Open Access Original Research Article

Algae Oil Transesterification by Ultrasonic Irradiation on Sn-nano Sulfated Zirconia- Silica Catalyst

S. D. Sharma, Shailandra Singh

Chemical Science International Journal, Page 71-81
DOI: 10.9734/ACSJ/2015/17259

Biodiesel production from algae oil by transesterification reaction using ultrasonic irradiation on heterogeneous catalyst was done at atmospheric condition to make the process sustainable and parsimonious. Ultrasonication reduces the reaction time as compared to the conventional methods and the solid acid catalyst gives 99.15% biodiesel yield which was obtained for oil to methanol molar ratio 1:10, catalyst 2 wt.% of oil, metal 0.4 wt.% of catalyst and 15min. reaction time. Heterogeneous catalyst and ultrasonic irradiation gives good yield and handling for biodiesel production.

 

Open Access Original Research Article

Star-shaped Thiourea Derivative as Single Molecule Conductive Thin Film

Wan M. Khairul, Choon- Wan Yeap, Hasiah Salleh, Rafizah Rahamathullah

Chemical Science International Journal, Page 82-90
DOI: 10.9734/ACSJ/2015/16916

The electronic delocalization in extended π-orbital system of conjugated organic molecules brings significant contribution and has lead for further investigation to exploit this system to be used as potential conductive thin film. In this work, a star-shaped thiourea, N1,N3,N5-tris(4-(nonyloxy)phenyl)-N’-(benzene-1,3,5 tricarbonyl) thiourea (STU) based on Donor(D)-π-Acceptor(A) system was successfully synthesized from continuous reactions of intermediate compound 4-nonyloxy aniline hydrochloride with benzene-1,3,5-tricarboxylic acid chloride prior to form active substrate in the form of film. These compounds were characterized via several spectroscopic and analytical methods namely IR, UV-Vis, CHNS elemental analysis, 1H and 13C NMR as well TGA analysis. The investigation of its potential as dopant system in conductive film was fabricated on ITO substrate prior to the evaluation of its conductivity properties which was carried out by Four Point Probe. The findings from the conductivity analysis revealed that the prepared film performed better and exhibited increasing conductivity up to 0.1066Scm-1 under maximum light intensity of 50Wm-2. Thus, this proposed molecular structure of A-C(O)NHC=SNHAr-D has given ideal indication to act as conductive film and has opened wide potential for various applications particularly in molecular electronic devices.

 

Open Access Original Research Article

A Microcontroller-based Design for Energy Efficient Nickel-chrome Plating Process

Olabode Oladipo Olakanmi, Ogundare Margaret Ojone, Adesina Olanrewaju Seun, Isadare Dayo Adeyemi, Akinluwade Kunle Joseph, Taiwo Adeyinka Taofeek, Odejobi Olusegun Abel, Adetunji Adelana Rasaki

Chemical Science International Journal, Page 91-101
DOI: 10.9734/ACSJ/2015/12741

This paper presents a microcontroller-based design system for automated Nickel-chrome plating process using time flow of current. Given fixed electroplating parameters, the amount of a substance discharged will be a function of time and current density. These oftentimes are traditionally read using a stop clock and ammeter on a rectifier. This conventional method lacks capacity for instantaneous measurement and is usually prone to error due to open circuit. The present study unveils an energy saving microcontroller-based design capable of monitoring the current flow and accurately determining the time in computing the instantaneous mass deposited on the cathode (work piece).

Open Access Original Research Article

Application of Multi-criteria Decision Making Approach and Experimental Design and Development of Stability-indicating UPLC Method for Simultaneous Determination of Losartan Potassium and Hydrochlorothiazide in Bulk and Tablet Dosage Form

Hamed Hamed Abu Seada, Khalid Abdelsalam Attia, Mohammed Wafaa Nassar, Adel Mohammed Ahmed

Chemical Science International Journal, Page 102-119
DOI: 10.9734/ACSJ/2015/16233

This paper describes a multi response optimization methodology in combination with experimental design as a powerful technique for development of a RP-UPLC method for the simultaneous determination of losartan potassium and hydrochlorothiazide in combined dosage forms. The response surface design by means of 24 full factorial design was used taking resolution, symmetry of two peaks, and two retention factors as the responses with four important factors, pH of the mobile phase, percentage of the organic modifier, buffer concentration and column temperature, were used to design mathematical models. Derringer’s desirability function was used for reaching a suitable compromise among the responses. Optimal conditions included mobile phase consisting of acetonitrile–acetate buffer 38:62 v/v, pH 5.25 and buffer concentration of 28 mM as the mobile phase and at a flow rate of 0.3 ml/min and a column temperature of 37°C. The calibration plot was linear over the concentration ranges of 0.05–7 µg/mL for Losartan and 0.0125-4 µg/mL for hydrochlorothiazide having correlation coefficients not less than 0.999. Limits of detection and quantification were 0.287, 0.869 µg/mL and 0.487, 1.47 µg/mL, for Losartan and hydrochlorothiazide respectively. The specificity and stability-indicating capability of the method was proven through forced degradation studies, which showed no interference of the excipients. The robustness of the method was evaluated by Youden and Steiner’s robustness test. The method is simple, rapid, and robust for simultaneous determination of losartan potassium and hydrochlorothiazide with minimum amount of solvent mobile phase and shortest run time about 4.5 min.

 

Open Access Original Research Article

Phase Equilibria in the YbTe-PbTe-Bi2Te3 System

K. D. Rasulova, Z. S. Aliev, A. Y. Zavrajnov, S. Z. Imamalieva, M. B. Babanly

Chemical Science International Journal, Page 120-128
DOI: 10.9734/ACSJ/2015/16932

The phase equilibria in the YbTe-PbTe-Bi2Te3 system were investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscope with energy dispersive analysis (SEM-EDS) techniques. Isothermal sections at 300 and 800 K, the liquidus surface projection as well as some isopleth sections were experimentally plotted. The already reported ternary YbPbTe2, YbBi2Te4 and YbBi4Te7 compounds were not confirmed. Wide solid solubility field of initial binary compounds was revealed and a solubility of YbTe in the ternary tetradymite-like layered compounds in the PbTe-Bi2Te3 system are found to be about 2 mol%.

 

Open Access Original Research Article

Discharge of Cr, Mn, Ni, Cu and Zn from E-waste Components into Dumpsites Soil at Westminster Market, Lagos Nigeria

Edwin Andrew Ofudje, Olubunmi Kolawole Akiode, Gabriel Opeoluwa Oladipo, Adebusayo Emmanuel Adedapo, Lateefah Olanike Adebayo

Chemical Science International Journal, Page 129-138
DOI: 10.9734/ACSJ/2015/16113

The generation of electronic waste (e-waste) has increased due to the advancement in electrical and electronic industries. E-waste is term used to describe unwanted electronic products. E-waste contained toxic heavy metals such as barium, cadmium, chromium, copper, arsenic, zinc, nickel and lead. This study evaluated the discharge of heavy metals from e-waste in dumpsites soil located at Westminster Market, Lagos, Nigeria using Atomic Absorption Spectrometer. Four dumpsites from where e-waste are regularly being dumped were taken along side with control samples at a distance of 20 and 50 m away from each site for the analysis of Cr, Mn, Ni, Cu and Zn contents. The concentrations of the metals were found to range from 23.0±0.1 to 46.0±3.2 μg/g for Cr, 124.8±1.2 to 406.0±6.2 μg/g for Mn, 62.8±2.4 to 78.0±1.0 μg/g for Ni, 23.6±0.8 to190.2±4.0 μg/g for Cu and 236.2±5.6 to 746.0±1.2 μg/g for Zn. Statistical analyses of the data obtained via Pearson correlation indicated that some of the metals showed positive correlations, while others displayed negative correlations with each other. When compared with standard values, some of these metals exceeded the tolerable limit recommended which indicates the contribution of e-waste to the concentrations of heavy metals in the soil.