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1
Heshmat, H. "Advancements in the Performance of Aerodynamic Foil Journal Bearings: High Speed and Load Capability." Journal of Tribology 116, no. 2 (1994): 287–94. http://dx.doi.org/10.1115/1.2927211.
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An advanced-design, aerodynamic, air-lubricated foil journal bearing achieved a landmark speed of 2200 cps (132,000 rpm) and a major breakthrough in load performance of 673.5 kPa (97.7 psi). At 20°C (68°F) room temperature, normal ambient pressure, 995 cps (59,700 rpm) rotor speed, and with bearing projected pad area of 1081 mm2 (1.675 in2), the bearing demonstrated a load capacity of 727.8 N (163.6 lb). The bearing also exhibited low heat generation, with about 40°C (104°F) average side leakage temperature rise. For this demonstration, a highspeed spindle utilizing a pair of 35-mm (1.375-in.) bearings and supporting a test rotor with a mass of 1.545 kg (weighing 3.41 lb) and overall length of 211 mm (8.3 in.) was successfully taken to the limiting speed of the test apparatus. This speed was set by the maximum sound velocity (Mach 1) in the spindle’s turbine wheel. The rotor/bearing speed of 4.62 × 106 DN is beyond the capability of any advanced oil-lubricated ball bearings or conventional gas-lubricated bearings. The net result is a highly stable bearing at high operating speed. This paper presents the development of this air-lubricated foil journal bearing, the operational procedures used during testing, test results (dynamic analyses), and load performance characteristics.
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Septriani, Shafira, Norman Arie Prayogo, Asrul Sahri, and Christopher L. Brown. "Efficiency of suspended solid removal from tofu production using Rotating Biological Contractor (RBC)." E3S Web of Conferences 322 (2021): 01034. http://dx.doi.org/10.1051/e3sconf/202132201034.
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Tofu is a common food in Indonesia, made from soybean, and needs gigantic water for the process. The liquid waste of the tofu industry is usually directly discharged into the river without being processed. Liquid wastes of tofu have high organic content and become a problem in water pollution. Rotating Biological Contactor (RBC) is efficient method to treat waste with a high organic matter load by utilizing microorganisms to consume organic matter through biofilms. Biofilm will degrade organic matter aerobically. The purpose of the study is to determine the capability of RBC to reduce the organic content of tofu wastewater with different rotations of the disk. Rotation was experimentally varied from 30, 40, 50, 60 RPM and control. Results were considered in percentage decrease from the untreated waste: TSS of 87.56 ± 6.48%, BOD of 99.13 ± 0.21 %, and COD of 98.53 ± 0.08%. To conclude, the optimum rotation is 50 RPM for decreasing BOD and COD, otherwise 40 RPM for reducing TSS. The results effluent RBC on three parameters passed the quality standards legally for the soybean processing company or activity.
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Sun, Fei, Hong Ji, Shengqing Yang, and Chen Li. "Numerical Investigation on Pairing Solutions of Non-Positive Displacement Pumps and Internal Gear Pump for High-Speed Design." Fluids 8, no. 6 (2023): 178. http://dx.doi.org/10.3390/fluids8060178.
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Raising the working speed of hydraulic pumps to maximize the efficient matching range of electric motors is one of the possible ways to achieve energy efficiency in electric machinery. By means of a simulation method verified with subsequent experiments in terms of filling efficiency, this paper first analyzed the suction capacity of crescent-type internal gear pumps with different geometric parameters at high speed, and the gear pair that is more suitable for high-speed operation was obtained. Subsequently, as the more significant contributions, two pairing solutions of a non-positive displacement pump and an internal gear pump were proposed to pressurize the inlet of the gear pump to keep it from cavitating. In the compact design solution, the inclined-holes type and axial-flow blade pumps share the same speed as the hydraulic pump, while the decentralized layout solution allows for flexible adjustment of the centrifugal impeller-type pump speed to maximize the filling capability. The final simulation results show that, with the help of inclined-holes type and centrifugal impeller type pumps, the filling efficiency of the internal gear pump at 6000 rpm can be improved by 3.59% and 5.84%, respectively, while the axial-flow blades pump fails to eliminate cavitation regardless of speed. Moreover, when the hydraulic pump works at 6000 rpm, the centrifugal impeller speed needs to be set above 2500 rpm to make sense.
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Woro Fittrin Selo Nur Giyatno, Dhanis, Tommy Richard Orlando, and Nining Supriatin. "Analog tachometer as an indicator motorcycle machine wearing based on moving coil." E3S Web of Conferences 43 (2018): 01004. http://dx.doi.org/10.1051/e3sconf/20184301004.
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As an increasing highly mobility and high traffic, the necessary of motorcycle is highly increasing. The condition makes user ride motorcycle with highly speed in highly frequency. Then, these conditions make motorcycle machine reliability is highly decreasing. Finally, it made machine is run to damage and maintenance cost to be high. Analog tachometer is an electronic instrumentation that proposed to solve these problems. Actually, instrumentation system of tachometer is an electromechanical system. A wire in a control unit is embedded into shaft of crank. Then, magnet in control unit will convert rotary machine energy into electrical energy with d’Arsonval meter. Current sensor and small variable resistor are the kind of sensor that are used in tachometer. Small variable resistor is used for tuning and recalibration. Utilization small variable resistor in tachometer circuit is make calibration and recalibration current sensing of electrical current that rectified by diode. Tachometer for counting rotation per minute (RPM) motorcycle machine is built up. The tachometer has capability to count RPM motorcycle machine 1,000 – 13.000 RPM. The range is reliable as an indicator for user to minimize motorcycle machine wearing.
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Wardani, Citra Sari, Dwi Anung Nindito, and Allan Restu Jaya. "Inovasi Dan Desain Turbin Hidrokinetik Darrieus Berdasarkan Bentuk Distribusi Kecepatan Aliran." Media Ilmiah Teknik Sipil 9, no. 1 (2020): 32–43. http://dx.doi.org/10.33084/mits.v9i1.1771.
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Darrieus turbine use blades with a hydrofoil shape, so the rotational ability is influenced by lift force. This caused the initial rotation capability to be very low when compared to the drag turbine type. The flow velocity distribution in the vertical direction indicates a small cross-sectional speed of flow approaching the base of the flow channel, then rising towards the surface. Darrieus Spinning Top turbine is the result of innovation and design based on the concept of flow velocity distribution. Darrieus Spinning Top turbine’s blade shapes are circular-arc and straight-line, adjusting flow velocity distribution of 0.2H, 0.6H and 0.8H from the top of the turbine. In this study, a performance comparison was conducted between Darrieus turbine and Spinning Top Darrieus. Darrieus turbines produce RPM and torque values of 54.59 – 67.90 and 0.014 – 0.029 Nm, respectively. Darrieus Spinning Top turbines produce RPM values and torque of 69.24 – 82.02 and 0.012 – 0.020 Nm respectively. RPM improvements in Darrieus Spinning Top turbine design increase the influence of lift force (increased λ value). This results in a high lap rate, but requires a high self starting to perform the turbine rotation cycle.
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Hosseinkhani, Hossein. "Viral/Non-Viral Vectors in DNA/RNA Delivery Technology." Recent Progress in Materials 06, no. 04 (2024): 1–45. https://doi.org/10.21926/rpm.2404027.
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Viral and non-viral vectors for nucleic acids (DNA/RNA) therapeutics are important in development of pharmaceutical industries. Although viral vectors have shown significant impact in transfection of DNA/RNA, but numerus studies have shown that non-viral vectors are also effective for the safe and targeted delivery of DNA/RNA to exact location in the body with high percentage of efficacy, safety, and low-immunogenicity. It is also important to protect the nucleic acids from degradation and large-scale production capability at low cost. This review article discusses the potential applications of viral vectors in DNA/RNA delivery technology, while some of the applications of non-viral vectors are compared with viral vectors.
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El-Sousy, Sara M., Saadia M. Easa, Amira A. Hassan, and Abdel-Mohsen S. Ismail. "Production of a bacterial extracellular L-glutaminase possessing high antioxidant capability." Egyptian Pharmaceutical Journal 20, no. 1 (2021): 59–71. http://dx.doi.org/10.4103/epj.epj_51_20.
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Background and objectives L-glutaminase has utmost practical importance in many fields, such as medicine, pharmacy, and some industries as an effective antioxidant, anticancer, flavor enhancer, and used as an analytical reagent in the determination of glutamate and glutamine. The objective of the present article was to formulate the production medium and to pinpoint the proper growth conditions for the most potent microorganism producing highly active glutaminase enzyme. The general properties of the crude enzyme preparation were determined to detect the proper conditions for enzyme activity. Under the specified conditions, the capabilities of the crude L-glutaminase preparation for antimicrobial and antioxidant activities were investigated. Materials and methods A total of 12 recommended microbial strains were screened for highly active L-glutaminase enzyme production. Factors influencing the production of L-glutaminase enzyme were optimized, and the important properties of the crude enzyme were pinpointed. Finally, biological activities of the crude enzyme were investigated as a preliminary index for the validity of the partially purified L-glutaminase form for medical applications. Results and conclusion Among all tested microorganisms, Bacillus subtilis NRRL 1315 was the most potent producer for L-glutaminase enzyme. The maximum glutaminase production was obtained after 48 h of incubation on a rotary shaker (150 rpm) with the medium containing 5 g/l glucose, 0.1 g/l sodium nitrate, and 10 g/l L-glutamine at 37°C and pH 7.5. The important properties of the crude L-glutaminase were duly pinpointed as follows: optimum enzyme protein concentration and substrate concentration were 2 mg/ml and 40 mM, respectively, and optimum reaction pH and temperature were 7.5 and 37°C, respectively. Under the specified conditions, the crude enzyme exhibited considerable 2, 2′-diphenyl-1-picrylhydrazyl radical scavenging activity.
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Statscewich, Hank, Hugh Roarty, Michael Smith, Ed Page, Scott Glenn, and Tom Weingartner. "Enhancing Arctic Maritime Domain Awareness Through an Off-Grid Multi-sensor Instrument Platform." Marine Technology Society Journal 48, no. 5 (2014): 97–109. http://dx.doi.org/10.4031/mtsj.48.5.1.
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AbstractSurface current mapping high-frequency radars were installed along the northwest corner of Alaska during the open water periods of 2011‐2013. A combination of wind and solar renewable energy inputs supplied electricity to a single radar site operating at Point Barrow, Alaska, via an off-grid remote power module (RPM). The radar at Point Barrow was able to simultaneously collect measurements of ocean surface currents, measure the position and velocity of passing vessels, and provide meteorological data in real time. This paper provides a summary of the performance of the power module from 2011 to 2013 and vessel detection results from 2013 with corresponding Automated Identification System (AIS) data. The RPM provided infrastructure to meteorological stations, high-frequency radars, and AIS in a resilient and robust manner and serves as an example of how the multi-use capability of integrated sensor modules can provide enhanced maritime domain awareness and persistent surveillance capabilities in remote Arctic environments.
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Wang, Shuo, Weiran Zhang, Yong Zhang, Jinqiang Zhao, Ruixuan Li, and Yujie Zhong. "Effect of Reduced Graphene Oxide on Microwave Absorbing Properties of Al1.5Co4Fe2Cr High-Entropy Alloys." Entropy 26, no. 1 (2024): 60. http://dx.doi.org/10.3390/e26010060.
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The microwave absorption performance of high-entropy alloys (HEAs) can be improved by reducing the reflection coefficient of electromagnetic waves and broadening the absorption frequency band. The present work prepared flaky irregular-shaped Al1.5Co4Fe2Cr and Al1.5Co4Fe2Cr@rGO alloy powders by mechanical alloying (MA) at different rotational speeds. It was found that the addition of trace amounts of reduced graphene oxide (rGO) had a favorable effect on the impedance matching, reflection loss (RL), and effective absorbing bandwidth (EAB) of the Al1.5Co4Fe2Cr@rGO HEA composite powders. The EAB of the alloy powders prepared at 300 rpm increased from 2.58 GHz to 4.62 GHz with the additive, and the RL increased by 2.56 dB. The results showed that the presence of rGO modified the complex dielectric constant of HEA powders, thereby enhancing their dielectric loss capability. Additionally, the presence of lamellar rGO intensified the interfacial reflections within the absorber, facilitating the dissipation of electromagnetic waves. The effect of the ball milling speed on the defect concentration of the alloy powders also affected its wave absorption performance. The samples prepared at 350 rpm had the best wave absorption performance, with an RL of −16.23 and −17.28 dB for a thickness of 1.6 mm and EAB of 5.77 GHz and 5.43 GHz, respectively.
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Thirumala, M., E. Sai Krishna, P. Sindhu Priya, and S. Vishnuvardhan Reddy. "Characterization of a novel Fluoride resistant bacterial isolate and its capability of Fluoride bioremediation." AIMS Microbiology 8, no. 4 (2022): 470–83. http://dx.doi.org/10.3934/microbiol.2022031.
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<abstract> <p>A Gram positive rod shaped bacterium designated as isolate H1 with Fluoride resistance up to 4 g/L sodium fluoride (NaF) in LB (Luria-Bertani) agar was isolated from a ground water sample of Narketpally area, Nalgonda district, Telangana, India. The colonies of isolate H1 were off white in color. Growth patterns of isolate H1 were observed at two different concentrations, 100 and 250 ppm, of NaF and also without NaF in the medium. In cases where NaF was present in the media, the lag phases of the growth curves were extended when compared to the absence of NaF. Optimum pH required for the organism's growth was 8. Isolate H1 required a temperature of 37 °C with 150 rpm and 2% NaCl for its optimal growth in the medium without NaF. Meanwhile, isolate H1 could thrive in a diverse pH range, i.e., pH 5–10, and at an NaCl concentration of up to 11% in the medium with NaF. Based on morphological, biochemical and molecular characterization, isolate H1 was identified as belonging to the genus <italic>Bacillus</italic>. It showed 98.47% 16S rDNA gene sequence similarity with <italic>Bacillus australimaris</italic> NH71_1<sup>T</sup>. Isolate H1 showed high fluoride removals of 22.5% and 38.2% with 100 and 250 mg/L of NaF in the LB broth when incubated at pH 8 and a temperature of 37 °C with 150 rpm for 3 day. Hence, this organism could be a promising isolate to apply for defluoridation of ground water in fluoride contaminthe ated areas.</p> </abstract>
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Dimas Vrisnanda Yulio Diva Prakasa and Haris Puspito Buwono. "Analisis Pengaruh Kecepatan dan Waktu Pengadukan terhadap Homogenitas Sampah Organik dalam Proses Pengomposan." Venus: Jurnal Publikasi Rumpun Ilmu Teknik 3, no. 1 (2025): 30–40. https://doi.org/10.61132/venus.v3i1.707.
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The problem of household waste, which accounts for 50-70% of the total waste in Indonesia, mainly in the form of organic waste such as food and vegetable scraps, is a major challenge in environmental management. Composting is an effective method of managing organic waste by turning it into compost. However, organic waste management in Indonesia is still minimally practiced because it is considered to have no economic value. A 50 kg capacity composter machine equipped with a vertical mixer and using an electric motor can increase composting efficiency. This study aims to analyze the feasibility of composter machines and to analyze the effect of speed and mixing time on composter machines on the homogeneity of organic waste. The research method used is quantitative experimental with factorial experimental design (DOE) to analyze the effect of speed and stirring time on the composter machine on the homogeneity of organic waste. The stirring speed variations tested were 30, 45, and 60 RPM, with mixing times of 20, 30, and 40 minutes. The results showed that the single mixer composter machine proved to be feasible and reliable in producing homogeneous organic waste, with a high process capability value of 5.86. The use of mixing speed from 30 RPM to 60 RPM and mixing time from 20 minutes to 40 minutes significantly increased the homogeneity of organic waste, with the highest value of 97.54% at 60 RPM speed for 40 minutes.
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Budijono, Agung Prijo. "Friction Losses During Slip Conditions in Regenerative Braking of Electric Vehicles." Journal of Mechanical Engineering SI 11, no. 1 (2022): 95–108. http://dx.doi.org/10.24191/jmeche.v11i1.23591.
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The regenerative braking system (RBS) in electric vehicles (EVs) enhances its capability against internal combustion engines (ICE). Antilock braking system (ABS) is widely used in RBS because of its maneuverability and safety. One of the purposes of applying ABS is to avoid slippage. Slip on the braking process, especially hydraulic brakes, results in a difference in time to stop the wheels and the vehicle. It is avoided because it relies on friction between the tires and the road to stop transportation. Timing results showed that ABS with high frequency, above 30 Hz, tended to act like hydraulic brakes. Hydraulic brakes achieved the highest time difference, 8 seconds at 2250 rpm. It increased the distance of 350 m in slipping while the lowest time difference ABS 10 Hz owned, 0.1 seconds at the same rpm. Slips caused losses. These losses could be minimized with low-frequency ABS. It converted the friction between the wheels and the brakes into electrical energy instead of stopping the vehicle. As a result, the 10 Hz ABS had the highest potency stored despite the lowest performance.
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Suzuki, Shinya, and Masaru Miyayama. "Lithium Intercalation Properties of Octatitanates Composed of Nanosheets with Various Dimensions." Key Engineering Materials 301 (January 2006): 135–38. http://dx.doi.org/10.4028/www.scientific.net/kem.301.135.
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Lithium intercalation properties of octatitanates composed of nanosheets were examined. Several types of nanosheet-octatitanates were prepared by the reassembly of tetratitanate nanosheets in colloidal suspension, which were separated centrifugally at various revolutions, and then by a heat treatment. The colloidal suspension was obtained by the exfoliation of tetrabutylammonium tetratitanate intercalation compound. The capacities of the octatitanates composed of nanosheets were approximately 160 mAh/g, and they were maintained even after the exfoliation and the reassembly. The octatitanate composed of nanosheets with relatively small dimensions centrifugally separated at 6000 rpm exhibited a large capacity of 140 mAh/g at a relatively high current density of 1 A/g. The nanosheet process was found to be effective in improving the high rate capability.
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Dudam, Akshay. "Design and Experimental Investigation of Composite Automotive Drive Shaft." International Journal for Research in Applied Science and Engineering Technology 9, no. 10 (2021): 1088–94. http://dx.doi.org/10.22214/ijraset.2021.38578.
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Abstract: Replacing composite bodies by the conventional metallic bodies have many advantages because of high specific strength and high specific stiffness of the composite materials. As compared to the conventional drive shafts, Composite drive shafts have the potential of lighter and longer life with high rotational speed. Nowadays drive shafts are used in two pieces. However, the main advantage of the current design is that only one piece of composite drive shaft is possible that fulfils all the drive shaft requirements. The torsional strength, torsional buckling and bending natural frequency are the main basic requirements considered here. This work is all about the replacing the conventional two-piece steel drive shaft with a one-piece carbon/epoxy. Design of composite drive shaft Classical Lamination Theory is used for the design of composite drive shaft. Finite element analysis (FEA) was used to design composite drive shafts incorporating carbon within an epoxy matrix. From experimental results, it was found that the developed one-piece automotive composite drive shaft had 64% mass reduction, 74% increase in torque capability compared with a conventional two-piece steel drive shaft. It also had 6380 rpm of natural frequency which was higher than the design specification of 3050 rpm. Index Terms: Bending frequency, Composite Materials, Drive shaft, Finite Element Analysis (FEA), Power transmission, Torsion, Torsional buckling.
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Akber, Ahmed A., Ali A. Khleif, and Abbas N. Hasein. "Evaluation of Mechanical Properties and Finite Element Modeling in Friction Stir Welding of C12200 Copper Alloy to C36000 High-Leaded Brass Pipe." Engineering and Technology Journal 38, no. 8A (2020): 1106–16. http://dx.doi.org/10.30684/etj.v38i8a.602.
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In systems transporting fluids like petrol, water, or any fluids. Copper and brass pipes are used because of the capability to resist corrosion. The copper alloys can be welded by several methods like arc, resistance, friction welding, and gas methods and they can be readily soldered and brazed. In the present study, mechanical properties and finite element modeling evaluation for friction stir welding of two dissimilar pipes (C12200 copper alloy pipe with C36000 copper alloy pipe). During this study six parameters were used where rotation speed of (775,1000,1300 and1525rpm), welding speed of 1.7 mm/min, axial force of 8.5KN, with a CW direction of rotation, and zero degree of tilt angle, using a threaded cone geometry of the tool. The results showed that the best weld quality was in case when the speed of rotation was 1525 rpm.
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Okpala, Izuchukwu F., Ifeanyichukwu U. Onyenanu, Vincent C. Ezechukwu, and Chukwunwendu E. Ilochonwu. "Performance Optimization of a Locally Developed Charcoal Briquette Machine Using Response Surface Methodology." Scientific Journal of Engineering, and Technology 2, no. 1 (2025): 55–66. https://doi.org/10.69739/sjet.v2i1.486.
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This study focuses on optimizing the performance of a charcoal briquette machine using Response Surface Methodology (RSM). Charcoal briquettes represent a sustainable energy alternative with significant potential for addressing energy challenges, particularly in developing regions. A custom-designed screw extruder briquetting machine was fabricated and evaluated under varying operational parameters. Using Central Composite Design, the research investigated the influence of machine speed (50-200 RPM), die diameter (30-50 mm), and compression pressure (15-30 MPa) on machine efficiency and throughput. Analysis of variance revealed that machine speed significantly affected both performance metrics, while the interaction between speed and compression pressure proved significant for machine efficiency. The quadratic models developed demonstrated high predictive capability with R² values of 0.9601 and 0.9548 for efficiency and throughput, respectively. Finite Element Analysis validated the structural integrity of the machine design under operational stresses. Optimal operating conditions were identified at 79.46 RPM machine speed, 41.88 mm die diameter, and 20.62 MPa compression pressure, yielding 84.75% efficiency and 235.77 kg/hr throughput. These findings provide valuable insights into the design and operation of briquetting machinery, contributing to the advancement of sustainable biomass utilization technologies.
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Hosseinzadeh, Mostafa, Jochen Petersen, and Asghar Azizi. "Solvent Extraction Studies of Copper from a Heap Leach Liquor Using Mextral 5640H." Minerals 12, no. 10 (2022): 1322. http://dx.doi.org/10.3390/min12101322.
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In this study the extractive capability of Mextral 5640H was investigated for extraction of copper from a heap leach liquor. In this regard, the influence of parameters such as pH (0.2–2.8), extractant concentration in kerosene diluent (5%–15% v/v), temperature (25–70 °C), contact time (0–300 s), stirring speed (100–1200 rpm), phase ratio (O/A) (0.6–1.8) and Cu initial concentration (0.5–2 g/L) in the leach liquor were examined and optimized. The findings demonstrated that the Mextral 5640H extractant had a very high efficiency and selectivity in copper extraction from the leachate. 98.17% Cu, with less than 0.5% of Fe and Mn, were extracted at pH 1.6, 10% (v/v) Mextral 5640H concentration, ambient temperature (25 °C), 400 rpm stirring speed, 2 min contact time and an O/A phase ratio of 1:1. Under equilibrium conditions it was found that one mol of Cu is extracted by 7 mol of Mextral 5640H. Additionally, analysis using a McCabe–Thiele diagram suggests a two-stage extraction to reach the maximum extraction of copper (99.5%) from the leachate at operational condition using industrial mixer-settlers. Furthermore, a thermodynamic study was conducted, and the measured values of ΔH = 15.13 kJ/mol, ΔG = −6.95 kJ/mol and ΔS = 74.10 J/mol/K indicate an endothermic, spontaneous nature and high affinity of copper extraction.
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Ottaviani, Marco, Luca Giammichele, and Renato Ricci. "Design, Assembly and Testing of a Mobile Laboratory Based on a VTOL Scale Motorglider." Tecnica Italiana-Italian Journal of Engineering Science 65, no. 2-4 (2021): 414–21. http://dx.doi.org/10.18280/ti-ijes.652-440.
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The objective of this paper is to explain the design steps and performance analysis of a vertical take-off and landing (VTOL) unmanned air vehicle (UAV) based on a Pilatus B4 glider scale model. Energy consumption, forces and thrust analyses are carry out to determinate the perfect match between low take-off weight and high aerodynamic performance. As a first approach a complete analysis of glider aerodynamic performances are settle to understand and design a proper support for VTOL conversion. Longitudinal static stability is fulfilled by evaluating the center of gravity location with respect to neutral position, nevertheless dynamic stability, and V-n diagram in VTOL configuration are evaluated to guarantee a correct behavior during fixed wing flight mode. In addition, power requirements, motor thrust capability and tilt-motors servo assisted system performance are determinate in perspective of flight performance to find out the perfect transition from multirotor take-off and landing mode to fixed-wing flying state. For these purposes a test bench has being designed to evaluate thrust, electrical absorption and rpm motor behavior along the throttle range. Finally, the assembly and preliminary tests are performed in order to validate the VTOL and Forward flight capability.
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Him, Nik Raikhan Nik, and Nurul Shafika Azmi. "Potential of a Novel Thermotolerant Lipase Bacillus stearothermophilus nr22 (Lip.nr-22) as Additive in High Temperature Operated-Neutral pH Liquid Detergent." Key Engineering Materials 735 (May 2017): 136–42. http://dx.doi.org/10.4028/www.scientific.net/kem.735.136.
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Enzyme-added detergent must have the capability to operate at high temperature to support the enzyme proteins to clean soiled-fabrics at optimum conditions. Lipase from Bacillus stearothermophilus nr22 (Lip.nr-22) has improved the oil removal from soiled-cotton fabric by 38.8-51.4% in 4 types of local commercial detergents. The later was the oil removal from an unrevealed detergent. The optimum conditions were 108U/ml Lip.nr-22 in 0.1M, pH 7.0, washing temperature and washing time interval as 80°C and 40 min, respectively; shaking wash at 300 rpm and percentage of detergent concentration as 0.5. Lip.nr-22 is a very potential enzyme in high temperature-neutral pH operated laundry detergent formulations. It has exhibited a very excellent thermostability at 80°C, was very stable with surfactants, commercial detergents as well as with oxidizing agents (H2O2, NaBO3H2O and NaClO). Lip.nr-22 as additive in detergent formulation is a promise for better detergent formulation.
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Travieso-Torres, Juan Carlos, Manuel A. Duarte-Mermoud, Matías Díaz, Camilo Contreras-Jara, and Francisco Hernández. "Closed-Loop Adaptive High-Starting Torque Scalar Control Scheme for Induction Motor Variable Speed Drives." Energies 15, no. 10 (2022): 3489. http://dx.doi.org/10.3390/en15103489.
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This article proposes a closed-loop (CL) high-starting torque (HST) scalar control scheme (SCS) for induction motors (IM). It endows the recently proposed HST-SCS with high-output torque capability beyond starting after using an outer speed control loop feeding an inner current control loop with adaptive controllers. Presenting a cascade normalized adaptive passivity-based controller (N-APBC) for nonlinear systems encompassing the IM allows obtaining this result. It extends the normalized adaptive controller for the cascade case. As a result, it keeps the HST-SCS simple control scheme without needing variable observers or parameter estimators and employing tuning information only from the motor nameplate and datasheet. Test bench experiments with a 10 HP motor validate the proposal’s effectiveness. Comparative experimental results show that the CL HST-SCS has a required stator phase voltage lower than HST-SCS. The CL HST-SCS applies the adaptive starting voltage curve for a more extended time than HST-SCS, from the start to 1.9 s versus 1.2 s, respectively. Hence, CL HST-SCS assures HST not only for starting but almost up to 600 rpm, resulting in a smoother transient behavior than HST-SCS under this speed.
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Sobczynski, Dariusz. "A CONCEPT OF A POWER ELECTRONIC CONVERTER FOR A BLDC MOTOR DRIVE SYSTEM IN AVIATION." Aviation 19, no. 1 (2015): 36–39. http://dx.doi.org/10.3846/16487788.2015.1015294.
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Realisation of a high-speed drive using a BLDC motor, especially that of low and medium power and with rotational speed of up to 40 000 rpm designed for use in aviation appliances, became possible due to rapid progress in electronic power control technology. An increase of both capability and diversity of electronic power circuits results from the increase of semiconductor element voltage and current operational ranges simultaneously with the improvement of their dynamical parameters, as well as from application of up-to-date microprocessor and programmable circuits for control purposes. Choice of topology for a drive system to be used in aviation appliances, including the electronic power converter, is based on the following quality and economy-related criteria: single-phase supply and sinusoidal waveform of power network current; high efficiency and reliability; small overall dimensions; minimum number of semiconductor elements; and low price. Various technical solutions are possible here, concerning both the scope of the power circuit and the control system.
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Wang, Mengyao, Baoquan Kou, Lu Zhang, Yuansheng Zhao, and Jian Xu. "A Novel Hybrid Excitation Doubly Salient Generator with Separated Windings by PM Inserted in Stator Slot for HEVs." Energies 15, no. 21 (2022): 7968. http://dx.doi.org/10.3390/en15217968.
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Aiming to design a generator with high reliability, high efficiency, and especially a constant output voltage over a wide speed range for hybrid electric vehicles (HEVs), this paper proposes a novel topology of a hybrid excitation doubly salient generator with separate windings (HEDSGSW). The topology herein utilizes a hybrid excitation type of PMs and DC windings to generate parallel magnetic circuits. In addition, PMs are embedded in the magnetic bridge to insulate the excitation windings with armature windings. This design can achieve compactness, efficiency, and especially constant output capability over a wide speed range. The geometry and flux regulation principles, including magnetic flux circuits, are elaborated. After comparing three power generation modes, the most suitable mode, namely, the doubly salient generation 2 (DSG2) mode, is confirmed to ensure a stable voltage output performance. Then, considering the non-uniformity effect of the stator and rotor slots, the no-load back electromotive force (EMF) expressions are derived based on the EMF to air-gap relative permeance method. Furthermore, a 1 kW HEDSGSW FEA model, with an output voltage of 42 V and a rated speed of 6000 rpm, is built to demonstrate the effectiveness of the proposed method. Finally, the operating properties of the HEDSGSW, such as no-load characteristics and adjustment characteristics, are analyzed to further verify the rationality of its magnetic flux circuit and the flexibility of the excitation regulation capability.
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Marwa F. Abed and Ayad A.H. Faisal. "NA-ALGINATE BEADS OF CALCIUM / IRON-LAYERED DOUBLE HYDROXIDE FOR TREATING WATER CONTAMINATED WITH AMOXICILLIN ANTIBIOTIC." IRAQI JOURNAL OF AGRICULTURAL SCIENCES 55, no. 2 (2024): 858–67. http://dx.doi.org/10.36103/x9f67y59.
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The objective of this study was to prepare an adsorbent material from eggshells of chicken banished to the ambient as wastes to satisfy the ecological requirements of sustainable. The preparation process based on the extraction of calcium ions from eggshells and these ions must be reacted with iron to form nanoparticles of (Ca/Fe)-layered double hydroxides (LDHs) which immobilized as Na-alginate beads. Molar ration of calcium to iron, pH and dosage of LDH nanoparticles must be equal to 1, 12 and 5 g/100 mL to ensure that the prepared beads have highest ability to remove of Amoxicillin (AMOX) antibiotic with removal efficiency equal to 32% for operational conditions of Co=100 mg/L, beads dosage=0.5 g/50 mL, speed=200 rpm, pH=7 for 3 hrs. To increase this efficiency to ≥ 90%, best conditions must be time 90 min, pH 7, and beads mass 1.2 g/ 50 mL for Co 100 mg/L at 200 rpm in the batch mode. The Pseudo second order has high capability in the description of such tests with coefficient of determination (R2) ≥ 0.9924 and sum of squared error (SSE) ≤ 0.1287. Hence, the sorption of AMOX onto beads is governed by the chemisorption process. The reflections of XRD analysis proved the presence of (Ca/Fe)-LDH nanoparticles with size of 13.49 nm, calcium hydroxide (Ca(OH)2) and calcium carbonate (CaCO3)
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Shi, Liangtong, Minghao Lv, and Pengwei Li. "Sensorless Position Control in High-Speed Domain of PMSM Based on Improved Adaptive Sliding Mode Observer." Processes 12, no. 11 (2024): 2581. http://dx.doi.org/10.3390/pr12112581.
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To improve the speed buffering and position tracking accuracy of medium–high-speed permanent magnet synchronous motor (PMSM), a sensorless control method based on an improved sliding mode observer is proposed. By the mathematical model of the built-in PMSM, an improved adaptive super-twisting sliding mode observer is constructed. Based on the LSTA-SMO with a linear term of observation error, a sliding mode coefficient can be adjusted in real time according to the change in rotational speed. In view of the high harmonic content of the output back electromotive force, the adaptive adjustment strategy for the back electromotive force is adopted. In addition, in order to improve the estimation accuracy and resistance ability of the observer, the rotor position error was taken as the disturbance term, and the third-order extended state observer (ESO) was constructed to estimate the rotational speed and rotor position through the motor mechanical motion equation. The proposed method is validated in Matlab and compared with the conventional linear super twisted observer. The simulation results show that the proposed method enables the observer to operate stably in a wide velocity domain and reduces the velocity estimation error to 6.7 rpm and the position estimation accuracy error to 0.0005 rad at high speeds, which improves the anti-interference capability.
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Sargeant, Ben, Pablo Puerto, Charles Richards, Ibai Leizea, Asier Garcia, and Stuart Robson. "High-Speed 6DoF Tool Monitoring Using a Low-Cost Photogrammetric System." Metrology 5, no. 1 (2025): 13. https://doi.org/10.3390/metrology5010013.
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The capability of low-cost photogrammetric systems to provide live six degrees of freedom (6DoF) tracking of multiple objects offers great value in providing high-quality and consistent part production by automated manufacturing systems. However, monitoring of high-speed components, such as cutting heads, presents several unique challenges that existing systems struggle to meet. The solution given here uses a small number of short-exposure imaging sensors coupled with high-intensity lighting and retrorefective markers to allow for high-speed capture. The use of an initial characterization process carried out using IDEKO’s VSET© system is followed by live object tracking in bespoke image processing software running on a consumer-grade computer. Once this system is in use, it can simultaneously capture images of multiple markers in less than 0.1 milliseconds and use these to determine the 6DoF of the objects that the markers define. 6DoF recalculation of all objects within each measurement instance makes the system resilient to large movements, object occlusion, and sensor relocation. Feasibility tests of a four-camera system as a machine characterization tool tracking a cutting tool spinning at up to 3000 rpm across a volume of 1 m3 achieved a mean reference marker agreement between tool poses of 2.5 µm with markers moving at up to 17.5 ms−1. Given good photogrammetric geometry, 6DoF parameters of the spinning tool were determined to standard deviations of 37.7 µm and 0.086°.
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Rokicki, Edward, Radoslaw Przysowa, Jerzy Kotkowski, and Paweł Majewski. "High Temperature Magnetic Sensors for the Hot Section of Aeroengines." Aerospace 8, no. 9 (2021): 261. http://dx.doi.org/10.3390/aerospace8090261.
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Magnetic sensors are widely used in aeroengines and their health management systems, but they are rarely installed in the engine hot section due to the loss of magnetic properties by permanent magnets with increasing temperature. The paper presents and verifies models and design solutions aimed at improving the performance of an inductive sensor for measuring the motion of blades operated at elevated temperatures (200–1000 °C) in high pressure compressors and turbines. The interaction of blades with the sensor was studied. A prototype of the sensor was made, and its tests were carried out on the RK-4 rotor rig for the speed of 7000 rpm, in which the temperature of the sensor head was gradually increased to 1100 °C. The sensor signal level was compared to that of an identical sensor operating at room temperature. The heated sensor works continuously producing the output signal whose level does not change significantly. Moreover, a set of six probes passed an initial engine test in an SO-3 turbojet. It was confirmed that the proposed design of the inductive sensor is suitable for blade health monitoring (BHM) of the last stages of compressors and gas turbines operating below 1000 °C, even without a dedicated cooling system. In real-engine applications, sensor performance will depend on how the sensor is installed and the available heat dissipation capability. The presented technology extends the operating temperature of permanent magnets and is not specific for blade vibration but can be adapted to other magnetic measurements in the hot section of the aircraft engine.
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Yang, Chun-Hao, Shao-Hua Yu, and Hai-Ping Tsui. "Observation of Gap Phenomena and Development Processing Technology for ECDM of Sapphire." Processes 12, no. 6 (2024): 1149. http://dx.doi.org/10.3390/pr12061149.
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The main purpose of this study was to develop observation techniques and processing technology for the electrochemical discharge machining (ECDM) of sapphire wafers. To measure the effect of gas-film thickness, discharge-spark conditions, and droplet sliding frequency on machining quality and efficiency in ECDM, this research utilized high-speed cameras to observe the gas film thickness and formation of the gas film during ECDM. Additionally, this study observed the machining-gap phenomena during ECDM. The formation mechanism and machining characteristics of the gas film were understood through experiments. The machining parameters included the liquid level, working voltage, rotation speed, and duty factor. This study analyzed and discussed the effect of each machining parameter on the gas-film thickness, current, electrode consumption, and droplet sliding frequency. Moreover, this study aimed to obtain optimized machining parameters to overcome the difficulty of machining sapphire. The experimental results indicated that utilizing a high-speed camera to capture the phenomena between electrodes during electrochemical discharge could effectively observe the gas-film thickness and the coverage of the gas film. A higher bubble coalescence rate enhanced the machining capability and reduced the lateral discharge. Therefore, this study could obtain better machining-hole depths through observation and analysis to improve gas-film stability and machining capability. This study demonstrated that a liquid level of 700 µm, a working voltage of 48 V, a duty factor of 50%, and a tool electrode rotational speed of 200 rpm could achieve a hole depth of 86.7 µm and a hole diameter of 129.5 µm.
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He, Quanyu, Hyunwoo Cho, Inkyum Kim, Jonghwan Lee, and Daewon Kim. "Self-Powered Triboelectric Ethanol Sensor Based on CuO-Doped Electrospun PVDF Fiber with Enhanced Sensing Performance." Polymers 17, no. 10 (2025): 1400. https://doi.org/10.3390/polym17101400.
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Electrospinning techniques have been widely applied in diverse applications, such as biocompatible membranes, energy storage systems, and triboelectric nanogenerators (TENGs), with the capability to incorporate other functional materials to achieve specific purposes. Recently, gas sensors incorporating doped semiconducting materials fabricated by electrospinning have been extensively investigated. TENGs, functioning as self-powered energy sources, have been utilized to drive gas sensors without external power supplies. Herein, a self-powered triboelectric ethanol sensor (TEES) is fabricated by integrating a TENG and an ethanol gas sensor into a single device. The proposed TEES exhibits a significantly improved response time and lower detection limit compared to published integrated triboelectric sensors. The device achieves an open-circuit voltage of 51.24 V at 800 rpm and a maximum short-circuit current of 7.94 μA at 800 rpm. Owing to the non-contact freestanding operating mode, the TEES shows no significant degradation after 240,000 operational cycles. Compared with previous studies that integrated TENGs and ethanol sensors, the proposed TEES demonstrated a marked improvement in sensing performance, with a faster response time (6 s at 1000 ppm) and a lower limit of detection (10 ppm). Furthermore, ethanol detection is enabled by modulating the gate terminal of an IRF840 metal-oxide semiconductor field-effect transistor (MOSFET), which controls the illumination of a light-emitting diode (LED). The LED is extinguished when the electrical output decreases below the setting value, allowing for the discrimination of intoxicated states. These results suggest that the TEES provides a promising platform for self-powered, high-performance ethanol sensing.
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Jaafar, Hassen, Chiheb Slama, Ines Sahli, Férid Mokhtar, and Mohieddine Abdellaoui. "Mechanical Alloying Synthesis of AB3 Zirconium Substituted Intermetallic." Tehnički glasnik 18, no. 1 (2024): 49–55. http://dx.doi.org/10.31803/tg-20230321121204.
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Abstract: Several ternary RareEarth-Magnesium-Nickel intermetallics (RE-Mg-Ni) emerged in last decade for their specific hydrogen storage capability. Nickel is now considered among strategic metals with recurrent rising price, Magnesium although its good gravimetric facility suffers from frequent oxidation or irreversible poisoning. Zirconium alloys are recognized for their improved anti-corrosion properties with enhanced wear resistance for high temperature machinability in industrial applications or energy research purposes. We proposed in this paper double substitution possibility replacing Magnesium and reducing Nickel charge. We developed new generation of quaternary Zirconium-AB3 intermetallic LaZr2Ni5Al4 using mechanical alloying method. Two binary raw materials are involved in this alloying reaction, the first is LaNi5 and the second is ZrAl2 (Laves phase C14) and both precursors are achieved quasi-quantitively using high frequency induction melting. The final target AB3 compound crystallizes in Trigonal system with space group R-3m (166) and following experimental conditions (Fritsch P7, Ω = 450 rpm) an acceptable synthesis yield (&gt;80%) is obtained starting from 20 hours mechanical alloying. Rietveld refinement is performed to have real matrix parameters and AB3 powder surface is analyzed using Scanning Electron Microscopy.
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Rante, Milka, Muhammad Syahid, and Onny Sutresman. "The Corrosion Erossion of Ship Propeller Al 7075 Produced by Gravity Sand Casting." EPI International Journal of Engineering 2, no. 2 (2019): 172–77. http://dx.doi.org/10.25042/epi-ije.082019.13.
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Propeller is one of the important components of ships and boats that function as motor or boat propulsion. The mechanical properties required in propeller material are high toughness, easy to cast, and good engine capability, as well as good resistance to corrosion and erosion. One of the aluminum alloys that have been widely used in major vessels in propeller systems is the Nickel-aluminum-bronze (NAB) alloy because it has an excellent combination of mechanical properties and corrosion-erosion resistance. Another type of aluminum alloy that is widely used as a machining component is the Al 7075 T651 because it has the highest strength among other aluminum alloys. The mechanical properties of the Al 7075 T651 are directly proportional to the erosion resistance of the propeller which agrees with the pot tester porridge. The higher the value of the erosion propeller failure that occurs also increases with increasing testing rotational speed. For corrosion, a propeller with air testing media at a speed of 1000 rpm which results in significant corrosion products.
 Keywords: Al 7075 T651, Slurry Pot Tester, Corrosion Erosion
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Faizollahzadeh Ardabili, Sina, Bahman Najafi, Meysam Alizamir, Amir Mosavi, Shahaboddin Shamshirband, and Timon Rabczuk. "Using SVM-RSM and ELM-RSM Approaches for Optimizing the Production Process of Methyl and Ethyl Esters." Energies 11, no. 11 (2018): 2889. http://dx.doi.org/10.3390/en11112889.
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The production of a desired product needs an effective use of the experimental model. The present study proposes an extreme learning machine (ELM) and a support vector machine (SVM) integrated with the response surface methodology (RSM) to solve the complexity in optimization and prediction of the ethyl ester and methyl ester production process. The novel hybrid models of ELM-RSM and ELM-SVM are further used as a case study to estimate the yield of methyl and ethyl esters through a trans-esterification process from waste cooking oil (WCO) based on American Society for Testing and Materials (ASTM) standards. The results of the prediction phase were also compared with artificial neural networks (ANNs) and adaptive neuro-fuzzy inference system (ANFIS), which were recently developed by the second author of this study. Based on the results, an ELM with a correlation coefficient of 0.9815 and 0.9863 for methyl and ethyl esters, respectively, had a high estimation capability compared with that for SVM, ANNs, and ANFIS. Accordingly, the maximum production yield was obtained in the case of using ELM-RSM of 96.86% for ethyl ester at a temperature of 68.48 °C, a catalyst value of 1.15 wt. %, mixing intensity of 650.07 rpm, and an alcohol to oil molar ratio (A/O) of 5.77; for methyl ester, the production yield was 98.46% at a temperature of 67.62 °C, a catalyst value of 1.1 wt. %, mixing intensity of 709.42 rpm, and an A/O of 6.09. Therefore, ELM-RSM increased the production yield by 3.6% for ethyl ester and 3.1% for methyl ester, compared with those for the experimental data.
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Yan, Peifeng, Chenzhang Chang, Dong Hua, Haomin Huang, Suisheng Liu, and Peiyi Cui. "Adaptive Disconnector States Diagnosis Method Based on Adjusted Relative Position Matrix and Convolutional Neural Networks." Sensors 25, no. 6 (2025): 1701. https://doi.org/10.3390/s25061701.
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Due to long-term outdoor working, High-Voltage Disconnectors (HVDs) are prone to potential faults. Currently, most studies on HVD state diagnosis methods have tested only one type of HVD, and the generalization capability of these methods for other HVDs has not been verified. In this paper, we propose an HVD state diagnosis method featuring adaptive recognition capabilities based on Fault Difference Signals, Adjusted Relative Position Matrix and Convolutional Neural Networks (FDS-ARPM-CNN). First, we align the measured operational power signal of the HVD drive motor with the recorded normal operational power signal, deriving the FDS through subtraction. Next, to address the issue of traditional Relative Position Matrix (RPM) conversion processes that lose sample amplitude information, we introduce a targeted improvement to the relative position matrix calculation method, converting the one-dimensional FDS into a two-dimensional image. Finally, we achieve high-accuracy diagnosis and classification of HVD states using a CNN that incorporates Batch Normalization (BN) and GELU activation functions. Experimental validation demonstrates that the neural network model, trained on one model of HVD, maintains strong generalization capabilities on data from other HVD models. This method effectively alleviates the challenges of acquiring fault samples in data-driven approaches for HVD state diagnosis, showcasing significant practical value.
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Narueworanon, Patthranit, Lakkana Laopaiboon, and Pattana Laopaiboon. "Capability of Immobilized Clostridium beijerinckii TISTR 1461 on Lotus Stalk Pieces to Produce Butanol from Sugarcane Molasses." Processes 9, no. 4 (2021): 573. http://dx.doi.org/10.3390/pr9040573.
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Immobilized Clostridium beijerinckii TISTR 1461 was used to enhance the butanol production efficiency from sugarcane molasses. Lotus stalk (LS) pieces were used as carriers for cell immobilization. Sugarcane molasses containing 50 g/L of sugar supplemented with 1 g/L of yeast extract was found to be an appropriate medium for bacterial cell immobilization on the LS pieces. Carrier size (4, 12 and 20 mm in length) and carrier loading (1:15, 1:30 and 1:45, w/v) were optimized for high levels of butanol production using response surface methodology (RSM). The batch fermentation was carried out under anaerobic conditions in 1 L screw-capped bottles at 37 °C and an agitation rate of 150 rpm. It was found that the optimum conditions for the butanol production were the carrier size of 4 mm and carrier loading of 1:31 (w/v). Under these conditions, the butanol concentration (PB) was 12.89 g/L, corresponding to the butanol productivity (QB) of 0.36 g/L∙h and butanol yield (YB/S) of 0.36 g/g. These values were higher than those using free cells (PB, 10.20 g/L, QB, 0.28 g/L∙h and YB/S, 0.32 g/g). In addition, it was found that a 24 h incubation time for cell immobilization was appropriate for the immobilization process, which was confirmed by the results of the scanning electron microscope (SEM) and atomic force microscopy (AFM) images and specific surface area measurement. When the fermentation using the immobilized cells was carried out in a stirred-tank reactor (STR), column reactor (CR) and CR coupled with STR, the results showed that all reactors could be used to produce butanol production from the immobilized cells on LS pieces. However, the PB using CR and CR coupled with STR were only 75% and 45% of those using the screw-capped bottle and STR.
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Omar, M. F., E. Sulaiman, H. A. Soomro, and L. I. Jusoh. "Performance Comparison between Salient and Segmental Rotors Single-Phase FEFSM Using Non-Overlap Windings for Home Appliances." International Journal of Engineering & Technology 7, no. 4.30 (2018): 189. http://dx.doi.org/10.14419/ijet.v7i4.30.22111.
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Field excitation flux switching machines (FEFSMs) in which their torque performance produced by interaction between armature and field excitation (FE) coils have been widely designed for various applications. In this regard, three-phase salient rotor FEFSM with overlap windings is considered the most suitable candidate for high speed applications because of their advantages of flux controllability, and robust due to single piece of rotor structure. However, the overlap windings cause a high copper loss, hence efficiency of the motor becomes low and higher stack length. Besides, the salient rotor structure is found to produce low torque performance due to the longer flux path in stator and rotor yielding weak flux linkage. In this paper, a new single-phase FEFSM using non-overlap windings between armature coils and FE coils is proposed. Both non-overlap windings FEFSMs with salient and segmental rotors have been designed using JMAG Designer version 15 and the investigation process is conducted via 2D finite element analysis. The proposed motor performances verification has been done by comparing the results of flux linkage, flux line and distribution, flux strengthening, various torque capability, and torque-power versus speed characteristics. As a conclusion, single-phase non-overlap windings FEFSM using segmental rotor with power, torque and speed capabilities of 277.5 W, 0.91 Nm and 2,899 rpm, respectively considered as the best candidate for low torque high speed applications.
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Ravikumar, R. N., K. J. Rathanraj, Kumar Arun, and S. Supreeth. "Experimental and CFD analysis of a gas-lubricated foil thrust bearing for various foil configurations." FME Transactions 51, no. 4 (2023): 532–40. http://dx.doi.org/10.5937/fme2304532r.
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Thrust foil bearings operating at hydrodynamic conditions are self-acting (aerodynamic) bearings that support high-speed shafts at mild loading conditions with air as a lubricant and are generally used in low-power gas turbines. This paper presents an experimental study and a detailed computational analysis of dynamic characteristics of the foil thrust bearing (FTB) in terms of load-carrying capabilities as a function of thrust runner speed and gap between the bearing assembly and the runner by considering the effect of bearing parameters such as number of foils, shape of the foils, and assembly of foils on the bearing pad. The parametric study was conducted on a newly conceptualized bearing test rig capable of rotating up to 45,000 rpm speeds that measured the axial loads of the air foil thrust bearings (AFTB). The computational model of the foil thrust bearings for various configurations with top foils is simulated using multiphysics software for foil deflections and pressure distributions on the foil surface. The numerical results were compared with the experimental values, while the air foil thrust bearings with multilayered foils called cascaded foils (patented) had higher load capability in comparison to other conventional bearing models.
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Khatun, Mst Rita, Amitava Bhattacharyya, Maral Gunbayar, Minsik Jung, and Insup Noh. "Study on Bioresponsive Gelatin-Hyaluronic Acid-Genipin Hydrogel for High Cell-Density 3D Bioprinting." Gels 9, no. 8 (2023): 601. http://dx.doi.org/10.3390/gels9080601.
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The Development of bioresponsive extrudable hydrogels for 3D bioprinting is imperative to address the growing demand for scaffold design as well as efficient and reliable methods of tissue engineering and regenerative medicine. This study proposed genipin (5 mg) cross-linked gelatin (1 to 1.5 g)-hyaluronic acid (0.3 g) hydrogel bioink (20 mL) tailored for 3D bioprinting. The focus is on high cell loading and a less artificial extra-cellular matrix (ECM) effect, as well as exploring their potential applications in tissue engineering. The bioresponsiveness of these hydrogel scaffolds was successfully evaluated at 37 °C and room temperature (at pH 2.5, 7.4, and 9). The rheological and mechanical properties (more than three times) increased with the increase in gelatin content in the hydrogel; however, the hydrogel with the least amount of gelatin showed the best extrusion capability. This optimized hydrogel’s high extrusion ability and post-printing shape fidelity were evident from 3D and four-axis printing of complex structures such as hollow tubes, stars, pyramids, and zigzag porous tubular (four-axis) scaffolds (printed at 90 kPa pressure, 70 mm/s speed, 22G needle, fourth axis rotation of 4 rpm). 3 million/mL MC3T3-E1 mouse osteoblast cells were used in preparing 3D bioprinted samples. The in vitro cell culture studies have been carried out in a CO2 incubator (at 37 °C, 5% CO2). In the cytocompatibility study, almost three times more cell viability was observed in 3 days compared to day 1 control, proving the non-toxicity and cell-supportiveness of these hydrogels. High cell viability and cell-to-cell interactions observed at the end of day 3 using this moderately stable hydrogel in 3D bioprinting exhibit high potential for precise cell delivery modes in tissue engineering as well as regenerative medicine.
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Uddin, Md Nashir, Ganesh Chandra Saha, Md Abul Hasanath, M. A. H. Badsha, Mohaiminul Haider Chowdhury, and Abu Reza Md Towfiqul Islam. "Hexavalent chromium removal from aqueous medium by ternary nanoadsorbent: A study of kinetics, equilibrium, and thermodynamic mechanism." PLOS ONE 18, no. 12 (2023): e0290234. http://dx.doi.org/10.1371/journal.pone.0290234.
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Although many studies have focused on chromium removal from aqueous media by ternary Nano adsorbents, still the integrated kinetics, equilibrium, and thermodynamic mechanisms of chromium removal remain unknown. Thus in this study, we have synthesized a novel ternary oxide nanocomposite comprising iron, manganese, and stannous (Fe2O3-MnO2-SnO2) in a facile method as a promising adsorbent for the removal of Cr(VI) from an aqueous medium. The Fe2O3-MnO2-SnO2 system was firstly characterized by FTIR, XRD, TGA, BET, and SEM/EDX. The effect of parameters, for instance, pH, temperature, initial Cr(VI) intensity, and adsorbent dose, have been examined to optimize the Cr(VI) adsorption performance. The adsorption of Cr(VI) onto Fe2O3-MnO2-SnO2 nanoadsorbent is associated with an adsorption/reduction mechanism. Using an initial Cr(VI) intensity of 50 mg L-1, 200 rpm agitation, 2.5-g L-1 of adsorbent, pH 2, 90 minutes adsorption time, and 298 K temperature, a maximum adsorption capability of 69.2 mg Cr(VI) g-1 for Fe2O3-MnO2-SnO2 was obtained. Models of pseudo-2nd-order kinetics and Langmuir’s isotherm were best suited to the investigated data. Besides, thermodynamic parameters show that Cr(VI) adsorption onto Fe2O3-MnO2-SnO2 was random and dominated by entropy. The reusability of Fe2O3-MnO2-SnO2 was found to be consistently high (remaining above 80% for Cr(VI)) over four adsorption-desorption cycles. Chromium adsorption from the tannery wastewater was achieved 91.89% on Fe2O3-MnO2-SnO2. Therefore, Fe2O3-MnO2-SnO2 nanoparticles, being easy to be synthesized, reusable and having improved adsorption capability with higher surface area, could be a desirable option for removing Cr(VI) from aqueous environments.
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Xin, Boyu, Qianshi Zhang, Lizhi Hu, et al. "Wide-Temperature-Range Tachometer Based on a Magnetoelectric Composite." Sensors 25, no. 3 (2025): 829. https://doi.org/10.3390/s25030829.
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In this work, a tachometer based on a Metglas/PZT/Metglas magnetoelectric (ME) composite was developed to achieve high-precision rotational speed measurement over a wide temperature range (−70 °C to 160 °C). The tachometer converts external magnetic signals into electrical signals through the ME effect and operates stably in extreme temperature environments. COMSOL Multiphysics software was used for simulation analysis to investigate the ME response characteristics of the composite in such environments. To evaluate the properties of the ME composite under different conditions, its response characteristics at various frequencies, DC bias, and temperatures were systematically investigated. A permanent magnet and a DC motor were used to simulate gear rotation, and the voltage output was analyzed by adjusting the position between the sensor and the DC motor. The results show that the measured values of the ME tachometer closely match the set values, and the tachometer demonstrates high measurement accuracy within the range of 480 to 1260 revolutions per minute (rpm). Additionally, the properties of the ME composite at different temperatures were examined. In the temperature range from −70 °C to 160 °C, the ME coefficients exhibit good regularity and stability, with the measured trend closely matching the simulation results, ensuring the reliability and accuracy of the ME tachometer. To verify its practicality, the measurement capability of the ME tachometer was comprehensively tested under extreme temperature conditions. The results show that in high-temperature environments, the tachometer can accurately measure speed while maintaining a high signal-to-noise ratio (SNR), demonstrating excellent anti-interference ability. The proposed ME tachometer shows promising application potential in extreme temperature conditions, particularly in complex industrial environments that require high reliability and precision.
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Alahmer, Hussein, Ali Alahmer, Razan Alkhazaleh, Mohammad Alrbai, and Malik I. Alamayreh. "Applied Intelligent Grey Wolf Optimizer (IGWO) to Improve the Performance of CI Engine Running on Emulsion Diesel Fuel Blends." Fuels 4, no. 1 (2023): 35–57. http://dx.doi.org/10.3390/fuels4010004.
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Water-in-diesel (W/D) emulsion fuel is a potential alternative fuel that can simultaneously lower NOx exhaust emissions and improves combustion efficiency. Additionally, there are no additional costs or engine modifications required when using W/D emulsion fuel. The proportion of water added and engine speed is crucial factors influencing engine behavior. This study aims to examine the impact of the W/D emulsion diesel fuel on engine performance and NOx pollutant emissions using a compression ignition (CI) engine. The emulsion fuel had water content ranging from 0 to 30% with a 5% increment, and 2% surfactant was employed. The tests were performed at speeds ranging from 1000 to 3000 rpm. All W/D emulsion fuel was compared to a standard of pure diesel in all tests. A four-cylinder, four-stroke, water-cooled, direct-injection diesel engine test bed was used for the experiments. The performance and exhaust emissions of the diesel engine were measured at full load and various engine speeds using a dynamometer and an exhaust gas analyzer, respectively. The second purpose of this study is to illustrate the application of two optimizers, grey wolf optimizer (GWO) and intelligent grey wolf optimizer (IGOW), along with using multivariate polynomial regression (MPR) to identify the optimum (W/D) emulsion blend percentage and engine speed to enhance the performance, reduce fuel consumption, and reduce NOX exhaust emissions of a diesel engine operating. The engine speed and proportion of water in the fuel mixture were the independent variables (inputs), while brake power (BP), brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), and NOx were the dependent variables (outcomes). It was experimentally observed that utilizing emulsified gasoline generally enhances engine performance and decreases emissions in general. Experimentally, at 5% water content and 2000 rpm, the BSFC has a minimal value of 0.258 kJ/kW·h. Under the same conditions, the maximum BP of 11.6 kW and BTE of 32.8% were achieved. According to the IGWO process findings, adding 9% water to diesel fuel and running the engine at a speed of 1998 rpm produced the highest BP (11.2 kW) and BTE (33.3%) and the lowest BSFC (0.259 kg/kW·h) and reduced NOx by 14.3% compared with the CI engine powered by pure diesel. The accuracy of the model is high, as indicated by a correlation coefficient R2 exceeding 0.97 and a mean absolute error (MAE) less than 0.04. In terms of the optimizer, the IGWO performs better than GWO in determining the optimal water addition and engine speed. This is attributed to the IGWO has excellent exploratory capability in the early stages of searching.
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Chen, Xianglan, Shuangfei Li, Wenxuan Zhang, Shaofeng Li, Yurong Gu, and Liao Ouyang. "A Newly Isolated Rhodococcus sp. S2 from Landfill Leachate Capable of Heterotrophic Nitrification and Aerobic Denitrification." Water 16, no. 3 (2024): 431. http://dx.doi.org/10.3390/w16030431.
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Nitrogen removal through heterotrophic nitrification–aerobic denitrification (HN–AD) has been acknowledged as one of the most efficient and cost-effective nitrogen removal processes. This study involved the isolation of a novel HN–AD bacterium (Rhodococcus sp. S2) from landfill leachate. Rhodococcus sp. S2 exhibited high nitrogen removal performance under aerobic conditions without the accumulation of nitrite as an intermediate. The maximum removal efficiencies for NH4+-N, NO2−-N, and NO3−-N were found to be 99.97 ± 0.3%, 99.79 ± 0.14%, and 83.53 ± 0.31%, respectively. Additionally, Rhodococcus sp. S2 demonstrated simultaneous nitrifying and denitrifying capabilities and showed a preference for utilizing NH4+-N in mixed nitrogen sources. The optimal nitrogen removal conditions for Rhodococcus sp. S2 were as follows: sodium acetate as a carbon source, a C/N ratio of 16, a shaking speed of 200 rpm, a pH of 9, and a temperature of 35 °C. Genome sequencing results revealed the presence of nitrate reductases (NarG), nitrate oxidoreductase (NxrA), and nitrite reductase (NirBD) in Rhodococcus sp. S2, providing further evidence of its HN–AD capability. In treating raw wastewater under the aforementioned experimental conditions, S2 achieved a maximum TN removal efficiency of 57.16 ± 0.52% with the addition of sodium acetate as a carbon source. These results suggest that Rhodococcus sp. S2 might be a promising candidate for wastewater nitrogen removal.
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Menghani, Jyoti, Akash Vyas, Satish More, Christ Paul, and Amar Patnaik. "Parametric investigation and optimization for CO2 laser cladding of AlFeCoCrNiCu powder on AISI 316." High Temperature Materials and Processes 40, no. 1 (2021): 265–80. http://dx.doi.org/10.1515/htmp-2020-0075.
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Abstract The purpose of the current investigation is to analyze the effect of the operating parameters of laser-assisted cladding process on clad height, clad depth, clad width and the percentage dilution in a cladding of AlFeCuCrCoNi high-entropy powder on SS-316 through CO2 laser and to optimize the cladding process parameters for optimum dilution. The experiments were designed by the full factorial method and analyzed by ANOVA. The analysis results indicate that dilution is most influenced by scanning speed followed by the powder feed rate. The outcomes of the single clad profile in terms of dilution, microhardness, composition and the microstructures produced in various cladding conditions are investigated briefly, and through which the optimum set of laser cladding operating parameters for maximum hardness of the clad material is determined. The optimum cladding conditions in the experimental range were obtained at 4 g/min powder feeding rate, 500 mm/min laser scanning speed and 1.1 kW laser beam power through multi-response optimization. Furthermore, the multi-track coating with 60% overlapping ratio was deposited using optimized parameters. The wear behavior of multi-track coating was determined using pin on disk wear apparatus with applied load of 20 N, sliding speed of 300 RPM and test duration of 15 min. The pin on disk wear test results indicates that the friction coefficient of SS-316 is larger than that of high-entropy alloy cladded SS-316. The wear resistivity of SS-316 improved by 40.35% after laser-assisted high-entropy alloy coating, which confirms that the laser cladding layer plays an essential role in enhancing the wear resistance capability of austenite steel.
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Sead, Mojtaba Hosseini, Cheraghi Mehrdad, Jamebozorgi Saeed, Shahriari Ali, and Kiani Sadr Maryam. "Investigating the effectiveness of 2-4 dichlorophenoxyacetic acid toxin removal using the combined method of ultrasonic and N-TiO2@SiO2@Fe3O4 magnetic nanocatalyst from aqueous environments." Tob Regul Sci. 9, no. 1 (2022): 898–912. https://doi.org/10.5281/zenodo.7866182.
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<strong>The herbicide2,</strong><strong>4 </strong><strong>dichlorophenoxyacetic acid can cause diseases such as neurotoxicity, hepatotoxicity, immunotoxicity, teratogenicity, endocrine disruption, hepatotoxicity in the human body. Also, due to their polar properties and relatively good solubility in water, they easily enter water sources after use and pollute water and soil. The use of magnetic nanocomposites is due to their selectivity in absorption, environmental friendliness, stability in environmental conditions, low manufacturing cost, high manufacturing speed, regeneration and reuse capability, and high efficiency of these compounds. This study was conducted with the aim of synthesizing N-TiO2@SiO2@Fe3O4 nanocomposite as a catalyst with ultrasonication to remove 2-4 dichlorophenoxyacetic acid from aqueous solutions. In this study, the effect of pH variables, pollutant concentration, stirrer speed, doscatalyst and contact time on the removal efficiency and determining the optimal conditions using the One factor at the time method was used. The catalyst was synthesized by co-precipitation and sol-gel method. The morphology of the synthesized N-TiO2@SiO2@Fe3O4 catalyst was determined using XRD, FT-IR, SEM, EDX, and BET devices. The results of this research showed that the highest percentage of 2-4 dichlorophenoxyacetic acid removal was obtained at pH= 6, initial concentration=5 mg/L, stirring speed of 300 rpm, duration of 90 minutes and dose catalysts, 0.3 g/L, 88.4</strong><strong>9</strong><strong>% using nano catalyst. Modified titanium dioxide magnetization in the visible range with ultrasonic can be an effective method to remove organic and inorganic pollutants from aqueous solutions.</strong>
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Sarvesh, S. Phatak, B. Mandake Yogesh, and S. Bankar D. "Development and performance analysis of switched reluctance motor for E-rickshaw." Indian Journal of Science and Technology 14, no. 38 (2021): 2916–33. https://doi.org/10.17485/IJST/v14i38.1713.
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Abstract <strong>Objectives:</strong> The main purpose of this study is to investigate switched reluctance motor for E-rickshaw propulsion system. <strong>Methods:</strong> The paper gives details of Literature review of current system incorporated in electric three wheeled propulsion, selection process of SRM, the design procedure of 8/6, 48V, 0.5 kW, 2000 rpm Switched reluctance motor for E-Rickshaw. Design validation and performance estimation is done by virtue of finite element analysis (FEA) tool using Ansys Maxwell Software.<strong> Findings:</strong> In this present work we found that it is possible to deploy SRM instead of current existing brushless direct current motors (BLDC) and PMSM (Permanent magnet synchronous motors) which are used in power train of electric three wheelers. Incorporating SRM would boost to promote “MAKE IN INDIA” and thus the country would become independent in electric vehicle market, hardware of the proposed SRM is also developed and tested. <strong>Novelty:</strong> The work done with investigation of SRM for E-rickshaw has not been studied until now although it possesses various advantages over existing system like high reliability and wide torquespeed range which is the basic requirement of propulsion motor in electric vehicles. SRM also provides several benefits like simple construction, high speed, resilience and good fault tolerance capability as all phases function independently. <strong>Keywords:</strong> ERickshaw; Brushless direct current motors; finite element analysis; Ansys Maxwell Software; Switched reluctance motor; Make in India
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Liu, Xiaole, Shaohua Liu, Lizhong Shen, Yuhua Bi, and Longjin Duan. "Study on the Effects of the Hydrogen Substitution Rate on the Performance of a Hydrogen–Diesel Dual-Fuel Engine under Different Loads." Energies 16, no. 16 (2023): 5971. http://dx.doi.org/10.3390/en16165971.
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Due to having zero carbon emissions and renewable advantages, hydrogen has great prospects as a renewable form of alternate energy. Engine load and hydrogen substitution rate have a considerable influence on a hydrogen–diesel dual-fuel engine’s efficiency. This experiment’s objective is to study the influence of hydrogen substitution rate on engine combustion and emission under different loads and to study the impact of exhaust gas recirculation (EGR) technology or main injection timing on the engine’s capability under high load and high hydrogen substitution rate. The range of the maximum hydrogen substitution rate was determined under different loads (30%~90%) at 1800 rpm and, then, the effects of the EGR rate (0%~15%) and main injection timing (−8 °CA ATDC~0 °CA ATDC) on the engine performance under 90% high load were studied. The research results show that the larger the load, the smaller the maximum hydrogen substitution rate that can be added to the dual-fuel engine. Under each load, with the increase of the hydrogen substitution rate, the cylinder pressure and the peak heat release rate (HRR) increase, the equivalent brake-specific fuel consumption (BSFCequ) decreases, the thermal efficiency increases, the maximum thermal efficiency is 43.1%, the carbon dioxide (CO2) emission is effectively reduced by 35.2%, and the nitrogen oxide (NOx) emission decreases at medium and low loads, and the maximum increase rate is 20.1% at 90% load. Under high load, with the increase of EGR rate or the delay of main injection timing, the problem of NOx emission increases after hydrogen doping can be effectively solved. As the EGR rate rises from 0% to 15%, the maximum reduction of NOx is 63.1% and, with the delay of main injection timing from −8 °CA ATDC to 0 °CA ATDC, the maximum reduction of NOx is 44.5%.
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Huang, Yi, Mi Zhao, Yunong Wang, Hong Zhang, and Min Lu. "An Improved Full-Speed Domain Sensorless Control Scheme for Permanent Magnet Synchronous Motor Based on Hybrid Position Observer and Disturbance Rejection Optimization." Electronics 12, no. 18 (2023): 3759. http://dx.doi.org/10.3390/electronics12183759.
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A sensorless control algorithm not only reduces the cost of a permanent magnet synchronous motor (PMSM) system, but also broadens its application scope. Expanding speed threshold and enhancing dynamic performance are crucial aspects. To optimize the adaptability of observers and the immunity of the controller in a full-speed domain, an improved sensorless control scheme for a PMSM based on a hybrid position observer and disturbance compensation is proposed. Firstly, the precise detection of the initial position and the scheme of starting with the load at any position are proposed based on high-frequency rotation injection, magnetic pole direction calibration and square-wave high-frequency injection (HFI). Secondly, a higher-order sliding mode observer (HSMO) is designed to improve high-speed observation performance by introducing an extended electromotive force (EEMF). Correspondingly, a speed controller called PI plus is developed utilizing a reverse control algorithm and the observed disturbance quantity, which further enhances the system’s disturbance rejection capability. Subsequently, a linearly weighted observer switching method and a linear signal withdrawal scheme are proposed to suppress torque and speed oscillations in medium-speed threshold. Furthermore, a normalized linear extended state observer (LESO) is designed to enhance rotor information estimation accuracy and enable the observation of unknown disturbances in full-speed thresholds. Finally, the effectiveness of the proposed sensorless control system is tested through experiments involving variations in speed, load, and parameter. The experimental results indicate that the proposed sensorless strategy is capable of achieving a loaded start. The designed observer switching strategy and the scheme of injection signal withdrawal contribute to a smoother acceleration process. Furthermore, load variation test results at high-speed thresholds demonstrate that the proposed controller can reduce speed drop by 45 rpm compared to a traditional PI. Additionally, the results of parameter variation testing validate the observer’s robustness in the disturbances of ψf within the range of ±0.3 pu.
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Divinagracia-Luzadas, Maricor, and Joey Ocon. "Graphitic Carbon Nitride/Carbon Nanotube Cathodes for Non-Aqueous Lithium-Oxygen Batteries." ECS Meeting Abstracts MA2022-02, no. 7 (2022): 2480. http://dx.doi.org/10.1149/ma2022-0272480mtgabs.
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Although non–aqueous lithium–oxygen (Li–O2) batteries have been gaining attention in recent years for their potentially high energy density, their actual performances are still inferior to that of state–of–the–art Li–ion batteries. To overcome the high overvoltage, low rate capability, and poor cycle performance, the development of O2 electrode structures and electrocatalysts is of great importance. Herein, a graphitic carbon nitride/carbon nanotube composite (GCN/CNT) was synthesized using a facile annealing method and evaluated as a cathode for non–aqueous Li–O2 batteries, where CNT can provide storage sites for the reactants and products while facilitating electron transfer, and GCN can act as catalytic centers for oxygen reactions. Due to its large surface area, high nitrogen content and synergistic coupling, GCN/CNT (18 wt.% GCN) demonstrated improved activity and stability towards ORR and OER (ΔE = 1.07 V), compared to pure CNT. Consequently, GCN/CNT exhibited lower overpotentials and better cycling stability when applied as a Li–O2 battery cathode. It delivered a specific discharge capacity of 3796 mAh g–1 at a current density of 100 mA g–1, and a relatively stable cycling performance of up to 35 cycles at a limited capacity of 1000 mAh g–1. Moreover, the reversible formation and decomposition of the Li2O2 product after cycling was confirmed in the characterization data (SEM images and XRD patterns). Hence, this GCN/CNT composite could be a promising cathode material in Li–O2 batteries. Figure 1. ORR LSV curves of CNT, Pt/CNT, and GCN/CNT electrodes in an O2−saturated 0.1 M KOH electrolyte at a scan rate of 5 mV s−1 and rotation speed of 1600 rpm Figure 1
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Ko, Htet Yamin Ko, Nitin Kumar Tripathi, Chitrini Mozumder, Sombat Muengtaweepongsa, and Indrajit Pal. "Real-Time Remote Patient Monitoring and Alarming System for Noncommunicable Lifestyle Diseases." International Journal of Telemedicine and Applications 2023 (November 20, 2023): 1–13. http://dx.doi.org/10.1155/2023/9965226.
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Telemedicine and remote patient monitoring (RPM) systems have been gaining interest and received adaptation in healthcare sectors since the COVID-19 pandemic due to their efficiency and capability to deliver timely healthcare services while containing COVID-19 transmission. These systems were developed using the latest technology in wireless sensors, medical devices, cloud computing, mobile computing, telecommunications, and machine learning technologies. In this article, a real-time remote patient monitoring system is proposed with an accessible, compact, accurate, and low-cost design. The implemented system is designed to an end-to-end communication interface between medical practitioners and patients. The objective of this study is to provide remote healthcare services to patients who need ongoing care or those who have been discharged from the hospital without affecting their daily routines. The developed monitoring system was then evaluated on 1177 records from MIMIC-III clinical dataset (aged between 19 and 99 years). The performance analysis of the proposed system achieved 88.7% accuracy in generating alerts with logistic regression classification algorithm. This result reflects positively on the quality and robustness of the proposed study. Since the processing time of the proposed system is less than 2 minutes, it can be stated that the system has a high computational speed and is convenient to use in real-time monitoring. Furthermore, the proposed system will fulfil to cover the lower doctor-to-patient ratio by monitoring patients from remote locations and aged people who reside in their residences.
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Shinde, Mr Bhushan Subhash, Dr Usha C. Pawar, and Mr Rajesh Kumar. "Diesel Engine Fuel Pump Pressure, Time Setting and Calibration." International Journal for Research in Applied Science and Engineering Technology 10, no. 3 (2022): 2014–31. http://dx.doi.org/10.22214/ijraset.2022.41025.
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Abstract: For a diesel engine, fuel pressure time setting and calibration are very important parameters, which influence and increase the engine efficiency, performance, emissions, and combustion. Other injection parameters affecting engine performance are rate of injection, injection pattern, number of injections etc. A single cylinder research engine was used to experimentally determine the effects of fuel injection strategies and injection timings on engine combustion, performance and emission characteristics. The experiments were conducted at constant speed (2500 rpm) with two FIPs (500 and 1000 bars respectively) and different start of injection (SOI) timings. Cylinder pressure and rate of heat release (ROHR) were found to be higher for lower FIPs however advanced injection timings gave higher ROHR in early combustion stages. Brake thermal efficiency (BTE) increased with increased injection pressures while exhaust gas temperature and brake mean effective pressure (BMEP) increased up to 500 bars. These parameters reduced slightly with increase in fuel pressure time pump. Diesel engine combustion quality is based on the formation of fuel-air mixture. Enormous efforts have made to reduce the harmful diesel engine emissions. High engine noise, Particulate matter (PM) and NOx production are the results of improper combustion process and considered as the major constraints. The performance and emission characteristics of diesel engines depend on many parameters. Precise control over the fuel injection process is one of the most important factors and plays a very important role in combustion to increase the engine performance with minimal exhaust emission. The injection system must satisfy high pressure capability, injection pressure control, flexible timing control, and injection rate control. The purpose of this study is to find the performance and exhaust emission of diesel engines by implementing the combination of various high injection pressures and variable injection timings. Present paper is concentrated towords optimization of the best combination of high pressure injection with suitable injection timing in a diesel engine fueled with pure diesel, to reduce the emission and fuel consumption with increased engine power. Keywords: Diesel Engine fuel pump pressure, time,setting and calibration.
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Tewari, Hemlata, and Vivekanand. "Removal of heavy metals from industrial effluent using Pinus roxburghii leaves as biosorbent: equilibrium modelling." Water Science and Technology 67, no. 9 (2013): 1894–900. http://dx.doi.org/10.2166/wst.2013.034.
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In the present study, biosorption capability of pine (Pinus roxburghii) leaves for the removal Cr6+, Cu2+, Fe2+ and Zn2+ ions, present in brass and electroplating industry effluent, were investigated with respect to different adsorbent doses, contact time and pH. Heavy metals concentrations were estimated by atomic absorption spectrophotometry. Initial concentration of Cr6+, Cu2+, Fe2+ and Zn2+ ions in the effluent were found to be 2.741, 4.551, 8.820 and 5.529 mg/L respectively. Biosorption studies revealed that Cr6+, Cu2+, Fe2+ and Zn2+ showed maximum removal of 99.85, 94.54, 97.10 and 89% at pH 4, 4, 4 and 8, respectively, with 4 g pine leaves when shaken at 150 rpm for 60 min. The applicability of the three equilibrium isotherm models was investigated and the data obtained fitted the three investigated isothermal models in the order: Langmuir &gt; Temkin &gt; Freundlich for all the studied metal ions. The adsorption isotherm coefficients, Qmax, b, Kf, n, at, bt were also calculated. Very high regression correlation coefficients (R2 &gt; 0.9) were found for Cu2+, Fe2+ and Zn2+; Cr6+ (Temkin isotherm) when pH (2–8) was varied; Cr6+, Cu2+,Fe2+ and Zn2+ when contact time (15–60 min) was varied; Cu2+ (Langmuir isotherm) Fe2+ (Freundlich and Temkin isotherms) when adsorbent was varied from 2 to 5 g. Results also revealed that among all the studied ions Cr6+ at varied pH and Fe2+ at different adsorbent doses satisfy the Temkin and Freundlich isotherm models to describe the biosorption equilibrium by pine (Pinus roxburghii) adsorbent.
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Sang, Brian, Haoran Wen, Gregory Junek, Wendy Neveu, Lorenzo Di Francesco, and Farrokh Ayazi. "An Accelerometer-Based Wearable Patch for Robust Respiratory Rate and Wheeze Detection Using Deep Learning." Biosensors 14, no. 3 (2024): 118. http://dx.doi.org/10.3390/bios14030118.
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Wheezing is a critical indicator of various respiratory conditions, including asthma and chronic obstructive pulmonary disease (COPD). Current diagnosis relies on subjective lung auscultation by physicians. Enabling this capability via a low-profile, objective wearable device for remote patient monitoring (RPM) could offer pre-emptive, accurate respiratory data to patients. With this goal as our aim, we used a low-profile accelerometer-based wearable system that utilizes deep learning to objectively detect wheezing along with respiration rate using a single sensor. The miniature patch consists of a sensitive wideband MEMS accelerometer and low-noise CMOS interface electronics on a small board, which was then placed on nine conventional lung auscultation sites on the patient’s chest walls to capture the pulmonary-induced vibrations (PIVs). A deep learning model was developed and compared with a deterministic time–frequency method to objectively detect wheezing in the PIV signals using data captured from 52 diverse patients with respiratory diseases. The wearable accelerometer patch, paired with the deep learning model, demonstrated high fidelity in capturing and detecting respiratory wheezes and patterns across diverse and pertinent settings. It achieved accuracy, sensitivity, and specificity of 95%, 96%, and 93%, respectively, with an AUC of 0.99 on the test set—outperforming the deterministic time–frequency approach. Furthermore, the accelerometer patch outperforms the digital stethoscopes in sound analysis while offering immunity to ambient sounds, which not only enhances data quality and performance for computational wheeze detection by a significant margin but also provides a robust sensor solution that can quantify respiration patterns simultaneously.