiber content.

Energy saving and emission reduction effects from the application of green light optimized speed advisory on plug-in hybrid vehicle

Green Light Optimized Speed Advisory (GLOSA) is being rapidly extended worldwide as an innovative technology for intelligent transportation. However, the energy consumption, pollutant emissions and the corresponding driving behaviors changes for plug-in hybrid vehicle (PHEV) before and after applying GLOSA have not been adequately studied. Here, we quantitatively analyze for the first time the environmental and energy benefits of PHEVs after GLOSA application by combining acquired real-road driving cycles (DCs) and chassis dynamometer tests. We found that GLOSA significantly reduced the frequency of PHEV engine starts and throttle openings by reducing the number of stops and starts, the intensity of acceleration and the ratio of acceleration to idle time, and shifted more engine and motor operating points into the efficiency zone. The improved powertrain operating conditions significantly reduced the energy consumption and pollutant emissions of PHEV. GLOSA helps to reduce energy consumption by 23.50%, 26.01% and 27.94% when the initial state of charge (SOC) of the PHEV is 20%, 50% and 100% respectively. When the initial SOC of the PHEV is 20%, GLOSA contributed to a reduction in CO2, CO, total hydrocarbons (THC), NOx and particle number (PN) emissions of 17.37%, 22.58%, 36.07%, 30.39% and 16.38%. Our study aims to highlight the key role of GLOSA in reducing the pollutant emissions and energy consumption of PHEVs, while demonstrating that GLOSA is a valuable option for future transportation retrofitting.

A Review of Fibre Reinforced Polymer Bridges

Fibre-reinforced polymer composites (FRPs) offer various benefits for bridge construction. Lightweight, durability, design flexibility and fast erection in inaccessible areas are their unique selling points for bridge engineering. FRPs are used in four bridge applications: (1) FRP rebars/tendons in concrete; (2) repair and strengthening of existing bridges; (3) new hybrid–FRP bridges with conventional materials and (4) all–FRP composite new bridges made entirely of FRP materials. This paper reviews FRP bridges, including all–FRP and hybrid–FRP bridges. FRP bridges’ history, materials, processes and bridge components—deck, girder, truss, moulded parts and cables/rebars are considered. This paper does not discuss the use of FRP as an architectural element and a strengthening system. While lack of design codes, material specifications and recycling are the major challenges, the high cost of FRPs still remains the most critical barrier to the progress of FRPs in bridges.