Mohammad Abdul Gafur

Variations in fat content and lipid class composition in ten different mango varieties

The kernels of 10 different mango varieties were extracted. The physico-chemical characteristics and lipid class composition of fats were studied. The fat content of mango kernels grown under the soil and climatic conditions of Bangladesh varied from 7.1% to 10%, depending on the variety. The total lipid extracts were fractionated into lipid classes by a combination of column and thin layer chromatography (TLC). The hydrocarbon and sterol esters varied from 0.3% to 0.7%, triglycerides from 55.6% to 91.5%, partial glycerides from 2.3% to 4% and free sterol from 0.3% to 0.6%. Free fatty acids amounted to 3.0–37% as oleic; glycolipids were 0.6–1.2% and phospholipids 0.11–0.8%. The fatty acid composition of triglyceride (TG) fractions was analyzed by gas liquid chromatography (GLC). Palmitic acid varied from 7.9 molar % to 10.0 molar %, stearic from 38.2% to 40.2%, oleic from 41.1% to 43.8%, linoleic from 6.0% to 7.6%, linolenic from 0.6% to 1.0% and arachidic acid from 1.7% to 2.6%. TLC revealed the presence of lyso-phosphatidylcholine, phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and phosphatidic acid in the phospholipid fraction.

Biocompatible microcrystalline cellulose particles from cotton wool and magnetization via a simple in situ co-precipitation method

This investigation describes the preparation of magnetically doped degradable microcrystalline cellulose (MCC) nanocomposite particles with application potential in biotechnology, solid support for biomolecule/water purification, oil recovery from water and beyond. MCC was first extracted from cotton wool, the most abundant biocompatible polymer, by sulfuric acid hydrolysis and the effect of acid strength was examined. The size of the elongated fiber structure was reduced with increasing acid strength. MCC particles extracted by treatment with 70% sulfuric acid were used to prepare magnetic MCC nanocomposite particles. The nanocomposite particles named as MCC/Fe3O4 were prepared via in situ co-precipitation of Fe+3/Fe+2 from their alkaline solution. The precipitated Fe3O4 nanoparticles are expected to be bonded with MCC particles via hydrogen bonding. The nanocomposite dispersion was colloidally stable and the particles responded when external magnetic field was applied. It was possible to control the magnetic property by regulating the content of iron oxide.

ZnO nanoparticles preparation from spent zinc–carbon dry cell batteries: studies on structural, morphological and optical properties

ABSTRACT Recovery and recycling of valuable materials from battery waste is challenging as well as important from economic and environmental point of view. In this work, spent zinc–carbon batteries were processed with HCl and NaOH to synthesize ZnO nanoparticles. ZnO nanopowders were also prepared by using ZnCl2 as precursors with varying amount of NaOH using sol–gel method. In both cases, ZnO nano particles were characterized with XRD, XRF, FESEM, EDAX, particle size analyzer and UV–visible (UV–Vis) spectroscopy. The purity of the synthesized ZnO from spent zinc–carbon batteries was found to be 99.69%. FESEM micrographs showed the reduction in particle size from 50 nm to 20 nm with a decrease in NaOH concentration. UV–Vis study showed significant peak shift with maximum absorption between 365 nm and 359 nm region of the visible spectrum. Because of these remarkable properties, as prepared ZnO nanoparticles can find applications in biomedicine, nanoelectronic devices, sensors, nanomedicine, GATE dielectrics, photovoltaic devices, etc.

Effect of sintering temperature on structural and dielectric properties of (Bi 2 O 3 Fe 2 O 3 ) 0.4 (Nb 2 O 5 Nd 2 O 3 ) 0.6

(Bi<inf>2</inf>O<inf>3</inf>Fe<inf>2</inf>O<inf>3</inf>)<inf>0.4</inf>(Nb<inf>2</inf>O<inf>5</inf>Nd<inf>2</inf>O<inf>3</inf>)<inf>0.6</inf> was syhthesised by solid state reaction method for studying the properties of the material. Synthesized material was sintered at two different temperature (1000°C and 1150°C). X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Dielectric property and DC resistivity of the materials are reported in this paper. Existance of bismuth iron niobium oxide and neodymium iron(lll) oxide phases were confirmed by XRD. SEM image yielded that the size of grain increases with the increase of sintering temperature. Low dielectric constant and loss tangent were observed from dielectric property. Insulating nature of the material was found by DC resistivity analysis.

Microstructure evolution and electrical characterization of Lanthanum doped Barium Titanate (BaTiO3) ceramics

In the current work, we investigated the structural and dielectric properties of Lanthanum oxide (La2O3) doped Barium Titanate (BaTiO3) ceramics and established a correlation between them. Solid state sintering method was used to dope BaTiO3 with 0.3, 0.5 and 0.7 mole% La2O3 under different sintering parameters. The raw materials used were La2O3 nano powder of ~80nm grain size and 99.995% purity and BaTiO3 nano powder of 100nm grain size and 99.99% purity. Grain size distribution and morphology of fracture surface of sintered pellets were examined by Field Emission Scanning Electron Microscope and X-Ray Diffraction analysis was conducted to confirm the formation of desired crystal structure. The research result reveal that grain size and electrical properties of BaTiO3 ceramic significantly enhanced for small amount of doping (up to 0.5 mole% La2O3) and then decreased with increasing doping concentration. Desired grain growth (0.80-1.3u2005µm) and high densification (<90% theoretical density) were found by pr...