Green-synthesized nanocatalysts and nanomaterials for water treatment: Current challenges and future perspectives.

Electroporation is a simple yet powerful technique for breaching the cell membrane barrier. The applications of electroporation can be generally divided into two categories: the release of intracellular proteins, nucleic acids and other metabolites for analysis and the delivery of exogenous reagents such as genes, drugs and nanoparticles with therapeutic purposes or for cellular manipulation. In this review, we go over the basic physics associated with cell electroporation and highlight recent technological advances on microfluidic platforms for conducting electroporation. Within the context of its working mechanism, we summarize the accumulated knowledge on how the parameters of electroporation affect its performance for various tasks. We discuss various strategies and designs for conducting electroporation at the microscale and then focus on analysis of intracellular contents and delivery of exogenous agents as two major applications of the technique. Finally, an outlook for future applications of microfluidic electroporation in increasingly diverse utilities is presented.

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Microfluidic electroporation for cellular analysis and delivery

ioremediation is a remediation technology using biological systems to cope pollution problems. “Bioremediation is an ecologically sound and state-of-the-art technique that employs contaminants”(Dr. Barware All). “Bioremediation is the process of using bacteria and other biological enhancements under controlled conditions to control pollution caused by different components of gasoline and fuel oxygenates in the contaminated land and groundwater”(David Laughlin and Randy Mueller).

Bioremediation을 활용한 수질정화

Multi metal oxide NiO-CdO-ZnO nanocomposite–synthesis, structural, optical, electrical properties and enhanced sunlight driven photocatalytic activity

a b s t r a c t This article reports the controlled size of ZnO nanoparticles synthesized via simple aqueous chemical route without the involvement of any capping agent. The effect of different calcination temperatures on the size of the ZnO nanoparticles was investigated. X-ray diffraction (XRD) results indicated that all the samples have crystalline wurtzite phase, and peak broadening analysis was used to evaluate the average crystallite size and lattice strain using Scherrer’s equation and Williamson–Hall (W–H) method. Morphology and elemental compositions were investigated using atomic force microscopy (AFM) and scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy. The average crystallite size of ZnO nanoparticles estimated from Scherrer’s formula and W–H analysis was found to increase with the increase in calcination temperature. These results were in good agreement with AFM results. Optical properties were investigated using UV–vis spectroscopy in diffused reflectance (DR) mode, with a sharp increase in reflectivity at 375 nm and the material has a strong reflective characteristic after 420 nm at 500

Aqueous chemical route synthesis and the effect of calcination temperature on the structural and optical properties of ZnO nanoparticles

Photocatalytic degradation of methylene blue by ZnO/NiFe2O4 nanoparticles

Biosynthesizing of silver nanoparticles using microorganisms or various plant parts have proven more environmental friendly, cost-effective, energy saving and reproducible when compared to chemical and physical methods. This investigation demonstrated the plant-mediated synthesis of silver nanoparticles using the aqueous leaf extract of Thevetia peruviana. UV–Visible spectrophotometer was used to measure the surface plasmon resonance of the nanoparticles at 460 nm. Fourier Transform Infrared showed that the glycosidic –OH and carbonyl functional group present in extract were responsible for the reduction and stabilization of the silver nanoparticles. X ray diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy and Selected Area Electron Diffraction analyses were used to confirm the nature, morphology and shape of the nanoparticles. The silver nanoparticles are spherical in shape with average size of 18.1 nm. The synthesized silver nanoparticles showed activity against fungal pathogens and bacteria. The zone of inhibition observed in the antimicrobial study ranged between 10 and 20 mm.

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Biosynthesis of silver nanoparticles using aqueous leaf extract of Thevetia peruviana Juss and its antimicrobial activities

Dye-sensitized solar cell is one of the generations of solar cells that generate clean energy and needs inexpensive equipment for fabrication. We report the performances of the natural dye based-solar cells compared with synthetic dye-based solar cells. Zinc oxide (ZnO) is synthesized by the green synthesis technique. The structural property of the ZnO film shows good behavior with preferred (101) orientation. The lattice parameters, a and c, calculated from the X-ray diffraction (XRD) peak of (101) are 2.9214  ​A and 5.3600  ​A , respectively. The crystallite size, induced strain and dislocation density of the film are 24.58 ​nm, 4.708 × 10 − 3 and 1.655 × 10 − 3 ( nm ) − 2 , respectively. The absorption spectra of the dyes were measured using a UV–Vis spectrophotometer, and the dyes showed high average absorption values of 0.2872, 1.6585, and 0.5886 for beetroot, Eosin y, and yombotumtum, respectively. The current-voltage (I–V) measurement of the cells showed that beetroot, yombotumtum and Eosin y dyes based solar cells have power conversion efficiencies (PCEs) of 0.75%, 1.17%, and 2.65%, respectively. This shows that the black mineral dye that is easily available, and eco-friendly serves as active material in dye-sensitized solar cells (DSSCs).

Zinc oxide-based dye-sensitized solar cells using natural and synthetic sensitizers

Water samples from Hadejia River in the north eastern part of Nigeria were studied in order to ascertain the suitability and radiological safety of water from the river for human consumption. Radioactive measurements, using a lead shielded sodium iodide detector coupled to a multichannel analyzer were used to estimate eight radiological parameters of water samples from Hadejia River. The results show that the values of all the parameters fall within the minimum universal standard, indicating that consuming the water pose no serious radiological hazard, especially for adults. The values of the Absorbed Dose Rate (50.10511 nGyh-1) and AEDE (12.458 mSvy-1) for the infant however portend that infant consumer could be susceptible to radiation hazard on consuming water from the River. It is however recommended that activities that are capable of enhancing the radiological content of the River be avoided within the area.

https://iopscience.iop.org/article/10.1088/1755-1315/173/1/012036/pdf

Radiological Safety of Water from Hadejia River

This paper presents a low-cost temperature-controlled chamber based on the natural radiation principle. The temperature-controlled chamber assembled using a 1.0 mm thick aluminum sheet equipped with expanded polystyrene lagging material, temperature controller, K-type thermocouple and solid-state relay. A high precision temperature sensor (K-type thermocouple) attached to the sample under test (SUT) near the instrument’s measuring point gives a feedback signal to the temperature integrated derivative (TID) controller. The accuracy of temperature readings from the chamber investigated and the chamber itself, calibrated with temperature sensor by Fluke, show temperature readings that correspond to the set temperature values. In addition, perovskite thin film deposited on a glass substrate of 75 × 25 mm was tested and the temperature readings equally correspond to the temperature set values. This low-cost and low-energy-consumption chamber could use in laboratories in the developing world where there is scarce power supply.

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A. B. Alabi

Papers

Photocatalytic degradation of methylene blue by ZnO/NiFe2O4 nanoparticles

Biosynthesis of silver nanoparticles using aqueous leaf extract of Thevetia peruviana Juss and its antimicrobial activities

Zinc oxide-based dye-sensitized solar cells using natural and synthetic sensitizers

Radiological Safety of Water from Hadejia River

A Low-Cost Temperature-Controlled Chamber Fabricated for Materials Testing