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Zirconia has become widely used in dentistry due to its mechanical strength, biocompatibility, and esthetics. However, durable resin bonding to zirconia remains a challenge due to its inert surface chemistry. This study demonstrates an approach for tribochemical silica coating of zirconia using a silica-coated zirconia powder synthesized via sol-gel chemistry from upcycled zirconia milling waste. Systematic variation of blasting pressures and durations revealed an optimized protocol of 0.28 MPa for 10 s, achieving an exceptional resin bond strength of 39.13 MPa. Extensive materials characterization, including field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and X-ray diffraction (XRD) elucidated the interfacial mechanisms governing adhesive performance. These techniques confirmed the uniform deposition of a nano-silica layer through mechanical embedding and heating upon particle impact. This silicatization transformed the intrinsic hydrophobicity and created reactive hydroxyl groups for subsequent silanization. Precisely controlled roughening was evidenced by atomic force microscopy, with a root mean square roughness of 676 nm for optimal coatings. X-ray diffraction confirmed silica incorporation generated some transformation from the metastable tetragonal to the monoclinic phase, however less than for an analogous commercial alumina-based powder. Realization of stronger, imperceptible ceramic modification introduces possibilities for thinner, aesthetically superior restorations. This demonstration of upcycling zirconia waste into tunable surface coatings represents a paradigm shift in sustainable materials design and unprecedented value creation from disposal debris. Insights gained can inspire scalable, broadly applicable surface engineering solutions utilizing waste streams. Highlights: Developed SiO2-coated ZrO2 particles from recycled zirconia. Optimized blasting process to achieve high resin bond strength. Confirmed nano-silica layer deposition and surface chemistry transformation. Caused less damage to zirconia compared to commercial alumina powder. Demonstrated sustainable upcycling of waste into tunable coatings. [ABSTRACT FROM AUTHOR]

In the present work, we used a pulsed laser deposition technique to embed TiO2 nanostructure on porous silicon substrates using a pulsed laser deposition process. Nanocrystalline porous silicon was synthesized using the photo-assisted electrochemical method. The study analyzed the optoelectronic characteristics of double junctions of TiO2/PS/n-Si structures as well as the PS/n-Si structure. We investigated the properties of TiO2/PS/n-Si and PS/n-Si structures, focusing on their structural, optical, and electrical features under ambient conditions. The XRD measurement indicated the formation of the anatase and rutile tetragonal phases with the preferred orientation anatase (101) plane in the prepared sample. The mean sizes of The TiO2 nanostructures deposited onto porous silicon substrates range from 45.97 to 109.23 nm. The degree of pore filling depends upon the laser fluences employed, varying from moderate to close to complete packing. The optical properties of TiO2/PS/n-Si structures showed decreasing reflectance after depositing on porous silicon. The TiO2 nanostructure produced on porous silicon exhibits five different spectra in the UV and visible range, as displayed in the room-temperature photoluminescence analysis. The current density–voltage characteristics of formed samples in dark and photoilluminated conditions are examined at room temperature. The properties of the TiO2/PS/n-Si structure enhance those of the PS/n-Si device. The highest specific detectivity of the TiO2/PS/n-Si devices is 32.45 × 1010 Jones in the visible region, while the ultraviolet region is 30.04 × 1010 Jones. The TiO2/PS/n-Si photodetectors possess an optimal relative quantum efficiency of 80.1% in the near UV region, whereas, in the visible range, the values of relative quantum efficiency are 51.8% at 531 nm and 54.5% at 634 nm. The findings reveal that formed photodetectors exhibit UV and visible light sensitivity after depositing TiO2 layers on porous silicon. However, the photodetectors produced using TiO2 nanostructures placed on porous silicon demonstrate greater sensitivity than those made from as-synthesized porous silicon. [ABSTRACT FROM AUTHOR]

In this study, graphene–silver (G–Ag) nanocomposite films on glass substrates were synthesized and characterized using a spray method with different concentrations (0.05, 0.1, 0.15, 0.2, 0.25 and 0.3 g) of AgNO3. The films were heated to 300 °C, and X-ray diffraction and scanning electron microscopy were used to analyze the crystalline structure and morphology of the G–Ag nanocomposites, respectively. UV–visible/NIR spectrophotometry was used to determine the optical properties of the films, which showed improved transparency and conductivity due to the attachment of silver nanoparticles to the graphene sheets. The results confirmed the successful attachment of silver nanoparticles to graphene as shown by the XRD and SEM analyses, and the presence of surface plasmon resonance (SPR) of the AgNPs was confirmed by the absorption peak at 410–430 nm in the UV–Vis spectra. Depicts a cross section of a thin film with a thickness of approximately (500 nm). XRD analysis indicated the presence of Ag and graphene, while Raman spectroscopy showed a slight difference between the spectra of the nanocomposites and AgNPs. UV–visible spectroscopy analysis revealed the presence of AgNPs on the graphene films and their surface plasmon resonance properties; the graphene–silver nanocomposite films were found to be a promising method for fabricating thin, homogeneous graphene films with improved optical properties, which could have potential applications in optoelectronics, touch screens and solar cells. It was found that the calculated figure of merit (FOM) increased with increasing Ag concentration and reached a maximum value of 0.25, indicating that the G–Ag nanocomposite films have a good balance between optical transparency and electrical conductivity. Overall, this study provides valuable insights into the synthesis and characterization of G–Ag nanocomposite films and their potential for various applications. [ABSTRACT FROM AUTHOR]

In this paper, two wavelength division multiplexing (WDM) optical communication systems employing an enhanced L-shape hybrid fiber amplifier (E-L-shape-HFA) are designed and simulated. Both scenarios utilize a combination of the second-order stimulated Raman scattering (SO-SRS) and a tunable optical filter (TOF) technique. One system consists of 16 channels, while the other has 23 channels. Three different frequency ranges: short band (S-band), conventional band (C-band), and long band (L-band) are covered. The integration of two techniques SO-SRS and TOF has been enhanced the system's performance to meet the tremendous development of the optical communication systems nowadays. The first scenario results achieved high average gain ( G av. ) of 35 dB and wide flat gain bandwidth of 75 nm expanded from 1520 to 1595 nm. In addition, the second scenario results achieved an ultra-wide flat gain bandwidth of 110 nm extended from 1515 to 1625 nm and G av. of 26 dB. Furthermore, a desirable average noise figure (NFav.) of 4 dB has been obtained for both scenarios at input signal power of − 25 dBm. Moreover, the system is examined and optimized at input signal power range from − 25 to 20 dBm a step of 5 dbm in terms of bit error rate (BER) and quality factor (Q-factor). [ABSTRACT FROM AUTHOR]

Recently, due to the fast development in multimedia applications of wireless communication systems and demands of increasing the capacity and data rates to meet the requirements of 5G mobile communication systems, new transmission techniques are needed. One of the powerful enabling tools of the 5G communication systems is the multi-input multi-output (MIMO) antenna system employing multiple antennas and utilizing the multipath fading mobile environment to increase the channel capacity without any additional bandwidth and/or transmitted power. However, because of the limited space of mobile devices, the distances between antennas are decreasing. The mutual coupling between antennas severely affects the overall performance of the MIMO system. So, isolation improvement methods are applied to reduce these influences. In this review, different isolation techniques and their features and drawbacks are presented, and the techniques for applying them in modern MIMO antenna systems are illustrated. Besides, the performance characteristics of these MIMO systems are compared. The review also contains basic concepts of the MIMO antenna system and its performance metrics. Finally, the future directions and trends for the MIMO antenna system design are discussed briefly. [ABSTRACT FROM AUTHOR]

Rapid technological advancements have created opportunities for new solutions in various industries, including healthcare. One exciting new direction in this field of innovation is the combination of skin-based technologies and augmented reality (AR). These dermatological devices allow for the continuous and non-invasive measurement of vital signs and biomarkers, enabling the real-time diagnosis of anomalies, which have applications in telemedicine, oncology, dermatology, and early diagnostics. Despite its many potential benefits, there is a substantial information vacuum regarding using flexible photonics in conjunction with augmented reality for medical purposes. This review explores the current state of dermal augmented reality and flexible optics in skin-conforming sensing platforms by examining the obstacles faced thus far, including technical hurdles, demanding clinical validation standards, and problems with user acceptance. Our main areas of interest are skills, chiroptical properties, and health platform applications, such as optogenetic pixels, spectroscopic imagers, and optical biosensors. My skin-enhanced spherical dichroism and powerful spherically polarized light enable thorough physical inspection with these augmented reality devices: diabetic tracking, skin cancer diagnosis, and cardiovascular illness: preventative medicine, namely blood pressure screening. We demonstrate how to accomplish early prevention using case studies and emergency detection. Finally, it addresses real-world obstacles that hinder fully realizing these materials' extraordinary potential in advancing proactive and preventative personalized medicine, including technical constraints, clinical validation gaps, and barriers to widespread adoption. [ABSTRACT FROM AUTHOR]

In this study deposited zinc oxide (ZnO) nanostructures were prepared by pulsed laser deposition (PLD) technique on porous silicon (PS) substrates that were prepared via photoelectrochemical etching of silicon n-type (100). The study investigated the influence of laser energy on various characteristics of the fabricated devices, including their optical, morphological, structural, electrical, and photodetector features. The X-ray diffraction results indicate a dominant broad diffraction peak at 69.14°, and the ZnO phase aligns with the hexagonal wurtzite structure. The field emission scanning electron microscopy micrograph illustrates that porous silicon has a sponge-like fashion, while ZnO nanostructures have spherical grains distributed randomly and grow larger with laser energy. The optical characteristics of the manufactured samples were examined using techniques that include UV–vis absorption spectroscopy, UV–vis diffuse reflectance spectrometry, and photoluminescence spectroscopy. The findings indicated that decreased laser energy led to a blue shift in the energy gap. The reflectivity of the produced samples decreased after the deposition of a zinc oxide layer over porous silicon. The photoluminescence examination showed the presence of four distinct emission peaks, namely, UV, violet-blue, blue, and green, consequent to coating a ZnO layer onto the porous silicon substrate. Fourier transform infrared spectroscopy confirmed that ZnO thin films deposited on porous silicon cause surface oxidation and produced a new peak at 455.2 cm−1 related to the Zn–O stretching band. The current density–voltage properties of the fabricated devices in the absence and presence of white light were investigated as a function of laser energy. The ZnO NPs/PS/n-Si photoreactors displayed rectifier features and had outstanding spectral responsivity from ultraviolet to near-infrared. Moreover, the fabricated photoreactor showed the most prominent external quantum efficiency (EQE) in the UV region. The results of this study are of great importance to the advancement of photodetectors and optoelectronic devices based on ZnO and porous silicon. [ABSTRACT FROM AUTHOR]

To evaluate the efficiency and effectiveness of three minimally invasive (MI) techniques in removing deep dentin carious lesions. Forty extracted carious molars were treated by conventional rotary excavation (control), chemomechanical caries removal agent (Brix 3000), ultrasonic abrasion (WOODPECKER, GUILIN, China); and Er, Cr: YSGG laser ablation (BIOLASE San Clemente, CA, USA). The assessments include; the excavation time, DIAGNOdent pen, Raman spectroscopy, Vickers microhardness, and scanning electron microscope combined with energy dispersive X-ray spectroscopy (SEM–EDX). The rotary method recorded the shortest excavation time (p < 0.001), Brix 3000 gel was the slowest. DIAGNOdent pen values ranged between 14 and 18 in the remaining dentin and laser-ablated surfaces recorded the lowest reading (p < 0.001). The Ca:P ratios of the remaining dentin were close to sound dentin after all excavation methods; however, it was higher in the ultrasonic technique (p < 0.05). The bur-excavated dentin showed higher phosphate and lower matrix contents with higher tissue hardness that was comparable to sound dentin indicating the non-selectiveness of this technique in removing the potentially repairable dentin tissue. In contrast, the MI techniques exhibited lower phosphate and higher organic contents associated with lower microhardness in the deeper dentin layers. This was associated with smooth residual dentin without smearing and patent dentinal tubules. This study supports the efficiency of using MI methods in caries removal as conservative alternatives to rotary excavation, providing a promising strategy for the clinical dental practice. [ABSTRACT FROM AUTHOR]

The main objective of this work is to investigate viscous dissipation with thermal radiation impact on hybrid nanofluid flow past an exponentially stretching/shrinking surface along with magnetic field, and heat source/sink, slip boundary conditions. Water ( H 2 O ) is taken into account as a host fluid with copper (Cu) and alumina ( Al 2 O 3 ) as nanoparticles to form a hybrid nano liquid (Cu- H 2 O - Al 2 O 3 ). The coupled nonlinear partial differential equations are transmuted into ordinary differential equations using similarity transformations with boundary conditions and these ODEs are simplified using numerical solver, bvp4c in MATLAB. The behavior of momentum profiles, thermal profiles, coefficient of heat transfer ( Nux 1 ) and skin friction ( C f ) are explored using the pertinent parameters such as Eckert Number ( Ec 1 ), Suction Parameter ( S 1 ), Magnetic Parameter ( M 1 ), Radiation Parameter ( Nr 1 ), Stretching/Shrinking Parameter (λ ), Velocity and thermal slip Parameters ( A 1 and B 1 ), Heat source/sink Parameter ( β 1 ), variable thermal Parameter (ϵ ), thermal conductivity (K) are depicted through tables and graphs. The present simulation is more stable and convergence when compared with the existing literature, which is portrayed in the tables. The presence of dual solution is noticed for Ec 1 = 0.1, 0.11,0.12 when the critical value of λ (= λ c ) are λ c 1 = - 1.60355799, λ c 2 = - 1.60322884 and λ c 3 = - 1.6031348, respectively. The existence of the dual solution is reported due to the presence of shrinking surface and suction, further, the first solution is found to be more stable. The novelty of the current simulation includes MHD hybrid nano liquid flow stability with the impact of viscous dissipation and thermal radiation past stretching/shrinking permeable plane to fill the research gap in the existing literature. The applications of transmission of heat by stretching/shrinking surface in boundary layers is used in various fields such as polymer and material processing, biomedical engineering, heat exchangers, etc. [ABSTRACT FROM AUTHOR]

The combination of common semiconductors with porous materials has the potential to augment the splitting of electrons and holes, hence increasing the efficiency of photodetectors. In the current study, we present the efficient fabrication of photodetectors consisting of vanadium pentoxide (V2O5) and macroporous structures via the pulsed laser deposition technique. The structure, surface morphology, and optical properties of V2O5 nanostructures embedded in porous silicon were examined using an X-ray diffractometer, a field emission scanning electron microscope, and a UV–Vis–NIR diffuse reflectance spectrophotometer, photoluminescence emission spectra, and Fourier transformation infrared spectroscopy. The findings indicate that the V2O5 nanostructure exhibits an orthorhombic crystal structure, which tends to align along the (001) plane. These nanostructures were distributed on porous silicon surfaces, mainly within the pores, which range in size from 52.4 nm to 106.5 nm. The level of pore filling varies depending on the laser energy used, ranging from partial to almost complete filling. The room-temperature photoluminescence peaks of V2O5 nanostructure/porous silicon possess four distinct spectra characterized by their maximum emission wavelengths of around 461 nm and 664 nm.However, the electrical and spectral responsivity properties were measured before and after introducing V2O5 nanostructures into porous silicon. The ideality factor of porous silicon has decreased after embedding V2O5 nanostructure in porous silicon. The deposition of V2O5 nanostructures into porous silicon resulted in a significant rise in spectrum responsivity, particularly at a wavelength of 471 nm. Moreover, the spectral responsivity exhibited a rising trend with increasing laser energy, reaching a maximum value of 0.31 A/W. The external quantum efficiency found its highest value at 78.93% when more incredible laser energy was used. The V2O5 nanostructure/porous silicon device fabricated in this work, consisting of a V2O5 nanostructure integrated with porous silicon, has remarkable potential as a high-efficiency photodetector in several photoelectronic technologies. [ABSTRACT FROM AUTHOR]

Jeffrey fluids, a subset of non-Newtonian fluids, have received substantial research attention owing to their versatile utility in industries, such as polymer processing, cosmetics, and glass manufacturing. This paper endeavors to introduce a pioneering outlook on the behavior of Jeffrey fluids by researching their intricate responses to an array of influencing factors, including slip conditions, thermal effects, magnetic fields, chemical influences, and pivotal roles in the enhancement of drug delivery systems. Jeffrey fluids hold particular significance in modeling physiological fluids found in biological systems, representing blood circulation with precision in terms of relaxation time and stress retardation. Interestingly, under specific conditions, when subjected to wall shear stress exceeding the yield strength, Jeffrey fluids transition to exhibit Newtonian fluid characteristics. Hence, we embark on a comprehensive exploration of the applicability of the Jeffrey fluid model across diverse industrial domains and its contribution to the realm of flow control. Our research focuses on the study of mixed convective Jeffrey fluid flow across an inclined vertical plate, considering the combined impacts of the Soret and Hall currents, along with slip conditions involving velocity, temperature, and concentration disparities. This intricate problem is analytically resolved through the careful use of the perturbation technique. Furthermore, the inclined angle parameter enhances the velocity profile, while the velocity slip parameter exhibits the opposite effect. Additionally, the thermal and concentration slip parameters attenuate the temperature and concentration profiles. [ABSTRACT FROM AUTHOR]

Transformer oil is used to maintain the core and winding of the transformer. The main tasks of transformer oil as an industrial oil are insulation and cooling of a transformer. In the current study, the thermophysical and thermal properties of transformer oil nanofluid with volume percentages of 0.017% and 0.56% have been experimentally investigated which improves the performance of the base fluid due to the high thermal conductivity coefficient of carbon nanotubes compared to transformer oil. Ultrasonic baths and chemically functionalizing techniques were utilized in a two-step process to create nanofluids, which were stabilized by these techniques. In a double-tube carbon steel heat exchanger, the nanofluids were employed, and the thermal characteristics of the base fluid and nanofluids were evaluated. The findings indicated that the effective thermal conductivity improves with increasing temperature and CNT concentration, reaching its maximum value at a temperature of 45 °C in a volume fraction of 0.56. Observations showed that the heat transfer coefficient rose with rising Reynolds number and volume percentage, whereas the friction factor reduced when the hot fluid flowed at an intake temperature of 80 °C compared to the nanofluid in the outer tube. The flow rates for the nanofluids were calculated to be 0.2, 0.3, 0.4 lit/s, and 0.18 lit/s for the hot fluid, respectively. As a general conclusion, carbon nanotubes have a very high potential to improve the thermal performance of transformer oils, which is a serious challenge. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO NPs) were formed in the present paper, employing a pulsed laser irradiation approach on a pure zinc target surrounding double deionized water. The structure, morphology, chemical bonding, and optical characteristics of prepared ZnO nanoparticles were investigated using X-ray diffraction, transmission electron microscopy, spectrophotometer, and Fourier-transform infrared spectroscopy. The nanoparticles have a nanocrystalline structure with a hexagonal wurtzite arrangement and are spherical with diameters ranging from 5 to 60 nm depending on the laser energy. The analysis of ultraviolet–visible spectroscopy shows a blue shift with decreasing laser energy, and the optical energy bandgap increases as particle size decreases. The FTIR spectrum of ZnO nanoparticles identified at 512.37 cm−1 and 448.63 cm−1 was ascribed to Zn–O-Zn stretching vibrations. However, using the agar well diffusion technique, ZnO nanoparticles were tested for their antibacterial properties towards two distinct strains of bacteria. Antibacterial inspection demonstrated that ZnO nanoparticles were most effective against Staphylococcus aureus, followed by Escherichia coli. Furthermore, the anticancer potential treated with the ZnO nanoparticles was evaluated against the ovarian tumor cell line (SKOV-3), as well as the results suggest that the nanoparticles can function against an antiproliferative agent towards SKOV-3 cells. The present work illustrates the promise of biomedical applications of ZnO nanoparticles obtained by laser irradiation in water. [ABSTRACT FROM AUTHOR]

In this paper, we are studying the effect of different concentrations of CuO on the activation energy of ZnO/Ag2O/CuO ternary metal oxide nanocomposites. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Raman spectroscopy were used to determine the structural and topographical features of the produced samples. XRD data indicates that crystalline size increases while crystalline % decreases as the concentration of CuO increases. A FESEM result shows that particle size increases as the CuO concentration increases in ternary metal oxides. Raman spectroscopy indicates that the peaks that are obtained are ZnO, Ag2O and CuO peaks. In a dc conductivity measurement, we have seen that when we increase the concentration of CuO in ternary metal oxide, the activation energy increases. We have found that the less concentrated CuO in ternary metal oxides ZnO/Ag2O/CuO which have low activation energies indicates that this may be a very stable catalyst with a high rate of activity. [ABSTRACT FROM AUTHOR]

The aim of the current effort was to analyze two-dimensional unsteady squeezing Casson fluid flow among porous channels. Flow field was impressed into uniform magnetic field affecting normal through that plate axes. The interaction on flow model into chemically reacting solute was formed over this advection–diffusion equation on that temperature dependency by that reaction rate of activation energy was studied. The Energy equation comprising thermal stratification and source terms was considered. To make the solutions on governing equations that was partial differential equations in kind, they have transformed them along ordinary differential equations to utilizing suitable comparison transformation and it is used in finite element method. This effect on sundry parameters by flow, concentration and temperature fields was considered into the use of graphic illustrations. Solutions display into improvement on that values of this magnetic parameter and Casson parameter, this velocity reduces nearby bottom plate although that indicates opposite performance into the above one. This temperature on the fluid raises into developing the two radiation parameter along the Eckert number although reduces into augmenting values by the stratification parameter. The significant data were the activation energy on chemical reaction unusually changes the solute concentration in that fluid flow. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: In pregnancies where the mother has glucokinase-MODY (GCK-MODY), fetal growth is determined by fetal genotype. When the fetus inherits a maternal pathogenic GCK variant, normal fetal growth is anticipated, and insulin treatment of maternal hyperglycaemia is not recommended. At present, fetal genotype is estimated from measurement of fetal abdominal circumference on ultrasound. Non-invasive prenatal testing of fetal GCK genotype (NIPT-GCK) using cell-free DNA in maternal blood has recently been developed. We aimed to compare the diagnostic accuracy of NIPT-GCK with that of ultrasound, and determine the feasibility of using NIPT-GCK to guide pregnancy management. Methods: We studied an international cohort of pregnant women with hyperglycaemia due to GCK-MODY. We compared the diagnostic accuracy of NIPT-GCK with that of measurement of fetal abdominal circumference at 28 weeks' gestation (n=38) using a directly genotyped offspring sample as the reference standard. In a feasibility study, we assessed the time to result given to clinicians in 43 consecutive pregnancies affected by GCK-MODY between July 2019 and September 2021. Results: In terms of diagnostic accuracy, NIPT-GCK was more sensitive and specific than ultrasound in predicting fetal genotype (sensitivity 100% and specificity 96% for NIPT-GCK vs sensitivity 53% and specificity 61% for fetal abdominal circumference 75th percentile). In terms of feasibility, a valid NIPT-GCK fetal genotype (≥95% probability) was reported in all 38 pregnancies with an amenable variant and repeated samples when needed. The median time to report was 5 weeks (IQR 3–8 weeks). For the 25 samples received before 20 weeks' gestation, results were reported at a median gestational age of 20 weeks (IQR 18–24), with 23/25 (92%) reported before 28 weeks. Conclusions/interpretation: Non-invasive prenatal testing of fetal genotype in GCK-MODY pregnancies is highly accurate and is capable of providing a result before the last trimester for most patients. This means that non-invasive prenatal testing of fetal genotype is the optimal approach to management of GCK-MODY pregnancies. [ABSTRACT FROM AUTHOR]

CPU computes several complex algorithms at billions of cycles per second. It is acceptable to generate some heat while working at such great speed. In order to reduce the problem of high temperature, which slows down the performance of tasks, a new heat sink with convex-parabolic fins was designed to study the best heat dissipation methods to reach the cooling efficiency of the processor so that it performs all tasks without any problems. On the other hand, the new heat sink was cooled by the hybrid nanofluid, and all the equations governing the phenomenon were solved by the finite volume method, and the results were reported at Reynolds numbers and fin numbers. From the results, the cooling efficiency was improved by 74% when a large number of fins were used. Besides that, the maximum temperature of the heat sink decreases by increasing the number of convex-parabolic fins, giving the processor a cool surface to perform tasks without having to fear the problem of overheating. The results of this study can be used for the initial design of the heat sink and the improvement in the efficiency of cooling the Core I7 CPU. [ABSTRACT FROM AUTHOR]

In the current study, SnO2 nanoparticles were fabricated using laser ablation in water and characterized using ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The XRD results showed that the fabricated nanoparticles had a tetragonal crystal structure. TEM micrographs revealed that the nanoparticles were spherical, with average sizes ranging from 10 to 50 nm, depending on the laser energy used. The band gap energy of the SnO2 nanoparticles was found to increase with decreasing particle size. The antibacterial activity of the SnO2 nanoparticles was tested against Staphylococcus aureus and Escherichia coli, and the results showed that the nanoparticles were more effective against S. aureus. In addition, the anticancer activity of the SnO2 nanoparticles was tested against the lung cancer cell line A549 cells, and the findings suggest that the nanoparticles can act as an anti-proliferative agent against A549 cells. This study reveals that SnO2 nanoparticles that are synthesized by laser ablation in water could be a future strategy for other biomedical applications such as antifungal, antiviral, and immune modulators. [ABSTRACT FROM AUTHOR]

The numerical simulation of a shell-and-tube heat exchanger (STHE) depends on a large number of computational cells. The number of computational cells increases dramatically with increasing heat transfer surfaces in heat exchangers, such as increasing the number of tubes or using dimples as modified surfaces. Computational cost is one of the critical parameters in many industrial applications for heat exchanger analysis. The present study uses the P-NTU thermal analysis method, proposes correlations to predict heat transfer inside and outside the tubes, and then analyzes the STHE with elliptical dimples. The analytical approach shows 0.8% and 9% errors for two STHEs with specified heat performance, which is entirely acceptable. Also, for the STHE with elliptical dimples, the results indicate a 40.6% increase in the heat capacity of STHE. Increasing the heat capacity of STHE by using modified surfaces such as dimples significantly reduces the dimensions and weight of STHE in industrial applications. Furthermore, the analytical method can be used for different types of dimples with different geometries and arrangements. [ABSTRACT FROM AUTHOR]

Buildings' segmentation is a fundamental task in the field of earth observation and aerial imagery analysis. Most existing deep learning-based methods in the literature can be applied to a fixed or narrow-range spatial resolution imagery. In practical scenarios, users deal with a broad spectrum of image resolutions. Thus, a given aerial image often needs to be re-sampled to match the spatial resolution of the dataset used to train the deep learning model, which results in a degradation in segmentation performance. To overcome this challenge, we propose, in this manuscript, scale-invariant neural network (Sci-Net) architecture that segments buildings from wide-range spatial resolution aerial images. Specifically, our approach leverages UNet hierarchical representation and dense atrous spatial pyramid pooling to extract fine-grained multi-scale representations. Sci-Net significantly outperforms state-of-the-art models on the open cities AI and the multi-scale building datasets with a steady improvement margin across different spatial resolutions. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the properties of WO3 thin films deposited on glass and silicon substrates using the thermal spray technique. The films were prepared with a WO3 concentration of 10 mM and a deposition temperature of 350 °C. Different numbers of spray cycles ranging from 3 to 39 were applied. The X-ray diffraction analysis revealed that the crystal structure of the WO3 films exhibited a monoclinic phase, with a preferred orientation along the (hkl) (200) direction, which varied with the number of sprays. Field emission scanning electron microscopy images showed an increase in grain size with the number of sprays, ranging from 30.14 nm to 39.4 nm. Energy-dispersive X-ray spectroscopy (EDX) analysis indicated that the stoichiometry of the WO3 films was optimized at 12 spray cycles and a substrate temperature of 350 °C. The atomic ratio of tungsten to oxygen was found to be 26–74%, resulting in a W/O ratio of 2.84. Atomic force microscopy (AFM) images displayed varying average roughness values and root mean square values across different numbers of sprays, ranging from 19.73 to 49.74 nm and 25.85 to 54.76 nm, respectively. The Ultraviolet–Visible properties of the WO3 films demonstrated an absorption edge at a wavelength of 320 nm, which decreased at longer wavelengths. The energy gap of the films decreased from 3.63 to 2.98 eV, while the Urbach energy (Eu) increased from 0.455 to 2.639 eV. Electrical conductivity and activation energy (Ea) measurements were conducted under optimal conditions, resulting in a conductivity of 3.449 × 10–7 (Ω cm)−1 and an activation energy of 0.214 eV. [ABSTRACT FROM AUTHOR]

Hybrid nanofluids were popularized by heat transfer fluids into higher surface strength, dispersion and diffusion prospects related into traditional nanofluid. The novel characteristics of a single-phase hybrid nanofluid profile coincidence in studying nanoparticles mass including base fluid mass to produce solid equivalent density and addition to solid equivalent specific heat about constant pressure. On this work, flow and volumetric entropy generation and convective heat transport on Powell–Eyring hybrid nanofluid have been consider. Hybrid nanofluids attend the space through the systematic horizontal porous stretching surface. Impact on exponential space-dependent heat generation and nonlinear thermal radiation was more combined on the specified sketch. Mathematical equations about conservation of energy, mass, entropy and momentum are interpreted below acceptance on boundary layer flow of Powell–Eyring hybrid nanofluid. Comparison results were collected as conversion away from governing partial differential equations into ordinary differential equations, applying correlation variables. Finite element method was an external for finding the relative results of decreased ordinary differential equations. Numerical computing was achieved about zinc oxide–gold water (ZnO–Au/H2O) hybrid nanofluid and conventional gold water (Au–H2O) nanofluid. The notable allegation indicated to the hybrid Powell–Eyring nanofluid was best thermal conductor although related into a conventional nanofluid and pure water. Every rising on Reynolds number and Brinkman number developed into total entropy for that structure. [ABSTRACT FROM AUTHOR]

Recently, due to the fast development in multimedia applications of wireless communication systems and demands of increasing the capacity and data rates to meet the requirements of 5G mobile communication systems, new transmission techniques are needed. One of the powerful enabling tools of the 5G communication systems is the multi-input multi-output (MIMO) antenna system employing multiple antennas and utilizing the multipath fading mobile environment to increase the channel capacity without any additional bandwidth and/or transmitted power. However, because of the limited space of mobile devices, the distances between antennas are decreasing. The mutual coupling between antennas severely affects the overall performance of the MIMO system. So, isolation improvement methods are applied to reduce these influences. In this review, different isolation techniques and their features and drawbacks are presented, and the techniques for applying them in modern MIMO antenna systems are illustrated. Besides, the performance characteristics of these MIMO systems are compared. The review also contains basic concepts of the MIMO antenna system and its performance metrics. Finally, the future directions and trends for the MIMO antenna system design are discussed briefly. [ABSTRACT FROM AUTHOR]

Heavy metal pollution is a serious threat to the environment. The current study aims to assess the role of Bacillus anthracis PM21 for the adsorption of cadmium Cd(II), chromium Cr(VI), and nickel Ni(II) from contaminated water. Possible mechanisms and bacterial surface changes during the adsorption process were evaluated at constant temperature (35 ± 2 °C). The maximum biosorption (q) values 22, 57.04, and 5 mg/g for Cd, Cr, and Ni were observed at pH 8, 6, and 4, respectively. The optimum contact time for biosorption was 60 min at 50 mg L−1 concentration of heavy metals. Isotherm models were used to simulate the metals biosorption onto Bacillus anthracis PM21 surface at equilibrium. Langmuir's model gave the best fit with R2 values for Cd = 0.997, Cr = 0.996, and Ni = 0.976. The adsorption kinetics followed the pseudo-second-order kinetic model. The Fourier-transform infrared spectroscopy analysis showed that different surface ligands: OH, C–O–C, C=O, S=O, N–O, CH2, and C–H, could be involved in the biosorption of metals on to Bacillus anthracis PM21. The scanning electron microscope analysis showed that bacterial cells exposed to Cd, Cr, and Ni were rough and exhibited more cell size relative to the unexposed cells. There was adhesion of polymeric substances on the bacterial cell wall. Results revealed a variation in cell size, but cells maintained their shape. It is concluded that the B. anthracis PM21 is a promising biosorbent for the elimination of Cd(II), Cr(VI), and Ni(II) from aqueous solutions. [ABSTRACT FROM AUTHOR]

In the current investigation, hydromagnetic third grade pulsating nanofluid flow through a channel under the influence of Brownian motion, thermophoresis, radiative heat has been inspected. The influence of viscous dissipation, chemical reaction, and Ohmic heating is considered in the current investigation. The Buongiorno nanofluid model is implemented, and the analysis of entropy generation is carried out. The present investigation may be applicable in the fields of biomedical engineering, manufacturing industries as coolants, pressure surges, energy conservation, and nano-drug suspension in pharmaceuticals. The perturbation technique is employed on flow governing equations (partial differential equations (PDEs)) to convert into a set of ordinary differential equations (ODEs). The shooting process along with the support of Runge–Kutta fourth-order method is employed to solve the set of nonlinear ODEs. The impressions of dimensionless emerging physical parameters on pertinent flow variables are demonstrated by using graphical illustrations. The results portrayed that intensifying the Hartmann number, non-Newtonian, frequency, and material parameters decline the velocity of the nanofluid. Augmenting the Eckert number, Brownian motion, and thermophoresis parameter enhance the temperature whereas accelerating the radiation parameter and Hartmann number reduces the temperature. The nanoparticles concentration is enhanced for a rise in Brownian motion, while it decelerates for the higher values of Lewis number. The entropy and Bejan number are accelerated with the increment in radiation parameter. The heat and mass transfer rates are raised for augmenting the value of Brownian motion parameter. [ABSTRACT FROM AUTHOR]

Insulin resistance (IR) during obesity is linked to adipose tissue macrophage (ATM)-driven inflammation of adipose tissue. Whether anti-inflammatory glucocorticoids (GCs) at physiological levels modulate IR is unclear. Here, we report that deletion of the GC receptor (GR) in myeloid cells, including macrophages in mice, aggravates obesity-related IR by enhancing adipose tissue inflammation due to decreased anti-inflammatory ATM leading to exaggerated adipose tissue lipolysis and severe hepatic steatosis. In contrast, GR deletion in Kupffer cells alone does not alter IR. Co-culture experiments show that the absence of GR in macrophages directly causes reduced phospho-AKT and glucose uptake in adipocytes, suggesting an important function of GR in ATM. GR-deficient macrophages are refractory to alternative ATM-inducing IL-4 signaling, due to reduced STAT6 chromatin loading and diminished anti-inflammatory enhancer activation. We demonstrate that GR has an important function in macrophages during obesity by limiting adipose tissue inflammation and lipolysis to promote insulin sensitivity. Obesity and a high-fat diet can lead to insulin resistance in a process involving macrophage-mediated inflammation of adipose tissue. Here the authors show that glucocorticoid receptor-deficient macrophages have an elevated inflammatory response which aggravates insulin resistance implicating that glucocorticoids promote insulin-sensitizing actions via adipose tissue macrophages during obesity. [ABSTRACT FROM AUTHOR]

Colored dyes are major sources of environmental pollution. Mineralization using heterogeneous catalysts is the method to remove such environmental pollutants. Herein, a green approach is used to prepare the nanocomposites, in which pulsed laser ablation of liquid (PLAL) is used. The synthesis of a ternary nanocomposite of ZnO/CuO/Al2O3 as a photocatalyst to degrade methylene blue (MB) dye is performed in an optimized ratio of 3:1:1 at pH = 10.37. To evaluate the structural, morphological, and optical features of the synthesized ternary nanocomposite, XRD, Raman spectroscopy, scanning electron microscopy (SEM), EDS, atomic force microscope (AFM), and UV–vis spectroscopy are used. The XRD pattern confirms that the ternary nanocomposite is highly crystalline in nature. The Raman spectra confirm the formation of the ternary ZnO/CuO/Al2O3 heterostructures. The AFM images of the ratio 3:1:1 show less agglomeration than the 1:3:1 and 1:1:3 ratios. The SEM images show agglomerated spheroids with rice-like morphologies and a mean particle size of around 40 nm. The energy bandgap (Eg) values lie in the UV region at 5.05, which means that the photocatalyst has enhanced its photocatalytic activity under sunlight. The degradation efficiency of 3:1:1 at pH = 10.37 achieves the highest value of 98.55% with a rate constant of 0.2265 min−1 after 15 min of illumination. [ABSTRACT FROM AUTHOR]

A novel mathematical model for improving heat transfer using tri hybrid nanofluids is described in this paper. This study investigates the slip flow and radiative heat transfer over a moving sheet with polymer-based tri hybrid nanofluid. Under the imposed assumptions, equations governing the flow will be modeled. For nonlinear partial differential equations that cannot be solved accurately using similarity transformation, an ordinary differential equations system may be obtained. Numerical solutions to the streamlined equations will be found with the help of a BVP4C solver (MATLAB). The effects of the pertinent parameters on the velocity and temperature profiles along with the skin friction and heat transfer rates are discussed in detail through figures for both hybrid and tri hybrid nanofluid cases. It is reported that the Nusselt number, which measures the rate at which heat is transferred, is higher in tri hybrid nanofluid when compared to hybrid nanofluid flow. [ABSTRACT FROM AUTHOR]

At room temperature (RT), Tin dioxide (SnO2) nanoparticles (NPs) have been created through pulsed laser ablation (PLA) of tin in various liquid mediums. FTIR, TEM, electrical characteristics and UV–Visible absorption spectrum were used for investigating the particle properties. The prepared material is spherical NP, with size and size dispersion are dependent upon liquid media, as seen by TEM micrographs. The shift of the Sn–O band from 681 cm−1, 663.4 cm−1 to 657 cm−1 in double deionize water, ethanol and methanol, respectively, could be related to the increase of the concentration of SnO2 NPS and change of particles size. Depending on the quantum confinement model, the band gap energy related to SnO2 NPs is larger in various liquid medium compared to that of bulk SnO2 because of a decrease in size of the particle. Poor rectification properties because of charge carriers' recombination of holes and electrons in depletion region, along with the tunneling effect based on the two sides of heterojunction and existence of defect states can be seen in the J–V characteristics of Al/SnO2 NPs/c-Si/Al heterojunction. [ABSTRACT FROM AUTHOR]

Recently, Nanoparticles have supplied diverse challenges to several scientific issues. Nanoparticles dispersed in a variety of conventional fluids can change the flow and heat transmission properties of the fluids. The mathematical technique is used in this work to investigate the MHD water-based nanofluid flow via an upright cone. The heat and mass flux pattern is used in this mathematical model to examine MHD, viscous dissipation, radiation, chemical reactions and suction/injection processes. The finite difference approach was used to find the solution to the basic governing equations. A combination of nanofluids comprising nanoparticles including aluminum oxide (Al 2 O 3 ), silver (Ag), copper (Cu) and titanium dioxide (TiO 2 ) with a volume fraction of nanoparticles (0, 0.01, 0.02, 0.03, 0.04), viscous dissipation ( ϵ = 0.4 , 0.8 ), MHD (M = 0.5, 1.0), radiation (Rd = 0.4, 1.0, 2.0), chemical reaction ( λ = 0.2 , 2.0 ) and heat source/sink ( Δ = - 3 , - 2 , 0.5 , 1 ). The mathematical findings of velocity, temperature, concentration, skin friction, heat transfer rate as well as Sherwood number distributions are analyzed diagrammatically using non-dimensional flow parameters. It has been discovered that by increasing the value of the radiation parameter, velocity and temperature profiles enhance. The production of safe, high-quality products for consumers across the world depends on vertical cone mixers, from food to medicine, household cleansers to personal hygiene products. Every vertical cone mixer type we provide was especially developed to meet the demands of industry. As the mixer warms up on the slanted surface of the cone while vertical cone mixers are being utilized, the effectiveness of the grinding may be felt. The temperature is transferred along the cone's slant surface as a consequence of the mixture being mixed quickly and repeatedly. This study describes the heat transmission in these events and their parametric properties. The heated cone's temperature is then convective to its surroundings. [ABSTRACT FROM AUTHOR]

Studies show positive affect buffers against stress for people living with HIV, however, limited research has examined its potential health benefits for sexual minority men living with HIV (SMM-LHIV). In our proof-of-concept pilot, we adapted a Positive Affect intervention for mobile app delivery. The Positively Healthy app was designed as an ecological momentary intervention using a just-in-time adaptive intervention (JITAI) delivery format. Participants were 22 SMM-LHIV (Mage = 37.82; SD = 10.52), who completed a 90-day ecological momentary assessment (EMA). JITAI activities were triggered based on reported stress in the EMA survey. Participants completed a post-intervention assessment assessing usability, feasibility, and acceptability. On average, participants reported stress in 58.21% of the EMAs and responded to 82.1% of the intervention activities. Qualitative interview data indicated that app-based delivery was acceptable and feasible. Participant feedback also revealed our intervention would benefit from further adaptation to enhance system usability and tailored content to optimize acceptability for SMM-LWH. [ABSTRACT FROM AUTHOR]

This study aims to investigate the application of amorphous carbon nitride (CNx) as an alternative anti-reflection coating (ARC) to crystalline silicon solar cells. The CNx films were deposited by reactive RF magnetron sputtering. The measured optical constants were used as input parameters in the PC1D program to simulate the photovoltaic performance of the solar cells. The impact of various refractive indexes and the thickness of the CNx coating as ARC were investigated. Findings revealed that the average reflectance was reduced by 64% using the CNx coating in the 300–1300 nm wavelength range. At the optimum thickness of 85 nm, the power conversion efficiency has increased by 57% compared with the bare silicon solar cell. The results confirm that the contribution to efficiency improvement comes from the gain in short circuit current density rather than the increment in open-circuit voltage. Results also show that the fill factor has an insignificant contribution to efficiency improvement. The external quantum efficiency (EQE) for coating thicknesses between 70 and 90 nm increased by 69% at a wavelength of 600 nm. The present simulation study confirmed that the application of CNx coating is a potential candidate as ARC material for efficient c-Si solar cells. [ABSTRACT FROM AUTHOR]

Crystalline silicon (c-Si) solar cells have dominated the photovoltaic industry for decades. However, due to high reflectivity and the presence of numerous types of surface contaminants, the solar cell only absorbs a limited amount of the incident solar radiation. To improve the efficiency of the solar cell, anti-reflection and self-cleaning coatings must be applied to the surface. The main objective of this work is to synthesize an amorphous carbon nitride CNx thin film as a novel dual-function anti-reflection coating (ARC) for c-Si solar cells. The CNx film was synthesized by the RF magnetron sputtering technique and characterized by different chemical, structural, and optical analysis techniques. The performance of CNx film was investigated via measuring the reflectance, photoelectric conversion efficiency, and external quantum efficiency. The minimum reflectance was 0.3% at 550 nm wavelength, and the external quantum efficiency achieved was more than 90% within the broad wavelength range. The open circuit voltage and short circuit current density that have been achieved are 578 mV and 33.85 mAcm−2, respectively. Finally, a photoelectric conversion efficiency of 13.05% was achieved with the coated c-Si solar cell in comparison with 5.52% for the uncoated c-Si solar cell. This study shows that CNx films have promising application potential as an efficient ARC for c-Si solar cells as compared to traditional ARC materials. [ABSTRACT FROM AUTHOR]

The energy transport enhancement is a topical problem for many engineering applications. One of the possible solutions to this problem is an improvement of the heat transfer surface. The present investigation is devoted to numerical simulation regarding turbulent forced convective energy transport inside a curved channel under the isothermal heating from the upper wavy wall and cooling from the inlet section. The governing partial differential equations written using the Reynolds-averaged Navier-Stokes formulation including the standard k - ε approach have been solved numerically by the finite-element procedure. Impacts of the Reynolds number, undulations number and undulations amplitude toward fluid motion and energy transport have been scrutinized. With the undulations number, a significant energy carrier condensation has been detected. [ABSTRACT FROM AUTHOR]

The study investigates the approach to enhance the thermal management of battery cell module by attaching number of inverted triangular cavity to its casing. A sinusoidal heating is considered to battery cell module or a left wall of the cavity. The sinusoidal heated region is considered to be a function of amplitude ratio. The objective is to transfer the heat from module using natural convection process. The enhanced heat transfer is possible by adopting hybrid nanofluid in a triangular cavity due to its improved thermophysical properties. Thus, the investigation on natural convection heat transfer, fluid flow, and irreversibility within an inverted right-angled triangular porous cavity is conducted. Numerical results are obtained through an own-house FORTRAN coding, that uses the streamfunction–vorticity algorithm. The numerical results are derived for various values with Rayleigh number (103-106\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${10}^{3}-{10}^{6}$$\end{document}), Darcy number (10-5-10-1)\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${10}^{-5}-{10}^{-1})$$\end{document}, Hartmann number (0-50)\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$0-50)$$\end{document}, amplitude ratio (0.0-0.9\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$0.0-0.9$$\end{document}) and volume fraction of nanoparticles (0.01-0.04\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$0.01-0.04$$\end{document}), respectively. The irreversibility and flow results are compared with the various hybrid nanofluids. The study indicates that opting inverted right-angled triangular cavity rather than a square shape leads to an improvement in heat transfer. Accordingly, this inverted right-angled triangular cavity natural convective cooling can be considered as optimum design with the battery cell module for improved thermal management.Graphical abstract: The study investigates the approach to enhance the thermal management of battery cell module by attaching number of inverted triangular cavity to its casing. A sinusoidal heating is considered to battery cell module or a left wall of the cavity. The sinusoidal heated region is considered to be a function of amplitude ratio. The objective is to transfer the heat from module using natural convection process. The enhanced heat transfer is possible by adopting hybrid nanofluid in a triangular cavity due to its improved thermophysical properties. Thus, the investigation on natural convection heat transfer, fluid flow, and irreversibility within an inverted right-angled triangular porous cavity is conducted. Numerical results are obtained through an own-house FORTRAN coding, that uses the streamfunction–vorticity algorithm. The numerical results are derived for various values with Rayleigh number (103-106\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${10}^{3}-{10}^{6}$$\end{document}), Darcy number (10-5-10-1)\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${10}^{-5}-{10}^{-1})$$\end{document}, Hartmann number (0-50)\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$0-50)$$\end{document}, amplitude ratio (0.0-0.9\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$0.0-0.9$$\end{document}) and volume fraction of nanoparticles (0.01-0.04\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$0.01-0.04$$\end{document}), respectively. The irreversibility and flow results are compared with the various hybrid nanofluids. The study indicates that opting inverted right-angled triangular cavity rather than a square shape leads to an improvement in heat transfer. Accordingly, this inverted right-angled triangular cavity natural convective cooling can be considered as optimum design with the battery cell module for improved thermal management. [ABSTRACT FROM AUTHOR]

This study examines the magnetohydrodynamic flow of hybrid silver-alumina (Ag-Al 2 O 3 )/water nanofluid within a corrugated trapezoidal cavity that contains a heat-generating rotating solid cylinder. The hybrid nanofluid flow and convective heat transfer are modelled using a single-phase approach. The governing equations for fluid flow and convective heat transfer are solved using the penalty finite element method. The finite element algorithm was validated against previously published work, and it was found to be in good agreement with the existing literature. We investigate the effects of the Ag and Al 2 O 3 nanoparticle diameters and the radius of the heat-generating solid cylinder on streamlines, isotherms and average Nusselt number. The results of this study reveal that the flow circulation regions near the rotating cylinder are enhanced with increased nanoparticle diameters and cylinder radius. Moreover, the nanofluid temperature and heat transfer rate are increased with reduced nanoparticle diameters and increased cylinder radius. [ABSTRACT FROM AUTHOR]

The present work elucidates the hydrothermal characteristics within a non-Darcian porous complex wavy enclosure saturated with Al 2 O 3 –Cu– H 2 O hybrid nanofluid considering a uniform magnetic field. The left sidewall of the enclosure is wavy and heated isothermally, whereas the other sidewall is maintained at ambient temperature, all other walls are insulated. The Forchheimer–Brinkman-extended Darcy model is implemented to analyze the flow through porous media. The dimensionless transport equations are numerically solved following the finite volume-based in-house computational code with successive staggered non-uniform mesh distribution. The hydrothermal behaviors are investigated meticulously changing the dimensionless variables like undulation amplitude (λ ), Hartmann number (Ha), Darcy number (Da), and modified-Rayleigh number ( Ra m ). The remarkable results reveal that enhancing the heating surface area by heightening the amplitude of the undulation always leads to higher heat transfer, but does not always favor the growth of the flow strength. The heightening of the flow strength with amplitude is noted for higher Ra m only. The flow intensity, as well as heat transfer, increases with the growing Ra m . The same decreases with increasing Da and Ha. Local distribution of heat transfer characteristics shows complex behavior depending on the amplitude of the undulations and associated dimensionless numbers. [ABSTRACT FROM AUTHOR]

A numerical study was conducted to determine the impact of MHD on mixed convection of a Cu-water nanofluid in a horizontal channel attached to two open enclosures filled with a porous material is implemented in this paper. Uniform heat is supplied on the base of the two enclosures while the other walls are considered adiabatic. The finite element method has been utilized in this study to solve the considered equations and other numerical simulations that needed to be validated, assessed with previous papers to ensure that the model works correctly. Furthermore, this study considers a range of each of the Reynolds number (Re = 25, 50, 100, 150, 200), Richardson number (Ri = 0.1, 1, 3, 5, 8, 10) and the Hartmann number (Ha = 0, 5, 10, 15, 30, 50) at a constant volume fraction ( φ = 0.08) and porous media properties (Da = 10-2, and ε = 0.7). The results stated that the strength of the streamlines, isotherms, and the average Nusselt number (Nu avg ) increases with increasing values of the Richardson and Reynolds numbers while they decrease upon increasing the Hartmann number. The result shows that no big difference between cases 2 and 3, and the maximum enhancement in Nu avg is 9.84% in case 2 compared with case 1 at Re = 200, Ri = 1, and Ha = 0. [ABSTRACT FROM AUTHOR]

In this study, natural laminar convection of Al 2 O 3 /water nanofluid in a cavity slightly different from shaped H was investigated using the monophasic model. The various parameters of this flow were determined numerically using CFD-Fluent software using the finite-volume method by introducing Boussinesq approximation. The analysis is carried out for three values of the Rayleigh number (10 5 ; 2.3 · 10 5 and 3.072 · 10 5) and for three values of the form factor defined for this enclosure (0.2; 0.3 and 0.4). The impact of Rayleigh number, nanofluid concentration and cavity form factor on dynamic and thermal structure of the flow was analyzed. The results are shown in form of streamlines, isotherms, and profiles of velocity, temperature, and Nusselt number. Nusselt number rises with increasing Rayleigh number and nanofluid concentration and decreases with the form factor of the cavity. This study is well developed relative to those carried out before. With using Al 2 O 3 nanofluid, the heat transfer is improved because its thermal conductivity is increased compared to that of the base fluid. Finally, to predict heat transfer inside cavity, correlations for the Nusselt number were proposed for each form factor of the cavity. These correlations are rarely presented in this type of study. [ABSTRACT FROM AUTHOR]

A nanofluid flow under the influence of magnetic field with heat generation/absorption is considered in the cooling of electronic systems, nuclear reactors and physical phenomena such as geology. For the first time, in the present work, natural convection heat transfer in a two-dimensional enclosure with three types of wall shapes filled with a cu-water nanofluid in terms of the effect of Brownian motion of nanoparticles with heat generation/absorption and in the presence of a magnetic field is investigated by using the Lattice Boltzmann Method (LBM). The left vertical wall of the enclosure is examined in two modes: constant temperature heating and linear temperature heating and the cold wall of the enclosure in three different forms (a) diagonal, (b) curved and (c) smooth. The effect of parameters such as the Hartmann number, nanoparticle volume fraction, heat generation/absorption coefficient, cold wall shape and the type of wall heating on the nature of flow and heat transfer is investigated. The results of the authors' research were validated with other sources, and the accuracy of the outputs was ensured. The outcomes of research show that in all instances, increasing the strength of the magnetic field and the heat generation/absorption coefficient decrease the average Nusselt number. In addition, the effect of Hartmann number in various states is different. The highest heat transfer also occurs when the vertical wall has a constant temperature. In this case, the average Nusselt number is about 35% higher on average. The effect of the magnetic field is greater when the cold wall is smooth. By keeping all the parameters constant, the diagonal wall design increases the average Nusselt number by an average of about 30%. The effect of adding nanoparticles to the base fluid on decreasing or increasing the average Nusselt number depends on the Hartmann number and the heat generation/absorption coefficient. Using this numerical simulation, a comprehensive view on the optimal design of heat transfer from equipment can be obtained. [ABSTRACT FROM AUTHOR]

In this paper, a hybrid computational fluid dynamics technique is proposed to study turbulent flow and conjugate heat transfer patterns. A typical shaped room with a radiant heating panel is considered. The mesoscopic lattice Boltzmann method coupled with the finite difference solution of macroscopic energy equation is used to compute the thermal and flow fields. To describe the radiant flux distribution along the solid–fluid interfaces, the Lambert law is implemented. An in-house code written in MatLab is validated against direct numerical simulation data obtained for a Rayleigh number up to 1011. A computational study is conducted when varying the Rayleigh number, heat flux density, radiant panel length, physical properties of the enclosure and external heat transfer coefficients with constant walls thickness and the ambient temperature. It is found that the air temperature is decreased in the room as the Rayleigh number is raised. The panel length is found to drastically affect the thermal field. However, the flow structure is altered insignificantly. The stagnant zone of air is formed at the bottom corners with low values of heat fluxes. [ABSTRACT FROM AUTHOR]

Millions of confidential images are transmitted every day by people through the multimedia systems of the internet. Such confidential information in the images may be belong to the political, business, medical or military authorities. Protecting the privacy and integrity of these images in the era of the internet and multimedia technologies has drawn more attention by the research community. Image encryption is one of the most important tools to secure digital images from the unauthorized access and malicious manipulation. In this paper, a new digital image encryption method is proposed based on bit replacing technique, chaotic systems and DNA coding algorithm. It aims to protect the confidentiality and privacy of the digital images sent over unsecure open channels. Firstly, in this method each pixel of the image is converted to its corresponding binary sequence comprising of zeros and ones bits. Then, the zero bit is replaced by (1 and 0) bits and the one bit is replaced by (0 and 1) bits. Two different images are eventually generated by repeating consistently the replacing operation for all bits of the image pixels. Secondly, the generated images are encrypted using high dimensional chaotic systems based on the principle of permutation and diffusion processes in objective to vary the positions and values of the digital image pixels. Thirdly, the resultant encrypted images are encoded by adopting DNA algorithm rules and then these images are merged by exploiting DNA addition operation. Finally, the coded DNA images are decoded to obtain the output encrypted image. The numerical and visual simulation results confirm that the proposed method is sufficiently robust and secure against several known attacks in comparsion with the state-of-art approaches. Also, the conducted experiments show significant improvement in terms of entropy, correlation, differential, discrepancy metrics, key space and computational speed analysis performance parameters. To sum up, the proposed approach produced large secret key space of (2747), a comparable differential analysis performance NPCR (99.61%) and UACI (34.61%) and passed all security and randomness tests. [ABSTRACT FROM AUTHOR]

This study employs a numerical solution approach to examine the impacts of viscous dissipative, MHD, among various nanofluid flows across an up straight cone with iso-thermal surface velocity and temperature. After being converted into dimensionless form, the flow field equation is numerically evaluated using an outstanding finite difference approach. Our experiment used different types of nanofluids (Cu, Al2O3, TiO2 and Ag) and volume fractions (0, 0.01, 0.02, 0.03, 0.04) to detect differences in heat transfer occurrence depending on temperature and velocity. Graphs have been used to show a parametric analysis for various flow field features. [ABSTRACT FROM AUTHOR]

The present study analyzes the forced convective boundary layer flow of viscous incompressible time-established fluid. The base fluid containing water-based nanoparticles and gyrotactic microbes. The flat surface is considered with leading-edge accretion (or) ablation. Characteristics of flow are explored by the impacts of thermal radiation and constructive/destructive chemical reaction. The present flow problem is formed with the partial differential equations, and transformed nonlinear boundary value problems are solved mathematically by the finite difference with the collocation method. There is a good correlation between present work and previous work. Results of selected parameters on velocity, temperature, nanoparticles volume fraction, and microbe density function are discovered. Skin friction, heat transport, mass transfer, and microbes transfer rates are tabular. Efforts of the current work rise in progressive microflow devices to bio-modified nanomaterial dispensation. [ABSTRACT FROM AUTHOR]

This paper examines the capability of hybrid lattice Boltzmann method to simulate developed turbulent buoyancy-driven flows in closed rectangular cavities. The two-relaxation time mesoscopic lattice Boltzmann method is used as a fluid dynamics solver, whereas the thermal behavior is described in terms of the macroscopic energy equation. Numerical simulation is performed for air-filled square and tall cavities in a range of the Rayleigh number 10 9 ≤ R a ≤ 10 11 . An in-house numerical code is developed in this study and successfully validated against up-to-date numerical and experimental data of other researches. It is found that the proposed hybrid approach accurately predicts the location of thermal plumes at the isothermal walls despite an insignificant error in the heat transfer rate with the R a ≥ 3 · 10 10 . [ABSTRACT FROM AUTHOR]

Exergy efficiency, Nusselt number, friction factor, pressure drop, thermal and frictional entropy generation of water-based nanodiamond + Fe3O4 nanofluid flow in a tube and with various coiled wire inserts have been studied experimentally under turbulent and constant heat flux boundary conditions. The experiments were conducted in the Reynolds number range from 2000 to 22,000, particle concentrations of 0.05%, 0.1% and 0.2% and coiled wire inserts of different p / d values of 3.67, 2.34 and 1.00, respectively. Results indicate that at 0.2% vol. and Reynolds number of 20,095, without coiled wire inserts, the heat transfer coefficient, Nusselt number, friction factor, pressure drop and pumping power are enhanced to 44.36%, 29.55%, 11.1%, 29.58% and 39.49% over the base fluid data. Similarly, at 0.2% vol. and Reynolds number of 20,095, with coiled wire inserts of p / d = 1, the heat transfer coefficient, Nusselt number, friction factor, pressure drop and pumping power are further enhanced to 107.19%, 66.36%, 38.84, 64.44% and 76.54% over the base fluid data without inserts. The thermal entropy generation is decreased to 30.80% and it is further decreased to 46.34% at 0.2% vol. and Reynolds number of 20,095 with coiled wire inserts of p / d = 1. The exergy efficiency of water is 18.95%, and it is increased to 24.06% for 0.2% vol. and it is further increased to 51.85% for 0.2% vol. and Reynolds number of 20,095 with coiled wire inserts of p / d = 1. The study indicates that the hybrid nanofluids with coiled wire inserts are guaranteed choice for augmenting the exergy efficiency of flow through tube. [ABSTRACT FROM AUTHOR]

This paper examines the capability of hybrid lattice Boltzmann method to simulate developed turbulent buoyancy-driven flows in closed rectangular cavities. The two-relaxation time mesoscopic lattice Boltzmann method is used as a fluid dynamics solver, whereas the thermal behavior is described in terms of the macroscopic energy equation. Numerical simulation is performed for air-filled square and tall cavities in a range of the Rayleigh number 10 9 ≤ R a ≤ 10 11 . An in-house numerical code is developed in this study and successfully validated against up-to-date numerical and experimental data of other researches. It is found that the proposed hybrid approach accurately predicts the location of thermal plumes at the isothermal walls despite an insignificant error in the heat transfer rate with the R a ≥ 3 · 10 10 . [ABSTRACT FROM AUTHOR]

The heat transport characteristics, flow features, and entropy-production of bi-convection buoyancy induced, radiation-assisted hydro-magnetic hybrid nanofluid flow with thermal sink/source effects are inspected in this study. The physical characteristics of hybrid nanofluids (water-hosted) are inherited from the base liquid (water) and none has considered the physical characteristics of base liquid (water) in the study of temperature-sensorial hybrid nanofluid investigations, though the water physical characteristics are not constants in temperature variations. So, the temperature-sensorial attributes of base liquid (water) are taken into account for this hybrid nanofluid ( C u + Al 2 O 3 + water ) flow analysis. The mathematical forms of the flow configuration (i.e., the set of coupled, nonlinear PDE form of governing equations) are solved by utilizing the subsequent tasks: (i) congenial transformation; (ii) quasilinearization; (iii) methods of finite differences to form block matrix system, and (iv) Varga's iterative algorithm. The preciseness of the whole numerical procedure is ensured by restricting the computation to follow strict convergence conditions. Finally, the numerically extracted results representing the impacts of various salient parameters on different profiles ( F , G , H ), gradients, and entropy production are exhibited in physical figures for better perception. A few noticeable results are highlighted as: velocity graph shows contrast behaviour under assisting and opposing buoyancy; temperature ( G (ξ , η) ) is dropping for heightening heat source (Q ) surface friction remarkably declines with the outlying magnetic field ( St ); thermal transport confronts drastic abatement under radiation ( R 1 ), and St ; the characteristics Reynolds and Brinkman numbers promote entropy. Furthermore, the bounding surface acts as a strong source of S G -production. Summarizations are listed at the end to quantify percentage variations. [ABSTRACT FROM AUTHOR]

In this study, a theoretical analysis is performed to address the features of heat and mass transfer phenomena of two-dimensional viscous fluid flow of Oldroyd-B nanofluid over a vertical stretched sheet which contains gyrotactic microorganisms by considering the mixed convection and inclined magnetic field effects. The induced flow features have been considered by triple stratified medium. Additionally thermal radiation effect is included in the energy equation. To make the present study reasonably worthy, impact of Joule heating and heat sink/source is also considered. By applying the defined similarity transformations physical flow system is reduced to nonlinear system. Thereafter, numerical solution with desired accuracy is obtained with the help of RKF-45 method. Graphical representation is done for the flow controlling parameters involved in this analysis. Main observations of the present study are velocity distribution declined with a relaxation time and thermal stratification parameter and motile density profile is promoted by increasing bioconvection Rayleigh number and buoyancy ratio. These results are reasonable correlated with the previous findings reported in literature. Based on these scientific reports, this work is relevant to bio-inspired nanofluid-enhanced fuel cells and nanomaterials fabrication processes. [ABSTRACT FROM AUTHOR]