Aluminum Dioxide Research Articles

RSM Hybrid Modeling of a BSFC for a Single Cylinder Four Stroke CI Engine Fueled with Nano-additives Added to Diesel-biodiesel Fuel Blends

Introduction: The expanding need for fossil fuels emphasizes the necessity to comprehend renewable energy sources. Methods: This study examined the performance of a single-cylinder diesel engine using Jatropha biodiesel and aluminum dioxide—the research aimed to evaluate engine reactivity to compression ratio and load variations. The experiment employed with varitaion compression ratios. Results: This study used the Response Surface Methodology to find the best Brake Specific Fuel Consumption performance indicator location. The researchers used a Central Composite Design setup for analysis. A regression model employing the response surface approach was then created to predict fuel phase-out likelihood. Conclusion: This study examines multiple factors' effects. According to studies, Jatropha biodiesel and its blends may improve engine efficiency and lower brake-specific fuel consumption compared to diesel fuel. Minor input parameter modifications are needed to gain these benefits.

Performance and emissions of a CI engine using a diesel, jatropha biodiesel and biodiesel adopting Al2O3 nanomaterial as fuel blend.

A nanocomposites of aluminum dioxide was employed as a fuel additive in a compression engine test. Nanoparticle stability in diesel was measured by their impact on the fuel's flash point, density, and viscosity. When compared to other forms of fuel, conventional biodiesel has superior qualities. Al2O3 was also put through its paces in terms performance of engine and pollution testing. The thermal efficiency of the engine's brakes may be improved by adding nanoparticles in to the jatropha biodiesel. Using Al2O3 nanoparticles has been shown to reduce brake-specific fuel consumption by 23%. In addition, this solution can cut hydrocarbon emissions by 19%.

Aluminum exposure levels in workers at electrolytic production

Introduction. Occupational exposure to aluminum has been established to lead to accumulation of metal in tissues and create a risk of functional impairment in the central nervous system. The aim of the work was to assess the levels of external and internal aluminum exposure in workers at the electrolytic production of aluminum under modern occupation conditions. Materials and methods. Two hundred fifty measurements of the average shift aluminum oxide concentration were analyzed at various stages of the technological process. The urine aluminum concentration urine was determined by the atomic absorption method. Results. The aluminum oxide concentration in the housings with the unbaked anode technology varied from 0.59 to 17.95 mg/m3. The MPC was exceeded at the electrolyzer workplace in 10% of measurements, the anode maker — in 40%, and the crane operator – in 50%. In housings with a baked anode, the aluminum oxide concentration in all measurements did not exceed the MPC. The highest aluminum emission was observed in occupational groups associated with unbaked anodes. A trend model was constructed for the dependence of urine aluminum concentration on the aluminum dioxide level in the air, which has the form of an exponential curve. The bend in the curve begins with an air aluminum dioxide content of about 4.2 mg/m3. Limitations. The study is limited by the number of examined workers who underwent periodic medical examination. Conclusion. The results of biomonitoring showed the elimination of aluminum with urine to reflect the level of exposure to the toxicant. The equation of the dependence of the urine aluminum concentration on the air aluminum dioxide level was calculated.

Performance analysis of Plate type Steam Condenser Using Nano-fluid

Abstract This paper investigates the application of nanofluid coolant, specifically a mixture of water and aluminium dioxide (Al2O3) nanoparticles, to augment heat transfer efficiency within flat plate heat exchanger. Beginning with an introduction highlighting the pivotal role of heat exchangers in industrial processes, the study emphasizes the imperative for enhanced efficiency and reduced energy consumption. The system description delineates the components and functionality of flat plate heat exchanger, elucidating operational and experimental conditions including initial temperatures and subsequent temperature transitions during cooling. Key parameters such as effectiveness and overall heat transfer coefficient are identified, with an exploration of their variation when comparing water alone to nanofluid coolant. Comparative data showcases experimentally obtained effectiveness and heat transfer coefficient values for both coolant types, revealing a substantial enhancement in efficiency with nanofluid coolant. Like effectiveness for water was 18% while that for nanofluid was 35%. The future potential and broader applications of nanofluid coolant in heat transfer technologies, advocating for continued research to unlock further advancements and efficiencies in industrial processes. By this technology we can reduce water losses as well as reduce power consumption in plants.

Gamma-ray shielding effectiveness, thermal, and dielectric properties of filler-reinforced high-density polyethylene/boron carbide composites

The present research prepared samples of pure high-density polyethylene (HDPE)/boron carbide reinforced with iron dioxide, aluminum dioxide, iron, and aluminum. The effectiveness of the prepared samples as a shielding material against gamma-rays and their thermal and dielectric properties have been evaluated. The shielding characteristics of the prepared composites were investigated theoretically using the Phy-X/PSD program and experimentally for gamma-rays emitted from 131Cs and 60Co radioactive isotopes. The shielding evaluation included the mass attenuation coefficient (μ/ρ), half value layer (HVL), mean free path (MFP), atomic and electronic cross-sections (σa&σe), effective atomic number and electron density (Zeff &Neff), and exposure build-up factor (EBF). The EBF peaks of samples containing Fe and Fe2O3 are 103 times lower than pure HDPE. The results indicate that samples C2 and C3 have a higher ability to protect against gamma radiation than that of the other investigated samples. X-ray diffractometer (XRD) spectrum shows that adding B4C, Fe, Fe2O3, Al, and Al2O3 to HDPE caused an increase in its full width at half maximum (FWHM) value and a decrease in its average crystallite diameters (D) at its primary characteristic scattering angle of 21.49°. Adding multiple types of fillers to HDPE results in a minor shift in the melting temperature of the hosting matrix as proved from differential scanning calorimetry (DSC) data. The composite of HDPE/B4C/Al2O3 60/10/30 demonstrated the most significant values of dielectric parameters in comparison with the other composites, in good accord with the XRD results. The ac conductivity relied on the dopant type in the hosting matrix; the highest value was observed for HDPE/B4C/Al2O3 composite.

Combined Experimental and Computational Insight into the Role of Substrate in the Synthesis of Two-Dimensional WSe2.

Synthesis of large-area transition-metal dichalcogenides (TMDs) with controlled orientation is a significant challenge to their industrial applications. Substrate plays a vital role in determining the final quality of monolayer materials grown via the chemical vapor deposition process by controlling their orientation, crystal structure, and grain boundary. This study determined the binding energy and equilibrium distance for tungsten diselenide (WSe2) monolayers on crystalline and amorphous silicon dioxide and aluminum dioxide substrates. Differently oriented WSe2 monolayers are considered to investigate the role of the substrate in the orientation, binding strength, and equilibrium distance. This study can pave the way to synthesizing high-quality two-dimensional (2D) materials for electronic and chemical applications.

ATROPHIC SCARS AS AN OBJECT OF INORGANIC GEL TREATMENT

Atrophic scars are a complex problem, covering a huge number of patients with striae gravidarum, acne, atrophic surgical scars, and striae due to hypercortisolism and other metabolic disorders. Taking into account patients’ social status (pregnant women, adolescents, people with chronic hormonal disorders), our goal was to systematize the literature data on the least invasive treatment modality – atrophic scar therapy with inorganic gels – to identify new chemical classes with potential anti-scar activity.
 When summarizing research data over the past 10 years, it was found that the effect of anti-scar therapy depends on the atrophic scar color – hyper- or hypopigmented, its type – wedge-shaped, scaphoid, or rectangular, its origin – post-acne, cicatricial alopecia, infectious scars, stretch marks, or post-traumatic atrophic. The stage of pathogenesis also plays a significant role: aseptic inflammation, infiltration of hematogenous differential cells, mast cell degranulation, release of bioactive substances and changes in the VEGF, TGF-β1, EGF, FGF, PDGF growth factors, migration of activated macrophages, damage to elastic and collagen fibers, perivascular lymphocytic infiltration, impaired hemorheology, chronic inflammatory process, increased number of senescent fibroblasts, decreased synthetic activity of atrophic scar cells, decreased cellularity and vascularization of the atrophic scar area. In case of high bioinertness of inorganic gels, the anti-scar effect is achieved due to the exfoliating effect, epidermal-mesenchymal interactions, and the impact of the mesoporous gel structure on scar hydration. In addition to the well-known silicone gel, sol-gels based on aluminum dioxide have similar properties, which makes it possible to consider sol-gel as an alternative to silicone gel.

Entropy generation and Cattaneo-Christov heat flux effects on Williamson hybrid nanofluid flow through various radiations and geometries: A comparative study

This entire study aims to prove the impacts of linear radiation, nonlinear thermal radiation, and quadratic radiation entropy generation on Williamson hybrid nanofluids through a comparative analysis of the magnetohydrodynamic flow in a porous material over a stretching cylinder and plate. We used hybrid nanofluid blood based on silver (Ag) and aluminum dioxide () nanoparticles. Using the Runge-Kutta technique of fourth order, the controlling nonlinear coupled Partial Differential Equations (PDE) are converted into nonlinear coupled Ordinary Differential Equations (ODE). Both numerical and homotopy perturbation methods are used to find the best solution for the nonlinear system. The findings are presented in a table and as graphical representations for a variety of parameters, including temperature, Bejan number, streamlines, entropy generation, and three-dimensional graphs of skin friction and Nusselt number. In this model, we compare the three different thermal radiations over the cylinder and plate compression, and those are represented via graphs. The velocity profile decreases for Williamson hybrid nanofluids over both cylinders and plates, while the magnetic field parameters increase. Furthermore, the results demonstrate a high level of agreement with earlier literature when compared. Our model may apply to physiological systems, pharmacological transport phenomena, and medical simulation tools. During endoscopy, a magnetic force field identifies or treats diseases. surgical procedures, nano-pharmacological delivery systems, etc.

Dielectric Properties of Compacts Sintered after High-Pressure Forming of Lithium Fluoride

High-pressure forming at 300 MPa and room temperature was applied before the sintering of a lithium fluoride (LiF) powder. The as-fired samples were tested as dielectrics and showed very interesting characteristics. The best sample, sintered at 750 °C for 8 h, had a relative permittivity of 12.1 and a loss tangent of 0.0006, both of them frequency-independent and temperature-independent up to at least 150 °C, and moreover, the volume DC resistivity was 27.4 × 1012 Ωm at room temperature. These parameters are comparable with oxide ceramics, processed at temperatures over 1300 °C, as for example, aluminum dioxide (Al2O3) or Y3Al5O12 (YAG). LiF material is advantageous because of its very low sintering temperature, which is only about one-half of typical oxide ceramic dielectrics.

Influence of process parameters on the tribological behaviour of dual reinforcement (Al2O3 / Si3N4) in AA6061 metal matrix composite

The wear behaviour of AA6061 aluminium alloy composites reinforced with aluminium dioxide, silicon nitride, and graphite was investigated and predicted in this study. The combined effect of input factors such as sliding speed, sliding distance, and applied load on the composite's friction coefficient and wear loss was investigated. The wear examinations were carried out with the help of a computerised pin on disc tribometer. To ensure that the tests were carried out in a systematic manner, the response surface methodology (RSM) technique was adopted. The ANOVA technique was selected to find the significant parameters that influence the selected responses. According to the results, RSM technique has better reliability in predicting composite's wear behaviour. The wear loss of the hybrid composite materials increases as the sliding speed, sliding distance, and applied load increase.

Entropic analysis of cilia-modulated slip flow of trimetallic nanofluid through electroosmotic corrugated pump in the presence of inclined magnetic field

An incredible eradication of thermal indulgence is required to enhance the flow and heat transfer enhancement in micro/nanofluidic devices. In addition, the rapid transport and instantaneous mixing of colloidal suspensions of metallic particles at nanoscale are exceptionally crucial at ascendency of inertial and surface forces. To address these challenges, the present work is intended to investigate the role of trimetallic nanofluid comprising of three kinds of nano-sized granules (titanium oxide, Silica and Aluminium dioxide) with pure blood through a heated micropump in the presence of inclined magnetic field and axially implemented electric field. To ensure rapid mixing in unidirectional flow, the pump internal surface is lined-up with mimetic motile cilia with slip boundary. The embedded cilia whip in pattern due to dynein molecular motion controlled by time and produce a set of metachronal waves along the pump wall. The shooting technique is executed to compute the numerical solution. In a comparative glance it is revealed that the trimetallic nanofluid exhibits 10% higher heat transfer efficiency as compared to bi-hybrid and mono nanofluids. Moreover, the involvement of electroosmosis results in almost 17% decrease in the heat transfer rate if it values jumps from 1 to 5. The fluid temperature in case of trimetallic nanofluid is higher and thus keeps the heat transfer entropy and the total entropy lower. Furthermore, involvement of thermal radiated and momentum slip significantly contribute in reducing heat losses.

Role of phase change materials in thermal energy storage: Potential, recent progress and technical challenges

Thermal energy storage (TES) using phase change materials (PCM) have become promising solutions in addressing the energy fluctuation problem specifically in solar energy. However, the thermal conductivity of PCM is too low, which hinders TES and heat transfer rate. In recent days thermally enhanced PCMs are a promising candidate for TES and heat transfer applications. This research designates the review on various thermal conductivity and heat transfer enhancement techniques of PCMs like, increasing the heat transfer area, use of various highly conductive porous foam materials (copper, aluminium, nickel, graphite, and carbon), mix of materials, use of multiple PCM and nano dispersed PCM (Copper oxide (CuO), Aluminium dioxide (Al2O3), Carbon nanotubes (CNTs), graphene, etc.). Also, the long-term stability, phase segregation and super colling are extensively discussed. Furthermore, energy storage applications of highly conductive PCMs in advanced fields like solar thermal system, desalination units, pharmaceutical industry, fabrics, food processing, battery thermal management etc are discussed. It has been observed that porous materials/foam dispersed PCM had better heat transfer/storage capacity (thermal conductivity 2–500 times more). In addition, organic PCMs have been widely used, due to its long-term stability, low or no supercooling, less or no corrosion, and recyclability. The highly stable thermally enhanced PCMs are used for long-term TES/heat transfer applications.

Numerical investigation of the nanoparticles nature effect on the MHD behavior in a square cavity with a metallic obstacle

In this paper, a study is conducted to determine numerically the effect of the nanoparticles nature (Al2O3, CuO, and Fe3O4) on the thermo-magnetohydrodynamic behavior of a nanofluid in a square cavity with a circular obstacle. The left wall of this cavity is movable and provided with a cold temperature (Tc) and the right wall is exposed to a hot temperature (Th). However, the upper and lower walls are considered adiabatic. The purpose of this paper is to highlight the effect of aluminum dioxide, copper oxide, and iron trioxide nanoparticles on the thermal and hydrodynamic behavior under the influence of different volume fractions(0 ≤ φ ≤ 0.1), different Hartmann numbers (0 ≤ Ha ≤ 75) and Richardson number (0 ≤ Ri ≤5). The system of governing équations was solved by the finite element method adopting the Galerkine discretization. The obtained results showed that the CuO nanoparticles improve the heat transfer at the fluid and obstacle, in addition, the increase of Hartmann number reduces the heat capacity, especially with the use of Fe3O4 nanoparticles. This study falls within the context of improving the cooling rate of industrial equipment.

МОРФОЛОГИЧЕСКОЕ ИССЛЕДОВАНИЕ ПЕРЕВЯЗОЧНЫХ МАТЕРИАЛОВ ГЕМОСТАТИЧЕСКОЙ АКТИВНОСТИ У ЭКСПЕРИМЕНТАЛЬНЫХ ЖИВОТНЫХ

Subject. In recent years, scientific research has been carried out to create new means for stopping bleeding, developed on the basis of hybrid organic-inorganic materials that contrib-ute to ensuring effective stopping of bleeding, regardless of blood clotting factors.
 The purpose of the study. To conduct a morphological study in experimental conditions on animals for a comparative assessment of the hemostatic effect of dressings coated with aluminum dioxide and iron nanoparticles.
 Methodology. To assess the hemostatic effect, an experimental study was conducted in the morphological laboratory of the Central Research Institute of State Medical University named after Abuali Ibni Sino on male white rats of the Vistar breed, weighing from 202 to 395, divided into 3 groups: 1st (control) – a bleeding wound was observed before its sponta-neous stop; 2nd group – nanostructured Aloobene was used; 3rd – a bleeding wound was treat-ed nanostructured Fe2O3. When setting up the experiment, the following main indicators of bleeding were determined: the time of stopping bleeding and the volume of blood loss.
 Results. When using nanostructured Aloobene, elements of necrosis of the epidermis and dermis were noted – scab; fragments of destroyed hair follicles, hair, sebaceous and sweat glands in the scab; stagnant full-blooded vessels; inflammatory cellular infiltrates. In the der-mis and hypoderma, fullness and stagnation in the vessels, pronounced edema and destruction of fibrous-fibrous tissue were determined. Diffuse leukocyte infiltrates, foci of hemorrhage and necrosis were detected in places in the tissues. The inflammatory infiltrate forms clear contours of the de-marking line.
 Conclusions. The obtained results of a morphological study in experimental animals in-dicate a greater effectiveness of the blood-reducing effect when using aluminum oxide com-pared with iron oxide, the absence of toxic and teratogenic effects.

Synthesis and applications of nano aluminum dioxides

This review provides an overview of aluminium dioxide nanoparticles' synthesis, characterization,and applications in various methods. Aluminium dioxide is the main class of nanometal oxides used in different applications depending on the properties of the particles, which can control many chemical processes such as in imaging, catalysis, and environmental and medical applications. The reactivity of aluminum dioxide is mostly a candidate for various mechanical and energy research. It is noticed that the most abundant aluminum dioxide type is α- Al2O3 due to its higher density than other aluminum dioxide phases. Fabricating aluminum dioxide with a relatively small distribution has significant advantages in controllable deposition applications. It can give a highquality surface area with small particle sizes, which favors forming films and catalytic activity. There is a broad range of methods to synthesize metal oxides, but the most widely used method is based on less time-consuming processes and green condition systems.

Nanofluids for the cooling system

This work consists in studying the effect of the volume fraction on the thermophysical properties of three metal oxide nanofluids; titanium dioxide “TiO2”, copper oxide “CuO” and aluminum dioxide “Al2O3” dispersed in water, with the aim of using the nanofluids to reach Our goal is to improve the efficiency of solar energy systems by improving heat transfer and performance. This work allows to solve them by computer software. The model is performed with volume concentrations from 0% to 5%. The results obtained show that the thermal conductivity of TiO2/Water, CuO/Water and Al2O3/Water is increased by 7%, 8% and 9% respectively, as well as the specific heat decreases with the increase of the nanoparticles concentration.

Chemical and Mineralogical Composition Analysis of Different Nigerian Metakaolins

In this work, four different metakaolin samples (C01, A6060, B6075, and C12090) were investigated to determine their constituent elements and the relative quantities of the oxide contents associated with each of the elements. Kaolin samples were collected from different sites at Okpella, a village in the Edo state of Nigeria, West Africa. The metakaolin was produced by calcination at 750℃, which was followed by the dealumination process. The prepared samples were characterized by Field Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Resonance (FTIR) spectroscopy, and X-ray diffraction (XRD) technique. Digital images were obtained and analyzed to determine the texture and porosity of the samples. FE-SEM images showed a slight difference in the morphology of the samples. Differing percentages of metal oxides were determined from the samples using EDS analysis. The major oxides present in all the samples were Silica (Silicon oxide) and Alumina (Aluminium dioxide). Aluminium was completely absent in C12090 but had a large percentage of silicon (36%).

Broadband absorber using ultra-thin plasmonic metamaterials nanostructure in the visible and near-infrared regions

In this work, an ultra-thin plasmonic metamaterial nanostructure absorber is simulated using the finite difference time domain method in the visible and near-infrared regions. A periodic square titanium-silica cap coated with glass medium is mounted on top of a silver substrate. The presence of the glass host enhances the absorption bandwidth by 276%. With an almost perfect metal–insulator-metal absorber, over 90% absorbance has been obtained for wavelengths from 440 to 1850 nm, producing an absorption bandwidth of 1410 nm. The impact of changing dimensions and using different materials on the absorption spectra has been investigated in both visible and near-infrared regimes. The considered metals for the top layer are titanium, nickel, silver, aluminum, and gold; however, the insulators are silica, quartz, vanadium dioxide, methyl methacrylate, and aluminum dioxide. In addition, aluminum, silver, copper, and gold are then simulated as a substrate. The optimum structure, which produces the maximum absorber bandwidth, 1410 nm, with a higher absorption, over 90%, is Glass-Ti–SiO2–Ag. The finding illustrates that the optimum dimensions of the Ti–SiO2 cab and the square base unit cell of the silver substrate are 250 nm and 200 nm, respectively. Finally, the absorption bandwidth is calculated using different polarization angles ranges from 10° to 70° with a step10°.

Studies on the effect of applied load, sliding speed and temperature on the wear behavior of M50 steel reinforced with Al2O3 and / or graphene nanoparticles

The effects of applied load, sliding speed & temperature on the wear behavior of pure M50 alloy steel (M sample) and M50 reinforced with 10 wt.% Al2O3 (MA sample) & M50 hybrid reinforced with Al2O3 and graphene (MAG sample) were studied. The powders were mechanically mixed and sintered by spark plasma sintering (SPS) technique under Argon atmosphere at 1000 °C for 5 min under 35 MPa pressure. The sample surfaces were mechanically prepared to study the wear & friction behaviors via applying mechanical polishing using 0.05 μm diamond pastes and 1200 grit emery papers to enhance the surface roughness. The phase structure and microstructure were estimated using XRD, Electron Probe Micro-Analysis (EPMA, JAX-8230) and Energy Dispersive Spectroscopy (EDS, GENESIS 7000). The hardness and density of all samples were investigated according to HVS-1000 Vickers' hardness test and Archimedes’ principles, respectively. Friction and wear tests were carried on a high-temperature pin-on-disk tribometer (HT-1000). The investigated samples were cut into disk-shaped specimens with 8 mm thickness and 25 mm diameter. Then, the prepared specimens were sliding against silicon nitride (Si3N4) balls. The samples were exposed to four different loads (2, 5, 8, and 11 N). Also, four different sliding speeds (0.18, 0.36, 0.54, and 0.72 m/s) was performed at room temperature (RT). Another group of samples were tested at constant applied load of 11 N and constant sliding speed of 0.72 m/s for four different temperatures (RT, 150, 300, and 450 °C). MAG exhibited enhanced tribological properties compared with M and MA thanks to the synergic action between Al2O3 and graphene as well as the creation of iron oxides, aluminum dioxide, chromium oxide, molybdate, and silicon oxide on the formed tribo-film.

A review of passive methods in microchannel heat sink application through advanced geometric structure and nanofluids: Current advancements and challenges

AbstractMicrochannel heat sink (MCHS) is an advanced cooling technique to fulfil the cooling demand for electronic devices installed with high-power integrated circuit packages (microchips). Various microchannel designs have been innovated to improve the heat transfer performance in an MCHS. Specifically, the utilisation of nanotechnology in the form of nanofluid in an MCHS attracted the attention of researchers because of considerable enhancement of thermal conductivity in nanofluid even at a low nanoparticle concentration. However, a high-pressure drop was the main limitation as it controls the MCHS performance resulted from heat transfer augmentation. Therefore, this study aimed to critically summarise the challenges and limitations of both single and hybrid passive methods of MCHS. Furthermore, the performance of nanofluid as a coolant in the MCHS as affected by the type and concentration of nanoparticle and the type of base fluid was reviewed systematically. The review indicated that the hybrid MCHS provides a better cooling performance than MCHS with the single passive method as the former results in a higher heat transfer rate with minimal pressure drop penalty. Besides that, further heat transfer performance can be enhanced by dispersing aluminium dioxide (Al2O3) nanoparticles with a concentration of less than 2.0% (v/v) in the water-based coolant.