Concentration Of Nanoparticles Research Articles

Chitosan and Hyaluronic Acid Nanopolyelectrolyte Combined with Tanshinone IIA Targets Signal Transduction Pathway to Prevent Atherosclerosis

The purpose of this study was to evaluate the in vitro target impact of manufactured nanocarriers on vascular endothelial cells, as well as the effect of stable concentration and physicochemical properties of chitosan and hyaluronic acid nanoparticles loaded with tanshinone IIA, on the successful adsorption of targeting antibody. Polyelectrolyte composite nanoparticles were prepared by neutralizing chitosan (CS) and hyaluronic acid (HA). Anti-atherosclerosis antibody was quantitatively adsorbed on CS-HA nanoparticles after 4 h in water or PBS. Nanocarriers created in a lab are put through in vivo and in vitro tests on vascular endothelial cells and atherosclerotic plaques. Complexation and physicochemical properties of colloids were affected by external factors including charge mixing ratio and polymer content. The aforementioned method was used to produce non-stoichiometric CS-HA nano-colloids that were stable in water or PBS (pH 7.4) for over a month. Its morphology was analyzed using a scanning electron microscope. Nanoparticles of the CS-HA/CD47 antibody have a positive Zeta potential. Using this nanocarriers in vivo adsorbed to endothelial cells and plaques quite efficiently. Chitosan and hyaluronic acid nanopolyelectrolyte combined with tanshinone IIA nanoparticles were successfully synthesized. Customized nanocarriers may adsorb to endothelial cell lines and atherosclerotic plaques in vitro.

Heat and mass transfer analysis for bi-dimensional bioconvective MHD nanofluid with varying thermal traits

ABSTRACT Bioconvection phenomena offer practical applications in biomicrosystems, fuel cells, biosensors, biocomputing, electronic thermal management, and renewable energy systems, showcasing their relevance and potential impact across various engineering sectors. Consequently, this study delves into the examination of a bi-dimensional magnetohydrodynamic nanofluid flow model encompassing the intricate dynamics of gyrotactic microorganisms, subject to the effects of suction and thermal radiation. The primary objective of the investigation is to optimize the thermal energy transfer efficiency of the fluid while concurrently minimizing associated costs, with the secondary aim of diminishing the frictional resistance at the fluid-solid interface. The basis for energy and momentum equations incorporating radiation using Rosseland’s approximation is established by the Buongiorno nanofluid model. The foundational PDEs along with their BCs, are reformulated into ODEs utilizing similarity variables, then transformed into a set of first-order ODEs ensuring compatibility with MATLAB’s bvp4c solver, which offers high convergence rates and accuracy due to its efficient algorithms and precision handling. Heat transfer rate boosts up by increasing suction and radiation parameters, while it dwindles due to an increase in the magnetic field. Enhancing suction and the magnetic field lowers skin friction. Microbial concentration surges by increasing the magnetic field, while suction minimizes it. Intensifying the thermophoresis parameter increases the concentration of nanoparticles.

Ecotoxicological assessment of UV filters benzophenone-3 and TiO2 nanoparticles, isolated and in a mixture, in developing zebrafish (Danio rerio)

ABSTRACT The increasing use of UV filters, such as benzophenone-3 (BP-3) and titanium dioxide nanoparticles (TiO2 NPs), has raised concerns regarding their ecotoxicological effects on the aquatic environment. The aim of the present study was to examine the embryo-larval toxicity attributed to BP-3 or TiO2 NPs, either alone or in a mixture, utilizing zebrafish (Danio rerio) as a model after exposure to environmentally relevant concentrations of these compounds. Zebrafish embryos were exposed to BP-3 (10, 100, or 1000 ng/L) or TiO2 NPs (1000 ng/L) alone or in a mixture (BP-3 10, 100, or 1000 ng/L plus 1000 ng/L of TiO2 NPs) under static conditions for 144 hr. After exposure, BP-3 levels were determined by high-performance liquid chromatography (HPLC). BP-3 levels increased in the presence of TiO2 NPs, indicating that the BP-3 degradation decreased in the presence of the NPs. In addition, in the presence of zebrafish, BP-3 levels in water decreased, indicating that zebrafish embryos and larvae might absorb BP-3. Data demonstrated that, in general, environmentally relevant concentrations of BP-3 and TiO2 NPs, either alone or in a mixture, did not significantly induce changes in heart and spontaneous contractions frequencies, levels of reactive oxygen species (ROS), morphological and morphometric parameters as well as mortality rates during 144 hr exposure. However, the groups exposed to TiO2 NPs alone and in a mixture with BP-3 at 10 ng/L exhibited an earlier significant hatching rate than the controls. Altogether, the data indicates that a potential ecotoxicological impact on the aquatic environment exists.

The enhanced photocatalytic performance of CPAA doping with different concentrations of Titanium oxide nanocomposite against MB dyes under simulated sunlight irradiations

The pure conjugated polyarylene azomethine (CPAA) and its nanocomposites (CPAA-TiO2) with different concentrations of TiO2 nanoparticles were successfully prepared by in-situ technique and analyzed by different advanced techniques. XRD has confirmed the structural properties and crystallinity of (CPAA) and nanocomposites. The SEM clearly shows that the (CPAA) is uniform and homogeneous, with tightly connected aggregate layers in shape. However, the amount of TiO2 in the nanocomposites greatly affects their morphology, revealing structural differences and indicating a reaction between (CPAA) and TiO2, especially at a higher concentration of 5% TiO2. A new composite of (CPAA) was introduced and the photocatalytic effect for MB was studied. The removal efficiency of (pure-CPAA) over MB dye under simulated sunlight was 62%. However, (CPAA-TiO2 1%) destroyed 90% of MB dyes. It was discovered that the low band gap of (CPAA-TiO2 1% (2.84 eV)) accelerates high electron–hole recombination, increasing photocatalytic activity.

Experimental study of preparing the CoFe2O4 magnetic nanofluid and measuring thermal-fluid characteristics of the stabilized magnetocaloric nanofluid

The purpose of this study was to examine the rheological features of CoFe2O4 superparamagnetic nanoparticles dispersed in water-ethylene glycol (EG) coolant as the basis fluid. The experiments are carried out at temperatures between 10 and 50 degrees Celsius, with five mass fraction concentrations of magnetocaloric nanofluid as well as different shear rates. The solvothermal-produced cobalt ferrite metallic compounds are disseminated in EG-water (50:50) coolant. Evaluation of functional groups and organic compounds, the crystal structure of spinel ferrite, the size and morphology of nanoparticles, and the specific surface area, respectively, were carried out. For the developed magnetocaloric nanofluid, shear rate variation illustrates the non-Newtonian behavior of Bingham plastic. The results show that increasing the mass concentration of nanoparticles from 0.05 % to 0.8 % results in about 80 % increase in viscosity at 10 °C. Additionally, thermal conductivity has increased to a maximum of 9.4 % at 50 °C and is improved by increasing temperature.

Precision individual dosimetry in Yttrium-90 transarterial radioembolization in the presence of Au nanoparticles

Individual post-treatment dosimetry plays a crucial role in assessing the effectiveness of Y-90 transarterial radioembolization (TARE) treatment. Y-90 positron emission tomography (PET) imaging is widely regarded as the gold standard for post-TARE dosimetry. However, a major limitation of Y-90 PET imaging is the low positron yield of Y-90. This study aimed to address this limitation and improve individual dosimetry using Au nanoparticles (NPs)-induced pair production in Y-90 PET imaging. The GATE Monte Carlo platform was used to simulate post-TARE PET imaging. The study examined five levels of Au NP concentration in the liver tumor: 1%, 5%, 10%, 15%, and 20% by weight. The quality of the acquired PET images was evaluated by calculating the signal-to-background ratio (SBR) and contrast-to-noise ratio (CNR). The errors in PET-based dose volume histograms (DVHPET-based) and reference dose volume histograms (DVHrefrence) were evaluated through various metrics, including root-mean-square error (RMSE), mean absorbed dose (Dmean), and maximum absorbed dose (Dmax). The results showed that as the concentration of Au NPs increased in the tumor, the CNR and SBR values also increased. At concentrations 5 wt% and above, the difference in the values of Dmean and Dmax obtained from the reference dosimetry and PET-based dosimetry is less than 5%. The calculated RMSE values indicated that concentrations 5 wt% and above exhibited acceptable agreement between the DVHPET-based and DVHrefrence. When the concentration of Au NPs increases up to 5 wt%, the presence of Au NPs within the tumor does not significantly affect the Dmean. Conversely, with the presence of Au NPs, at concentrations of 10, 15, and 20 wt%, the Dmean within the tumor experiences reductions of approximately 6%, 10%, and 14%, respectively. The pair production was induced by simultaneously injecting Y-90 and Au NPs into the tumor. Our study demonstrated that dosimetry accuracy in TARE improved through induced positron PET imaging. As a consequence of the dose reduction phenomenon observed upon introducing Au NPs into the tumor, the optimal concentration of Au NPs for enhancing dosimetric precision was determined to be 5 wt%.

Effect of Graphene Oxide Incorporation on the Strength of Denture Repair Resin

To evaluate the effect of incorporating graphene oxide nanoparticles (GO NPs) and graphene sheets on the flexural strength of an auto-polymerized (AP) acrylic resin-repaired denture. 60 heat-activated (HA) resin specimens were fabricated and randomly divided into 6 groups (n = 10). The specimens in Group I were kept intact. 50 specimens were cut into two parts with a 45-degree bevel. Group II specimens were repaired with AP resin and Group III specimens were repaired with HA resin. In the repair of Group IV, Group V, and Group VI specimens, 1%, 2% GO NPs, and graphene sheets were added to AP resin, respectively. A 3-point bending test with a universal test device measured the flexural strength. Statistical analyses of the results were performed with the Kruskal Wallis H-test. (α = 0.05) The flexural strength of Group I (130.05 ± 20.20 MPa) was the highest among all groups. The flexural strength of Group IV (67.49 ± 12.70 MPa) was significantly higher than Group V (50.87 ± 15.02 MPa) and Group VI (44.77 ± 10.70 MPa). The lowest strength value was obtained in Group VI. Adding 1% GO NPs to AP acrylic resins increases flexural strength. However, the increase in nanoparticle concentration and the addition of graphene sheets negatively affect strength.

Effects of particle size on toxicity, bioaccumulation, and translocation of zinc oxide nanoparticles to bok choy (Brassica chinensis L.) in garden soil

The indiscriminate use of zinc oxide nanoparticles (ZnO NPs) in daily life can lead to their release into soil environment. These ZnO NPs can be taken up by crops and translocated to their edible part, potentially causing risks to the ecosystem and human health. In this study, we conducted pot experiments to determine phytotoxicity, bioaccumulation and translocation depending on the size (10 – 30 nm, 80 – 200 nm and 300 nm diameter) and concentration (0, 100, 500 and 1000 mg Zn/kg) of ZnO NPs and Zn ion (Zn2+) in bok choy, a leafy green vegetable crop. After 14 days of exposure, our results showed that large-sized ZnO NPs (i.e., 300 nm) at the highest concentration exhibited greater phytotoxicity, including obstruction of leaf and root weight (42.5 % and 33.8 %, respectively) and reduction of chlorophyll a and b content (50.2 % and 85.2 %, respectively), as well as changes in the activities of oxidative stress responses compared to those of small-sized ZnO NPs, although their translocation ability was relatively lower than that of smaller ones. The translocation factor (TF) values decreased as the size of ZnO NPs increased, with TF values of 0.68 for 10 – 30 nm, 0.55 for 80 – 200 nm, and 0.27 for 300 nm ZnO NPs, all at the highest exposure concentration. Both the results of micro X-ray fluorescence (μ-XRF) spectrometer and bio-transmission electron microscopy (bio-TEM) showed that the Zn elements were mainly localized at the edges of leaves exposed to small-sized ZnO NPs. However, the Zn elements upon exposure to large-sized ZnO NP were primarily observed in the primary veins of leaves in the μ-XRF data, indicating a limitation in their ability to translocate from roots to leaves. This study not only advances our comprehension of the environmental impact of nanotechnology but also holds considerable implications for the future of sustainable agriculture and food safety.

Synthesis of silver nanoparticles embedded on silica by gamma irradiation for utilization as antimicrobial agents

Silver nanoparticles deposited on silica (Ag nano/SiO2) have been prepared by Co-60 gamma irradiation of the mixture Ag+/SiO2/H2O/ethanol. The reduction of Ag+ in the suspension of SiO2 is brought by e-aq and H· generated during the radiolysis of water/ethanol solution. The presence of SiO2 prevents agglomeration of Ag clusters. The conversion dose (Ag+® Ag0) was determined by UV-Vis spectroscopy. Transmission electron microscopy (TEM) characterized the size of Ag nanoparticles. As a result, the particle sizes were determined to be in the range of 5-20 nm for an Ag+ concentration of 5 mM. The crystal structure of silver nanoparticles was also investigated by X-ray diffraction (XRD). In addition, the antifungal activity of Ag nano/SiO2 was tested against Aspergillus niger var Tieghn by plate count method. The results indicated that the antifungal efficiency of Ag nano/SiO2 was about 64, 71, 81, 82, and 96% at the concentrations of Ag nanoparticles of 30, 50, 70, 100, and 150 ppm, respectively.

On the accuracy bounds of high-order image correlation spectroscopy

High-order image correlation spectroscopy (HICS) or related image-based cumulant analysis of emitter species are important for identifying properties and concentrations of biomolecules or nanoparticles. However, lack of a thorough parameter space test limits its use in full potential. The current study focused on mapping accuracy bounds of bimodal species concentration space by simulating and analysing more than 2 × 105 images (∼1011 data points). Concentration space maps for four values of quantum yield contrast ratio between two species in a mixture and two sampling spaces (834 and 13357 beam areas in an image) were created, which showed clear accuracy bounds governed by two factors, Poisson fluctuation and quantum yield ratio. Typically, brighter species concentration was 1-3 orders of magnitude lower than that of dimmer species, and higher brightness contrast allowed higher concentration difference. Upper limit of accuracy bounds was governed by resolvable Poisson fluctuation, where this condition was violated for emitter density beyond 10 particles per beam area. The accuracy bounds are shown to be largely invariant under noise correction or the calculation method, and are compared against previous experimental results, showing consistent agreement. This study shows that concentration limit needs to be observed when using HICS or related image moment or cumulant analysis techniques. As a rule of thumb, a large quantum yield contrast and large sampling points allow more concentration difference between two species to be resolved in an analysis.

Green nanoparticles blending with polyacrylonitrile ultrafiltration membrane for antifouling oily wastewater treatment

This work prepares novel polyacrylonitrile (PAN) membranes by incorporating eggplant waste (EGW) as eco-friendly green nanoparticles (NPs) with PAN membranes to enhance the antifouling of PAN membranes to separate oil from oily wastewater (OWW). The modified PAN membranes are characterized by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FE-SEM), and measurements of the contact angle, porosity, and mechanical properties. The effect of EGW NPs content on membrane properties and morphology, its entire performance, and its antifouling characteristics is investigated. The performance of the PAN-EGW membranes is evaluated by pure water flux and oil rejection. The PAN membrane incorporated with 0.1 wt% EGW NPs enhances a pure water flux to 204.71 L/m2 h, exceeding that of the pristine PAN membrane (136.51 L/m2 h). This can be attributed to the low contact angle (39.66◦), high surface membrane porosity (91%), and good tensile strength (8.2 MPa) for PAN-EGW membranes compared to the contact angle (68.56◦), surface membrane porosity (69%), and tensile strength (5.1 MPa) for the pristine PAN membrane. Another significant improvement noticed is the excellent oil rejection by the modified membranes (about 99.95%, 95.50%, and 90.00% at oil concentrations of 1000, 100, and 10 ppm, respectively, and a transmembrane pressure (TMP) of 2 bar); treated-wastewater oil content that complies with the World Health Organization (WHO) environmental discharge standards (< 5 ppm) is achieved. Also, the antifouling performance is improved; a higher flux recovery ratio (FRR) is obtained (about 94.43%). In addition, the oil separation efficiency remains stable with a minor decrease in permeate flux after four cycles. This study demonstrates that the novel PAN-EGW membranes have great promise and potential for purifying OWW, particularly at low oil concentrations (10 ppm) compared to pristine PAN membranes, attributable to their high separation efficiency, oil-fouling resistance, and excellent environmental durability.

Optimization of Al2O3 nanoparticle concentration and cutting parameters in hard milling under nanofluid MQL environment

The high cutting heat and cutting forces are still the big obstacles in hard machining technology, which puts more pressure to find out the alternative solution for these problems. The work content presents an experimental study on the effect of nanoparticle concentration and cutting parameters on surface roughness and cutting force during hard milling under MQL environment using Al2O3 nano-cutting oil. The Box-Behnken experimental designs for response surface methodology was used to evaluate the influence of the input parameters and determine the optimal values. The obtained results show that the nanoparticle concentration, cutting speed, and feed rate all have the great influences on surface roughness R z and resultant cutting force F, so the study of the influence of these parameters on the efficiency of the hard milling process is very significant. The proposed reasonable value ranges will help technicians quickly choose to meet their demands for specific objective functions. Furthermore, the optimal parameter set of nanoparticle concentration of 1.27 wt%, cutting speed V c = 103 m/min, and feed rate [Formula: see text] = 0.09 mm/tooth was determined. It revealed that the use of MQL with nano-cutting oils contributed to improve the lubrication and cooling performance in the cutting zone.

Study of Chlorella vulgaris from Different Growth Phases as Biosensor for Detection of Titanium and Silver Nanoparticles in Water

The increased use of metallic nanoparticles has led to concern for environmental contamination and disruption in water quality. Therefore, effective screening of metallic nanoparticles is important for detecting metallic nanoparticles in aquatic environments. Biosensors offer several advantages, including high sensitivity to pollutants, short response time, energy efficiency, and low waste generation. In this study, a whole-cell biosensor was developed using microalga Chlorella vulgaris as a recognition element, and its fluorescence response was used as a measuring parameter for detecting the presence of titanium dioxide (TiO2) and silver (Ag) nanoparticles in water. The responses of C. vulgaris at the lag, exponential, and stationary phases to different concentrations of TiO2 and Ag nanoparticles were studied. The results showed that in TiO2 and Ag nanoparticles exposures, the highest fluorescence change (50-150%) was observed at the lag phase, whereas the lowest fluorescence change (40-75%) was observed at the stationary phase. A significant fluorescence change was observed in 15 min. The immobilized C. vulgaris under TiO2 and Ag nanoparticles exposures showed 30-180% higher fluorescence change than the negative control, indicating the potential of C. vulgaris as a biosensor for rapid detection of TiO2 and Ag nanoparticles in water. The mathematical modeling of the responses of C. vulgaris to TiO2 and Ag nanoparticles at 15 min of exposure with high R2 indicated that this biosensor is sensitive to the concentration tested (0.010–10.000 mg.L-1). Taken together, these results reveal that, for the first time, it is possible to detect TiO2 and Ag nanoparticles in water within a very short time using a microalgae-based biosensor. Moreover, no genetic engineering requirement makes this biosensor simple, economical, and free from the restriction on genetically modified microorganisms for environmental applications.

Impact of coated and non-coated magnetic nanoparticles on oil-water separation in green surfactant-based emulsions

This study investigates the efficacy of magnetite nanoparticles as a means of demulsifying surfactant-based emulsions, focusing on light and medium crude oil emulsions. The demulsification capabilities of bare, amine-coated, and oleic acid-coated magnetite nanoparticles were tested. Nanoparticle concentrations ranged from 0.25 % to 8 %. The emulsions used Alpha Olefin Sulfonate and two environmentally friendly surfactants, Coco Glucoside and Greenzyme with sodium and potassium formate as eco-friendly alternatives and sodium chloride as the standard brine. Magnetic demulsification efficacy is highly dependent on the interplay between the nanoparticle surface charge and surfactant, thereby affecting surfactant adsorption onto the particle surface. While gravimetric separation alone has partial effectiveness, the magnetic field enhances particle movement, promoting greater instability. The nanoparticles play a key role in adsorbing surfactant species from the interfacial region, thus facilitating demulsification. Notably, magnetic demulsification is more effective with environmentally friendly surfactants, achieving 100 % separation in most cases. Demulsification of emulsions containing synthetic surfactants is most successful with light crude oil emulsions, and in select cases, achieves 100 % separation with medium crude oil emulsions.

Ni-W composite coating reinforced with CrN nanoparticles on X80 pipeline steel: Preparation and characterization

X80 pipeline steel is crucial for oil and gas pipelines. Friction between particulate matter and the inner wall causes abrasive wear during transport, while corrosive environments further degrade the pipeline, leading to leaks. In this study, a nanoscale Ni-W-CrN composite coating was successfully prepared on X80 steel via electrodeposition for protection. The coating's surface morphology, microstructure, and composition were analyzed. The effects of CrN nanoparticle concentration and deposition temperature on the coating's structure, wear, and corrosion resistance were investigated. At 10 g/L CrN and 60°C, the Ni-W-CrN film showed a fine-grained surface with 8.13 wt% CrN, achieving 810 HV microhardness and improving wear and corrosion resistance by 81 % and 89 % compared to Ni-W coatings.

A numerical study on MHD micropolar nanofluid flow over a Darcian porous stretching surface: impacts of thermophoretic and Brownian diffusions

This article provides a quantitative analysis of the flow of MHD micropolar fluid through a Darcian permeable medium bounded by a stretched surface. The RK45 method, along with the shooting approach, is employed to perform the analysis. The impacts of Joule heating, thermophoretic, and Brownian diffusions over the fluid flow are particularly, focused in this research work. The study's findings can be applied in nanofluid technology for optimizing heat transfer, porous media engineering for designing efficient systems, and magnetohydrodynamics for applications like magnetic drug targeting and liquid metal cooling in nuclear reactors. The nonlinear partial differential equations (PDEs) that govern the flow are altered into nonlinear ordinary differential equations (ODEs) by using appropriate variable similarity transformations. Displayed the graphical effects of various physical factors over the velocity, angular velocity, concentration, and temperature profiles. Velocity profiles are enhancing as the micropolar fluid and porous factor rises whereas the opposite trend exists for the boosting estimations of the magnetic parameter. Temperature distribution is escalating for the rising estimations of the magnetic, Eckert, Brownian, and thermophoresis parameters but there is an opposite scenario deploys as the Prandtl number upsurges. As Schmidt and Brownian motion parameters increase, the micropolar nanoparticle concentration decelerates and elevates when the thermophoresis parameter is boosted. The micro-rotation profiles are enhanced as the values of the micropolar fluid parameter rise. The drag force was enhanced as the magnetic and micropolar fluid parameters upsurged but diminished when the porous parameter was elevated. The rate of heat flow diminishes with higher estimates of the micropolar fluid parameter but improves when the magnetic and Prandtl number parameters increase. The rate of mass flux escalates for the enhanced values of thermophoresis, Brownian, Schmidt, and chemical reaction parameters. Considerable numerical outcomes have been produced and cross-referenced with the latest study, which unveiled remarkable concurrence.

Morphology and electrical conductivity of carbon-coated Nickel reinforced high-performance polymer nanocomposites

Novel nanocomposites of poly (ether-ketone) (PEK) reinforced with carbon-coated Nickel nanoparticles (CCNi) were synthesized through a sequential process involving cost-effective ball milling and hot compaction. Scanning electron microscopy revealed an excellent dispersion and a three-dimensional network of CCNi nanoparticles in the matrix, causing a significant improvement in the electrical conductivity and electromagnetic interference shielding effectiveness (SE). Carbon coating of about 5 nm thick over Ni nanoparticle probably helps in uniform dispersion, avoids its oxidation and reduces its agglomeration in the matrix. An exceptionally low percolation threshold of 2.1 vol.% CCNi was found, and eight-orders of magnitude enhancement in the dc-electrical conductivity was achieved. The highest dc- and ac-electrical conductivities achieved were more than 0.01 S cm−1 at 5.89 vol.% CCNi nanoparticles content which were the highest values amongst reported Ni-filled polymer composites and comparable with those of carbon nanotubes filled PEK nanocomposites. Electromagnetic interference SE of the CCNi/PEK nanocomposites was measured in the X-band, and a total SE (SET) of 17.52 dB was obtained for 5.89 vol.% CCNi reinforced PEK nanocomposite.

Green-synthesized zinc oxide nanoparticles by Enterobacter sp.: unveiling characterization, antimicrobial potency, and alleviation of copper stress in Vicia faba (L.) plants

BackgroundThe biosynthesis of zinc oxide nanoparticles (ZnO NPs) using Enterobacter sp. and the evaluation of their antimicrobial and copper stress (Cu+ 2)-reducing capabilities in Vicia faba (L.) plants. The green-synthesized ZnO NPs were validated using X-ray powder diffraction (XRD); Fourier transformed infrared (FTIR), Ultraviolet-Visible spectroscopy (UV-Vis), Transmission electron microscope (TEM) and scanning electron microscopy (SEM) techniques. ZnO NPs could serve as an improved bactericidal agent for various biological applications. as well as these nanoparticles used in alleviating the hazardous effects of copper stress on the morphological and physiological traits of 21-day-old Vicia faba (L.) plants.ResultsThe results revealed that different concentrations of ZnO NPs (250, 500, or 1000 mg L-1) significantly alleviated the toxic effects of copper stress (100 mM CuSO4) and increased the growth parameters, photosynthetic efficiency (Fv/Fm), and pigments (Chlorophyll a and b) contents in Cu-stressed Vicia faba (L.) seedlings. Furthermore, applying high concentration of ZnO NPs (1000 mg L-1) was the best dose in maintaining the levels of antioxidant enzymes (CAT, SOD, and POX), total soluble carbohydrates, total soluble proteins, phenolic and flavonoid in all Cu-stressed Vicia faba (L.) seedlings. Additionally, contents of Malondialdehyde (MDA) and hydrogen peroxide (H2O2) were significantly suppressed in response to high concentrations of ZnO NPs (1000 mg L-1) in all Cu-stressed Vicia faba (L.) seedlings. Also, it demonstrates strong antibacterial action (0.9 mg/ml) against various pathogenic microorganisms.ConclusionsThe ZnO NPs produced in this study demonstrated the potential to enhance plant detoxification and tolerance mechanisms, enabling plants to better cope with environmental stress. Furthermore, these nanoparticles could serve as an improved bactericidal agent for various biological applications.

Thermal analysis of hybrid nanoliquid contains iron-oxide (Fe3O4) and copper (Cu) nanoparticles in an enclosure

The major aim of this work is to analyze the thermophysical properties of hybrid nanoliquid inside a square lid driven enclosure under the effect of applied magnetic field and mixed convection. The Hybrid nanofluid is considered a suspension of Iron-oxide (Fe3O4) and Copper (Cu) nanoparticles into water. The cavity walls have varying properties such as top adiabatic wall is moving continuously while the lower wall is maintained at a high constant temperature, in addition, the vertical walls are kept at a low fixed temperature. The magnetic field is applied to the right vertical wall in a horizontal direction. Additionally, the effects of buoyancy forces caused by temperature gradients and shear forces caused by continuous lid motion are considered. The mathematical modelling of problem with all assumptions yields the nonlinear partial differential system. First this system is transferred into non-dimensional form and then transformed system is solved by using Galerkin finite element method (GFEM) along with Gaussian elimination method. Results for isotherms, streamlines and average Nusselt number are obtained versus Richardson number (0.1 ≤ Ri ≤ 15), Grashof number (10 ≤ Gr ≤ 10000), Hartmann number (0 ≤ Ha ≤ 100), volume fractions of solid nanoparticles (0.005 ≤ ϕ1 ≤ 0.02) and (0.005 ≤ ϕ2 ≤ 0.02). It is observed that the Richardson number and Grashof number have significant impacts on both flow velocity and temperature. In addition, concentration of hybrid nanoparticles improves the heat transfer performance. The obtained results may be crucial for thermal management in the cooling of electronics, heat exchangers, solar thermal collectors, industrial operations, medical equipment, HVAC systems, food processing, and renewable energy systems.

An experimental investigation of the convective heat transfer augmentation in U-bend double pipe heat exchanger using water-MgO-Cmc fluid

One of the major problems of using nanofluids in heat exchange applications is the forming and deposition of nanoparticles on the inner surface of the heat exchanger. In this paper, Water-Cmc fluid is used as a surfactant for nanoparticles to prevent deposition and congregation. The pressure drops and heat transfer in U-bend double pipe heat exchanger based on water-MgO-Cmc fluid, are examined. Nanoparticles of Magnesium Oxide (MgO) and Carboxymethyl Cellulose (Cmc) are used with pure water as a base fluid. The experimental rig and procedures are designed to facilitate various operational conditions such as flow rate, volume concentration of MgO particles and weight concentration of Cmc particles. Furthermore, convective heat transfer coefficient, heat exchanger effectiveness, pressure drop, friction factor, under different conditions, are measured. The results demonstrate convective heat transfer coefficient of U-bend double pipe heat exchangers is enhanced by 35% for 1 MgO vol.% and 0.2 Cmc wt.% compared to base fluid (Water-Cmc). It is concluded that pressure drops are directly proportion to the increase of MgO nanoparticles at same Cmc concentration by 23% at 0.2 wt.%. Whilst, friction factor of the system is inversely proportion to the increase of volumetric flow rate of water-MgO-Cmc fluid. An increase in MgO nanoparticle concentration increases the friction factor, hence maximum friction factor enhancement by 38% for MgO concentration of 1 vol.%. The effectiveness of heat exchanger is slightly increased by 8% with increase of MgO concentration and flow rate. Finally, thermo-physical characteristics of water-MgO-Cmc fluid at various temperatures, are measured