Saeed F.,Knowledge Sector |
Saidan M.,University of Jordan |
Said A.,Knowledge Sector |
Mustafa M.,Knowledge Sector |
And 2 more authors.
Energy Conversion and Management | Year: 2013
In order to evaluate the performance of Proton Exchange Membrane Fuel Cell (PEMFC) with an active area of 25 cm2, several variables were studied (flow pattern, flow rate, degradation in the Pt-Ru/C catalyst). Polarization curves revealed that the electrochemical reaction on both sides of the fuel cell is under the effect of mass transfer and the values of the cell voltage, current density, and power density were inversely proportional with the increase of the hydrogen and oxygen flow rates for both flow patterns (counter current and cocurrent) and clear corrosion phenomenon was observed on the surface of the Pt-Ru/C catalyst before and after exposure to the hydrogen and oxygen. On the other hand and in order to increase the performance of Nafion membrane, SiO 2 particles were introduced to the Nafion polymeric matrix using sol-gel method to form composites. The surface morphology of the Nafion-SiO 2 composite membrane was investigated and compared with the existing commercial Nafion membrane. It was found that water uptake of the Nafion- silica composite membrane as a function of temperature is higher than that of the existing commercial Nafion membrane. © 2013 Elsevier Ltd. All rights reserved.
Abdelhadi A.N.,Knowledge Sector |
Abbasi G.Y.,University of Jordan |
Saeed F.F.M.,Knowledge Sector
International Journal of Electrochemical Science | Year: 2010
The aim of this study is to investigate the corrosion behavior of iron in aerated hydrochloric acid at different operating conditions using multiple regression analysis based on 32 factorial design by generating a model to show the effect of the suggested operating conditions on the corrosion rate of iron as follows: CR (mm/y) = 90.85-5.02x10-3TS+4.08x10-4T3+2.3x10-7T2S2-10-9T3S2 This model was selected among three suggested models according to the highest R2 and R2adj based on T-test with 95% confidence limit. Three speeds of agitation (stagnant, 300 and 900RPM) and three temperatures (30, 45, and 60°C) were tested as independent variables in the proposed statistical model, while the corrosion rate was selected as the dependent variable. The results revealed that the model is significant according to ANOVA statistical analysis based on F and P-tests. On the other hand 3D mapping was generated using MATLAB in order to reflect the interactions among these independent variables, which showed that both independent variables might work inversely on each other, or they might work together in destructing the working electrode (iron). © 2010 by ESG.
Saeed F.,Knowledge Sector |
Alsyouri H.M.,University of Jordan |
Al-Ghandoor A.,Hashemite University |
Al-Husban Y.,Al - Hussein Bin Talal University |
And 2 more authors.
International Journal of Electrochemical Science | Year: 2013
This paper highlights efforts to design and fabricate a lab-scale integrated module to generate and purify hydrogen from sea water obtained from Gulf of Aqaba in a totally green process. The electrochemical reactor performance was controlled and monitored online. Multiple regression analysis was used to produce a model to show the effect of panel temperature (Tc), solar irradiation (Ir) and current (I) on the production of hydrogen (Q): Q = 158.0047- 0.37203×Tc1.6 + 0.02923×Ir1.4 + 0.006901×I2 This model was selected according to the highest R2 and R2adj and model significant according to ANOVA statistical analysis based on F- and P-tests. The produced hydrogen was further purified using a Pd-Cu membrane and the results revealed that the membrane was able to separate and purify hydrogen from the feed mixture with infinite selectivity in the studied range of variables. © 2013 by ESG.
Al-Hmoud N.,Biosafety Unit |
Al-Husseini N.,Environment Management and Technology Postgraduate Programme |
Ibrahim-Alobaide M.A.,Environment Management and Technology Postgraduate Programme |
Kubler E.,School for Life science |
And 3 more authors.
GM crops & food | Year: 2014
The Cauliflower Mosaic Virus 35S promoter sequence, CaMV P-35S, is one of several commonly used genetic targets to detect genetically modified maize and is found in most GMOs. In this research we report the finding of an alternative P-35S sequence and its incidence in GM maize marketed in Jordan. The primer pair normally used to amplify a 123 bp DNA fragment of the CaMV P-35S promoter in GMOs also amplified a previously undetected alternative sequence of CaMV P-35S in GM maize samples which we term V3. The amplified V3 sequence comprises 386 base pairs and was not found in the standard wild-type maize, MON810 and MON 863 GM maize. The identified GM maize samples carrying the V3 sequence were found free of CaMV when compared with CaMV infected brown mustard sample. The data of sequence alignment analysis of the V3 genetic element showed 90% similarity with the matching P-35S sequence of the cauliflower mosaic virus isolate CabbB-JI and 99% similarity with matching P-35S sequences found in several binary plant vectors, of which the binary vector locus JQ693018 is one example. The current study showed an increase of 44% in the incidence of the identified 386 bp sequence in GM maize sold in Jordan's markets during the period 2009 and 2012.
Saeed F.F.,Knowledge Sector |
Abdelhadi A.N.,Knowledge Sector
International Journal of Electrochemical Science | Year: 2012
This work is focused on modelling the galvanic behaviour of Cu: Fe: Zn couple in aerated 0.2 N HCl at various operating conditions as independent variables; temperatures (30 and 40 oC), speed of agitation (0, 300, 600 & 900 RPM) and area ratio (0.5:1:1) and (1:1:0.5) against the average galvanic current (I g) as dependent variable using a patented electrochemical system to measure the galvanic currents and coupling potentials. Multiple regression analysis was utilized to generate two models for the given area ratios (0.5:1:1) and (1:1:0.5) based on the highest R 2 and R 2 adj with reference to ANOVA statistical analysis based on F and P tests: Ig=363.863+14.866T-0.489S+0.017 T×S R 2=97.9%, R 2adj.=96.3% Ig=598.757-5.764T+0.399S-0.0126 T×S R 2=92.7%, R 2 adj.=87.3% Three dimensional mapping was generated using MATLAB in order to reflect the interactions among these independent variables. It was concluded that varying the area ratio with the other operating conditions (temp. and speed of agitation) have direct influence on changing the average galvanic current generated among the suggested couple based on the results which showed that increasing the temperature and the speed of agitation will increase the average galvanic current for the area ratio 0.5:1:1, while increasing the temperature and the speed of agitation will decrease the average galvanic current for the area ratio 1:1:0.5 because the area of Cu and Fe (cathode) in the Cu:Fe:Zn couple determined the extent of galvanic current. In other word the reduction of oxygen on Cu and Fe samples which is facilitated by large surface area of the exposed metals was the rate determining process. In contrast variations in the area of Zn in the Cu:Fe:Zn couple had negligible effect on the extent of galvanic current. It was also concluded that the patented electrochemical system gave better understanding for the behavior of Cu:Fe:Zn couple in the given corrosive environment under the various operating conditions.