•Coupling COMSOL simulations with acoustic pressure maps informs sono-reactor design.•Simulations show high acoustic pressures along the neck of a multi-stepped horn.•Hydrophone measurements indicate ...cavitation along horn neck and verify simulations.•Conical bottom reactor maximizes cavitational volume compared to typical reactors.
Scaled-up and economically viable sonochemical systems are critical for increased use of ultrasound in environmental and chemical processing applications. In this study, computational simulations and acoustic pressure maps were used to design a larger-scale sono-reactor containing a multi-stepped ultrasonic horn. Simulations in COMSOL Multiphysics showed ultrasonic waves emitted from the horn neck and tip, generating multiple regions of high acoustic pressure. The volume of these regions surrounding the horn neck were larger compared with those below the horn tip. The simulated acoustic field was verified by acoustic pressure contour maps generated from hydrophone measurements in a plexiglass box filled with water. These acoustic pressure contour maps revealed an asymmetric and discrete distribution of acoustic pressure due to acoustic cavitation, wave interaction, and water movement by ultrasonic irradiation. The acoustic pressure contour maps were consistent with simulation results in terms of the effective scale of cavitation zones (∼10cm and <5cm above and below horn tip, respectively). With the mapped acoustic field and identified cavitation location, a cylindrically-shaped sono-reactor with a conical bottom was designed to evaluate the treatment capacity (∼5L) for the multi-stepped horn using COMSOL simulations. In this study, verification of simulation results with experiments demonstrates that coupling of COMSOL simulations with hydrophone measurements is a simple, effective and reliable scientific method to evaluate reactor designs of ultrasonic systems.
Analysis of Shell and Tube Heat Exchanger Type Tanujaya, Harto; Riza, Abrar
IOP conference series. Materials Science and Engineering,
12/2020, Letnik:
1007, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The stationary-head prototypes unusually are designed using low cost manufacture and simple construction, without bolt or nut to join both the stationary-head and shell. The shell has four holes to ...supply hot/cold fluid, and next to the tube-sheet hole to supply cold/hot fluid, the position both of them are inside the stationary-head. The calculation of the dimensions of the heat exchanger aims to determine the quality of the heat exchanger based on the overall heat transfer coefficient, impurity factor, and the pressure drop that will occur.Calculations using the LMTD method, obtained that receive heat released has a large unity with time Q, then the heat received by cold fluid is Q = 4565.16 W, LMTD produced also shows the number 20, with a proven factor (F) is 1. Comparison obtained from the calculation of the tube side and shell side is the value of Re generated is greater than the value of Re on the shell side.
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•COMSOL simulation was employed to study the kinetics of electrochemical reduction of Au(S2O3)23–.•The activated carbon-coated electrode exhibited superior gold recovery.•Rich pore ...structure of electrode accelerated Au(S2O3)23– diffusion toward cathode.
It is a great challenge to highly recover gold from the E-waste leaching solution due to the low concentration and the resultant slow ion diffusion. In this research, COMSOL Multiphysics was employed for the first time to give a graphical display of the mass transfer behavior of Au(S2O3)23– under an electric field. An enhanced strategy for gold recovery from the leaching solution by utilizing porous activated carbon (AC) coated electrode was proposed as well. The recovery rate of gold with low concentration was limited by the slow ion diffusion from the solution to the interface of electrode, which had been confirmed through COMSOL Multiphysics. While, both the simulations and experiments demonstrated that the Ti cathode coated with AC could make a great facilitation for the ion diffusion to the electrode interface benefited from the rich pore network of AC. As a result, 96.9 % Au was efficiently recovered from the WPCBs leaching solution with AC electrode at 1.2 V. This study not only gives a new understanding on the reduction kinetics of Au(S2O3)23– under electric field, but also a valuable strategy for the efficient recovery of precious metal from electronic waste.
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•COMSOL Multiphysics reveal the electric field distribution of synthetic samples.•Discharge channel developed along the magnetite edge and retains the complete form.•Magnetite alters ...the distribution state of electric field within synthetic samples.•Quartz particles hinders the development of certain discharge channels.
Herein, COMSOL Multiphysics is proposed to discuss the electric field distribution of synthetic sample during the high voltage pulse discharge crushing. The pulses number required for high voltage pulse discharge to crush the synthetic sample filled with magnetite is lower than that required for quartz-filled samples. The embedding mode that the magnetite is located on the central line between the high voltage electrode and the grounding electrode of the synthetic sample is most conducive to electrical breakdown of synthetic sample. The discharge channel developed along the magnetite edge and retains the complete crystal form of magnetite. Differences in dielectric constants are responsible for variations in electric field distribution. Magnetite alters the distribution state of electric field within synthetic samples to derive higher electric field intensity and more extensive areas with high electric field intensity. The peak electric field intensity at the interface of magnetite particles is higher than that of quartz. The presence of quartz particles hinders the development of certain discharge channels.
Treatment of waste water via photocatalysis is one of the most effective, economical and environment friendly process. In this study, green method (leaf extract of Citrus Medica Linn.) is used to ...synthesize pure and lanthanum (La)-(1,2 & 3 wt%) doped copper oxide nanoparticles (CuO-NPs). Different characterization techniques such as XRD, SEM, EDS, UV/VIS, PL and FTIR are utilized to investigate their physical, chemical, optical and structural properties. The synthesized material is used as photocatalyst for degradation of methylene blue (MB) dye. Interestingly, the La doped CuO-NPs have exhibited unique results. Variation in dopant concentration reduces the particle size (40.82 ± 0.04 nm to 31.89 ± 0.02 nm) and band gap of material shifts towards visible region (3.03 eV–2.71 eV). During photocatalysis, doping reduces the electron-hole pair recombination rate which makes it a potential photocatalyst. Maximum degradation efficiency of 84% is observed in 150 min for 2% La doped CuO-NPs which reveals that 2% La doping is optimal. Further increase in dopant concentration increases band gap, therefore, degradation efficiency drops to 75%. Simulation of this work is carried out using COMSOL Multiphysics 5.3a Licensed version. A 2D model is constructed and CuO-NPs is considered as photocatalyst in order to correlate simulated and experimental photocatalytic degradation of MB and rhodamine B (RhB) dye. Comparative analysis of rate constants revealed that the trend given by simulation is very close to the experimental observations.
Cardiac troponin I (cTnI) is a critical biomarker for the diagnosis of acute myocardial infarction (AMI). Herein, we report a novel integrated lateral flow immunoassay (LFIA) platform for highly ...sensitive point-of-care testing (POCT) of cTnI using hierarchical dendritic copper-nickel (HD-nanoCu-Ni) nanostructures. The electrodeposited HD-nanoCu-Ni film (∼22 μm thick) on an ITO-coated glass substrate exhibits superior capillary action and structural integrity. These properties enable efficient sample transport and antibody immobilization, making it a compelling alternative to conventional multi-component paper-based LFIA test strips, which are often plagued by structural fragility and susceptibility to moisture damage. The biofunctionalized HD-nanoCu-Ni substrates were laser-etched with lateral flow channels, including a sample loading/conjugate release zone, a test zone, and a control zone. Numerical simulations were used to further optimize the design of these channels to achieve optimal fluid flow and target capture. The HD-nanoCu-Ni LFIA device utilizes a fluorescence quenching based sandwich immunoassay format using antibody-labeled gold nanoparticles (AuNPs) as quenchers. Two different fluorescent materials, fluorescein isothiocyanate (FITC) and CdSe@ZnS quantum dots (QDs), were used as background fluorophores in the device. Upon the formation of a sandwich immunocomplex with cTnI on the HD-nanoCu-Ni device, introduced AuNPs led to the fluorescence quenching of the background fluorophores. The total assay time was approximately 15 min, demonstrating the rapid and efficient nature of the HD-nanoCu-Ni LFIA platform. For FITC, both inner filter effect (IFE) and fluorescence resonance energy transfer (FRET) contributed to the AuNP-mediated quenching. In the case of CdSe@ZnS QDs, IFE dominated the AuNP-induced quenching. Calibration curves were established based on the relationship between the fluorescence quenching intensity and cTnI concentration in human serum samples, ranging from 0.5 to 128 ng/mL. The limits of detection (LODs) were determined to be 0.27 ng/mL and 0.40 ng/mL for FITC and CdSe@ZnS QDs, respectively. A method comparison study using Passing-Bablok regression analysis on varying cTnI concentrations in human serum samples confirmed the equivalence of the HD-nanoCu-Ni LFIA platform to a commercial fluorescence cTnI LFIA assay kit, with no significant systematic or proportional bias observed.
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•Developed a novel, integrated LFIA for cTnI detection using HD-nanoCu-Ni films.•Utilized laser etching and COMSOL simulation to optimize flow characteristics.•Achieved cTnI detection via fluorescence quenching and immunocomplex formation.
This study concerns the two-dimensional structure computational results of renal artery stenosis. In this paper, the turbulent flow of the stenosed vessel is stimulated and correlates the different ...stages of stenosis with each other. As we know that the blood flow in most blood vessels is laminar, but in case of stenosed vessel, the blood flow becomes turbulent; this is due to the blockage that blood does not flow linearly and produces chaos. Several liquid parameters are analyzed, such as pressure, velocity, turbulence kinetic energy, density, and shear rate. The inlet and outlet flow are especially concerning. For this purpose, we explored the stenosed behavior by the software COMSOL Multiphysics which provided us with a complete examination of the Computational fluid dynamics. With an increase in renal artery stenosis, there is a decrease in the blood flow which will automatically affect the pressure of the blood and can cause serious kidney diseases and, in some cases, permanent damage to the kidney sometimes. This paper highlights the early stages of renal artery stenosis, which are likely to be cured. Also, it shows the behavior of the severe late stages, which we consider nearly impossible to cure. The result explains that how different parameters vary according to stated cases.
This study aimed to investigate the effects of electron beam irradiation on the structural, optical, and electrical properties of polyvinyl chloride/pectin (PVC/PEC) nanocomposites incorporating ...hexagonal nanoplate Co3O4. Hexagonal nanoplate Co3O4 was synthesized and incorporated into PVC/PEC blends at 5 wt%. The nanocomposites were subjected to electron beam irradiation at varying doses (0, 10, 20, and 30 kGy). Various characterization techniques, including XRD, UV–Vis spectroscopy, AC conductivity, and dielectric measurements, were employed to analyze the irradiated samples. Additionally, electric field distribution simulations were performed for a 33 kV cable model. XRD analysis revealed the retention of Co3O4 crystallinity up to 30 kGy, while the polymer matrix showed degradation above 10 kGy. The optical bandgap decreased from 2.25 eV to 1.90 eV with increasing irradiation dose, indicating changes in the electronic structure. The optimized AC conductivity (37.17 × 10−6 S m−1) and minimum relative permittivity (2.28) were achieved for the 30 kGy irradiated sample with 5 wt% Co3O4. The electric potential distribution gradually decreased from 33,000 V to zero V. The systematic variations in structural, optical, and electrical properties demonstrated controlled tuning of charge transport mechanisms, making these nanocomposites potentially suitable for advanced cable systems. The simulation results showed that the inclusion of Co3O4 at 30 kGy helped maintain a uniform electric field distribution in the 33 kV cable model compared to an unfilled cable.
•This study focuses on the synthesis and characterization of hexagonal nanoplate of (PVC/PEC) Co3O4 nanocompsites.•The effects of varying electron beam irradiation doses (0, 10, 20, and 30 kGy) on PVC/PEC/Co3O4 nanocomposites.•The optimized AC conductivity with relative permittivity (2.28) is achieved for (PVC/PEC/Co3O4) 30 kGy with 5 wt% Co3O4NPs.•The Electric potential distribution gradually decreases from 33,000 V to zero V.
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