Plain concrete is strong in compression but brittle in tension,having a low tensile strain capacity that can significantly degrade the long-term performance of concrete structures,even when steel reinforcing is presen...Plain concrete is strong in compression but brittle in tension,having a low tensile strain capacity that can significantly degrade the long-term performance of concrete structures,even when steel reinforcing is present.In order to address these challenges,short polymer fibers are randomly dispersed in a cement-based matrix to forma highly ductile engineered cementitious composite(ECC).Thismaterial exhibits high ductility under tensile forces,with its tensile strain being several hundred times greater than conventional concrete.Since concrete is inherently weak in tension,the tensile strain capacity(TSC)has become one of the most extensively researched properties.As a result,developing a model to predict the TSC of the ECC and to optimize the mixture proportions becomes challenging.Meanwhile,the effort required for laboratory trial batches to determine the TSC is reduced.To achieve the research objectives,five distinct models,artificial neural network(ANN),nonlinear model(NLR),linear relationship model(LR),multi-logistic model(MLR),and M5P-tree model(M5P),are investigated and employed to predict the TSCof ECCmixtures containing fly ash.Data from115 mixtures are gathered and analyzed to develop a new model.The input variables include mixture proportions,fiber length and diameter,and the time required for curing the various mixtures.The model’s effectiveness is evaluated and verified based on statistical parameters such as R2,mean absolute error(MAE),scatter index(SI),root mean squared error(RMSE),and objective function(OBJ)value.Consequently,the ANN model outperforms the others in predicting the TSC of the ECC,with RMSE,MAE,OBJ,SI,and R2 values of 0.42%,0.3%,0.33%,0.135%,and 0.98,respectively.展开更多
Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of...Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.展开更多
Computational Intelligent(CI)systems represent a pivotal intersection of cutting-edge technologies and complex engineering challenges aimed at solving real-world problems.This comprehensive body of work delves into th...Computational Intelligent(CI)systems represent a pivotal intersection of cutting-edge technologies and complex engineering challenges aimed at solving real-world problems.This comprehensive body of work delves into the realm of CI,which is designed to tackle intricate and multifaceted engineering problems through advanced computational techniques.The history of CI systems is a fascinating journey that spans several decades and has its roots in the development of artificial intelligence and machine learning techniques.Through a wide array of practical examples and case studies,this special issue bridges the gap between theoretical concepts and practical implementation,shedding light on how CI systems can optimize processes,design solutions,and inform decisions in complex engineering landscapes.This compilation stands as an essential resource for both novice learners and seasoned practitioners,offering a holistic perspective on the potential of CI in reshaping the future of engineering problem-solving.展开更多
Transition metal carbides and nitrides(MXenes)are crystal nanomaterials with a number of surface functional groups such as fluorine,hydroxyl,and oxygen,which can be used as carriers for proteins and drugs.MXenes have ...Transition metal carbides and nitrides(MXenes)are crystal nanomaterials with a number of surface functional groups such as fluorine,hydroxyl,and oxygen,which can be used as carriers for proteins and drugs.MXenes have excellent biocompatibility,electrical conductivity,surface hydrophilicity,mechanical properties and easy surface modification.However,at present,the stability of most MXenes needs to be improved,and more synthesis methods need to be explored.MXenes are good substrates for nerve cell regeneration and nerve reconstruction,which have broad application prospects in the repair of nervous system injury.Regarding the application of MXenes in neuroscience,mainly at the cellular level,the long-term in vivo biosafety and effects also need to be further explored.This review focuses on the progress of using MXenes in nerve regeneration over the last few years;discussing preparation of MXenes and their biocompatibility with different cells as well as the regulation by MXenes of nerve cell regeneration in two-dimensional and three-dimensional environments in vitro.MXenes have great potential in regulating the proliferation,differentiation,and maturation of nerve cells and in promoting regeneration and recovery after nerve injury.In addition,this review also presents the main challenges during optimization processes,such as the preparation of stable MXenes and long-term in vivo biosafety,and further discusses future directions in neural tissue engineering.展开更多
The concept of“carbon neutrality”poses a huge challenge for chemical engineering and brings great opportunities for boosting the development of novel technologies to realize carbon offsetting and reduce carbon emiss...The concept of“carbon neutrality”poses a huge challenge for chemical engineering and brings great opportunities for boosting the development of novel technologies to realize carbon offsetting and reduce carbon emissions.Developing high-efficient,low-cost,energy-efficient and eco-friendly microfluidicbased microchemical engineering is of great significance.Such kind of“green microfluidics”can reduce carbon emissions from the source of raw materials and facilitate controllable and intensified microchemical engineering processes,which represents the new power for the transformation and upgrading of chemical engineering industry.Here,a brief review of green microfluidics for achieving carbon neutral microchemical engineering is presented,with specific discussions about the characteristics and feasibility of applying green microfluidics in realizing carbon neutrality.Development of green microfluidic systems are categorized and reviewed,including the construction of microfluidic devices by bio-based substrate materials and by low carbon fabrication methods,and the use of more biocompatible and nondestructive fluidic systems such as aqueous two-phase systems(ATPSs).Moreover,low carbon applications benefit from green microfluidics are summarized,ranging from separation and purification of biomolecules,high-throughput screening of chemicals and drugs,rapid and cost-effective detections,to synthesis of fine chemicals and novel materials.Finally,challenges and perspectives for further advancing green microfluidics in microchemical engineering for carbon neutrality are proposed and discussed.展开更多
With an excellent power conversion efficiency of 25.7%,closer to the Shockley–Queisser limit,perovskite solar cells(PSCs)have become a strong candidate for a next-generation energy harvester.However,the lack of stabi...With an excellent power conversion efficiency of 25.7%,closer to the Shockley–Queisser limit,perovskite solar cells(PSCs)have become a strong candidate for a next-generation energy harvester.However,the lack of stability and reliability in PSCs remained challenging for commercialization.Strategies,such as interfacial and structural engineering,have a more critical influence on enhanced performance.MXenes,two-dimensional materials,have emerged as promising materials in solar cell applications due to their metallic electrical conductivity,high carrier mobility,excellent optical transparency,wide tunable work function,and superior mechanical properties.Owing to different choices of transition elements and surface-terminating functional groups,MXenes possess the feature of tuning the work function,which is an essential metric for band energy alignment between the absorber layer and the charge transport layers for charge carrier extraction and collection in PSCs.Furthermore,adopting MXenes to their respective components helps reduce the interfacial recombination resistance and provides smooth charge transfer paths,leading to enhanced conductivity and operational stability of PSCs.This review paper aims to provide an overview of the applications of MXenes as components,classified according to their roles as additives(into the perovskite absorber layer,charge transport layers,and electrodes)and themselves alone or as interfacial layers,and their significant importance in PSCs in terms of device performance and stability.Lastly,we discuss the present research status and future directions toward its use in PSCs.展开更多
This study considers the effect of Eichhornia Crassipes Biodiesel(ECB)blends on the performances,combustion,and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode(D...This study considers the effect of Eichhornia Crassipes Biodiesel(ECB)blends on the performances,combustion,and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode(DFM)and equipped with an Exhaust gas recirculation technique(EGR).In particular,a single-cylinder,four-stroke,water-cooled diesel engine was utilized and four modes of fuel operation were considered:mode I,the engine operated with an ordinary diesel fuel;mode II,the engine operated with the addition of 2.4 L/min of lique-fied petroleum gas(LPG)and 20%EGR;mode III,20%ECB with 2.4 L/min LPG and 20%EGR;mode IV,40%ECB with 2.4 L/min LPG and 20%EGR.The operation conditions were constant engine speed(1500 rpm),var-iation of load(25%,50%,75%,and 100%),full load,with a compression ratio of 18,and a time injection of 23°BTDC(Before top died center).With regard to engine emissions,carbon dioxide(CO_(2)),carbon monoxide(CO),hydrocarbons(UHC),and nitrogen oxide(NOX)were measured using a gas analyzer.The smoke opacity was measured using an OPABOX smoke meter.By comparing the results related to the different modes with mode I at full load,the BTE(Brake thermal efficiency)increased by 20.17%,11.45%,and 12.66%with modes II,III,and IV,respectively.In comparison to the results for mode II,the BTE decreased due to the combustion of ECB blends by 7.26%and 6.24%for mode III and mode IV,respectively,at full load.In comparison to mode II,the Brake specific energy consumption(BSEC)increased with the ECB substitution.With ECB blends,there is a noticeable decrease in the CO,CO_(2),and UHC emissions at a partial load.Furthermore,the 20%ECB has no effect on CO emissions at full load.For modes II and IV,the CO_(2)increased by 33.33%and 19%,respectively,while the UHC emissions were reduced by 14.49%for mode III and 26.08%for mode IV.The smoke of mode III was lower by 7.21%,but for mode IV,it was higher by 12.37%.In addition,with mode III and mode IV,the NOx emissions increased by 30.50%and 18.80%,respectively.展开更多
This study aims to improve the competence of students of the Department of Industrial Engineering in Indonesia in the subject of Chemical Industry, in particular through the model-based teaching materials CAI (Compute...This study aims to improve the competence of students of the Department of Industrial Engineering in Indonesia in the subject of Chemical Industry, in particular through the model-based teaching materials CAI (Computer Assisted Instruction) in the form of an interactive CD. In particular, the study was carried out for the purposes of: 1) designing and developing models of devices based learning CAI (Computer Assisted Instruction) systematically in prototype form, 2) producing an interactive CD as a model learning devices Chemical Industry based CAI (Computer Assisted Instruction) to improve the competence of students of the Department of Industrial Engineering in Industrial chemistry courses. The benefits of this research are: 1) for the government, the results of this study can be used as a reference in implementing educational policies, especially to enhance the nation’s competitiveness in the era of informatics;and 2) for the Department of Industrial Engineering in Indonesia, the results of this research can be used to enhance learning that can improve the competence of students in the subject of Chemical Industry, which in turn can be passed with high achievement. Products produced in the first year are a design-based teaching materials CAI (Computer Assisted Instruction) in prototype form, with the following steps: 1) pre- production which includes needs analysis, identifying and analyzing the needs based on the content of curriculum and learning model based CAI (Computer Assisted Instruction), the development of a concept related to Chemical Industry, the development of multimedia content that includes developing materials, animation, and evaluation related to industrial chemicals, gathering material to make the recording sound, shooting, and editing with regard to the development of teaching materials chemical Industry based CAI (Computer Assisted Instruction), as well as developing the storyboard as the layout of the multimedia contents by involving experts multimedia;2) production process that includes design/design and conduct of programming a prototype which means at this stage of the design and development of teaching materials based CAI (Computer Assisted Instruction);and 3) post-production which includes the evaluation justification experts, conducted trials on stakeholders, being revised based on input from experts, and doing packing and labeling.展开更多
Using sunlight to drive chemical reactions via photocatalysis is paramount for a sustainable future.Among several photocatalysts,employing layered double hydrides(LDH) for photocatalytic application is most straightfo...Using sunlight to drive chemical reactions via photocatalysis is paramount for a sustainable future.Among several photocatalysts,employing layered double hydrides(LDH) for photocatalytic application is most straightforward and desirable owing to their distinctive two-dimensional(2D) lamellar structure and optical attributes.This article reviews the advancements in bimetallic/trimetallic LDHs and various strategies to achieve high efficiency toward an outstanding performing photocatalyst.Firstly,the tuning of LDH components that control the electro nic and structural properties is explained.The tu ning obtained through the adoption,combination,and incorporation of different cations and anions is also explained.The progress of modification methods,such as the adoption of different morphologies,delamination,and defect engineering towards enhanced photocatalytic activities,is discussed in the mainstream.The band engineering,structural characteristics,and redox tuning are further deliberated to maximize solar energy harvesting for different photocatalytic applications.Finally,the progress obtained in forming hierarchical heterostructures through hybridization with other semiconductors or conducting materials is systematically disclosed to get maximum photocatalytic performance.Moreover,the structural changes during the in-situ synthesis of LDH and the stability of LDH-based photocatalysts are deliberated.The review also summarizes the improvements in LDH properties obtained through modification tactics and discusses the prospects for future energy and environmental applications.展开更多
To improve the performances of diesel engines and to reduce the pollutants they emit,aluminum oxide nanopar-ticles in varying quantities(50,100,150 ppm)have been added to conventional diesel fuel.The results of such e...To improve the performances of diesel engines and to reduce the pollutants they emit,aluminum oxide nanopar-ticles in varying quantities(50,100,150 ppm)have been added to conventional diesel fuel.The results of such experimental tests have revealed that the addition of nano-Al_(2)O_(3) particles to the diesel fuel reduces its consump-tion by 0.488%,1.02%,and 1.377%,respectively and increases the brake thermal efficiency by 1.4%,2.6%,and 3.8%,respectively.The concentrations of undesired gases decrease accordingly by 1.5%,1.7%,and 2.8%for HC and by 5.88%,11.7%,and 17.6%,respectively,for CO.For the same percentages of nanoparticles,NO_(x) increases by 2.65,4.36,and 5.37,while the TSP(Total Suspended Particulate)decreases by 22%,34.66%,and 49.7%,respectively.In the same conditions,sulfur dioxide pollutants increase by 4.57%,8.8%and 12.89%,and H_(2)S levels by 4.7%,7.81%and 8.9%,respectively.展开更多
A comprehensive understanding of human intelligence is still an ongoing process,i.e.,human and information security are not yet perfectly matched.By understanding cognitive processes,designers can design humanized cog...A comprehensive understanding of human intelligence is still an ongoing process,i.e.,human and information security are not yet perfectly matched.By understanding cognitive processes,designers can design humanized cognitive information systems(CIS).The need for this research is justified because today’s business decision makers are faced with questions they cannot answer in a given amount of time without the use of cognitive information systems.The researchers aim to better strengthen cognitive information systems with more pronounced cognitive thresholds by demonstrating the resilience of cognitive resonant frequencies to reveal possible responses to improve the efficiency of human-computer interaction(HCI).Apractice-oriented research approach included research analysis and a review of existing articles to pursue a comparative research model;thereafter,amodel development paradigm was used to observe and monitor the progression of CIS during HCI.The scope of our research provides a broader perspective on how different disciplines affect HCI and how human cognitive models can be enhanced to enrich complements.We have identified a significant gap in the current literature on mental processing resulting from a wide range of theory and practice.展开更多
If the 20th century was the age of mapping and controlling the external world,the 21st century is the biomedical age of mapping and controlling the biological internal world.The biomedical age is bringing new technolo...If the 20th century was the age of mapping and controlling the external world,the 21st century is the biomedical age of mapping and controlling the biological internal world.The biomedical age is bringing new technological breakthroughs for sensing and controlling human biomolecules,cells,tissues,and organs,which underpin new frontiers in the biomedical discovery,data,biomanufacturing,and translational sciences.This article reviews what we believe will be the next wave of biomedical engineering(BME)education in support of the biomedical age,what we have termed BME 2.0.BME 2.0 was announced on October 122017 at BMES 49(https://www.bme.jhu.edu/news-events/news/miller-opens-2017-bmes-annual-meeting-with-vision-for-new-bme-era/).We present several principles upon which we believe the BME 2.0 curriculum should be constructed,and from these principles,we describe what view as the foundations that form the next generations of curricula in support of the BME enterprise.The core principles of BME 2.0 education are(a)educate students bilingually,from day 1,in the languages of modern molecular biology and the analytical modeling of complex biological systems;(b)prepare every student to be a biomedical data scientist;(c)build a unique BME community for discovery and innovation via a vertically integrated and convergent learning environment spanning the university and hospital systems;(d)champion an educational culture of inclusive excellence;and(e)codify in the curriculum ongoing discoveries at the frontiers of the discipline,thus ensuring BME 2.0 as a launchpad for training the future leaders of the biotechnology marketplaces.We envision that the BME 2.0 education is the path for providing every student with the training to lead in this new era of engineering the future of medicine in the 21st century.展开更多
In the article“BME 2.0:Engineering the Future of Medicine”[1],the competing interests statement was inadvertently omitted by the publisher from the published version of the article.This has now been corrected in the...In the article“BME 2.0:Engineering the Future of Medicine”[1],the competing interests statement was inadvertently omitted by the publisher from the published version of the article.This has now been corrected in the PDF and HTML(full text).展开更多
Reviewing the empirical and theoretical parameter relationships between various parameters is a good way to understand more about contact binary systems.In this investigation,two-dimensional(2D)relationships for P–MV...Reviewing the empirical and theoretical parameter relationships between various parameters is a good way to understand more about contact binary systems.In this investigation,two-dimensional(2D)relationships for P–MV(system),P–L1,2,M1,2–L1,2,and q–Lratiowere revisited.The sample used is related to 118 contact binary systems with an orbital period shorter than 0.6 days whose absolute parameters were estimated based on the Gaia Data Release 3 parallax.We reviewed previous studies on 2D relationships and updated six parameter relationships.Therefore,Markov chain Monte Carlo and Machine Learning methods were used,and the outcomes were compared.We selected 22 contact binary systems from eight previous studies for comparison,which had light curve solutions using spectroscopic data.The results show that the systems are in good agreement with the results of this study.展开更多
The primary goal of this study is to develop cost-effective shield materials that offer effective protection against high-velocity ballistic impact and electromagnetic interference(EMI)shielding capabilities through a...The primary goal of this study is to develop cost-effective shield materials that offer effective protection against high-velocity ballistic impact and electromagnetic interference(EMI)shielding capabilities through absorption.Six fiber-reinforced epoxy composite panels,each with a different fabric material and stacking sequence,have been fabricated using a hand-layup vacuum bagging process.Two panels made of Kevlar and glass fibers,referred to as(K-NIJ)and(G-NIJ),have been tested according to the National Institute of Justice ballistic resistance protective materials test NIJ 0108.01 Standard-Level IIIA(9 mm×19 mm FMJ 124 g)test.Three panels,namely,a hybrid of Kevlar and glass(H-S),glass with ceramic particles(C-S),and glass with recycled rubber(R-S)have been impacted by the bullet at the center,while the fourth panel made of glass fiber(G-S)has been impacted at the side.EMI shielding properties have been measured in the X-band frequency range via the reflection-transmission method.Results indicate that four panels(K-NIJ,G-NIJ,H-S,and G-S)are capable of withstanding high-velocity impact by stopping the bullet from penetrating through the panels while maintaining their structural integrity.However,under such conditions,these panels may experience localized delamination with variable severity.The EMI measurements reveal that the highest absorptivity observed is 88% for the KNIJ panel at 10.8 GHz,while all panels maintain an average absorptivity above 65%.All panels act as a lossy medium with a peak absorptivity at different frequencies,with K-NIJ and H-S panels demonstrating the highest absorptivity.In summary,the study results in the development of a novel,costeffective,multifunctional glass fiber epoxy composite that combines ballistic and electromagnetic interference shielding properties.The material has been developed using a simple manufacturing method and exhibits remarkable ballistic protection that outperforms Kevlar in terms of shielding efficiency;no bullet penetration or back face signature is observed,and it also demonstrates high EMI shielding absorption.Overall,the materials developed show great promise for various applications,including the military and defense.展开更多
Sodium hypochlorite has significant potential as a sanitation solution in hard-to-reach areas.Few studies have investigated the optimal electrolysis parameters for its production with volumes greater than 1o L.This st...Sodium hypochlorite has significant potential as a sanitation solution in hard-to-reach areas.Few studies have investigated the optimal electrolysis parameters for its production with volumes greater than 1o L.This study evaluated sodium hypochlorite production through electrolysis in a 22-L prototype and identified the optimal operating parameters.Tests were performed using graphite electrodes with areas of 68.4 cm²at the laboratory scale and 1865.0 cm?at the prototype scale.A design for experiments with different operating times,chloride concentrations,and electric current intensities was developed.The optimal operating time,sodium chloride concentration,and current intensity at the laboratory scale were 120 min,150 g of chloride per liter,and 3 A,respectively,leading to the production of 5.02 g/L of the disinfectant with an energy efficiency of 12.21 mg of Cl2 per kilojoule.At the prototype scale,the maximum sodium hypochlorite concentration of 3.99 g of chloride per liter was achieved with an operating time of 120 min,a sodium chloride concentration of 100 g of chloride per liter,and a current intensity of 70 A,reaching an energy efficiency of 42.56 mg of Cl2 per kilojoule.In addition,this study evaluated the influences of the chloride concentration,current intensity,and operating time on the production of sodium hypochlorite at the two scales,and formulated the equations showing the trends of sodium hypochlorite production and energy efficiency in the electrochemical systems.The 22-L prototype model for production of this oxidizing substance is promising for disinfection of large volumes of water in areas that are difficult to access.展开更多
Boulder spacing in mountain rivers and near-wake flow zones within the boulder array is very useful for fish habitat and growth of aquatic organisms.The present study aims to investigate how the boulder array and spac...Boulder spacing in mountain rivers and near-wake flow zones within the boulder array is very useful for fish habitat and growth of aquatic organisms.The present study aims to investigate how the boulder array and spacing influence the near-bed flow structures in a gravel-bed stream.Boulders are staggered over a gravel-bed stream with three different inter-boulder spacing namely(a)large(b)medium and(c)small spacing.An acoustic Doppler velocimeter was used for flow measurements in a rectangular channel and the results were compared with those acquired from numerical simulation.The time-averaged velocity profiles at the near-wake flow zones of boulders experience maximum flow retardation which is an outcome of the boulder-induced form roughness.The ratio of velocity differences associated to form and skin roughness and its positive magnitude reveals the dominance of form roughness closest to the boulders.Form roughness computed is 1.75 to 2 times higher than the skin roughness at the near-wake flow region.In particular,the collective immobile boulders placed at different inter-boulder spacings developed high and low bed shear stresses closest to the boulders.The low bed shear stresses characterised by a secondary peak developed at the trough location of the boulders is attributed to the skin shear stress.Further,the spatial averaging of time-averaged flow quantities gives additional impetus to present an improved illustration of fluid shear stresses.The formation of form-induced shear stress is estimated to be 17%to 23%of doubleaveraged Reynolds shear stress and partially compensates for the damping of time-averaged Reynolds shear stress in the interfacial sub-layer.The quadrant analysis of spatial velocity fluctuations depicts that the form-induced shear stresses are dominant in the interfacial sub-layer and have no significance above the gravel-bed surface.展开更多
Side lobe level reduction(SLL)of antenna arrays significantly enhances the signal-to-interference ratio and improves the quality of service(QOS)in recent and future wireless communication systems starting from 5G up t...Side lobe level reduction(SLL)of antenna arrays significantly enhances the signal-to-interference ratio and improves the quality of service(QOS)in recent and future wireless communication systems starting from 5G up to 7G.Furthermore,it improves the array gain and directivity,increasing the detection range and angular resolution of radar systems.This study proposes two highly efficient SLL reduction techniques.These techniques are based on the hybridization between either the single convolution or the double convolution algorithms and the genetic algorithm(GA)to develop the Conv/GA andDConv/GA,respectively.The convolution process determines the element’s excitations while the GA optimizes the element spacing.For M elements linear antenna array(LAA),the convolution of the excitation coefficients vector by itself provides a new vector of excitations of length N=(2M−1).This new vector is divided into three different sets of excitations including the odd excitations,even excitations,and middle excitations of lengths M,M−1,andM,respectively.When the same element spacing as the original LAA is used,it is noticed that the odd and even excitations provide a much lower SLL than that of the LAA but with amuch wider half-power beamwidth(HPBW).While the middle excitations give the same HPBWas the original LAA with a relatively higher SLL.Tomitigate the increased HPBWof the odd and even excitations,the element spacing is optimized using the GA.Thereby,the synthesized arrays have the same HPBW as the original LAA with a two-fold reduction in the SLL.Furthermore,for extreme SLL reduction,the DConv/GA is introduced.In this technique,the same procedure of the aforementioned Conv/GA technique is performed on the resultant even and odd excitation vectors.It provides a relatively wider HPBWthan the original LAA with about quad-fold reduction in the SLL.展开更多
文摘Plain concrete is strong in compression but brittle in tension,having a low tensile strain capacity that can significantly degrade the long-term performance of concrete structures,even when steel reinforcing is present.In order to address these challenges,short polymer fibers are randomly dispersed in a cement-based matrix to forma highly ductile engineered cementitious composite(ECC).Thismaterial exhibits high ductility under tensile forces,with its tensile strain being several hundred times greater than conventional concrete.Since concrete is inherently weak in tension,the tensile strain capacity(TSC)has become one of the most extensively researched properties.As a result,developing a model to predict the TSC of the ECC and to optimize the mixture proportions becomes challenging.Meanwhile,the effort required for laboratory trial batches to determine the TSC is reduced.To achieve the research objectives,five distinct models,artificial neural network(ANN),nonlinear model(NLR),linear relationship model(LR),multi-logistic model(MLR),and M5P-tree model(M5P),are investigated and employed to predict the TSCof ECCmixtures containing fly ash.Data from115 mixtures are gathered and analyzed to develop a new model.The input variables include mixture proportions,fiber length and diameter,and the time required for curing the various mixtures.The model’s effectiveness is evaluated and verified based on statistical parameters such as R2,mean absolute error(MAE),scatter index(SI),root mean squared error(RMSE),and objective function(OBJ)value.Consequently,the ANN model outperforms the others in predicting the TSC of the ECC,with RMSE,MAE,OBJ,SI,and R2 values of 0.42%,0.3%,0.33%,0.135%,and 0.98,respectively.
基金The authors are thankful to Ministry of Human Resource Development(presently Ministry of Education),Government of India,New Delhi,for providing research facility by sanctioning Center of Excellence(F.No.5-6/2013-TS VII)in Tissue Engineering and Center of Excellence in Orthopedic Tissue Engineering and Rehabilitation funded by World Bank under TEQIP-II.
文摘Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.
文摘Computational Intelligent(CI)systems represent a pivotal intersection of cutting-edge technologies and complex engineering challenges aimed at solving real-world problems.This comprehensive body of work delves into the realm of CI,which is designed to tackle intricate and multifaceted engineering problems through advanced computational techniques.The history of CI systems is a fascinating journey that spans several decades and has its roots in the development of artificial intelligence and machine learning techniques.Through a wide array of practical examples and case studies,this special issue bridges the gap between theoretical concepts and practical implementation,shedding light on how CI systems can optimize processes,design solutions,and inform decisions in complex engineering landscapes.This compilation stands as an essential resource for both novice learners and seasoned practitioners,offering a holistic perspective on the potential of CI in reshaping the future of engineering problem-solving.
基金supported by grants from the National Key R&D Program of China,Nos.2021YFA1101300,2021YFA1101803,2020YFA0112503the National Natural Science Foundation of China,Nos.82030029,81970882,92149304Science and Technology Department of Sichuan Province,No.2021YFS0371(all to RC)。
文摘Transition metal carbides and nitrides(MXenes)are crystal nanomaterials with a number of surface functional groups such as fluorine,hydroxyl,and oxygen,which can be used as carriers for proteins and drugs.MXenes have excellent biocompatibility,electrical conductivity,surface hydrophilicity,mechanical properties and easy surface modification.However,at present,the stability of most MXenes needs to be improved,and more synthesis methods need to be explored.MXenes are good substrates for nerve cell regeneration and nerve reconstruction,which have broad application prospects in the repair of nervous system injury.Regarding the application of MXenes in neuroscience,mainly at the cellular level,the long-term in vivo biosafety and effects also need to be further explored.This review focuses on the progress of using MXenes in nerve regeneration over the last few years;discussing preparation of MXenes and their biocompatibility with different cells as well as the regulation by MXenes of nerve cell regeneration in two-dimensional and three-dimensional environments in vitro.MXenes have great potential in regulating the proliferation,differentiation,and maturation of nerve cells and in promoting regeneration and recovery after nerve injury.In addition,this review also presents the main challenges during optimization processes,such as the preparation of stable MXenes and long-term in vivo biosafety,and further discusses future directions in neural tissue engineering.
基金the supports of the National Science Foundation of China (22008130, 22025801)the China Postdoctoral Science Foundation (2020M682124)+1 种基金the Qingdao Postdoctoral Researchers Applied Research Project Foundation (RZ2000001426)the Scientific Research Foundation for Youth Scholars from Qingdao University (DC1900014265) for this work
文摘The concept of“carbon neutrality”poses a huge challenge for chemical engineering and brings great opportunities for boosting the development of novel technologies to realize carbon offsetting and reduce carbon emissions.Developing high-efficient,low-cost,energy-efficient and eco-friendly microfluidicbased microchemical engineering is of great significance.Such kind of“green microfluidics”can reduce carbon emissions from the source of raw materials and facilitate controllable and intensified microchemical engineering processes,which represents the new power for the transformation and upgrading of chemical engineering industry.Here,a brief review of green microfluidics for achieving carbon neutral microchemical engineering is presented,with specific discussions about the characteristics and feasibility of applying green microfluidics in realizing carbon neutrality.Development of green microfluidic systems are categorized and reviewed,including the construction of microfluidic devices by bio-based substrate materials and by low carbon fabrication methods,and the use of more biocompatible and nondestructive fluidic systems such as aqueous two-phase systems(ATPSs).Moreover,low carbon applications benefit from green microfluidics are summarized,ranging from separation and purification of biomolecules,high-throughput screening of chemicals and drugs,rapid and cost-effective detections,to synthesis of fine chemicals and novel materials.Finally,challenges and perspectives for further advancing green microfluidics in microchemical engineering for carbon neutrality are proposed and discussed.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2022M3J7A1062940 and 2022033777)supported by Korea Electric Power Corporation(Grant Number:R21XO01-5)+2 种基金supported by the Technology Innovation Program(or Industrial Strategic Technology Development Program)(1415172732/20011410,Development of SPD smart film and service of aftermarket for energy saving in building and automobiles)the Ministry of Trade,Industry&Energy(MOTIE,Korea)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2018R1A6A1A03023788 and 2021R1I1A1A01055790).
文摘With an excellent power conversion efficiency of 25.7%,closer to the Shockley–Queisser limit,perovskite solar cells(PSCs)have become a strong candidate for a next-generation energy harvester.However,the lack of stability and reliability in PSCs remained challenging for commercialization.Strategies,such as interfacial and structural engineering,have a more critical influence on enhanced performance.MXenes,two-dimensional materials,have emerged as promising materials in solar cell applications due to their metallic electrical conductivity,high carrier mobility,excellent optical transparency,wide tunable work function,and superior mechanical properties.Owing to different choices of transition elements and surface-terminating functional groups,MXenes possess the feature of tuning the work function,which is an essential metric for band energy alignment between the absorber layer and the charge transport layers for charge carrier extraction and collection in PSCs.Furthermore,adopting MXenes to their respective components helps reduce the interfacial recombination resistance and provides smooth charge transfer paths,leading to enhanced conductivity and operational stability of PSCs.This review paper aims to provide an overview of the applications of MXenes as components,classified according to their roles as additives(into the perovskite absorber layer,charge transport layers,and electrodes)and themselves alone or as interfacial layers,and their significant importance in PSCs in terms of device performance and stability.Lastly,we discuss the present research status and future directions toward its use in PSCs.
文摘This study considers the effect of Eichhornia Crassipes Biodiesel(ECB)blends on the performances,combustion,and emission characteristics of a direct injection compression ignition engine operated in a dual-fuel mode(DFM)and equipped with an Exhaust gas recirculation technique(EGR).In particular,a single-cylinder,four-stroke,water-cooled diesel engine was utilized and four modes of fuel operation were considered:mode I,the engine operated with an ordinary diesel fuel;mode II,the engine operated with the addition of 2.4 L/min of lique-fied petroleum gas(LPG)and 20%EGR;mode III,20%ECB with 2.4 L/min LPG and 20%EGR;mode IV,40%ECB with 2.4 L/min LPG and 20%EGR.The operation conditions were constant engine speed(1500 rpm),var-iation of load(25%,50%,75%,and 100%),full load,with a compression ratio of 18,and a time injection of 23°BTDC(Before top died center).With regard to engine emissions,carbon dioxide(CO_(2)),carbon monoxide(CO),hydrocarbons(UHC),and nitrogen oxide(NOX)were measured using a gas analyzer.The smoke opacity was measured using an OPABOX smoke meter.By comparing the results related to the different modes with mode I at full load,the BTE(Brake thermal efficiency)increased by 20.17%,11.45%,and 12.66%with modes II,III,and IV,respectively.In comparison to the results for mode II,the BTE decreased due to the combustion of ECB blends by 7.26%and 6.24%for mode III and mode IV,respectively,at full load.In comparison to mode II,the Brake specific energy consumption(BSEC)increased with the ECB substitution.With ECB blends,there is a noticeable decrease in the CO,CO_(2),and UHC emissions at a partial load.Furthermore,the 20%ECB has no effect on CO emissions at full load.For modes II and IV,the CO_(2)increased by 33.33%and 19%,respectively,while the UHC emissions were reduced by 14.49%for mode III and 26.08%for mode IV.The smoke of mode III was lower by 7.21%,but for mode IV,it was higher by 12.37%.In addition,with mode III and mode IV,the NOx emissions increased by 30.50%and 18.80%,respectively.
文摘This study aims to improve the competence of students of the Department of Industrial Engineering in Indonesia in the subject of Chemical Industry, in particular through the model-based teaching materials CAI (Computer Assisted Instruction) in the form of an interactive CD. In particular, the study was carried out for the purposes of: 1) designing and developing models of devices based learning CAI (Computer Assisted Instruction) systematically in prototype form, 2) producing an interactive CD as a model learning devices Chemical Industry based CAI (Computer Assisted Instruction) to improve the competence of students of the Department of Industrial Engineering in Industrial chemistry courses. The benefits of this research are: 1) for the government, the results of this study can be used as a reference in implementing educational policies, especially to enhance the nation’s competitiveness in the era of informatics;and 2) for the Department of Industrial Engineering in Indonesia, the results of this research can be used to enhance learning that can improve the competence of students in the subject of Chemical Industry, which in turn can be passed with high achievement. Products produced in the first year are a design-based teaching materials CAI (Computer Assisted Instruction) in prototype form, with the following steps: 1) pre- production which includes needs analysis, identifying and analyzing the needs based on the content of curriculum and learning model based CAI (Computer Assisted Instruction), the development of a concept related to Chemical Industry, the development of multimedia content that includes developing materials, animation, and evaluation related to industrial chemicals, gathering material to make the recording sound, shooting, and editing with regard to the development of teaching materials chemical Industry based CAI (Computer Assisted Instruction), as well as developing the storyboard as the layout of the multimedia contents by involving experts multimedia;2) production process that includes design/design and conduct of programming a prototype which means at this stage of the design and development of teaching materials based CAI (Computer Assisted Instruction);and 3) post-production which includes the evaluation justification experts, conducted trials on stakeholders, being revised based on input from experts, and doing packing and labeling.
基金United Arab Emirates University (UAE) for providing funding of this research undergrant # 12N097。
文摘Using sunlight to drive chemical reactions via photocatalysis is paramount for a sustainable future.Among several photocatalysts,employing layered double hydrides(LDH) for photocatalytic application is most straightforward and desirable owing to their distinctive two-dimensional(2D) lamellar structure and optical attributes.This article reviews the advancements in bimetallic/trimetallic LDHs and various strategies to achieve high efficiency toward an outstanding performing photocatalyst.Firstly,the tuning of LDH components that control the electro nic and structural properties is explained.The tu ning obtained through the adoption,combination,and incorporation of different cations and anions is also explained.The progress of modification methods,such as the adoption of different morphologies,delamination,and defect engineering towards enhanced photocatalytic activities,is discussed in the mainstream.The band engineering,structural characteristics,and redox tuning are further deliberated to maximize solar energy harvesting for different photocatalytic applications.Finally,the progress obtained in forming hierarchical heterostructures through hybridization with other semiconductors or conducting materials is systematically disclosed to get maximum photocatalytic performance.Moreover,the structural changes during the in-situ synthesis of LDH and the stability of LDH-based photocatalysts are deliberated.The review also summarizes the improvements in LDH properties obtained through modification tactics and discusses the prospects for future energy and environmental applications.
文摘To improve the performances of diesel engines and to reduce the pollutants they emit,aluminum oxide nanopar-ticles in varying quantities(50,100,150 ppm)have been added to conventional diesel fuel.The results of such experimental tests have revealed that the addition of nano-Al_(2)O_(3) particles to the diesel fuel reduces its consump-tion by 0.488%,1.02%,and 1.377%,respectively and increases the brake thermal efficiency by 1.4%,2.6%,and 3.8%,respectively.The concentrations of undesired gases decrease accordingly by 1.5%,1.7%,and 2.8%for HC and by 5.88%,11.7%,and 17.6%,respectively,for CO.For the same percentages of nanoparticles,NO_(x) increases by 2.65,4.36,and 5.37,while the TSP(Total Suspended Particulate)decreases by 22%,34.66%,and 49.7%,respectively.In the same conditions,sulfur dioxide pollutants increase by 4.57%,8.8%and 12.89%,and H_(2)S levels by 4.7%,7.81%and 8.9%,respectively.
基金This work was supported by King Saud University through Researchers Supporting Project Number(RSP2022R426),King Saud University,Riyadh,Saudi Arabia.
文摘A comprehensive understanding of human intelligence is still an ongoing process,i.e.,human and information security are not yet perfectly matched.By understanding cognitive processes,designers can design humanized cognitive information systems(CIS).The need for this research is justified because today’s business decision makers are faced with questions they cannot answer in a given amount of time without the use of cognitive information systems.The researchers aim to better strengthen cognitive information systems with more pronounced cognitive thresholds by demonstrating the resilience of cognitive resonant frequencies to reveal possible responses to improve the efficiency of human-computer interaction(HCI).Apractice-oriented research approach included research analysis and a review of existing articles to pursue a comparative research model;thereafter,amodel development paradigm was used to observe and monitor the progression of CIS during HCI.The scope of our research provides a broader perspective on how different disciplines affect HCI and how human cognitive models can be enhanced to enrich complements.We have identified a significant gap in the current literature on mental processing resulting from a wide range of theory and practice.
基金This work was funded by NIH grants R01EB020062(M.I.M.),R01NS102670(M.I.M.)U19AG033655.
文摘If the 20th century was the age of mapping and controlling the external world,the 21st century is the biomedical age of mapping and controlling the biological internal world.The biomedical age is bringing new technological breakthroughs for sensing and controlling human biomolecules,cells,tissues,and organs,which underpin new frontiers in the biomedical discovery,data,biomanufacturing,and translational sciences.This article reviews what we believe will be the next wave of biomedical engineering(BME)education in support of the biomedical age,what we have termed BME 2.0.BME 2.0 was announced on October 122017 at BMES 49(https://www.bme.jhu.edu/news-events/news/miller-opens-2017-bmes-annual-meeting-with-vision-for-new-bme-era/).We present several principles upon which we believe the BME 2.0 curriculum should be constructed,and from these principles,we describe what view as the foundations that form the next generations of curricula in support of the BME enterprise.The core principles of BME 2.0 education are(a)educate students bilingually,from day 1,in the languages of modern molecular biology and the analytical modeling of complex biological systems;(b)prepare every student to be a biomedical data scientist;(c)build a unique BME community for discovery and innovation via a vertically integrated and convergent learning environment spanning the university and hospital systems;(d)champion an educational culture of inclusive excellence;and(e)codify in the curriculum ongoing discoveries at the frontiers of the discipline,thus ensuring BME 2.0 as a launchpad for training the future leaders of the biotechnology marketplaces.We envision that the BME 2.0 education is the path for providing every student with the training to lead in this new era of engineering the future of medicine in the 21st century.
文摘In the article“BME 2.0:Engineering the Future of Medicine”[1],the competing interests statement was inadvertently omitted by the publisher from the published version of the article.This has now been corrected in the PDF and HTML(full text).
基金The Binary Systems of South and North(BSN)project(https://bsnp.info/)。
文摘Reviewing the empirical and theoretical parameter relationships between various parameters is a good way to understand more about contact binary systems.In this investigation,two-dimensional(2D)relationships for P–MV(system),P–L1,2,M1,2–L1,2,and q–Lratiowere revisited.The sample used is related to 118 contact binary systems with an orbital period shorter than 0.6 days whose absolute parameters were estimated based on the Gaia Data Release 3 parallax.We reviewed previous studies on 2D relationships and updated six parameter relationships.Therefore,Markov chain Monte Carlo and Machine Learning methods were used,and the outcomes were compared.We selected 22 contact binary systems from eight previous studies for comparison,which had light curve solutions using spectroscopic data.The results show that the systems are in good agreement with the results of this study.
基金the generous support from the Deanship of Research-Jordan University of Science and Technology,IrbidJordan(Grant number 318/2021)。
文摘The primary goal of this study is to develop cost-effective shield materials that offer effective protection against high-velocity ballistic impact and electromagnetic interference(EMI)shielding capabilities through absorption.Six fiber-reinforced epoxy composite panels,each with a different fabric material and stacking sequence,have been fabricated using a hand-layup vacuum bagging process.Two panels made of Kevlar and glass fibers,referred to as(K-NIJ)and(G-NIJ),have been tested according to the National Institute of Justice ballistic resistance protective materials test NIJ 0108.01 Standard-Level IIIA(9 mm×19 mm FMJ 124 g)test.Three panels,namely,a hybrid of Kevlar and glass(H-S),glass with ceramic particles(C-S),and glass with recycled rubber(R-S)have been impacted by the bullet at the center,while the fourth panel made of glass fiber(G-S)has been impacted at the side.EMI shielding properties have been measured in the X-band frequency range via the reflection-transmission method.Results indicate that four panels(K-NIJ,G-NIJ,H-S,and G-S)are capable of withstanding high-velocity impact by stopping the bullet from penetrating through the panels while maintaining their structural integrity.However,under such conditions,these panels may experience localized delamination with variable severity.The EMI measurements reveal that the highest absorptivity observed is 88% for the KNIJ panel at 10.8 GHz,while all panels maintain an average absorptivity above 65%.All panels act as a lossy medium with a peak absorptivity at different frequencies,with K-NIJ and H-S panels demonstrating the highest absorptivity.In summary,the study results in the development of a novel,costeffective,multifunctional glass fiber epoxy composite that combines ballistic and electromagnetic interference shielding properties.The material has been developed using a simple manufacturing method and exhibits remarkable ballistic protection that outperforms Kevlar in terms of shielding efficiency;no bullet penetration or back face signature is observed,and it also demonstrates high EMI shielding absorption.Overall,the materials developed show great promise for various applications,including the military and defense.
基金supported by the America University,the Swiss Agency for Development and Cooperation,and the Central Technical Institute.
文摘Sodium hypochlorite has significant potential as a sanitation solution in hard-to-reach areas.Few studies have investigated the optimal electrolysis parameters for its production with volumes greater than 1o L.This study evaluated sodium hypochlorite production through electrolysis in a 22-L prototype and identified the optimal operating parameters.Tests were performed using graphite electrodes with areas of 68.4 cm²at the laboratory scale and 1865.0 cm?at the prototype scale.A design for experiments with different operating times,chloride concentrations,and electric current intensities was developed.The optimal operating time,sodium chloride concentration,and current intensity at the laboratory scale were 120 min,150 g of chloride per liter,and 3 A,respectively,leading to the production of 5.02 g/L of the disinfectant with an energy efficiency of 12.21 mg of Cl2 per kilojoule.At the prototype scale,the maximum sodium hypochlorite concentration of 3.99 g of chloride per liter was achieved with an operating time of 120 min,a sodium chloride concentration of 100 g of chloride per liter,and a current intensity of 70 A,reaching an energy efficiency of 42.56 mg of Cl2 per kilojoule.In addition,this study evaluated the influences of the chloride concentration,current intensity,and operating time on the production of sodium hypochlorite at the two scales,and formulated the equations showing the trends of sodium hypochlorite production and energy efficiency in the electrochemical systems.The 22-L prototype model for production of this oxidizing substance is promising for disinfection of large volumes of water in areas that are difficult to access.
文摘Boulder spacing in mountain rivers and near-wake flow zones within the boulder array is very useful for fish habitat and growth of aquatic organisms.The present study aims to investigate how the boulder array and spacing influence the near-bed flow structures in a gravel-bed stream.Boulders are staggered over a gravel-bed stream with three different inter-boulder spacing namely(a)large(b)medium and(c)small spacing.An acoustic Doppler velocimeter was used for flow measurements in a rectangular channel and the results were compared with those acquired from numerical simulation.The time-averaged velocity profiles at the near-wake flow zones of boulders experience maximum flow retardation which is an outcome of the boulder-induced form roughness.The ratio of velocity differences associated to form and skin roughness and its positive magnitude reveals the dominance of form roughness closest to the boulders.Form roughness computed is 1.75 to 2 times higher than the skin roughness at the near-wake flow region.In particular,the collective immobile boulders placed at different inter-boulder spacings developed high and low bed shear stresses closest to the boulders.The low bed shear stresses characterised by a secondary peak developed at the trough location of the boulders is attributed to the skin shear stress.Further,the spatial averaging of time-averaged flow quantities gives additional impetus to present an improved illustration of fluid shear stresses.The formation of form-induced shear stress is estimated to be 17%to 23%of doubleaveraged Reynolds shear stress and partially compensates for the damping of time-averaged Reynolds shear stress in the interfacial sub-layer.The quadrant analysis of spatial velocity fluctuations depicts that the form-induced shear stresses are dominant in the interfacial sub-layer and have no significance above the gravel-bed surface.
基金Research Supporting Project Number(RSPD2023R 585),King Saud University,Riyadh,Saudi Arabia.
文摘Side lobe level reduction(SLL)of antenna arrays significantly enhances the signal-to-interference ratio and improves the quality of service(QOS)in recent and future wireless communication systems starting from 5G up to 7G.Furthermore,it improves the array gain and directivity,increasing the detection range and angular resolution of radar systems.This study proposes two highly efficient SLL reduction techniques.These techniques are based on the hybridization between either the single convolution or the double convolution algorithms and the genetic algorithm(GA)to develop the Conv/GA andDConv/GA,respectively.The convolution process determines the element’s excitations while the GA optimizes the element spacing.For M elements linear antenna array(LAA),the convolution of the excitation coefficients vector by itself provides a new vector of excitations of length N=(2M−1).This new vector is divided into three different sets of excitations including the odd excitations,even excitations,and middle excitations of lengths M,M−1,andM,respectively.When the same element spacing as the original LAA is used,it is noticed that the odd and even excitations provide a much lower SLL than that of the LAA but with amuch wider half-power beamwidth(HPBW).While the middle excitations give the same HPBWas the original LAA with a relatively higher SLL.Tomitigate the increased HPBWof the odd and even excitations,the element spacing is optimized using the GA.Thereby,the synthesized arrays have the same HPBW as the original LAA with a two-fold reduction in the SLL.Furthermore,for extreme SLL reduction,the DConv/GA is introduced.In this technique,the same procedure of the aforementioned Conv/GA technique is performed on the resultant even and odd excitation vectors.It provides a relatively wider HPBWthan the original LAA with about quad-fold reduction in the SLL.