Improving the performance of a modified solar distiller with phase change material and parabolic trough collector.

The solar stills can solve the problem of freshwater shortage for the people living in remote areas. Through this work, the performance of hybrid solar desalination arrangement was investigated. The system comprised of parabolic trough solar collector, automatic solar tracking system, separation room, modified solar still, two condensation units, feed water tank, and supplementary and measuring tools. The effect of using various water flow rates on the effectiveness of parabolic trough solar collector was tested. Also, the influences of integrating condenser to the modified solar still with and without phase change material were studied. The experimental results revealed that the best flow rate for parabolic trough solar collector was obtained as 10 L/h (100 L/day), where its effectivity was 61%. Under this condition, the obtained freshwater was around 61 L/day from a total saline water of 100 L/day. In addition, integrating a condenser to the modified solar still improved its productivity. So, the total yields of conventional and modified solar stills were 2500 and 5145 mL/m2.day, respectively. Therefore, the distillate of modified solar still was improved by 105.8% as compared to that of the conventional solar still due to using the hot feed water and external condenser. Moreover, using phase change material enhanced the modified solar still yield. The total yield of conventional solar still and modified solar still with hot feed water, condenser, and phase change material was 2575 and 6150 mL/m2.day, respectively. Consequently, the productivity of the modified solar still with hot feed water, condenser, and phase change material was improved by around 138.83% over that of the conventional solar still. Finally, the conventional solar still had an average efficiency of 31.5%. Also, when using the hot feed water and external condenser with the modified solar still, the thermal efficiency was reported as 49.7%. Also, the modified solar still with hot water, condenser, and phase change material had a thermal efficiency of 56.5%. Finally, the water costs of 1 L from the CSS and MSS are 0.063 $ and 0.050 $, respectively.

Experimental and Computational Study of Mechanical and Thermal Characteristics of h-BN and GNP Infused Polymer Composites for Elevated Temperature Applications.

Polymer-based nanocomposites are being considered as replacements for conventional materials in medium to high-temperature applications. This article aims to discover the synergistic effects of reinforcements on the developed polymer-based nanocomposite. An epoxy-based polymer composite was manufactured by reinforcing graphene nanoplatelets (GNP) and h-boron nitride (h-BN) nanofillers. The composites were prepared by varying the reinforcements with the step of 0.1 from 0.1 to 0.6%. Ultrasonication was carried out to ensure the homogenous dispersion of reinforcements. Mechanical, thermal, functional, and scanning electron microscopy (SEM) analysis was carried out on the novel manufactured composites. The evaluation revealed that the polymer composite with GNP 0.2 by wt % has shown an increase in load-bearing capacity by 265% and flexural strength by 165% compared with the pristine form, and the polymer composite with GNP and h-BN 0.6 by wt % showed an increase in load-bearing capacity by 219% and flexural strength by 114% when compared with the pristine form. Furthermore, the evaluation showed that the novel prepared nanocomposite reinforced with GNP and h-BN withstands a higher temperature, around 340 °C, which is validated by thermogravimetric analysis (TGA) trials. The numerical simulation model is implemented to gather the synthesised nanocomposite's best composition and mechanical properties. The minor error between the simulation and experimental data endorses the model's validity. To demonstrate the industrial applicability of the presented material, a case study is proposed to predict the temperature range for compressor blades of gas turbine engines containing nanocomposite material as the substrate and graphene/h-BN as reinforcement particles.

Investigating the performance of dish solar distiller with phase change material mixed with Al2O3 nanoparticles under different water depths.

The problem of potable water shortage all over the world made the scientists seek for solutions to overcome this problem. Solar distiller is one of the introduced solutions, but it demerited by the low freshwater output. In this proposed paper, a design modification includes the use of a convex dish absorber instead of the flat absorber liner. The modified solar distiller is nominated by dish solar distiller. The base of dish solar distiller was circular. In addition, a cotton wick was used as a wetting material for facilitating the evaporation process inside the distiller. Besides, the effect of different water heights in the clearance around the dish dome was investigated for 1, 3, 5, 7, 9, and 12 cm. Finally, the space under the dish absorber is filled with a phase change material of paraffin wax mixed with aluminum oxide nanoparticles. Experimental results revealed that the best dish height that provided the highest freshwater productivity was 9 cm, where the average daily yields of dish solar distiller (at 9 cm) and conventional distillers were reported as 4500 and 3000 mL/m2.day, respectively. Then, the productivity of dish solar distiller was improved by around 50% over that of the conventional distiller. In addition, when using the phase change material, the average daily distillate of dish solar distiller was improved by approximately 95% compared to that of the conventional solar still, where the distillate of conventional still and dish solar distiller with phase change material at 9 cm water depth was 3580 and 6980 mL/m2.day, respectively. Besides, the maximum thermal efficiency of dish solar distiller was obtained when using phase change material at 9 cm water depth, where it was 62.4% compared to 30% for the conventional distiller.

Microwave assisted biodiesel production from chicken feather meal oil using Bio-Nano Calcium oxide derived from chicken egg shell.

Environmental concerns have initiated the search for greener measures to mitigate pollution issues. Bio Nano CaO was synthesized by reducing CaO extracted from chicken egg shell using tea decoction. The synthesized material was characterized by physico-chemical techniques such as XRD, TGA, BET surface area analyser, TGA and SEM techniques. XRD studied confirmed the crystalline nature of material. The prepared material was found to be stable till 450 οC from TGA study. The SEM pictures displayed uniform and discrete particles which portrays the high probable sites that maximises the catalytic activity. The optimization of microwave assisted Biodiesel synthesis from chicken feather oil through Transesterification process using the bio-synthesized catalytic material was the main aim of the study. A 500 W microwave irradiation of Chicken feather meal oil using 8:1 Methanol:Oil input, 1% Bio Nano CaO concentration, 5 min of reaction time resulted in 95% conversion of chicken feather meal oil into chicken feather meal methyl esters. The Biodiesel was showed low viscosity (4.15 mm2/s), high heating value (50 MJ/kg), high flash point (153οC), reasonable pour point (12 οC) and good cetane number (50 min). The future works will be concentrated on the engine studies related to Torque, fuel consumption, emission data by using the synthesized Biodiesel.

Eggshells biowaste for hydroxyapatite green synthesis using extract piper betel leaf - Evaluation of antibacterial and antibiofilm activity.

The present research work reports the biosynthesis of hydroxyapatite (HAp) from eggshells and green synthesis of HAp from eggshells with incorporation of Piper betel leaf extract (PBL-HAp) using microwave conversion method. Although there are several works on synthesis of HAp from eggshells and other calcium and phosphorus rich substrates, the incorporation of herbal extract with HAp to promote antimicrobial and antibiofilm activity is less explored and reported. This research work highlights a simple and cost-effective method for development of antimicrobial biomaterials by combining the concepts of waste management, biomaterial science, and herbal medicine. In the present study, characterization of synthesized HAp was applied by X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy, and morphological analysis using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The characterization results indicated that the prepared HAp and PBL-HAp were pure b-type carbonated HAp. The PBL-HAp was checked for its antibacterial activity using the well diffusion method and biofilm inhibitory activity by crystal violet assay against some common pathogens. The antibacterial activities against Staphylococcus aureus and biofilm inhibitory activities against Escherichia coli, Vibrio harveyi, Pseudomonas aeruginosa, and Staphylococcus aureus of Piper betel leaf extract coated HAp (PBL-HAp) were showed to be significant and offered a promising role for the development of potent dental biomaterials.

Green synthesis and characterization of titanium dioxide nanoparticles using leaf extract of Pouteria campechiana and larvicidal and pupicidal activity on Aedes aegypti.

The frequent application of synthetic insecticides creates resistance among insects, including mosquitoes, and causes environmental pollution and health issues. The current work aim at assessing the possibilities to produce and characterize the titanium dioxide (TiO2) nanoparticles (TiO2 NPs) mediated through the aqueous leaf extract of Pouteria campechiana, and their larvicidal and pupicidal activities against Aedes aegypti. The attained results showed that the aqueous leaf extract of P. campechiana had the efficiency to fabricate TiO2 NPs from TiO2. Under the UV-vis spectrum analysis, a sharp peak was recorded at 320 nm, which indicated the production of TiO2 NPs by the plant extract. The SEM analysis revealed that the synthesized TiO2 NPs were spherical, and 5 dissimilar diffractions were detected in the XRD spectrum analysis related to the TiO2 NPs. In FTIR analysis, a prominent peak was found at 1052.41 cm-1, corresponding to alcohol, and confirmed metal reduction. In the EDX analysis, there was a signal of around 58.44%, confirming the decrease in Ti from TiO2 NPs, and the remaining percentages were Ca, Al, and Mg. About 900 µg mL-1 of TiO2 NPs had excellent lethal activity against various larvae and pupa stages of Ae. aegypti. The attained results showed that the P. campechiana aqueous leaf extract could reduce TiO2 into TiO2 NPs and could be considered a mosquito control agent. Furthermore, this is the initial report about the aqueous leaf extract of P. campechiana effectively synthesizing the TiO2 NPs with anti-mosquito activity.

Synthesis and characterization of TiO2 NPs by aqueous leaf extract of Coleus aromaticus and assess their antibacterial, larvicidal, and anticancer potential.

The frequent applications of synthetic chemical insecticides and drugs create resistance among insects and microbes, creating a new threat to human and environmental welfare. This investigation focused on evaluating the possibilities of fabricating and characterizing the titanium dioxide nanoparticles (TiO2 NPs) from titanium dioxide (TiO2) through the aqueous leaf extract of Coleus aromaticus. Their biological applications were studied against the larvae of Aedes aegypti human pathogenic bacteria, and cancer cell line. The results revealed that the aqueous leaf extract had the metal reducing proficiency to produce nanoparticles from TiO2. The synthesized TiO2 NPs were initially confirmed by visible color changes and Ultraviolet-Visible Spectrophotometer analysis that showed a predominant peak at 332 nm. Furthermore, the nanocrystals, structural alignment, functional groups and elemental compositions were studied by following standard operating protocol in XRD (X-ray Powder Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), TEM (Transmission Electron Microscopy), and EDX (Energy-Dispersive X-ray Spectroscopy) techniques, respectively. The results attained from these techniques confirmed that the plant mediated and fabricated particles were in the nanoscale range (12-33 nm) with a hexagonal shape. The synthesized TiO2 NPs had an outstanding (1000 µg mL-1) larvicidal activity against the four stages of instars larvae of Ae. aegypti at 1000 µg mL-1. It also had an excellent antibacterial potential against E. faecalis (33 mm), followed by S. boydii (30 mm) at 30 mg L-1 concentration. The green fabricated TiO2 NPs had a fabulous (92.37%) cytotoxic activity on the HeLa cell line at 100 µg mL-1 dosage within one day of exposure. The entire results concluded that the C. aromaticus mediated TiO2 NPs have excellent biological applications and thus, could be considered for the welfare of human beings.