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Search Results: 1 - 10 of 14975 matches for " Mahmoud El-Rais "
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Removal of Some Heavy Metals from Wastewater by Using of Fava Beans  [PDF]
Abdunnaser Mohamed Etorki, Mahmoud El-Rais, Mohamed Tahher Mahabbis, Nayef Mohamed Moussa
American Journal of Analytical Chemistry (AJAC) , 2014, DOI: 10.4236/ajac.2014.54028
Abstract: The Fava Beans were used in this work as low cost adsorbent material for removal of Pb(II), Cd(II) and Zn(II) ions from aqueous solutions. The samples were prepared without farther treatment and sorted according to the particles diameter by standard sieves 250 - 500 μm. Batch adsorption experiments were carried out to study the adsorption process, several parameters such as Initial pH of adsorbent, effect of contact time, effect of adsorbent amount and effect of metal concentration were conducted in these experiments. The effects of any one of those previously mentioned parameters on the adsorption capacity were studied while the other parameters were kept constant. It was found that the obtained maximum adsorption capacities of Fave beans for the removal of selected heavy metals were very high. This provide us to use Fava beans as a low coast adsorbent material to clean up the water in the environment from toxic heavy metals such as Pb(II), Cd(II) and Zn(II) ions.
Removal of Aniline Blue from Aqueous Solutions Using Ce1-xBixCrO3 (x = 0, 0.5, 1)  [PDF]
Labib A. Awin, Mahmoud A. El-Rais, Abdunnaser M. Etorki, Najat A. Mohamed, Wesal A. Makhlof
Open Journal of Inorganic Non-metallic Materials (OJINM) , 2018, DOI: 10.4236/ojinm.2018.81001
Abstract: The removal of aniline blue dye from aqueous solutions using the A-site doped perovskite Ce1-xBixCrO3 (x = 0, 0.5, 1) was investigated. The perovskite oxides were synthesised using Sol-Gel method and characterised by conventional powder X-ray diffraction technique. The X-ray diffraction measurements suggested that doping with Bismuth Ion influences both the crystal structure and the particle size of the oxides, and consequently affects the adsorption properties. It was found that both CeCrO3 and Ce0.5Bi0.5CrO3 compounds are orthorhombic and have approximate particle size of 87 and 36 nm respectively, whereas BiCrO3 oxide has rhombohedral space group symmetry and the particle sizes are less than 49 nm. The batch mode study demonstrated that the removal capacities of Aniline Blue at 150 min and pH = 4.3 for Ce0.5Bi0.5CrO3, CeCrO3 and BiCrO3 are 779.67, 705.45 and 440.18 mg/g respectively. The results reflect the influence of the A site doping on the adsorption properties of the oxides. The removal of Aniline Blue was found to be negatively correlated with temperature and pH.
Applying MILP for 27-Level CMLIs to Obtain Low THD Values over Wide Voltage Range  [PDF]
Mahmoud El-Bakry
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54032
Abstract:

The 27-level cascaded multilevel inverter (CMLI) is a popular CMLI, since it can produce an output voltage with nearly sinusoidal wave form and may be realized as a trinary asymmetric CMLI that consists of only three H-bridges. A new approach using a mixed integer linear programming (MILP) model is applied, that can determine the switching angles of this CMLI that minimize the values of any undesired harmonics. The model is applied first to determine the number of harmonics to be minimized to obtain least percentage total harmonic distortion (%THD) utilizing the 13 positive levels of the inverter. The obtained result is then included in the model and it is solved for different values of the output voltage. Single phase and three phase cases are investigated. The results show very low values of %THD and low order harmonics over wide voltage range till the 91st harmonic in both cases, which agree with the IEEE standards 519-1992 for voltage distortion limits till 161 kv.

What Is New in Muslim Faith? Global Conflicts versus Moral Interests  [PDF]
Mahgoub El-Tigani Mahmoud
Open Journal of Philosophy (OJPP) , 2013, DOI: 10.4236/ojpp.2013.34075
Abstract: This paper ascertains genuine principles of Islam while exploring an emerging contradiction between authentic tenets of faith in the Muslims’ heritage of human rights and justice, and a variety of modern targets upheld by OIC Charter and other political and legal instruments to guide a far-sighted authority agenda in pursuit of global equilibrium over key Muslim concerns. The paper ends with operational strategies on sooth conflicting situations of this complex dilemma.
Effect of Overlap Stress as Well as Tie Beam Length and Width on Settlement of Isolated Footings Using Finite Element  [PDF]
Mahmoud Abo Bakr El Sideek
Open Journal of Civil Engineering (OJCE) , 2014, DOI: 10.4236/ojce.2014.41004
Abstract:

Effects of tie beam length, width and overlap stress on settlement of foundations have been investigated. In this investigation square concrete footings have been used with dimensions (B × B × d) where (d) is footing depth and (B) is footing width (1, 1.5,2 m). Width of tie beam (b) has been taken equal to 0.25, 0.30, 0.40, 0.50 and 0.75 (m). Tie beam length (L) has been taken varying from B till 3B with same footing depth = 0.50 m. Effect of overlap stress on settlement as well as effect of tie beam width and length on settlement has been determined. Also, the efficiency of tie beam length and width has been obtained. An equation is presented to compute the overlap stress zone in case of existing tie beam. It is found that the settlement increases with increasing the length of tie beam which is clear after the effect of the overlap stresses zone. The width of overlap stress zone case of existing tie beam has been found to be equal to (1.6 -1.75) B. The settlement of footings decreases with increasing tie beam width. It is found that the settlement after the effect of the overlap stress zone increases with increasing the length of tie beam.


Comparative study for success rate of vaginal birth after cesarean section following labor induction by two forms of vaginal dinosprostone: A pilot study  [PDF]
Mahmoud Fathy Hassan, Osama El-Tohamy
Open Journal of Obstetrics and Gynecology (OJOG) , 2014, DOI: 10.4236/ojog.2014.41007
Abstract:

Background: Cesarean delivery has become the most common major surgical procedure in many parts of the world. Induction of labor in women with prior cesarean delivery is an alternative to mitigate the rising cesarean rates. Objectives: To compare the VBAC success rate between two vaginal forms of dinoprostone for labor induction in women with prior cesarean section. Material and Methods: A pilot study was conducted at a large Governmental Hospital, Dhahran, Saudi Arabia, including 200 women with prior cesarean section and planned for labor induction. Participants were randomly allocated into two groups. Group A (n = 100) received dinoprostone 1.5 mg vaginal tablet. Group B (n = 100) received 10 mg dinoprostone sustained release vaginal pessary. Primary outcome was vaginal delivery rate. Secondary outcomes included maternal and neonatal outcomes. Results: The dinoprostone vaginal tablet and dinoprostone vaginal pessary had a comparable vaginal delivery rate (67% and 64%, respectively; p = 0.78). The median patient satisfaction with the birth process was superior in the dinoprostone vaginal pessary group (p = 0.04). Maternal and neonatal outcomes were similar in both groups. Conclusion: Both forms of dinoprostone were effective methods for labor induction in women with prior cesarean section. However, the patient satisfaction with the birth process was in favor of the dinoprostone sustained release vaginal pessary.

PPP Accuracy Enhancement Using GPS/GLONASS Observations in Kinematic Mode  [PDF]
Mahmoud Abd Rabbou, Ahmed El-Rabbany
Positioning (POS) , 2015, DOI: 10.4236/pos.2015.61001
Abstract: Commonly, kinematic PPP techniques employ un-differenced ionosphere-free linear combination of GPS observations. This, however, may not provide continuous solution in urban areas as a result of limited satellite visibility. In this paper, the traditional un-differenced as well as between-satellite single-difference (BSSD) ionosphere-free linear combinations of GPS and GLONASS measurements are developed. Except GLONASS satellite clock products, the final precise GPS and GLONASS satellites clock and orbital products obtained from the multi-GNSS experiment (MGEX) are used. The effects of ocean loading, earth tide, carrier-phase windup, sagnac, relativity, and satellite and receiver antenna phase-center variations are rigorously modeled. Extended Kalman filter (EKF) is developed to process the combined GPS/GLONASS measurements. A comparison is made between three kinematic PPP solutions, namely standalone GPS, standalone GLONASS, and combined GPS/ GLONASS solutions. In general, the results indicate that the addition of GLONASS observations improves the kinematic positioning accuracy in comparison with the standalone GPS PPP positioning accuracy. In addition, BSSD solution is found to be superior to that of the traditional un-diffe- renced model.
Integration of Multi-Constellation GNSS Precise Point Positioning and MEMS-Based Inertial Systems Using Tightly Coupled Mechanization  [PDF]
Mahmoud Abd Rabbou, Ahmed El-Rabbany
Positioning (POS) , 2015, DOI: 10.4236/pos.2015.64009
Abstract: We develop a new integrated navigation system, which integrates multi-constellations GNSS precise point positioning (PPP), including GPS, GLONASS and Galileo, with low-cost micro-electro-mechanical sensor (MEMS) inertial system, for precise positioning applications. To integrate GNSS and the MEMS-based inertial system, the process and measurement models are developed. Tightly coupled mechanism is adopted, which is carried out in the GNSS raw measurements domain. Both un-differenced and between-satellite single-difference (BSSD) ionosphere-free linear combinations of pseudorange and carrier phase GNSS measurements are processed. Rigorous models are employed to correct GNSS errors and biases. The GNSS inter-system biases are considered as additional unknowns in the integrated error state vector. The developed stochastic model for inertial sensors errors and biases are defined based on first order Gaussian Markov process. Extended Kalman filter is developed to integrate GNSS and inertial measurements and estimate inertial measurements biases and errors. Two field experiments are executed, which represent different real-world scenarios in land-based navigation. The data are processed by using our developed Ryerson PPP GNSS/MEMS software. The results indicate that the proposed integrated system achieves decimeter to centimeter level positioning accuracy when the measurement updates from GNSS are available. During complete GNSS outages the developed integrated system continues to achieve decimeter level accuracy for up to 30 seconds while it achieves meter-level accuracy when a 60-second outage is introduced.
Quranic Verse No. 8 of Surat Al-Jumu’ah Describes Cancer as a Complete and Accurate Description and Leads Us to Determine the True Cause of Cancer. “Part-1”  [PDF]
Mahmoud Saad Mohamed El-Khodary
CellBio (CellBio) , 2018, DOI: 10.4236/cellbio.2018.71001
Abstract: Cancer is the cell fleeing from death by blocking the pathways of the intrinsic and the extrinsic program of cell death (Apoptosis). The success depends on making the programs of cell death run again.
Quranic Verse No. 8 of Surat Al-Jumu’ah Leads Us to Describe Cancer and Determine its True Cause (Part-II)  [PDF]
Mahmoud Saad Mohamed El-Khodary
CellBio (CellBio) , 2018, DOI: 10.4236/cellbio.2018.72002
Abstract: Cancer is cell fleeing from death by blocking the intrinsic and extrinsic programs of cell death. The six elements that shut down those programs are: muc-1, muc-4, muc-16, Bcl-2, MMPs and decoy R3. The nuclear factor-kappa B (NF-Kb) stimulates the expression of genes responsible for the production of those elements, which are used by cells to block those two programs. In other words, the nuclear factor kappa B (NF-KB) is responsible for blocking both programs. Therefore, the nuclear factor kappa B (NF-Kb) is the true cause of cancer.
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