Open Access Original Research Article

Chirped Gaussian Pulse Excitation of a Harmonic Oscillator

R. A. Alharbey, H. Gasim, F. N. M. Al-Showaikh, S. S. Hassan

Physical Science International Journal, Page 1-12
DOI: 10.9734/PSIJ/2018/46248

We investigate the basic problem of the interaction of a single quantised mode of the radiation field, modelled as quantised harmonic oscillator (HO) with a laser pulse of chirped Gaussian line-shape. The average photon number and the transient emitted spectrum are calculated analytically in terms of the error function of complex argument. The spectral peaks of the line structure of the emitted radiation are examined for different system parameters and initial states of the HO.

Open Access Original Research Article

Determination of Heavy Metals in Young, Matured and Aged Leaves of Moringa setenopetala Tree Using Flame Atomic Absorption Spectroscopy in South Ethiopia

Yeshanew Fikre Ololo, Kusse Gudishe Goroya

Physical Science International Journal, Page 1-8
DOI: 10.9734/PSIJ/2018/45932

This study was aimed at concentration determination of some heavy metals (Cu, Pb, Fe, Zn and Cr) in Moringa stenopetala tree leaves at three growing stages (young, matured and aged). Determination was made on samples collected from Southern part of Ethiopia using flame atomic absorption spectrometry (FAAS) with acidic digestive method deployed.  In the results, three of five metals (Cu, Fe and Zn) are detected but Pb and Cr was not detected by the technique. Results indicated that presence of the metals in all the three growing stages (young, matured and aged) varied. It was observed that mean concentration of iron content increases as the age of the leave increases while mean concentration of zinc decreases as the age of the leave increases. Mean copper concentration was found to be higher in matured and lower in aged leaves. However, the heavy metals lead and chromium were not detected in this experiment.

Open Access Original Research Article

DFT-QSAR and Molecular Docking Studies on 1,2,3-Triazole-Dithiocarbamate Hybrids as Potential Anticancer Agents

Ehimen Annastasia Erazua, Abel Kolawole Oyebamiji, Babatunde Benjamin Adeleke

Physical Science International Journal, Page 1-10
DOI: 10.9734/PSIJ/2018/46207

Recently, considerable attention has been drawn on the search for novel anticancer drugs in order to improve survival rates and wellbeing of cancer patients. 1,2,3-triazole is an attractive scaffold possessing diverse biological activities. The quantitative structure–activity relationship (QSAR) is a powerful computational tool which has widened the scope of rational drug design, as well as the search for the mechanisms of drug actions. A series of novel 1,2,3-triazole-dithiocarbamate hybrids (1,2,3-TDHs) were studied for anticancer activity against human gastric cancer cell line (MGC-803) using Density Functional Theory (DFT), Quantitative Structure Activity Relation (QSAR) and Docking approaches. QSAR models were successfully constructed with acceptable predictive performance. The QSAR analysis indicated that certain molecular descriptors namely EHOMO, ELUMO, Log P, Area, the total electronic charges on the heteroatom (H), and the average electronic charge on the heteroatoms (H_HET4r) are important factors for the observed biological activity. The results from docking study predicted stable conformations of the ligands within the enzyme’s active gouge of the receptor. Compound E, tert Butyl 4-(((1-(4-methylbenzyl)-1H-1,2,3-triazol-4-yl)methylthio)carbonothioyl)-piperazine-1-arboxylate, formed the most stable complex with the protein receptor.

Open Access Original Research Article

The Effect of Relative Humidity and Temperature on Polycrystalline Solar Panels Installed Close to a River

Armstrong O. Njok, Julie C. Ogbulezie

Physical Science International Journal, Page 1-11
DOI: 10.9734/PSIJ/2018/44760

The effect of temperature and relative humidity on photovoltaics installed close to Calabar River was investigated to evaluate their performance. The data used in the research was obtained by in-situ measurement approach using a KT-908 precision digital hygrometer and thermometer, and a M890C+ digital multimeter. The result obtained shows a strong negative correlation for current, efficiency and relative humidity which indicates that high relative humidity adversely affects the performance of the photovoltaic. The results also show that voltage remains fairly stable between 65% to 75% relative humidity humidity and 33°C to 43°C (panel temperature), while efficiency increases with temperature up to the maximum operating temperature of the photovoltaic module before starting to decrease. Peak in efficiency was observed at a relative humidity value of 65% and module temperature of about 47°C at noon.

Open Access Original Research Article

Electrochemical Corrosion Inhibition Process, Adsorption Mechanism and Mechanical Effect of Newbouldia laevis Leaf Extract on Aluminum Alloy in Acidic Environment

Nwosu Okechukwu Francis, Israel O. Owate, Eziaku Osarolube

Physical Science International Journal, Page 1-12
DOI: 10.9734/PSIJ/2018/46346

Aims: This research is aimed at using advanced corrosion identification and corrosion inhibition technique to investigate the corrosion inhibition mechanism of Al Alloy (AA5052) in 1.0 M HCl solution using Newboudia laevis leaf extract.

Place and Duration of Study: The research was carried out at Material Science Laboratory Group, Physics/Electronic Department, Abia State Polytechnic, Aba Abia State.

Methodology: Extraction of the green leaf was done with reflux apparatus under constant temperature. The 100% inhibitor solvent was diluted to the various inhibitor concentrations. Gravimetric technique and electrochemical impedance spectroscopy (EIS) were employed to study the corrosion and corrosion inhibitory behavior of the metal in the various environments. Scanning Electron Microscope and OPTICAL emission microscopy were used to investigate the surface structure of the corroded and inhibited metal alloy. The influence of the leaf extract on the mechanical hardness of the Al alloy AA5052 was tested using Vickers indentation hardness test.

Results: The presence of the Newbouldia leavis leaf extract significantly reduced the weight loss and also decreased the rate of chemical attack on the AA5052 alloy. The inhibition efficiency of the inhibitor increases with increase in concentration but decreased with increase in temperature. The introduction of the leaf extract alters the electrochemical behaviours of the metal in the acidic environment. The inhibitor mechanism was found to be through adsorption on the metal surface according to Langmuir adsorption isotherm. The Gibb’s free energy confirms that the inhibition of the leaf to corrosion attacks is spontaneous. The calculated activation energy, heat of adsorption, enthalpy and the entropy implications of the leaf extract were appraised. The surface morphology of the metal was studied to ascertain the level of redemption offered by the green inhibitor molecules to the material degradation. Vickers hardness test revealed that the presence of the inhibitor improved the mechanical hardness of the corroded Al alloy.

Conclusion: The acidic corrosion of AA5052 has been studied. The study shows that Newboudia laevis extract can be used to combat the corrosion attacks on AA5052 alloy.