Concentrations Of CuO Nanoparticles Research Articles

Enhancement of antimicrobial properties of plasma electrolytic oxidation coatings on aluminum alloy surfaces with CuO nanoparticles

A coating containing copper oxide/cuprous oxide (CuO/Cu2O) nanoparticles with excellent antimicrobial properties was synthesized on the surface of an aluminum alloy substrate by plasma electrolytic oxidation (PEO) technology. This study focuses on the impact of incorporating CuO nanoparticles on the coating's composition, microstructure, mechanical properties, corrosion resistance, and antimicrobial efficacy. EDS and XPS analyses confirmed that the primary components of the coating are Al2O3 and Cu2O/CuO, with the Cu element predominantly located in the micropores and microcracks of the coating. The inclusion of CuO nanoparticles significantly increased the coating's thickness, hardness, and densification while reducing surface roughness. Electrochemical tests and antimicrobial experiments demonstrated that the PEO coating with added CuO nanoparticles exhibited excellent corrosion resistance, with an antimicrobial rate against Staphylococcus aureus reaching 99.06 %, compared to 45.12 % for the ordinary PEO coating. The study also investigated the effects of key process parameters (positive voltage, negative voltage, duty cycle, and CuO nanoparticle concentration) on the coating's antimicrobial rate, identifying optimal parameters for maximum antimicrobial performance. Studies have shown that the incorporation of CuO nanoparticles effectively enhances the overall performance of PEO coatings, particularly in terms of antibacterial and corrosion resistance. The process parameters mainly influence the antimicrobial properties of the coating by affecting the state and content of Cu. This coating shows promising application prospects in medical devices, such as orthopedic external fixation frames, microsurgical instruments, and prosthetic devices.

Comparative study of two-phase flow approaches for modeling conjugate heat transfer in a three-dimensional wavy microchannel-heat sink with CuO-water nanofluid

This study aims to numerically investigate the conjugate heat transfer (CHT) and the changes in the hydraulic and thermal terms of laminar flow (300 ≤ Re ≤ 800) in a 3-D wavy microchannel heat sink (MCHS). The obtained results from different nanofluid flow simulated models will be compared. The numerical simulation approaches used include single-phase, mixture, Eulerian, DPM, and DDPM. The effect of adding 1%, 3%, and 6% concentration of CuO nanoparticles (100 nm) in deionized water as the base fluid is examined on various parameters such as local and axial temperature, heat transfer convective coefficient, friction factor, Nusselt number (Nu), velocity distribution, and thermal and hydraulic boundary layer parameters. The substrate surface, due to its larger area surface and the amplitude of the sinusoidal wave, has a greater impact on the nanofluid flow as a channel bottom conjugate surface compared to others. The results obtained from the different models show close agreement with each other for various cases. For example, at Re = 304, the average Nu and friction factor for pure water are approximately 10.43 and 0.0260, respectively. For water with 0.01 concentration of CuO nanoparticles, Nu is found to be in the range of 10.43–10.78, and the friction factor ranges from 0.260 to 0.290, depending on the approach used for simulation. This shows a 2% increase in Nusselt number compared to a 0.05% increase in the friction factor. Moreover, these values increase by approximately 5.7% and 11.3% on average with an increase in CuO nanoparticle concentration to 0.06. Additionally, the DPM and DDPM models show a 15% difference in the scattering of CuO nanoparticles compared to the Eulerian-Eulerian models. The single-phase model presented in this study yields similar results to the multiphase approaches. Furthermore, the PEC parameter increases by about 1.9% with the addition of CuO nanoparticles at a concentration of 0.06.

Polyvinyl pyrrolidone/ carboxymethyl cellulose (PVP/CMC) polymer composites containing CuO nanoparticles synthesized via laser ablation in liquids

Polyvinyl pyrrolidone/carboxymethyl cellulose (PVP/CMC) polymer composites containing CuO nanoparticles synthesized via laser ablation in liquids were prepared. Fourier transform infrared (FTIR) spectroscopy, UV/Vis spectroscopy, and scanning electron microscopy (SEM) were used to characterize the structural, optical, and morphological properties of the polymer composites. The addition of CuO nanoparticles resulted in changes in the FTIR spectra, indicating interaction between the polymer matrix and nanoparticles. UV/Vis spectroscopy showed a red shift in absorption and a decrease in optical bandgap with increasing CuO nanoparticle content. SEM micrographs revealed increases in surface roughness with higher CuO nanoparticle loading. Antibacterial activity of the composites against Gram-positive and Gram-negative bacteria increased with greater CuO nanoparticle concentration. The results suggest these biofilms have potential for use as coating materials in biomedical applications.

Thermal management of Li-ion batteries in electric vehicles by nanofluid-filled loop heat pipes

An analytical model is developed to determine the thermal performance of a Loop Heat Pipe filled (LHP) with copper oxide–water and alumina–water nanofluids for battery thermal management in electric vehicles. The thermal performances of the LHP are predicted for different heat loads and nanoparticle concentrations. It is demonstrated that for fast charging operation corresponding to a heat load of 150 W, the LHP ensures evaporator temperatures of less than 60 °C for a heat sink temperature of 40 °C. The heat transport capacity of the LHP is enhanced and the evaporator temperature is deceased by augmenting the nanoparticle concentration. The water–CuO nanofluid-filled LHP performs better than the water–Al2O3 nanofluid-filled one. The addition of the nanoparticles increases the LHP total pressure drop and the driving capillary pressure. The capillary limit of the water–CuO nanofluid-filled LHP is hardly affected by CuO nanoparticle concentration until 6% beyond which the capillary limit starts decreasing. For the water–Al2O3 nanofluid-filled LHP, the capillary limit decreases when Al2O3 nanoparticle concentration increases. Beyond 6% Al2O3 nanoparticle concentration, the capillary limit of the Al2O3-filled LHP becomes lower than the water-filled one.

Exploring the anticancer potency and photocatalytic efficiency of bio-derived CuO nanoparticles using Moringa oleifera leaf extract

Copper Oxide nanoparticles (CuO NPs) were synthesized by a simple one-pot synthesis process using leaf extract from Moringa oleifera. A range of analytical methods were utilized to examine the physicochemical characteristics of CuO NPs in their prepared state. The existence of CuO nanoparticles is strongly suggested by the finding of a maximal absorption peak at 293 nm, which was then used to calculate the band gap energy (3.82 eV). The produced CuO NPs had a d-spacing value of 0.215 nm and an assessed crystalline size of approximately 21 nm, indicating good crystallinity. The EDAX spectrum confirms that the produced CuO NPs have a clearly aggregated structure and remarkable elemental purity. These data compellingly demonstrate the effectiveness of our preparatory strategy. Additionally, MCF7 and A549 breast and lung cancer cells were used to test the produced CuO NPs' potential for in vitro anticancer activities. These results demonstrated that different concentrations of CuO nanoparticles exhibited significant and proportionate toxicity toward the evaluated cell lines, underscoring its potential as an effective cancer-fighting strategy. Additionally, under UV light, the as-prepared CuO NPs were used to break down the dyes malachite green (MG) and titan yellow (TY). According to the present results, there was a discernible degree of degradation of 84.7 % and 79.03 % for MG and TY, respectively in basic medium at the 140th and 110th minute. The alignment of first order and 0th order kinetics for MG and TY dyes, respectively, was confirmed when the obtained data were later further examined for the reaction kinetic studies. In addition to being a powerful tool for developing novel treatments for lung and breast cancer, the produced CuO NPs can also be used to break down dangerous cationic and anionic dyes.

Changes in the mitochondrial function of fibroblast-like cells exposed to copper oxide nanoparticles

Introduction. Mitochondria are targets for almost all types of damaging agents, including toxins and oxidative stress. There is no doubt that possible effects on mitochondria should be taken into account in a comprehensive assessment of metal toxicity. Our objective was to establish changes in the mitochondrial function under the effect of copper oxide nanoparticles in vitro.
 Material and methods. A monolayer culture of human lung fibroblast-like cells of the FLECH-104 line were exposed to copper oxide nanoparticles (CuO NPs) 21±4 nm in size, final concentrations of which in the media were 25, 50, and 100 μg/mL. We measured the rate of oxygen consumption by the cells and its changes under the influence of modulators, such as oligomycin, carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone, and rotenone combined with antimycin A. We estimated parameters of mitochondrial function and the bioenergetics index.
 Results. At the concentration of 100 μg/mL in the incubation medium, CuO NPs induced changes in the culture of fibroblast-like cells that impeded further assessment of the mitochondrial function. At the lower concentrations of 25 and 50 μg/mL, we observed a dose-dependent trend toward a decrease in ATP-related respiration and bioenergetics index. It is noteworthy that the concentration of 25 μg/mL increased the maximum and reserve respiratory capacity of the cells, which was probably related to the dual effect of copper as a toxicant and an essential element.
 Limitations of the study. The study was conducted using only one cell line and three concentrations of CuO nanoparticles suspended in the culture medium.
 Conclusion. We established that copper oxide nanoparticles, when added to the incubation medium, have a multidirectional effect on the mitochondrial function of fibroblast-like cells potentially attributed to biotic properties of this metal.

Tailoring the rheological properties of biosynthesized Copper oxide nanoparticles decorated Carboxymethyl cellulose hydrogels for biomedical applications

Nanoparticle-decorated hydrogels have seized substantial momentum in recent years, exclusively in biomedical research. In this investigation, Copper oxide nanoparticles decorated carboxymethyl cellulose hydrogels were prepared in an eco-friendly approach without using toxic cross-linkers. Initially, Copper oxide nanoparticles were prepared by biosynthesis approach to diminish the harmful effects of chemicals and to improve the biological activities using the leaf extract of Justicia adhatoda. The prepared nanoparticles were incorporated into the Carboxymethyl solution and carbopol to form a hydrogel by non-covalent interactions. X-ray diffraction analysis of CuO nanoparticles revealed a monoclinic crystalline structure without impurity. Rheological investigation of the pure hydrogel and CuO-decorated hydrogels revealed that CuO contributed to the enhancement of the hydrogel's mechanical performance. All the hydrogels demonstrated shear thinning behavior and better flow behavior index with the addition of CuO nanoparticles. The yield stress of the hydrogels was improved and found to be in the range of 61–79 Pa, which matches the ideal yield stress values in transdermal drug delivery. Storage moduli of hydrogels as a function of frequency was doubled (14–47.5 Pa), endorsing the involvement of CuO nanoparticles in crosslinking the polymeric matrix. Temperature and time sweep measurements revealed that the stability of the hydrogels also improved with the addition of CuO nanoparticles. The antibacterial activity of the hydrogels was evaluated using biofilm inhibition and showed better inhibition of 70 ± 0.5%, 75 ± 0.9%, 86 ± 0.8%, and 83 ± 0.8% against Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, and Enterococcus faecalis, respectively with increased concentration of CuO nanoparticles. The cell viability of the CuO-decorated hydrogels against MCF-7 and A431 was found to be 39% and 42%, respectively. Therefore, the eco-friendly biosynthesized CuO nanoparticles decorated hydrogels with improved mechanical properties can be employed in injectable and transdermal drug delivery systems.

Optimizing geometrical structure of a residential parabolic solar collector relying on hydrothermal assessment and second law analysis

Researchers are interested in the optimization of thermal systems due to the rising demand towards renewable and green energy to reduce greenhouse gasses and expenses. To achieve this, the present work aims to conduct the numerical modeling on the residential scale trough solar collector. For this purpose, the lattice Boltzmann method is employed with special treatment for the curved physical boundaries. To enhance the thermal capability of the solar collector, the CuO-water nanofluid is utilized, which its thermal conductivity is estimated using Koo–Kleinstreuer and Li (KKL) model. Furthermore, the Brownian motion effect on the dynamic viscosity is taken into account. In addition, the local and volumetric second law analysis is performed. Besides, the heat line visualization is done to capture the path-line of heat energy within the solar collector. The thermal distribution, flow field, local entropy production (i.e. fluid friction irreversibility and heat transfer irreversibility maps), volumetric entropy generation, Bejan number, and average Nusselt number are the studied items in terms of the governing parameters. The Rayleigh number (103 ≤ Ra ≤ 106), CuO nanoparticle concentration (φ = 0, 0.01, 0.02, 0.03, 0.04) and four structural design of the solar collector (Single-pipe, Double-pipe, Triple-pipe, Quadruple-pipe) are assumed as the governing parameters.

Optimization of heat pipe charged with CuO nanofluid using Taguchi technique

Aim of this study is to investigate the influence of various working parameters on the performance of thermosyphon heat pipe, charged with aqueous copper oxide nanofluid. This heat pipe was used as an absorber in twin glass evacuated tube solar collector for heating edible oil stored in an insulated tank. Design of experiments was formulated using minitab™ 19 considering prominent heat pipe working parameters like CuO nanoparticle concentration, CuO nanoparticle size, copper heat pipe diameter, filling ratio, stirring speed and surfactant concentration and their levels through research gaps. Experiments were performed on clear sunny days and impact of parameters on heat pipe solar collector performance was examined using Main effect plot, signal to noise (S/N) ratio and ANOVA. From response table of signal to noise ratio and the ANOVA results, it is concluded that the nanoparticle concentration, nanoparticle size, filling ratio and stirring speed plays important role in heat pipe performance improvement while other parameters like heat pipe diameter and surfactant concentration are less significant. Thus Optimum levels of parameters for best heat pipe solar collector performance were obtained as, nanofluid concentration of 0.3 (% weight), nanoparticle size of 30–50 nm, 8 mm of heat pipe diameter, 45 % of filling ratio, stirring speed of 1200 rotations per minute while preparing nanofluid and surfactant mixing in nanofluid as 0.3 (% volume).

Transcriptomic profiling reveals differential cellular response to copper oxide nanoparticles and polystyrene nanoplastics in perfused human placenta

The growing nanoparticulate pollution (e.g. engineered nanoparticles (NPs) or nanoplastics) has been shown to pose potential threats to human health. In particular, sensitive populations such as pregnant women and their unborn children need to be protected from harmful environmental exposures. However, developmental toxicity from prenatal exposure to pollution particles is not yet well studied despite evidence of particle accumulation in human placenta. Our study aimed to investigate how copper oxide NPs (CuO NPs; 10–20 nm) and polystyrene nanoplastics (PS NPs; 70 nm) impact on gene expression in ex vivo perfused human placental tissue. Whole genome microarray analysis revealed changes in global gene expression profile after 6 h of perfusion with sub-cytotoxic concentrations of CuO (10 µg/mL) and PS NPs (25 µg/mL). Pathway and gene ontology enrichment analysis of the differentially expressed genes suggested that CuO and PS NPs trigger distinct cellular response in placental tissue. While CuO NPs induced pathways related to angiogenesis, protein misfolding and heat shock responses, PS NPs affected the expression of genes related to inflammation and iron homeostasis. The observed effects on protein misfolding, cytokine signaling, and hormones were corroborated by western blot (accumulation of polyubiquitinated proteins) or qPCR analysis. Overall, the results of the present study revealed extensive and material-specific interference of CuO and PS NPs with placental gene expression from a single short-term exposure which deserves increasing attention. In addition, the placenta, which is often neglected in developmental toxicity studies, should be a key focus in the future safety assessment of NPs in pregnancy.

Influence on tensile and yield strength in composites of heat-treated AA6463 alloy by copper oxide nano particles

The strength-to-weight ratio provided by AA6XXX alloys and their improved mechanical characteristics have emerged as key requirements for their use in light weight military vehicles, rockets, missiles, aircrafts, and cars, employed for both defense and civil purpose. The effects of the alloying elements that are often utilized for forged AA6XXX alloys are addressed while taking into account their interactions. We address the importance of alloying as well as processing to generate certain qualities and the underlying strengthening mechanisms. These AA6XXX alloys are often and effectively used in structural applications for both civil and military purposes. In this experimental investigation mainly focused on ultimate tensile strength and yield strength variations in AA6463 alloy by Copper oxide (CuO) nanoparticle. There are five composites of aluminium alloy and CuO nano particle combinations were created by stir casting method for the comparison with the individual AA6463 alloy specimen. Cuo nano particle concentration increased from 2% to 10% with 2% of variation in volume of material basis in the composite. Individual specimens were prepared and tested as per standards. 94 % of AA6463 with 6% of CuO nano particle mixed composite have the greatest tensile and yield strength among the composites in this investigation.

Structural and optical properties of polyvinyl alcohol/copper oxide (PVA/CuO) nanocomposites

In the present investigation, pristine polyvinyl alcohol (PVA) and copper oxide (CuO) incorporated nanocomposite films have been fabricated via simple solution cast technique. The structural and optical properties of the prepared films were studied in detail. Various concentrations of CuO NPs (0.1–0.4 wt %) incorporated in the PVA film were prepared. The X-ray diffraction (XRD) profiles indicate the presence of CuO nanoparticles (NPs) in PVA film. XRD results indicate that, the CuO NPs were successfully incorporated into the PVA host matrix with no additional impurity peaks. The obtained CuO NPs belong to the monoclinic phase as confirmed by the XRD results. The peak observed at 2θ = 19.4° evident for the formation of semi crystalline PVA polymer. The average crystallite size of the prepared NPs was observed to be ∼0.52 nm. The vibrational bands present in the prepared films were confirmed by the Fourier transform infra-red spectroscopy (FTIR) plots. The presence of the NPs in the films was further investigated with the help of Raman spectra. UV–visible optical absorption spectra was recorded to evaluate the band gap values of the prepared films. The band gap value for pristine PVA was found to be 5.35 eV and it decreases with increase of CuO NPs concnetration owing to the change in the electronic structure of the pure PVA. The dielectric properties were also evaluated and it was found that, with increase in the CuO NPs concentration the dielectric constant also increases owing to the increase in density of states leading to the formation of polarization. The optical conductivity of the prepared nanocomposites increases with increase in the NPs concentration due to the formation of the charge transfer complex. The obtained results reveal that, the addition of CuO NPs reduces the optical band gap of the PVA polymer films.

Experimental investigation of viscosity and thermal conductivity of ethylene glycol/water nanofluid containing low volume concentration of CuO nanoparticles, MWCNT and their mixture

Thermal conductivity and viscosity of CuO/ethylene glycol/water, multi walled carbon nanotubes (MWCNT)/ethylene glycol/water and CuO/MWCNT/ethylene glycol/water nanofluid systems were determined experimentally at temperature range of 5 to 50oC and very low concentration (less than 0.008 vol.%). The obtained results show that the thermal conductivity of nanofluids significantly increases with increasing nanofluid temperature. It is also verified that the enhancement in thermal conductivity of nanofluid systems containing mixed CuO/MWCNT is more than systems containing CuO or MWCNT individually. Analyses of the viscosity data indicate that the viscosity diminishes with increasing temperature. The higher concentrations of all nanofluid systems possess higher viscosity. The results also show that the viscosity of nanofluid systems containing mixed CuO/MWCNT is between the viscosities of the systems containing CuO and MWCNT individually.

Assessment of the Tolerance of a Chlorophyte Desmodesmus to CuO-NP for Evaluation of the Nanopollution Bioremediation Potential of This Microalga.

Broad application of CuO nanoparticles (CuO-NP) for industrial and household purposes leads to a continuous increase in their discharge to, and, hence, ever-increasing environmental hazards for aquatic ecosystems. Microalgae-based technologies hold promise for bioremediation of diverse hazardous micropollutants (HMP), including NP, from wastewater. In this study, we tested the ability of the green microalga Desmodesmus sp. to accumulate CuO-NP or their components. We also assessed the tolerance of this microalga to the environmentally relevant concentrations of CuO-NP. Using scanning electron microscopy, we demonstrated that the average size of CuO-NP was 50-100 nm, and their purity was confirmed with elemental composition analysis. Tests of the colloidal suspensions of CuO-NP showed that the hydrodynamic diameter of CuO-NP and their aggregates was below 100 nm. Flow cytometry analysis showed that CuO-NP at a concentration of 100 µg L-1 slightly inhibited the viability of microalgae cells and led to an increase in their oxidative stress. The assessment of the condition of photosystem II showed that CuO-NP exert a multifaceted effect on the photosynthetic apparatus of Desmodesmus sp., depending on the concentration of and the exposure to the CuO-NP. Desmodesmus sp. turned to be relatively tolerant to CuO-NP. In addition, the ICP-MS method revealed increased bioaccumulation of copper by microalgae cells in the experimental groups. The outcomes of this study indicate that the Desmodesmus sp. has a significant potential for bioremoval of the copper-based nanostructured HMP from an aquatic environment.

CuO Nanoparticle-Mediated Seed Priming Improves Physio-Biochemical and Enzymatic Activities of Brassica juncea.

The use of nanoparticles (NPs) in agricultural fields has risen to a level where people are considering NPs as an alternative to commercial fertilizers. The input of copper oxide NPs (CuO NPs) as seed primers was investigated in this study, and the growth indices of Brassica juncea such as phenotypic parameters, photosynthetic attributes, and biochemical parameters were measured during maximum vegetative growth stage, i.e., at 45 days after sowing. Surface sterilized seeds were soaked in varying concentrations (0, 2, 4, 8 and 16 mg/L) of CuO NPs for 15, 30, and/or 45 min. After those priming periods, the seeds were planted in pots and allowed to grow naturally. Among the different tested concentrations of CuO NPs, 4 mg/L of CuO NPs for 30 min seed priming proved to be best, and considerably increased the, shoot length (30%), root length (27%), net photosynthetic rate (30%), internal CO2 concentration (28%), and proline content (41%). Besides, the performance of the antioxidant enzymes, viz, superoxide dismutase, catalase, peroxidase, and biochemical parameters such as nitrate reductase and carbonic anhydrase were also increased by several folds after the application of CuO NPs in B. juncea. The present study suggests that CuO NPs can be effectively used to increase the performance of B. juncea and may also be suitable for testing on other crop species.

Photocatalytic degradation of metronidazole (MNZ) antibiotic by CuO nanoparticles for environmental protection from pharmaceutical pollution

Metronidazole (MNZ) is one of the extensively consumed generic antibiotics, which, due to its high resistance to biological degradation, is considered a potent environmental contaminant. In this study, we use CuO nanoparticles (NPs) for photocatalytic degradation of MNZ. Photocatalytic NPs with a crystallinity of over 80% were synthesized using a facile co‐precipitation method followed by calcination at a temperature of 500°C for a duration of 1 h. NPs were characterized thoroughly to investigate their opto‐structural properties. We investigated the efficiency of photocatalytic degradation with the variation of MNZ concentration, NP loading and the pH of the MNZ solution. Experimental results revealed that the pH of the MNZ solution strongly controlled the photocatalytic degradation efficiency. As pH was increased from 7 to 11, the degradation rate was enhanced remarkably. Degradation efficiency was also found to be strongly dependent on the concentration of both MNZ solution and CuO NPs.

Use of response surface methodology approach for development of sustainable Jojoba biodiesel diesel blend with CuO nanoparticles for four stroke diesel engine

This study focuses primarily on the optimization of performance parameters, namely Brake thermal efficiency (BTE), Brake power (BP) and emission characteristics, namely Hydrocarbon (HC), carbon monoxide (CO) and oxides of nitrogen (NOX) emissions of a diesel engine fuelled with jojoba biodiesel-diesel blend with copper oxide (CuO) nanoparticles dispersed into it with different concentrations of 25, 50, 75 and 100 ppm. Variables such as blend (%), nanoparticles concentration (ppm), fuel injection pressure (bar) and Load (kg) are considered as input parameters. A series of experiments are designed under the central composite rotatable design (CCRD) approach considering 4 input factors each with 5 levels. A nonlinear RSM model is developed between the response and input variables based on the interaction plots. The model is validated by regression coefficient of R2, Adj. R2and Pred. R2which shows satisfactory results.Based on the desirability approach the model retrieve the best combination of input factors as 7.45 kg engine load, 16.76 % mixing of jojoba biodiesel with diesel, 209.89 bar fuel injection pressure, and CuO nanoparticles concentration of 76.76 ppm. After RSM optimization, target values of engine responses (BTE, BP, CO, HC, and NOx) are 27.18 %, 2.5582 kW, 0.1981 % volume, 24.5720 ppm, and 710.9470 ppm, respectively. When the results of the optimization process were compared to the experimental results, the deviations were found to be within the acceptable range of errors which establish the robustness of RSM model.

Low-Temperature Industrial Waste Heat (IWH) Recovery Using a New Design for Fast-Charging Thermal Energy Storage Units

The dynamic melting of CuO–coconut oil was addressed in a latent-heat thermal energy storage unit loaded with copper foam. In a new design, the thermal storage unit is made of a shell-tube-shaped chamber, in which a liquid flow of hot phase-change material (PCM) is allowed to enter the chamber from a port at the bottom and exit at the top. A fin is mounted in the chamber to forward the entrance PCM liquid toward the solid regions. The control equations were solved using the finite element method. The impact of foam porosity, inlet pressure, fin length, and the concentrations of CuO nanoparticles on the thermal charging time of the chamber was investigated. A fast-charging time of 15 min with a foam porosity of 0.95 was achieved. A porosity of 0.95 can provide a maximum thermal charging power of 15.1 kW/kg. The inlet pressure was a significant parameter, and increasing the inlet pressure from 0.5 kPa to 4 kPa reduced the melting time by 2.6 times. The presence of the fin is not advantageous, and even a long fin could extend the thermal charging time. Moreover, dispersed nanoparticles were not beneficial to dynamic melting and extended the thermal charging time.

Enhancement of Natural Convection Heat Transfer Using Magnetic Nanofluid in a Square Cavity

Researchers in heat transfer are paying close attention to nanofluids because of their potential as high-performance thermal transport media. In light of natural convection's enormous significance, the addition of nanoparticles significantly enhances the thermophysical properties of the nanofluids compared to the base fluid. In this study, numerical work was used to evaluate the influence of CuO nanoparticles on natural convection with the magnetohydrodynamic (MHD) flow in a square cavity. The hollow's left and right vertical walls were maintained at different temperatures, and the top and bottom walls of the cavity were each insulated. This numerical study applied a horizontal magnetic field with uniform strength. Results were obtained for a variety of Hartmann numbers ranging from 0–300, Rayleigh numbers going from 2.76E+8 to 6.89E+8, and solid volume fractions ranging from 0 to 1.5%. Results showed that the heat transfer coefficient and Nusselt number values decreased with the increase in the values of the Hartmann number, except for the heat transfer coefficients at Ha=100 and 150 were larger than the heat transfer coefficients at Ha= 0. The maximum heat transfer coefficient enhancement was 40.8% at 1.5% volume concentration of CuO nanoparticles, Ra= 6.7E+8 and Ha=100 compared to water at Ha=0. The maximum enhancement of the Nusselt number was found to be 28.5% at a 1.5% volume concentration of CuO nanoparticles Ra= 6.7E+8 and Ha=100 compared to water at Ha=0. At a 1.5% volume concentration of CuO nanoparticles, Ra= 6.7E+8 and Ha=100, the increase in the heat transfer coefficient was 56 %, and the rise in the Nusselt number was 43 % compared to water at Ha=100.

Mitotic effects of copper oxide nanoparticle on root development and root tip cells of Phaseolus vulgaris L. seeds.

Copper oxide nanoparticle (CuO NP) is used widely in many fields in nanotechnology. For this reason, both production, use, and release to the environment are increasing with each passing day. With the increased use of products that contain nanoparticles (NP) (<100 nm), plants and organisms that constitute the food chain are at risk. In the present study, Phaseolus vulgaris L., a very common food plant, was exposed to metal-based CuO NPs. The anomalies that were caused by CuO NP in germination and mitosis of P. vulgaris were investigated. In the trials, a total of 4 groups (Control, 50, 150, and 300 ppm) were formed and examined in three replications. The determination of the accumulation and elimination rate because of NPs in P. vulgaris that was used in the study was made through X-ray diffraction (XRD), scanning electron microscope (SEM), mapping image, and EDX characteristic spectrum analysis. Also, the mitotic effects on germination, root development, and root tip cells of seeds that were grown by treatment with control, 50, 150, and 300 ppm concentrations were investigated. The study was conducted in three replications in a laboratory setting. All concentrations of CuO NPs caused significant decreases in the mitotic index in the root tip cells of P. vulgaris when compared to the control. The mitotic index reached the lowest level, especially at the highest concentration. Multiple analyzes in the study showed that CuO NPs cause abnormalities in cell division such as C-metaphase, distorted metaphase, distorted anaphase and telophase, chromosome breakage, asynchronous division, advanced chromosomes, micronucleus, and loss of genetic material. These findings also support that the Cytogenetic Test of P. vulgaris can be used to evaluate the genotoxicity of new nanomaterials that are used in many consumer products. In this respect, NPs that are taken up by the organisms in the food chain may pose a danger to higher consumer organisms when they accumulate in the tissue. A control mechanism must be established for the use and contamination of these particles and wider studies must be conducted regarding their effects. HIGHLIGHTS: The effects of CuO nanoparticle, which has a very wide usage area, on root development and mitosis of Phaseolus vulgaris L. plant were investigated in the study. The abnormalities of mitotic division on interphase, prophase, metaphase, anaphase, and telophase were visualized. Evaluation was made considering scanning electron microscopy (SEM) and X-ray diffraction (XRD) results as well.