Search Results (26)

In recent years, civil engineering has increasingly embraced communication tools for automation, with sensors playing a pivotal role, especially in structural health monitoring (SHM). These sensors enable precise data acquisition, measuring parameters like force, displacement, and temperature and transmit data for timely interventions to prevent failures. This approach reduces reliance on manual inspections, offering more accurate outcomes. This review explores various sensor technologies in SHM, such as piezoelectric, fibre optic, force, MEMS devices, GPS, LVDT, electromechanical impedance techniques, Doppler effect, and piezoceramic sensors, focusing on advancements from 2019 to 2024. A bibliometric analysis of 1468 research articles from WOS and Scopus databases shows a significant increase in publications, from 15 in 2019 to 359 in 2023 and 52 in 2024 (and still counting). This analysis identifies emerging trends and applications in smart sensor integration in civil and structural health monitoring, enhancing safety and efficiency in infrastructure management. Full article

Background: Six diverse Demographic Development and Environmental Surveillance System (DDESS) sites were established in urban slum, urban resettlement, peri-urban, rural, and tribal areas located in Northern, North-East, Eastern, and Southern regions of India from June 2020 to March 2022. Understanding the community dynamics and engaging people in the community is critically important in the process of establishing DDESS. We ascertained the barriers, challenges, and facilitators during the establishment of multiple DDESS sites across India. Methods: This was a cross-sectional descriptive mixed-methods study. Results: Multiple barriers and challenges encountered were reported in the process of community engagement (CE), such as geographical inaccessibility, language barriers, adverse weather, non-responsiveness due to perceived lack of individual benefit or financial gain, fear of contracting COVID-19, COVID-19 vaccine hesitancy, etc. Facilitators in the CE process were pre-existing links with the community, constitution of community advisory boards, community need assessment, concomitant delivery of outreach health services, and skill-building facilities. Conclusion: Most community barriers in the development of DDESS sites in resource-limited settings can be overcome through a multipronged approach, including effective community engagement by focusing on demonstrating trust at the local level, enlisting community mobilization and support, utilizing pre-existing community linkages, initiating community diagnosis, and meeting perceived community health needs. Full article

The global energy situation requires the efficient use of resources and the development of new materials and processes for meeting current energy demand. Traditional materials have been explored to large extent for use in energy saving and storage devices. Graphene, being a path-breaking discovery of the present era, has become one of the most-researched materials due to its fascinating properties, such as high tensile strength, half-integer quantum Hall effect and excellent electrical/thermal conductivity. This paper presents an in-depth review on the exploration of deploying diverse derivatives and morphologies of graphene in various energy-saving and environmentally friendly applications. Use of graphene in lubricants has resulted in improvements to anti-wear characteristics and reduced frictional losses. This comprehensive survey facilitates the researchers in selecting the appropriate graphene derivative(s) and their compatibility with various materials to fabricate high-performance composites for usage in solar cells, fuel cells, supercapacitor applications, rechargeable batteries and automotive sectors. Full article

This review article focuses on the aluminum-based metal matrix composites (Al-based MMCs). Studies or investigations of their mechanical and tribological properties performed by researchers worldwide in the past are presented in detail. The processing techniques and applications for Al-based MMCs are also documented here. A brief background on the composite materials, their constituents, and their classification, as well as the different matrix materials and particulates used in Al-based MMCs, can be found in this review. Then, an overview of dual-particle-size reinforced composites, heat treatment of Al alloys, and temper designations used in heat treatment are also included. In addition, the factors influencing the mechanical and wear properties of Al-based MMCs are discussed. The primary objective is that both present and future researchers and investigators will be assisted by the comprehensive knowledge compiled in this article to further explore and work towards the betterment of society in general. Full article

Properties such as superior specific strength, being imponderous, and the ability to reprocess are the key features that have drawn attention to magnesium. In the last few years, applications such as automotive, aerospace, and medical applications have been seeking light-weight equipment, and light-weight materials are required for making them. These demands were matched by developing metal matrix composites with magnesium as a base and reinforced with carbon nanotubes (CNTs), grapheme nanoplatelets (GNPs), or ceramic nanoparticles. CNTs have been adopted for developing high-strength metal matrix composites (MMCs) because of their delicately superior thermal conductivity, surface-to-volume ratio, and tensile strength, but lower density. In developing high-performance light-weight magnesium-based MMCs, a small number of CNTs result in refined properties. However, making Mg-based MMCs has specific challenges, such as achieving uniform reinforcement distribution, which directly relates to the processing parameters. The composition of CNT, CNT sizes, their uniform distribution, Mg-CNT interfacial bonding, and their in-between alignment are the characteristic deciding factors of Mg-CNT MMCs. The current review article studies the modern methods to develop Mg-CNT MMCs, specifications of the developed MMCs, and their vital applications in various fields. This review focuses on sifting and summarizing the most relevant studies carried out on the methods to develop Mg-CNT metal matrix composites. The article consists of the approach to subdue the tangled situations in highlighting the Mg-CNT composites as imminent fabrication material that is applicable in aerospace, medical, and automotive fields. Full article

Brackets are the load-bearing components in a satellite. The current age of satellites comprises specific brackets that set out as a link between the bodies of the satellite, reflector parts, and feeder facilities mounted at its upper end. Brackets are used to carry loads of the satellite body frame, supporting elements, batteries, and electronic goods. The article explicates the various brackets used in satellites and aircrafts. The strength of the bracket is of utmost importance since it is an important load supporting member in several assemblies of aircraft and satellites. In addition to the mechanical strength, the weight of the bracket is a major concern as it adds to the total weight of the aircraft and satellite. Thus, weight savings of brackets can be of paramount importance and Additive Manufacturing (AM) is found as an overall solution to achieve the same. Hence, in addition to various brackets used in satellites, the article presents an exhaustive review of the processing of various advanced functional materials using various AM techniques to make high strength-to-weight ratio satellite brackets. The use of DFAM by various satellite manufacturers globally for optimizing the structure of the brackets resulting in a significant weight saving of the brackets is also presented in the article. Full article

Significant advances in the field of composite structures continue to be made on a variety of fronts, including theoretical studies based on advances in structural theory kinematics and computer models of structural elements employing advanced theories and unique formulations. Plate vibration is a persistently interesting subject owing to its wider usage as a structural component in the industry. The current study was carried out using the C^o continuous eight-noded quadrilateral shear-flexible element having five nodal degrees of freedom, which is ground on first-order shear deformation theory (FSDT). For small strain and sufficiently large deformation, the geometric nonlinearity is integrated using the Von Kármán assumption. The governing equations in the time domain are solved employing the modified shooting technique along with an arc-length and pseudo-arc-length continuation strategy. This work explored the effect of fiber angle on the steady-state nonlinear forced vibration response. To explain hardening nonlinearity, the strain and stress fluctuation throughout the thickness for a rectangular laminated composite plate is determined. The cyclic fluctuation of the steady-state nonlinear normal stress during a time period at the centre of the top/bottom surfaces is also provided at the forcing frequency ratio of peak amplitude in a nonlinear response. Because of the variation in restoring forces, the frequency spectra for all fiber angle orientations show significantly enhanced harmonic participation in addition to the fundamental harmonic. Full article

Magnesium alloys are widely employed in various applications due to their high strength-to-weight ratio and superior mechanical properties as compared to unalloyed Magnesium. Alloying is considered an important way to enhance the strength of the metal matrix composite but it significantly influences the damping property of pure magnesium, while controlling the rate of corrosion for Mg-based material remains critical in the biological environment. Therefore, it is essential to reinforce the magnesium alloy with a suitable alloying element that improves the mechanical characteristics and resistance to corrosion of Mg-based material. Biocompatibility, biodegradability, lower stress shielding effect, bio-activeness, and non-toxicity are the important parameters for biomedical applications other than mechanical and corrosion properties. The development of various surface modifications is also considered a suitable approach to control the degradation rate of Mg-based materials, making lightweight Mg-based materials highly suitable for biomedical implants. This review article discusses the various binary and ternary Mg alloys, which are mostly composed of Al, Ca, Zn, Mn, and rare earth (RE) elements as well as various non-toxic elements which are Si, Bi, Ag, Ca, Zr, Zn, Mn, Sr, Li, Sn, etc. The effects of these alloying elements on the microstructure, the mechanical characteristics, and the corrosion properties of Mg-based materials were analyzed. The mechanical and corrosion behavior of Mg-based materials depends upon the percentage of elements and the number of alloying elements used in Mg. The outcomes suggested that ZEK100, WE43, and EW62 (Mg-6% Nd-2% Y-0.5% Zr) alloys are effectively used for biomedical applications, having preferable biodegradable, biocompatible, bioactive implant materials with a lower corrosion rate. Full article

Graphene has been widely and extensively used in mass sensing applications. The present study focused on exploring the use of single-layer graphene (SLG) and double-layer graphene (DLG) as sensing devices. The dynamic analysis of SLG and DLG with different boundary conditions (BDs) and length was executed using the atomistic finite element method (AFEM). SLG and DLG sheets were modelled and considered as a space–frame structure similar to a 3D beam. Spring elements (Combin14) were used to identify the interlayer interactions between two graphene layers in the DLG sheet due to the van der Waals forces. Simulations were carried out to visualize the behavior of the SLG and DLG subjected to different BDs and when used as mass sensing devices. The variation in frequency was noted by changing the length and applied mass of the SLGs and DLGs. The quantity of the frequency was found to be highest in the armchair SLG (6, 6) for a 50 nm sheet length and lowest in the chiral SLG (16, 4) for a 20 nm sheet length in the bridged condition. When the mass was 0.1 Zg, the frequency for the zigzag SLG (20, 0) was higher in both cases. The results show that the length of the sheet and the various mass values have a significant impact on the dynamic properties. The present research will contribute to the ultra-high frequency nano-resonance applications. Full article

Air pollution is a major issue all over the world because of its impacts on the environment and human beings. The present review discussed the sources and impacts of pollutants on environmental and human health and the current research status on environmental pollution forecasting techniques in detail; this study presents a detailed discussion of the Artificial Intelligence methodologies and Machine learning (ML) algorithms used in environmental pollution forecasting and early-warning systems; moreover, the present work emphasizes more on Artificial Intelligence techniques (particularly Hybrid models) used for forecasting various major pollutants (e.g., PM_2.5, PM₁₀, O₃, CO, SO₂, NO₂, CO₂) in detail; moreover, focus is given to AI and ML techniques in predicting chronic airway diseases and the prediction of climate changes and heat waves. The hybrid model has better performance than single AI models and it has greater accuracy in prediction and warning systems. The performance evaluation error indexes like R², RMSE, MAE and MAPE were highlighted in this study based on the performance of various AI models. Full article

Aerospace alloys with reduced wall thickness but possessing higher hardness, good tensile strength and reasonable corrosion resistance are essential in manufacturing of structures such as fuselage. In this work, friction stir welding has been carried out on such an aerospace aluminum alloy AA8090 T87 which contains 2.3% lithium. Tool rotational speed of 900 rpm and traverse speeds of 90 mm/min., 110 mm/min. are the welding parameters. Hardness analysis, surface roughness analysis and corrosion analysis are conducted to analyze the suitability of the joint for the intended application. The samples were corrosion tested in acid alkali solution and they resulted in the formation of pits of varying levels which indicate the extent of surface degradation. Hardness of the samples was measured after corrosion analysis to observe the changes. The analysis suggests that the change in tool traverse speed transformed the corrosion behavior of the joint and affected both the hardness and surface roughness which mitigated the quality of the joint. Full article

The feasibility of producing welding joints between 6061-T6 aluminum and pure copper sheets of 6 mm thickness by conventional friction stir welding (CFSW) and bobbin tool friction stir welding (BTFSW) by using a slot-groove configuration at the joining surface was investigated. The microstructure of the welded samples was examined by using an optical microscope and X-ray diffraction. Furthermore, the mechanical properties of the weld samples are compared based on the results of the tensile test, hardness measurement, and fractography test. The slot-groove configuration resulted in the presence of a bulk-sized Al block on the Cu side. The microscopic observations revealed the dispersion of fine Cu particles in the stir zone. The presence of intermetallic compounds (IMCs) CuAl₂, which are hard and brittle, lowered the strength of the weld joints. The strength of the weld joints produced with BTFSW was superior to that of the C-FSW. The maximum hardness values of 214 HV and 211 HV are reported at the stir zone for BTFSW and CFSW, respectively. The fracture location of all the joints was at the intersection of the stir zone and the thermomechanically affected zone was on the Cu side. Full article

The goal of this study is to improve concrete’s efficiency by using a microbiologically produced specific growth/filler. One such way of thinking has resulted in the invention of a highly unusual concrete known as microbial concrete, which uses bacteria to cure flaws in the concrete. Investigators working with various microorganisms suggested several microbial concretes. The bacterium “Pseudomonas” was used in this experiment. Pseudomonas bacteria, which can make calcite precipitates on a proper medium supplied with a calcium supply, is a typical science lab bacterium for calcite generation. Two different concentrations (10⁶ cfu/mL and 10⁷ cfu/mL) of bacteria were added to cement concrete and it was observed that the bacterial concrete with two different concentrations gives results as compared with normal concrete. According to the findings of this investigation, the inclusion of bacteria resulted in a considerable increase in compressive strength when the dilution factor was 10⁶ cells per ml of mixed water. With the incorporation of the microorganisms, it was discovered that holes were partly filled up by material growth, as shown by scanning electron micrography inspection of the sample. Concrete cubes without and with the inclusion of bacteria were molded, and it was discovered that the compressive strength of the cubes with the injection of microorganisms increased significantly. In this study, concrete cylinders without and with the inclusion of microorganisms were molded, and it was discovered that the split tensile strength of the cylinders with the injection of microorganisms increased significantly above the control. When compared with regular concrete, the results showed a maximum increase of 16 percent in compressive strength and a maximum increase of 12 percent in split tensile strength. It was discovered via durability testing that bacterial concrete had less weight loss and stronger tensile strength than conventional concrete when treated with 5 percent H₂SO₄ or 5 percent MgSO₄ compared with control concrete. Full article

This paper shows the novel approach of Taguchi-Based Grey Relational Analysis of Ti6Al4V Machining parameter. Ti6Al4V metal matrix composite has been fabricated using the powder metallurgy route. Here, all the components of TI6Al4V machining forces, including longitudinal force (F_x), radial force (F_y), tangential force (F_z), surface roughness and material removal rate (MRR) are measured during the facing operation. The effect of three process parameters, cutting speed, tool feed and cutting depth, is being studied on the matching responses. Orthogonal design of experiment (Taguchi L9) has been adopted to execute the process parameters in each level. To validate the process output parameters, the Grey Relational Analysis (GRA) optimization approach was applied. The percentage contribution of machining parameters to the parameter of response performance was interpreted through variance analysis (ANOVA). Through the GRA process, the emphasis was on the fact that for TI6Al4V metal matrix composite among all machining parameters, tool feed serves as the highest contribution to the output responses accompanied by the cutting depth with the cutting speed in addition. From optimal testing, it is found that for minimization of machining forces, maximization of MRR and minimization of Ra, the best combinations of input parameters are the 2nd stage of cutting speed (175 m/min), the 3rd stage of feed (0.25 mm/edge) as well as the 2nd stage of cutting depth (1.2 mm). It is also found that hardness of Ti6Al4V MMC is 59.4 HRA and composition of that material remain the same after milling operation. Full article

Magnesium is among the lightest structural metals available, with the capacity to replace traditional alloys in mass-saving applications while still providing increased stiffness and strength. The inclusion of reinforcing components into the metallic matrix has a substantial impact on stiffness, specific strength, wear behaviour, damping behaviour, and creep properties when compared to typical engineering materials. Due to their outstanding physical and mechanical characteristics along with low density, magnesium metal matrix composites are viable materials for numerous applications. This study discusses how to choose an appropriate technique and its process parameters for synthesising magnesium-based metal matrix composites (MMCs) and gives an overview of the impacts of various reinforcements in magnesium and its alloys, emphasising their benefits and drawbacks. The essential applications of various magnesium-based MMCs are also critically examined in this article. The impact of reinforcement on the microstructure as well as mechanical characteristics are thoroughly examined. Full article