Research Papers/Topics in Chemistry

Quality evaluation and antimicrobial activities of Adzuki bean seed oil (vigina Angularis)

ABSTRACT The crude oil extracted from Adzuki bean oil (Vigna Angularis), purchased from Owo in Oba market in Owo local government area of Ondo state Nigeria. The extraction of the oil from the seed was carried out by soxhlet method using hexane as the extractant. The physicochemical properties of the oil were determined using gas chromatography (GC) and other standard methods. The antimicrobial activities were carried out using five species of bacterial. The results of the investigation is a...

HISTORY & PHILOSOPHY OF SCIENCE/HEALTH, ENVIRONMENT & SUSTAINABLE DEVELOPMENT

I-DEFINITIONS & CLASSIFICATION OF SCIENCE Deinition On the simplest level, deined as the knowledge of the world of nature. Human investigative endeavour (HIE) whose object is the natural world and natural phenomena A tool developed and employed to interrogate the natural world However, science generally is viewed in three main ways as; i. A method for acquiring knowledge or studying and understanding the world. o The steps of that method includes; observation, problem deinition, hypothesis fo...

GST 104: Human Reproduction Infertility and Abortions

For a human being to be formed there must surely be a man and a woman. The man will produce sperm and the woman will produce eggs. 

Vibrational Circular Dichorism and Non Linear optics of Azobenzene Derivatives; A Theoretical Study

The present work reports a theoretical study on vibrational spectra and nonlinear optical properties of azobenzene derivatives. The theoretical geometrical parameters in the ground state have been investigated by density functional method using B3LYP functional and 6-311G++ (d, p) basis set. The analysis of calculated IR and VCD indicates that the binaphthyl and alkoxy side chain of azobenzenes derivatives contribute differently to spectral line shape. The out-of-phase bending and twisting of...

Antimicrobial activity assessment of certain anilide derivatives

Several physiochemical, structural and quantum-mechanics based descriptors were derived for a set of anilide derivatives, using DFT-B3LYP/6-311G (d, p) level of theory. The aim of this study was to develop QSAR model using multiple linear regression to predict the antimicrobial activity of anilides towards E. Coli in terms of several electronic and molecular descriptors. The best-fit model involved electrophilicity index (w) in conjunction with molecular weight (W) and logarithm of the octano...

Effect of sintering additives on the densification and dielectric properties of Sr0.5Ba0.5Nb2O6 ceramics synthesized by a soft-chemistry method

Nano-crystalline Sr0.5Ba0.5Nb2O6 powders with addition of LiNbO3 or LiF as sintering additives were prepared by a soft-chemistry synthesis using polyethylene glycol. Calcination at 600 C results in nanocrystalline powders (dcryst. 30 nm) which were sintered between 1000 and 1300 C to ceramic bodies. By addition of 10 and 20 mol % LiNbO3, the sintering temperature was reduced by about 200 K and the activation energy of the initial stage of sintering decreases from 386 to 271 kJ mol1. The sinte...

Investigations of Nano-crystalline Sr0.5Ba0.5Nb2O6 and Bulk Ceramics Synthesized by a Polymerization Method using PEG400

Abstract. J. Eur. Ceram. Soc. 39 (2019) 1156–1163. (DOI: 10.1016/j.jeurceramsoc.2018.11.043). Nano-crystalline Sr0.5Ba0.5Nb2O6 was synthesized by a one-pot method using PEG400 and citric acid. Calcination of the (Sr,Ba,Nb)-gel at 600 °C leads to Sr0.5Ba0.5Nb2O6 with a crystallite size of 24(2) nm and a specific surface area of 38.5(10) m2 g-1. Sintering upto 1325 °C leads to ceramics with globular or irregular-shaped grains and average grain sizes between 1.3 and 2.4 μm, whereas higher ...

Preparation and Characterization of Nano-sized Magnesium Ferrite Powders by a Starch-gel Process and Corresponding Ceramics

Abstract: J. Mater. Sci. 48 (2013) 6509–6518. (DOI: 10.1007/s10853-013-7447-x).The synthesis and characterization of nano-sized MgFe2O4 by a starch-gel method is described herein. A phase-pure nano-sized MgFe2O4 powder (1a) was obtained after calcining a (MgFe)-starch gel at 550 °C. The powder has a specific surface area of 60.6 m2/g and a crystallite size of 9 nm. TEM investigations reveal particles in the range of 7 to 15 nm. The activation energy of the crystallite growth process w...

BaGeO3 as Sintering Additive for BaTiO3-MgFe2O4 Composite Ceramics.

Abstract: RSC Adv. 5 (2015) 71491 (Open Access, DOI: 10.1039/c5ra12312g).BaTiO3-MgFe2O4 composites (30 wt.% MgFe2O4) with a small addition of BaGeO3 as a sintering additive were synthesized by a one-pot Pechini-like sol-gel process. Nano-crystalline composite powders with a crystallite size of about 10 nm were obtained after reaction at 700 °C for 1 h. Magnetic investigations suggest that the nano-powder is in its superparamagnetic state at room temperature. The addition of BaGeO3 leads to a...

Thermoanalytical, Optical, and Magnetic Investigations on Nanocrystalline Li0.5Fe2.5O4 and Resulting Ceramics Prepared by a Starch-based Soft-chemistry Synthesis.

Abstract. J. Solid State Chem. 287 (2020) 121380. (DOI: 10.1016/j.jssc.2020.121380). Nanocrystalline Li0.5Fe2.5O4 was prepared by a starch-based soft-chemistry synthesis. Calcining of the (LiFe)-gel between 350 and 1000 °C results in Li0.5Fe2.5O4 powders with crystallite sizes from 13 to 141 nm and specific surface areas between 35 and 7.1 m2 g-1. XRD investigations reveal the formation of ordered Li0.5Fe2.5O4. Sintering between 1050 and 1250 °C leads to ceramics with relative densities of ...

Magnetic and Optical Investigations on LaFeO3 Powders with Different Particle Sizes and Corresponding Ceramics

Abstract. Solid State Ionics 249–250 (2013) 1–5. (DOI: 10.1016/j.ssi.2013.07.001). The optical and magnetic properties of nano-LaFeO3 powders prepared by a starch assisted soft-chemistry synthesis and corresponding ceramics have been investigated. Magnetic measurements on LaFeO3 powders with crystallite sizes of 37−166 nm showpronounced magnetization hysteresis loops. Measurements at 300 K reveal that the coercivity (Hc) of 19−32 kOe depends on the crystallite size, whereas the low re...

Synthesis and Characterization of Nano-LaFeO3 Powders by a Softchemistry Method and Corresponding Ceramics

Abstract. Solid State Ionics 231 (2013) 43–48. (DOI: 10.1016/j.ssi.2012.10.017). The preparation of a nano-sized LaFeO3 powder by a soft-chemistry method using starch as complexing agent is described herein. Phase evolution and development of the specific surface area during the decomposition process of (LaFe)-gels were monitored up to1000 °C. A phase-pure nano-sized LaFeO3 powder with a high specific surface area of 25.7 m2/g and a crystallite size of 37 nm was obtained after calcining at...

Crystallite Growth, Phase Transition, Magnetic Properties, and Sintering Behaviour of Nano-CuFe2O4 Powders Prepared by a Combustion-like Process

Abstract. J. Solid State Chem. 213 (2014) 57–64. (DOI: 10.1016/j.jssc.2014.02.010). The synthesis of nano-crystalline CuFe2O4 powders by a combustion-like process is described herein. Phase formation and evolution of the crystallite size during the decomposition process of a (CuFe2)-precursor gel were monitored up to 1000 °C. Phase-purenano-sized CuFe2O4 powders were obtained after reaction at 750 °C for 2 h resulting in a crystallite size of 36 nm, which increases to 96 nm after calcinin...

Synthesis, Phase Evolution and Properties of Phase-pure Nanocrystalline BiFeO3 Prepared by a Starch-based Combustion Method

Abstract. J. Alloys Compd. 590 (2014) 324–330. (DOI: 10.1016/j.jallcom.2013.12.120). The preparation of phase-pure nano-sized BiFeO3 by a combustion-like method using starch as complexing agent is described herein. Phase evolution and development of the crystallite size during the synthesis were monitored depending on the heat treatment and the composition of the (BiFe)-gels. Phase-pure BiFeO3 was obtained at a low heating rate and calcination temperatures between 500 and 600 °C. Above...


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