30 research outputs found
Effect of quenching baths on microstructure and hardness of AISI1035 steel
No full textIn this study, influence of quenching baths on microstructure and hardness of AISI 1035 steel has been investigated. Two categories of quenching baths including water and oil based baths were selected. Water based baths include tape water, distilled water, brine solution, saline water and sodium hydroxide solution while oil based quenching baths include fish oil, coconut oil, olive oil, used engine oil and quench 310 oil. Microstructure and vicker hardness were characterized by optical microscopy and micro vicker hardness tester. Results showed that water based quenching baths exhibit higher hardness values due to formation of larger fractions of martensite with small fractions of retained austenite, whereas oil based baths produced moderate hardness values due to formation of bainite, pearlite with retained austenite structures.Keywords: Quenching; Martensite; Retained Austenit
Microstructural, mechanical and tribological investigation of 30CrMnSiNi2A ultra-high strength steel under various tempering temperatures
No full textRecent Progress in Isotropic Magnetorheological Elastomers and Their Properties: A Review
No full textMagnetorheological elastomers (MREs) are magneto-sensitive smart materials, widely used in various applications, i.e., construction, automotive, electrics, electronics, medical, minimally invasive surgery, and robotics. Such a wide field of applications is due to their superior properties, including morphological, dynamic mechanical, magnetorheological, thermal, friction and wear, and complex torsional properties. The objective of this review is to provide a comprehensive review of the recent progress in isotropic MREs, with the main focus on their properties. We first present the background and introduction of the isotropic MREs. Then, the preparation of filler particles, fabrication methods of isotropic MREs, and key parameters of the fabrication process—including types of polymer matrices and filler particles, filler particles size and volume fraction, additives, curing time/temperature, and magnetic field strength—are discussed in a separate section. Additionally, the properties of various isotropic MREs, under specific magnetic field strength and tensile, compressive, or shear loading conditions, are reviewed in detail. The current review concludes with a summary of the properties of isotropic MREs, highlights unexplored research areas in isotropic MREs, and provides an outlook of the future opportunities of this innovative field
Opportunities and Challenges of AC/DC Transmission Network Planning Considering High Proportion Renewable Energy
No full textA Secure and Scalable Authentication and Communication Protocol for Smart Grids
No full textThe growing adoption of smart grid systems presents significant advancements in the efficiency of energy distribution, along with enhanced monitoring and control capabilities. However, the interconnected and distributed nature of these systems also introduces critical security vulnerabilities that must be addressed. This study proposes a secure communication protocol specifically designed for smart grid environments, focusing on authentication, secret key establishment, symmetric encryption, and hash-based message authentication to provide confidentiality and integrity for communication in smart grid environments. The proposed protocol employs the Elliptic Curve Digital Signature Algorithm (ECDSA) for authentication, Elliptic Curve Diffie–Hellman (ECDH) for secure key exchange, and Advanced Encryption Standard 256 (AES-256) encryption to protect data transmissions. The protocol follows a structured sequence: (1) authentication—verifying smart grid devices using digital signatures; (2) key establishment—generating and securely exchanging cryptographic keys; and (3) secure communication—encrypting and transmitting/receiving data. An experimental framework has been established to evaluate the protocol’s performance under realistic operational conditions, assessing metrics such as time, throughput, power, and failure recovery. The experimental results show that the protocol completes one server–client request in 3.469 ms for a desktop client and 41.14 ms for a microcontroller client and achieves a throughput of 288.27 requests/s and 24.30 requests/s, respectively. Furthermore, the average power consumed by the protocol is 37.77 watts. The results also show that the proposed protocol is able to recover from transient network disruptions and sustain secure communication
Evaluation of the effect of high penetration of renewable energy sources (RES) on system frequency regulation using stochastic risk assessment technique (an approach based on improved cumulant)
No full textEffect of Crystallization on Electrochemical and Tribological Properties of High-Velocity Oxygen Fuel (HVOF)-Sprayed Fe-Based Amorphous Coatings
No full textAn Fe-based amorphous coating, with the composition Fe48Cr15Mo14C15B6Y2, was synthesized by the high-velocity oxygen fuel spray (HVOF) process on a substrate of AISI 1035. The effect of crystallization on the electrochemical and tribological properties of the HVOF-sprayed Fe-based coating was systematically studied. The XRD results validated the fully amorphous nature of the as-sprayed coating by showing a broad peak at 43.44° and crystallization of this coating after heat-treatment at 700 °C by demonstrating sharp peaks of Fe-, Mo-, and Cr-based carbides. After crystallization, an increase in the corrosion current density from 4.95 μAcm−2 to 11.57 μAcm−2 and in the corrosion rate from 4.28 mpy to 9.99 mpy, as well as a decrease in the polarization resistance from 120 Ωcm2 to 65.12 Ωcm2, were observed, indicating the deterioration of the corrosion resistance of the as-sprayed Fe-based coating. This can be attributed to the formation of porous ferrous oxide, providing an easy channel for charge transfer and promoting pit formation. However, a decrease in the coefficient of friction from 0.1 to 0.05 was observed, highlighting the significant improvement in the wear resistance of the Fe-based coating after crystallization. This can be associated with the precipitation of hard carbides (MxCy) at the boundaries of the crystallized regions
Assessment of Drinking Water Quality Status and its Impact on Health in Tandojam City
No full textUnsafe drinking water is one of the major concerns in developing countries. The southern Sindh is province of Pakistan that adjoins the Arabian Sea coast where the drinking water quality is deteriorating due to unrefined urban waste and excessive use of agro-chemicals. Present study aimed to assess the quality of ground water source and to compare it with WHO standards. Water borne diseases associated with drinking it in the vicinity Tandojam city were identified. Water from ground water source was sampled at selected locations in the study area. The samples were collected mostly from pumped waters. The samples were analyzed for physico-chemical properties in order to identify the quality problems and suggest safe source for drinking purpose. Findings revealed that the ground water quality in Muzaffrabad colony is deteriorating. The situation was much worse in Muzaffrabad colony, Jam Ghar and Mir colony with high TDS and salty taste, respectively at few sampling locations. In addition, laboratory analysis of the water quality parameters revealed the detail of variation in the groundwater. TDS, hardness, sodium (Na), chloride (Cl) and magnesium (Mg) etc. were considerably beyond the WHO permissible limits. The poor quality of the water has created different waterborne diseases like cholera, diarrhea etc. Moreover, the samples of SAU Colony and Amar Town showed that the water quality of these areas was within acceptable limits according to WHO standards and was suitable for the purpose of drinking.</jats:p
A Hybrid Model for Crop Disease Detection Based on Deep Learning and Support Vector Machine
No full textPakistan\u27s agriculture sector is the backbone of its economy, contributing significantly to its gross domestic product (GDP). However, a key challenge in this sector is to counteract the crop diseases timely because these diseases result in reduced production, increased cost and eventually lead to economic loss. Traditional disease control methods are costly, time-consuming, and often lack technical support, resulting in poor disease management and harmful environmental consequences. This research harnesses the unmatched capability of Artificial Intelligence (AI) and deep learning for timely disease detection in crops. This research introduces a hybrid model that combines deep learning models with a machine learning classifier for disease detection. AlexNet, Vgg-16, ResNet50, and MobileNet are the deep learning models that have been employed for the detection of various diseases in crop leaves of rice, potato, and corn. These models have been trained by using healthy and diseased leaf images of the mentioned crops and then these models are combined with a Support Vector Machine (SVM) classifier to enhance the accuracy of detection. Experimental results show the outstanding performance of this hybrid approach for timely disease detection in crops. It is further observed that the combination of MobileNet and SVM results in an impressive accuracy of 95.68% in disease detection. This technological approach would be beneficial for farmers in the effective management and control of crop diseases thus improving the crop yield and ultimately contributing to economic growth
Optimized Corrosion Performance of AISI 1345 Steel in Hydrochloric Acid Through Thermo-Mechanical Cyclic Annealing Processes
No full textThe thermo-mechanical treatments and cyclic annealing processes have the potential of optimizing the corrosion performance of carbon steels in corrosive environments. Herein, an attempt has been made to optimize the corrosion performance of AISI 1345 steel in hydrochloric acid by thermo-mechanical cyclic annealing treatments. AISI 1345 steel was produced and cast in the laboratory and subjected to three types of thermo-mechanical cyclic annealing treatments (TMCA). The first TMCA treatment comprised hot rolling at 1050 °C followed by oil quenching and single austenitizing at 900 °C followed by furnace cooling (TMSA). The second and the third TMCA treatments involved similar hot rolling processes with double austenitizing and furnace cooling (TMDA) and triple austenitizing and furnace cooling (TMTA) processes. Microstructure analysis showed that dual-phase (retained austenite + pearlite) microstructure was achieved after all TMCA treatments with an exception of secondary phase particles precipitation after TMSA treatment. Maximum fractions of retained austenite and minimum fractions of pearlite were achieved after TMTA treatment. Highly refined microstructure of size 26.7 µm was achieved after TMDA treatment whereas; TMSA treatment offered coarse grained microstructure of size 254 µm. Electrochemical analysis was performed in 5 vol% HCl solution using Tafel scan technique. Results revealed that both TMDA and TMTA treatments caused three-fold reduction in corrosion rates (3.025, 2.771 mpy) compared to non-treated steel sample. After 168 h of immersion corrosion analysis in 5 vol% HCl solution, the surface of TMTA treated sample was observed to be partially covered with a very thin, crack-free oxide layer exhibiting minimum oxygen (8.16%) percentage. These features indicated that the TMTA treated sample underwent a very low-intensity minor corrosion attack of HCl solution and exhibited the best immersion corrosion performance among all samples. Electrochemical and immersion corrosion analysis results were in good agreement
