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This paper presents an optimization of the Al2O3/distilled water-based nanofluid process parameters for enhancing its thermal conductivity. Nanoparticle volume concentration, nanoparticle size, sonication time, stirring time, and surfactant volume concentration are selected as optimization factors to obtain higher thermal conductivity. Eighteen different nanofluid samples having various preparation parameters are determined and prepared as per the Taguchi orthogonal array. Thermal conductivity was measured using the KD2 Pro thermal properties analyzer at a working temperature of 28 °C. To study the structure and crystallite size of alumina nanoparticles, we used X-ray diffraction. A scanning electron microscope is used to investigate the morphology and size of Al2O3 nanoparticles. To assess the effect of each parameter on thermal conductivity, the main effect plot for means and the signal-to-noise ratio are utilized. The statistical contribution percentage of each parameter on thermal conductivity is determined using an analysis of variance. The signal-to-noise ratio demonstrated that the nanoparticle concentration in a base fluid is the most affecting parameter, with a delta value of 0.715. Furthermore, with delta values of 0.461, 0.413, 0.272, and 0.177, the stirring time, sonication time, surfactant concentration, and nanoparticle size all play significant roles in nanofluid thermal conductivity. The outcome of the analysis of variance shows that the nanoparticle concentration in the base fluid has the most significant impact on the thermal conductivity of the nanofluid with a contribution of 36.64%, whereas initial stirring has a contribution of 26.82% and sonication time has a contribution of 19.76%, while surfactant concentration has an 8.83% contribution and nanoparticle size has a less significant contribution with a 4.06% contribution on the thermal conductivity of the nanofluid. The obtained results indicate that the thermal conductivity of the Al2O3/distilled water-based nanofluid increased by 7.146% compared to the base fluid, i.e., distilled water. The optimum thermal conductivity is obtained as 0.640732 W/m-K at optimum parameter settings of 0.3% of nanoparticle concentration, with a nanoparticle size of 50 nm, 40 minutes of sonication time, and 10 minutes of initial stirring time with 0.2% of surfactant concentration, A confirmation test with optimized parameters was finally carried out to ensure the method's confidence. [ABSTRACT FROM AUTHOR]

In recent years, researchers have used nanomaterials as additives in base lubricating oils to improve spesification, especially to minimize wear and friction in their applications. Nanolubricant is a new engineering lubricant, made of nanoparticles suspended in base lubricating oil. Calcium carbonate (CaCO3) nanoparticles were chosen as additives that can be a protective layer from direct contact friction between components that have anti-wear properties. As synthesized samples will be characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FTIR) to determine the phase, morphology and functional groups of CaCO3 from scallop shells. XRD results show a particle size of 35.48 nm. SEM images show irregular particle shape. FTIR results display carbonate groups and natural characteristics of dolomite at wavelengths of 715.59 cm-1 and 875.68 cm−1. The viscosity and density results increased in proportion to the addition of CaCO3 nanoparticles. This study will give an insight into how nanolubricant additives can contribute to the reduction of material wear and friction that occurs in vehicle engines. [ABSTRACT FROM AUTHOR]

Vegetable oil is a liquid that has great potential and many advantages as the base material for cutting fluids used in machining processes. Mineral oil reserves will run out and are not environmentally friendly, so it is necessary to look for alternatives. Nanotechnology is currently widely applied to lubricants as additives. This study aims to determine analysis the volume fraction variation of calcium carbonate (CaCO3) nanoparticles as a bio-based lubricant additive as cutting fluid for sustainable machining. Calcium carbonate can be a protective layer from direct contact friction between materials that have anti-wear properties. Calcium carbonate from scallops shell as an additive was synthesized and then characterized using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), and Fourier Transform Infra-Red (FTIR). Calcium carbonate from scallops shell used as an additive has a crystal size of 35.484 nm and including an irregular round agglomeration morphology structure. The results of density and viscosity are directly proportional to the magnitude of the variation of the volume fraction of nanoparticles, the higher the volume fraction, the value of density and viscosity will also increase, besides that the viscosity value is observed to decrease with increasing temperature. The highest density value was 804.7458 kg/m3 at 0.2% volume fraction variation, while the lowest density value was 765.1670 kg/m3 at 0% volume fraction variation. While the highest viscosity value was obtained at 0.2% volume variation in all variations of temperature and rotor rotational speed. [ABSTRACT FROM AUTHOR]

The major aim of the study is to biosynthesised silver nanoparticles fromGossypiumhirsutumand chitosan coated silver nanoparticles compare their morphology analysis using scanning electron microscopy depending on size and frequency. Materials and methods: Biosynthesised silver nanoparticles and chitosan coated silver nanoparticles were synthesized by biosynthetic approach. Here, two groups were analyzed with sample size for each group was 5 and the total sample size was 10 with ∝=0.05, G power 80% and confidence interval 95%. The morphological characteristics of both biosynthesised silver nanoparticles and chitosan coated nanoparticles were examined by scanning electron microscope (SEM). Results: Scanning electron microscope (SEM) analysis reveals that biosynthesised silver nanoparticles (2500nm) have larger size particles when compared to chitosan coated silver nanoparticles. Biosynthesized silver nanoparticles found to be statistically significant 0.002 (p<0.05). Conclusion: Biosynthesised silver nanoparticles have larger size particles when compared with chitosan coated silver nanoparticles are examined by scanning electron microscope (SEM) analysis. Biosynthesised silver nanoparticle is having good optical property and it can be used in therapeutic agents [ABSTRACT FROM AUTHOR]

Poly(lactic-co-glycolic acid) is a biocompatible, biodegradable synthetic polymer, has tunable mechanical and degradation rate properties and the capability for controlled drug release. Encapsulation diclofenac sodium using carboxymethyl chitosan-modified poly(lactic-co-glycolic acid) nanoparticles (CMCh/PLGA/DS) were synthesized to enhance gastric retention followed by a controlled release in the small intestine to reduce the side effects due to frequent administration, such as gastric irritation and renal damage. Synthesis of nanoparticles was carried out using a double emulsion (water/oil/water) solvent evaporation method with poly(vinyl alcohol) as the emulsifier. Studies using infrared spectrophotometer show that the interaction between diclofenac sodium and polymer on nanoparticles is non-covalent with a spherical shape based on scanning electron microscope characterization. When compared to unmodified PLGA nanoparticles (PLGA/DS), encapsulation efficiency of CMCh/PLGA/DS nanoparticles was increased with a minimum release at pH 1.2 of 0.2% and controlled release at pH 6.8 of 90.9% up to 24 hours. [ABSTRACT FROM AUTHOR]