Showing papers in "Applied Nanoscience in 2021"

Coronavirus disease (COVID-19) cases analysis using machine-learning applications.

Abstract: Today world thinks about coronavirus disease that which means all even this pandemic disease is not unique. The purpose of this study is to detect the role of machine-learning applications and algorithms in investigating and various purposes that deals with COVID-19. Review of the studies that had been published during 2020 and were related to this topic by seeking in Science Direct, Springer, Hindawi, and MDPI using COVID-19, machine learning, supervised learning, and unsupervised learning as keywords. The total articles obtained were 16,306 overall but after limitation; only 14 researches of these articles were included in this study. Our findings show that machine learning can produce an important role in COVID-19 investigations, prediction, and discrimination. In conclusion, machine learning can be involved in the health provider programs and plans to assess and triage the COVID-19 cases. Supervised learning showed better results than other Unsupervised learning algorithms by having 92.9% testing accuracy. In the future recurrent supervised learning can be utilized for superior accuracy.

Study the influence of using guide vanes blades on the performance of cross-flow wind turbine

Abstract: A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio; therefore, it is a good candidate for a self-starting turbine. This study aims to investigate the best configuration between guide vanes and cross-flow vertical axis wind turbine. The experiment test was carried out to determine the turbine with the highest power coefficient. The cross-flow turbine has 14, 18, and 22 blades with using 6,10 and 14 blades of guide vane (GV) was developed in this study, employing 15°, 25°, 35°, 45°, 55°, 65°, and 75° of tilt angles in fifth different wind speed conditions 4 m/s, 6 m/s, 7.5 m/s, 9.20 m/s, and 11 m/s. The turbine has 22 blades with 14 GV blades at 55° of tilt angle blades producing more remarkable turbine performance improvement than other blades. The highest power coefficient (CP) of cross-flow using 14 GV blades at 55° was 0.0162 at 0.289 TSR, which increased around 59% of the turbine's performance using GV.

Deepfake detection using rationale-augmented convolutional neural network

Abstract: Deepfake network is a prominent topic of research as an application to various systems about security measures. Although there have been many recent advancements in facial reconstruction, the greatest challenge to overcome has been the means of finding an efficient and quick way to compute facial similarities or matches. This work is created utilizing the rationale-augmented convolutional neural network (CNN) on MATLAB R2019a platform using the Kaggle DeepFake Video dataset with an accuracy of 95.77%. Hence, real-time deepfake facial reconstruction for security purposes is difficult to complete concerning limited hardware and efficiency. This research paper looks into rational augmented CNN state-of-the-art technology utilized for deepfake facial reconstruction via hardware such as webcams and security cameras in real time. Additionally, discuss a history of face reconstruction and provide an overview of how it is accomplished.

Experimental investigation on cooling the photovoltaic panel using hybrid nanofluids

Abstract: This work presents an experimental investigation on the use of CNT/Al $$_{2}$$ O $$_{3}$$ hybrid nanoparticles in a Photovoltaic/ Thermal (PV/T) system to enhance the photovoltaic electrical efficiency by reducing the temperature of PV cell. An experimental comparison on thermal and electrical efficiency of PV panel with and without cooling is experimentally analyzed. Furthermore, instead of using a serpentine tube collector, a spiral tube collector is used to enhance the rate of heat transfer from the photovoltaic panel. From the experimental results it is found that the enhancement is observed in the average electrical efficiency with water and nanofluid in the spiral tube collector and found as 7.15 and 8.2% respectively, whereas, the standalone photo voltaic panel it is found as 6.2%. The efficient removal of heat from the collector increased the power production by 11.7 and 21.4% using water and hybrid nanofluid in the PV/T system respectively, while compared to standalone PV system. Similarly, the overall PV/T efficiency using hybrid nanofluids in the spiral tube collector enhances by 27.3% than using water medium.

The optimization efficient energy cooperative communication image transmission over WSN

Abstract: We propose energy efficiency and quality-aware multi-hop one-way cooperative image transmission framework based on image pre-processing technique, wavelet-based two-dimensional discrete wavelet transform (2D-DWT) methodology, and decode-and-forward (DF) algorithm at relay nodes. The different cooperative communication methods that demonstrated their viability in various ways were reviewed. However, there are a few more issues that should be tended to while managing superb image transmission in WSNs, for example, extreme vitality utilization while preparing to proceed with image transmit, to achieve the broadcast between picture quality, and intensity of image transmitted. Before presenting the proposed model, this presents the review of recent and conventional techniques for cooperative image transmission.

Simulation of MHD impact on nanomaterial irreversibility and convective transportation through a chamber

Abstract: In the current investigation, numerical method (CVFEM) was selected to show the impact of Lorentz force on transportation of operate fluid (water with a mixture of Fe3O4 and CuO). Adding the source terms associated with MHD (magneto-hydrodynamic) and porous zone leads to a mathematical model and utilizing vorticity formulation can make the equations to simplify. Not only the viscous and heating irreversibility but also permeable and magnetic terms were calculated. Nu and Be have been measured and based on results, two correlations were defined. As permeability and buoyancy effects augment, the velocity of operating fluid augments while lower velocity will be reported if Lorentz forces increases. Sgen,th decreases about 44% with augment of Ha but it augments about 100% with grow of Ra. Velocity augments about 75% with rise of Da while it declines about 50% with the growth of Ha. Intensification of Ha causes Nu to reduce about 7.85% while Be augments about 13.62%. As Da enhances, Be declines about 5.79 while Nu enhances about 49.11%. With the growth of Ra, Be decreases about 49.79% while Nu augments about 392%.

Examination of the nanofluid convective instability of vertical constant throughflow in a porous medium layer with variable gravity

Abstract: In the current article, the impact of varying gravitational field and flow on the beginning of nanofluid convective instability in a permeable medium layer is studied numerically utilizing Galerkin technique. The permeable layer is directed to a regular vertical throughflow and irregular descendent gravitational force which changes with the length from the layer. The influences of three types of gravitational force inconsistency: (a) linear, (b) parabolic, and (c) exponential are examined on the formation of nanofluid convective instability with vanish nanoparticle flux condition at the plates. Results proved that the throughflow factor $$Q$$ and gravity inconsistency factor $$\delta$$ suspend the start of convective instability, while the nanoparticle Rayleigh-Darcy number $$R_{{{\text{np}}}}$$ and the altered diffusivity ratio $${\text{NA}}_{{{\text{nf}}}}$$ quick the start of nanofluid convection. The measurement of the convective cells diminishes with $$R_{{{\text{np}}}}$$ and $${\text{NA}}_{{{\text{nf}}}}$$ , while $$Q$$ , $$\delta$$ and the altered nanofluid Lewis number $${\text{Le}}_{{{\text{nf}}}}$$ have duel effects on the measurement of convective cells.

Effect of inclusion of nanoparticles on unsteady heat transfer

Abstract: New geometry with rectangular inner cylinder containing cold flow has been simulated in this article. Freezing phenomenon has been simulated and NEPCM was mixture of CuO and water. Time-dependent solid fraction term was added to energy equation. Software based on FEM with adaptive grid was implemented for modeling the problem. Diameter of nanomaterial and amplitude of outer wall were assumed as variable. To reach the reliability of assumption of neglecting buoyancy term, comparison with experimental data was illustrated. Providing greater value of A makes the freezing time to reduce about 5.82% which is associated with existence of more NEPCM near the rectangular cylinder when A = 0.3. Influence of A on Tave has no sensible impact for t 320 s. Increasing diameter of nano-powder can augment the conductivity but experimental observation shows that there is optimum value for this factor. As dp augments from 30 to 50 nm and 40 nm, the time of solidification alters from 186.57 s to 222.77 s and 149.37 s. With rise of dp, at first, the time declines about 19.98% then time augments about 49.16%. When A = 0.3 and dp = 40 nm, the quickest process takes place and it takes 149.37 s to reach full freezing.

Entropy optimization analysis on nonlinear thermal radiative electromagnetic Darcy–Forchheimer flow of SWCNT/MWCNT nanomaterials

Abstract: Carbon nanotubes (CNTs) are inevitable due to its tremendously high thermal and electrical conductivities, strength, stiffness, and toughness characteristics. The utilization of both porous media and nanofluids with CNTs as nanoparticles can augment the thermal efficiency of typical physical systems significantly. In view of such advantages, the present study is intended to convey the influence of entropy minimization and nonlinear thermal radiation on the electromagnetic flow of nanofluids with single wall carbon nanotubes (SWCNTs) and multiwall carbon nanotubes (MWCNTs) nanoparticles suspensions past the surface of thin needle. In addition, the famous Darcy Forchheimer flow and Cattaneo-Christov heat flux models are implemented. The required numerical solution is devised pragmatically via bvp4c in MATLAB for the system of highly nonlinear ordinary differential equations. It is found that the porous matrix and local Forchheimer parameter are detrimental to the regular flow of nanofluids. Thermal fields magnify in respect of hiked porosity and temperature ratio parameters and diminish due to rise in electric and thermal relaxation parameters. Entropy minimization due to porous irreversibility is prominent for MWCNTs than SWCNTs. Bejan number upsurges due to rise in volume fraction and porosity parameter for both SWCNT-water and MWCNT-water nanofluids.

Magnetized flow of sutterby nanofluid through cattaneo-christov theory of heat diffusion and stefan blowing condition

Abstract: Stefan blowing phenomenon in electrically conducting Sutterby material flow over stretchable rotating disk is demonstrated in this research. Cattaneo-Christov (CC) model of energy diffusion is adopted to analyze the heat transmission. Buongiorno model is carried out to evaluate the involvement of nanoparticles. The formulated system of partial differential expressions is re-structured by the enactment of similarity functions. Runge–Kutta-Fehlberg (RKF) fourth-fifth order process has been executed to communicate the solution of velocity, thermal and solutal fields. The velocity, concentration, thermal fields, skin friction, rate of mass and heat transportations are explored for the embedded non-dimensional parameters graphically. Result reveals that the rise in Stefan blowing factor leads to an enhancement in radial and tangential velocities gradients. The velocity of nanomaterial is reduced by the incrementing material parameter values. The augmenting magnetic parameter values reduced the liquid velocity but improves the temperature. The thermophoretic force and Brownian motion involvement resulted the higher thermal field.

Impact of oxytactic microorganisms and variable species diffusivity on blood-gold Reiner–Philippoff nanofluid

Abstract: Currently, researchers across the world achieved theoretical and experimental works to investigate the significance of nanofluid due to their diverse application in heat transport phenomena. Nanofluids are actually the suspension of nanoparticles in the base liquid. Embedding nanoparticles in the base fluid enhances thermal conductivity and heat transfer rate. The present article shed light on the influence of gold nanoparticles along with oxytactic microorganisms on radiative Reiner–philippoff fluid due to extendable sheet. Suitable transformation convert the partial differential equations (PDEs) are renovated into nonlinear ordinary differential equations (ODEs) and furthermore tackled these equations numerically via bvp4c Matlab builtin scheme. Further the investigations are carried out in the presence of molecular diffusivity, oxytactic microorganisms and nonlinear thermal radiation. The effect of influential parameters on heat transfer, mass transfer, motile density of microorganisms profile are investigated with the assistance of tables and graphs. Embedding the nanoparticles and nonlinear thermal radiation amplifies the heat transfer process and motile density profile depreciates owing to an augmentation in Peclet number. The novel outcomes of this investigation will advance the field of nanomaterials.

Anti-oxidant, anti-fungal and cytotoxic effects of silver nanoparticles synthesized using marine fungus Cladosporium halotolerans

Abstract: This study is to implement an easy and greener method for the preparation of silver nanoparticles (AgNPs) using fungal extract and investigate their antioxidant (DPPH), antifungal (Aspergillus niger) and cytotoxic effect against human breast cancer cell line MCF-7. The synthesized AgNPs were characterized by several analytical techniques, such as UV–Vis spectrophotometer (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results of analyses using spectroscopy (UV and FTIR) and diffraction (XRD) were compared and discussed with available literature. Electron microscopic techniques, such as SEM and TEM, illustrated spherical AgNPs. The inhibition of free radical DPPH by AgNPs was significant. The cytotoxicity of AgNPs was dose-dependent, and therefore, an increase in cell death was obtained with increasing concentrations of AgNPs. The IC50 values were found to be 34.27 µL/mL for the AgNPs and 17.69 µL/mL for the standard drug, Cisplatin. According to the knowledge of the authors and published literature, this is the first-ever report on the synthesis of AgNPs using the fungus Cladosporium halotolerans and evaluation of their biological activities.

Graphene oxide–ZnO nanocomposite: an efficient visible light photocatalyst for degradation of rhodamine B

Abstract: Lignin-based graphene oxide (L-GO), zinc oxide (ZnO), and modified L-GO–ZnO nanocomposites are prepared to explore the photocatalytic efficiency of the catalysts under UV–visible light irradiation. The absorbance of dye’s solution (rhodamine B) at regular intervals has been recorded at λmax = 553 nm using a UV–Vis spectrophotometer. The kinetics parameters, viz. half-life (t1/2), time constant τ (Tau), and rate constant (k), have been evaluated by integrated rate expression to predict the order of the reaction. The rate constant for the reactions has been evaluated to be k_L-GO–ZnO = 1.46 × 10–1, k_ZnO = 2.23 × 10–2, and k_L-GO = 1.740 × 10–2 min−1. The degradation reaction is predicted to follow the first-order kinetics when the data are fitted to the integrated rate expression, kt = -ln(D/D0). The interactions of the dye and the catalyst have been probed by FTIR spectroscopy. The percent degradation efficiency of ZnO, L-GO, and L-GO–ZnO catalyst is 85.96, 83.15, and 91.75, respectively.

Highly sensitive refractive index sensor optimized for blood group sensing utilizing the Fano resonance

Abstract: A metal–insulator–metal (MIM) waveguide coupled with two unequal vertical rectangular cavities optimized for high sensitivity is proposed in this study. Due to the interaction of the continuum and the discrete state in the waveguide mode, a Fano like profile is obtained in the transmission spectra, the shift of which is utilized to identify the material under sensing. In order to guarantee the maximum device performance, an optimization technique is imposed on the structural parameters, resulting in a maximum sensitivity of 2625.87 nm/RIU and figure of merit (FOM) of 26.04. The sensor has been exploited to determine the human blood group by using the refractive index model proposed for different blood groups A, B, and O. Furthermore, this structure can also be used as a temperature sensor with the temperature sensitivity of $$-1.04 \, \hbox {nm}/^\circ \hbox {C}$$ . The excellent performance along with the blood sensing and temperature sensing capabilities of the device paves the way toward refractive index sensors that have not only been utilized in microchip processors but also a wide range of biomedical applications.

Green synthesis of magnetic α–Fe2O3 nanospheres using Bridelia retusa leaf extract for Fenton-like degradation of crystal violet dye

Abstract: The reach of nanotechnology has permeated into a range of disciplines and systematically revolutionized many manufacturing techniques. Today, nanoparticles are fabricated using varied approaches, each with its pros and cons. Of them, the green synthesis approach has been very effective in terms of overall economics and the stability of nanoparticles. The current study investigates the use of the leaf extract of Bridelia retusa for the synthesis of iron oxide nanoparticles. Typical of these nanoparticles, no specific peak was discernible on employing UV–visible spectroscopy. The size, morphological features, and crystallinity of the nanoparticles were determined by employing scanning electron microscopy and electron diffraction spectroscopy. Almost uniformly sized at 38.58 nm, the nanoparticles were spherical, constituting elemental iron at 11.5% and elemental oxygen at 59%. Their relative composition confirmed the nanoparticles to be iron oxide. X-ray diffraction studies showed the particles to be hexagonal and rhombohedral, estimating the crystallite size at 24.27 nm. BET analysis put the pore volume at 0.1198 cm3/g and pore diameter at 7.92 nm. The unique feature of the nanoparticles was that the specific surface area was 75.19 m2/g, which is more than 12 times higher than commercial α-Fe2O3. The participation of a variety of biochemicals in the leaf extract towards the reduction-cum-stabilization was confirmed using FTIR analysis. The Fenton-like catalytic activity of the nanoparticles was put to test by attempting to degrade crystal violet dye, which was completely achieved in 270 min. The kinetics of the degradation was also modelled in the study.

Biosynthesis of silver nanoparticles by Cyperus pangorei and its potential in structural, optical and catalytic dye degradation

Abstract: The development of effective photocatalyst through green and eco-friendly approach has become a great concern for the light-induced degradation of organic pollutant dyes. This article reports a simple, cost-effective, and a benign environmental biosynthesis of Ag nanoparticles (NPs) using Cyperus pangorei, a plant extract with three different concentrations of AgNO3 in aqueous media. The synthesized silver nanoparticles were performed ultraviolet–visible spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), photoluminescence (PL), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The surface plasmon resonance (SPR) peak at 437 nm in UV–Vis spectroscopy confirmed the reduction of Ag+ ions into Ag nanoparticles. FTIR spectra revealed that plant extract could reduce/stabilize/capping to form Ag nanoparticles, and strong PL emission spectra tend to exhibit higher photocatalytic activity. The structural information is derived from XRD and TEM, which can exhibit the FCC structure and polydisperse with the spherical shape. EDX addresses the presence of Ag constitute. XPS confirmed the Ag nanoparticles in characteristic silver peaks, plant extract derivatives, and their oxidative states’ binding energy. The photocatalytic activity of Ag nanoparticles against dye Rhodamine B (Rh-B) under ultraviolet irradiation with periodic interval and pseudo-first-order kinetics were also studied. The obtained results show that the synthesized Ag nanoparticles can degrade dye (Rh-B) up to 86% within 2 h of irradiation time. Furthermore, the present study suggests that the biosynthesized Ag nanoparticles could be potential photocatalysts against various industrial dyes as well as C. pangorei; plant extract can be usto modify and develop more efficient nano-photocatalyst for other application.

Theoretical evaluation of the refractive index sensing capability using the coupling of Tamm–Fano resonance in one-dimensional photonic crystals

Abstract: Biophotonic sensing techniques are an accurate best way for biosensing measurements. The main aim of the proposed device is to make a more effective sensor to detect the change in the refractive index of a sample. This sensor is based on the Tamm–Fano resonance in gold/porous semiconductor photonic crystal. Porous Gallium nitride has been used as an alternative multilayer Bragg reflector. The proposed structure composed of prism/Au/porous GaN/(GaN/porous GaN) N/substrate. The numerical studies for the proposed structure are calculated using the transfer matrix method. The sensitivity, FoM, and Q-factor observed from this device are 3 × 104 nm/RIU, 6.6 × 104 RIU−1, and 9 × 108. This study records sensitivity 2875 times higher than the experimental study of a similar structure in other wavelength range. The proposed sensor can be used in biosensing applications because it records high local environment sensitivity.

Productivity enhancement of hemispherical solar still using Al 2 O 3 -water-based nanofluid and cooling the glass cover

Abstract: The hemispherical distiller characteristics are having a large surface area for receiving and condensing compared to a conventional single-slope distiller To achieve the maximum possible utilization of this feature, in first the Al2O3 nanoparticles were adding to the basin water to increase the evaporation rate, in the second modification the glass cover cooling technology was utilized to increase the condensation rate To investigate the influences of Al2O3-water nanofluid and the glass cover cooling technology by a water sprinkler on hemispherical solar distiller performance, three hemispherical solar distillers were designed and tested in the same climate conditions The first is the reference case (conventional hemispherical solar distiller), second is the modified hemispherical solar distiller with Al2O3-water nanofluid, and the third is the modified hemispherical solar distiller with Al2O3-water nanofluid and water sprinkler Three different concentrations of Al2O3 nanoparticles 01, 02, and 03% were studied Results showed that, the accumulative yield of traditional hemispherical solar distiller reached 3280 ml/m2/day, while the utilization of Al2O3-water nanofluid and the water sprinkler improve the accumulative yield to 6750, 6900, and 7250 ml/m2/day, with improvement 1058, 1104, and 121% of the volume friction of 01, 02, and 03%, respectively Also, the improvement in the daily efficiency for utilizing the Al2O3 nanoparticles and water sprinkler reached 1057, 1097, and 1201% for nanoparticle concentrations 01, 02, and 03%, respectively as compared to the reference case

Bioproduction of CuO and Ag/CuO heterogeneous photocatalysis-photocatalytic dye degradation and biological activities

Abstract: Water contamination is a critical and severe issue all over the world. The nano-based particles have the potency to overcome water contamination. In the present work, CuO and Ag/CuO nanoparticles (NPs) were synthesized by Cyperus pangorei extract using the co-precipitation method. The plant extract acts as a reducing and stabilizing agent. The purpose of plant extract is to reduce the negative impact of the synthesis method and its derivatives. The Ag+ and Cu+ reduction were confirmed through the surface plasmon resonance in the DRS spectrum. The bandgap decreasing is informed that the results have opted in the optical and catalytical applications. CuO bandgap is higher than the Ag/CuO NPs (∆Eg = 0.55 eV) reveals the Ag/CuO NPs have remarkable optical and catalytic applications. The NPs crystalline nature and size were analyzed by XRD. SEM and TEM analyses characterized the morphology and size variation of the CuO and Ag/CuO NPs. The EDX analysis analyzed the composition of the elements in the synthesized NPs. The FTIR analysis was performed to confirm the possible functional groups of plant extract involved in chemical reduction and bondings. Copper and silver metals and oxygen valencies and binding energies were examined by XPS. Occasionally, contagious diseases shake the world and affected human healthiness because of their pathogenic activity. Mostly, they are resolved by nanoparticles. The biosynthesized CuO and Ag/CuO NPs were performed against Gram-positive (Staphylococcus aureus—S. aureus) and Gram-negative (Escherichia coli—E. coli) bacteria. The results showed better activity in E. coli compared to S. aureus in both CuO and Ag/CuO NPs. The photocatalytic activity of CuO and Ag/CuO NPs were analyzed against Rhodamine B (Rh-B) dye under visible light irradiation. The metallic Ag-doped with CuO NPs improves the catalytic compared to pure CuO NPs. The pseudo-first-order kinetics were found to increase the rate of dye degradation by adding Ag ions to the CuO surface. The advanced oxidation process would increase the electron–hole pair activity and reactive oxygen species (ROS) formation. The AOP photocatalyst is widely used to remove the toxicity of wastewater. There is no secondary product formation and rich activated electrons. The obtained results indicate the CuO and Ag/CuO NPs may further use in wastewater treatment and biomedical applications.

Preparation and characterization of nanocellulose obtained by TEMPO-mediated oxidation of organosolv pulp from reed stalks

Abstract: Renewable plant materials are of interest for the development of new biodegradable materials. The study describes the preparation process of nanocellulose from organosolv reed pulp (ORP). ORP was obtained from reed stalks in two stages: by extraction of the raw material with NaOH solution and cooking using a mixture of acetic acid and hydrogen peroxide. Nanocellulose was extracted from ORP using 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) in a TEMPO/NaBr/NaClO system followed by ultrasonic treatment to obtain a stable nanocellulose gel. It was found that an increase in the TEMPO consumption and oxidation time increases the density and tensile strength, the content of carboxyl groups, and the transparency of the nanocellulose films, but decreases the yield and crystallinity of the nanocellulose. Structural and chemical changes and the crystallinity index of reed stalks, ORP, and nanocellulose were studied using SEM, FTIR, and XRD methods. Nanocellulose films had a density of up to 1.51 g/cm3, a transparency of up to 82.4%, a carboxyl group content of up to 1.18 mmol/g, and a tensile strength of up to 69.7 MPa. The crystallinity index of nanocellulose decreases from 78.8 to 64.9% with an increase in the oxidation time. TEM and AFM methods have shown that the width of nanocellulose particles is from 3 to 20 nm. TGA confirmed a decrease in the crystallinity index of nanocellulose as a result of its prolonged oxidation. The properties of the obtained nanocellulose from ORP demonstrate the great potential of its application for the preparation of new nanocomposite materials.

Application of microbial fuel cells energized by oil palm trunk sap (OPTS) to remove the toxic metal from synthetic wastewater with generation of electricity

Abstract: Microbial fuel cells (MFCs) is the bioelectrochemical typed approach in which bacterial species generate electricity and remove the metal ions from synthetic wastewater. To improve the performance of MFCs, a local oil palm trunk sap (OPTS) was used in the present study as an organic substrate to improve the bacterial activities. The present electrochemical and biological characterizations proved that OPTS can deliver good efficiency in MFCs operations. The maximum obtained power density was 0.37 mW/m2 and a current density of 55.26 mA/m2. Similarly, the obtained removal rate for Pb2+, Cd2+, Cr3+, Ni2+, Co2+ and Hg2+ was 75%, 70.10%, 75%, 80%, 78.10% and 60%, respectively. During biological characterization, conductive pili-type bacterial species such as Klebsiella pneumoniae, Bacillus species, Lysinibacillus, and Enterobacter were found for metal removal and energy generation. Additionally, the parameter optimization showed that room temperature and pH 7 are ideal conditions for the industrial-scale application of the MFCs.

Performance of PVC/SiO 2 nanocomposites under thermal ageing

Abstract: Accelerated thermal ageing test on nanocomposites of polyvinyl chloride (PVC/SiO2) is conducted at constant temperatures of 110 °C and 140 °C. Accordingly, different PVC/SiO2 nanocomposite samples with different silicon dioxide (SiO2) filler loading are prepared. The preparation of the samples was carried out based on the solution casting technique. The loading concentrations of SiO2 in the investigating samples are 0, 1, 2.5, 5 and 7.5 wt%. The breakdown strength of the prepared PVC/SiO2 nanocomposite samples is evaluated before and after the thermal ageing test. The evaluation of breakdown strength is carried out based on American Society for Testing and Materials (ASTM) standard. Also, dielectric spectroscopy, which includes dielectric constant (έ) and tangent loss (tan δ) of nanocomposite, is performed before and after the thermal ageing test. Also, the mass losses during thermal ageing of all samples are evaluated. The results show that the breakdown strength, tan δ, and the dielectric constant (έ) of pure PVC and PVC/SiO2 nanocomposites are significantly affected by the thermal ageing test. Adding a small amount of SiO2 nanoparticles to PVC leads to improvement in its dielectric properties before and after the thermal ageing process as compared to the pure PVC. The mass loss of PVC/SiO2 nanocomposite during thermal ageing is less than that of pure PVC and confirms the obtained result from breakdown strength.

Accuracy detection of coronary artery disease using machine learning algorithms

Abstract: Coronary artery disease, which involves a wide range of conditions, including narrowed or blocked coronary arteries, has remained the leading cause of death in the United States for over 50 years. The majority of cardiovascular disorders are preventable, which are identified through risk factors. Electrocardiogram (ECG), a routinely available test that provides information about one’s electrophysiologic health, may be beneficial in determining cardiovascular risk. Given the automated and highly correlated nature of its measurements, ECG data are suited well for analysis via machine learning. This research compares and demonstrates the improvements over standard methods for the discussed framework. The proposed framework demonstrates a novel approach to determine the severity of heart diseases using a traditional survival analysis and machine learning methods based on the blockages of major blood vessels in the heart. Hence, modern research demands to improve the accuracy of the predictive analysis. This work analyses the widespread predictive determination using various machine learning methods of heart disease and applies a cost-based matrix to enhance detection accuracy. An HD dataset to evaluate the classification performance following the classification algorithms.

Bio-synthesis of silver nanoparticles with the brackish water blue-green alga Oscillatoria princeps and antibacterial assessment

Abstract: This study describes the morphology of a filamentous non-heterocystous blue-green alga (cyanobacterium) Oscillatoria princeps isolated from the Bhabakundalswara sea mouth, its use in biogenic synthesis of silver nanoparticles (AgNPs), along with antimicrobial studies using multidrug resistant (MDR) methicillin-resistant strains of Staphylococcus aureus (MRSA), Streptococcus pyogenes and Escherichia coli, isolated from clinical samples. The synthesized O. princeps -AgNPs were characterized with UV–visible spectrometry, scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic light scattering analysis (DLS) and Fourier transform infrared spectroscopy (FT-IR) analyses. The synthesized AgNPs had remarkable antibacterial activities against MDR strains of MRSA, S. pyogenes and E. coli with the inhibitory zone sizes, 14–16 mm as recorded from agar well diffusion method, while MIC values were 100, 80, 60 µg/ml, for the respective cited bacterial species. Thus, O. princeps -AgNPs in future would be druggable antibacterials.

Antioxidant, anticancer and enhanced photocatalytic potentials of gold nanoparticles biosynthesized by common reed leaf extract

Abstract: This research discloses a single step, facile, cost-effective, and eco-friendly fabrication of gold nanoparticles (AuNPs) using the aqueous extract of common reed (Phragmites australis) leaf. Various techniques were employed to characterize the resultant AuNPs such as UV–Vis spectroscopy, high resolution transmission electron microscopy (HRTEM) mapping, fourier transform infrared (FT-IR), Zeta potential, X-ray diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX), and X-ray Photoelectron Spectroscopy (XPS) to confirm the bioformation of AuNPs. The results showed the formation of violet-colored, mainly spherical shaped AuNPs with about 18 nm diameter. The XRD results proved the crystalline structure of AuNPs. Furthermore, P. australis-AuNPs exhibited notable anticancer efficacy with an IC50 equals 129 μg/mL, good quenching for DPPH free radical with a scavenging percentage equals 10.26% and a superior photocatalytic activity as they completely removed methylene blue in just 1 min. The current study also provides an open option for the environmental management of the unwanted biomass of common reed.

Tin oxide nanoparticles (SnO 2 -NPs) synthesis using Galaxaura elongata and its anti-microbial and cytotoxicity study: a greenery approach

Abstract: The progression of green nanoscience towards greater heights and new standards is obvious due to the non-toxic methods of synthesis and other added advantages. With this background, this research focused to prepare stable tin oxide nanoparticles (SnO2-NPs) mediated by the ethanolic extract of Galaxaura elongata (red algae). The biosynthesized nanoparticles were subjected to analyses by Scanning (SEM) and Transmission Electron Microscopes (TEM), X-ray diffraction (XRD), UV–visible (UV–vis) and energy dispersive X-ray spectroscopies (EDS). The outcomes as indicated by characterization tools demonstrate that Galaxaura elongata extract reduced SnCl2 into SnO2-NPs within 60–90 min at room temperature. The nanocrystallite structures were 35 nm in size. Related to the applications at the nanoscale, the antibacterial activity was investigated against Bacillus subtilis, Staphyloccous aureus, Pseudomonas aeruginosa and Escherichia coli. The zone of inhibition did range between 16 and 24 mm for the NPs. Galaxaura elongata extract showed a moderate MIC value of 0.31–9.47 µg/ml on the tested organisms, while the MIC values of tin oxide nanoparticles are 15.6 µg/ml and 62.5 µg/ml. The SnO2-NPs were cytotoxic on A549 human lung carcinoma cells with an IC50 value of 28.08 μg/ml. The results of the study indicate that the NPs were effective antibacterial and cytotoxic agents.

Multi-scale surface patterning to tune friction under mixed lubricated conditions

Abstract: It is well accepted that the tribological performance of surfaces can be directly correlated with their energy efficiency and lifetime. Consequently, surface patterning has gained great attention to manipulate friction and wear under dry and lubricated conditions in the last 2 decades. Inspired by multi-scale surfaces found in nature, direct laser interference patterning (finer cross-pattern) and hot micro-coining (coarser hemispherical patterns) were used to create multi-scale patterns on stainless steel substrates. Using a ball-on-disk set-up, the running-in behavior and the maximum oil film lifetime were characterized for all single- and multi-scale patterns under mixed lubrication. Compared to the polished reference, all patterned surfaces helped to prolong the oil film lifetime. Synergetic effects induced by multi-scale patterns were observed leading to the best performance of the sample combining deep micro-coined patterns (intermediate area density) with the additional laser pattern. As a result of the additional hydrodynamic pressure generated by the finer laser pattern and the oil reservoir effect as well as the entrapment of wear particles induced by the coarser micro-coined pattern, the oil film lifetime was extended by a factor of 200 (200 times).

A review of the phytochemical mediated synthesis of AgNP (silver nanoparticle): the wonder particle of the past decade

Abstract: Silver nanoparticle (AgNP) has been one of the most commonly used nanoparticles since the past decade for a wide range of applications, including environmental, agricultural, and medical fields, due to their unique physicochemical properties and ease of synthesis. Though chemical and physical methods of fabricating AgNPs have been quite popular, they posed various environmental problems. As a result, the bioinspired route of AgNP synthesis emerged as the preferred pathway for synthesis. This review focuses extensively on the biosynthesis of AgNP-mediated through different plant species worldwide in the past 10 years. The most popularly utilized application areas have been highlighted with their in-depth mechanistic approach in this review, along with the discussion on the different phytochemicals playing an important role in the bio-reduction of silver ions. In addition to this, the environmental factors which govern their synthesis and stability have been reviewed. The paper systematically analyses the trend of research on AgNP biosynthesis throughout the world through bibliometric analysis. Apart from this, the feasibility analysis of the plant-mediated synthesis of nanoparticles and their applications have been intrigued considering the perspectives of engineering, economic, and environmental limitations. Thus, the review is not only a comprehensive summary of the achievements and current status of plant-mediated biosynthesis but also provides insight into emerging future research frontier.

A comparative study for convective flow of basefluid (gasoline oil), nanomaterial (SWCNTs) and hybrid nanomaterial (SWCNTs + MWCNTs)

Abstract: In this communication, we have investigated flow of hybrid nanomaterial (SWCNTs + MWCNTs) by a curved stretched surface. Relative analysis of nanomaterial (SWCNTs) and hybrid nanomaterial (SWCNTs + MWCNTs) is performed. Gasoline oil is treated as basefluid. Heat transfer features are elaborated via thermal radiation and convection. Equations relevant to flow field (PDEs) are transmitted into ODEs through adequate transformations. Solutions are developed via the shooting method. Furthermore, relative analysis of basefluid (gasoline oil), nanomaterial (SWCNTs) and hybrid nanomaterial (SWCNTs + MWCNTs) is presented through higher estimations of influential flow parameters during observation of flow, skin friction coefficient, temperature and Nusselt number.

One-step synthesized calcium phosphate-based material for the removal of alizarin S dye from aqueous solutions: isothermal, kinetics, and thermodynamics studies

Abstract: Calcium phosphate hydroxyapatite (Ca-Hap) synthesized from CaCO3 and H3PO5, it was characterized by scanning electron microscopy, Fourier transform infrared, and X-ray diffraction. The Ca-Hap was used for the removal of Alizarin Red S dye from its aqueous solution. The kinetics, equilibrium, and thermodynamic of the adsorption of the dye onto the Ca-Hap were investigated. The effects of contact time, initial dye concentration, pH as well as temperature on adsorption capacity of Ca-Hap were studied. Experimental data were analyzed using six model equations: Langmuir, Freudlinch, Redlich–Peterson, Temkin, Dubinin–Radushkevich, and Sips isotherms and it was found that the data fitted well with Sips and Dubinin–Radushkevich isotherm models. Pseudo-first-order, pseudo-second-order, Elovic, and Avrami kinetic models were used to test the experimental data in order to elucidate the kinetic adsorption process and it was found that pseudo-second-order model best fit the data. The calculated thermodynamics parameters (∆G°, ∆H° and ∆S°) indicated that the process is spontaneous and endothermic in nature.