Impact of SV40 T antigen on two multiple fission microalgae species Scenedesmus quadricauda and Chlorella vulgaris

Gomaa, Ahmed E.,Yang, Seung Hwan The Institute of Internet 2018 International journal of advanced smart convergenc Vol.7 No.1

The combination of Simian Virus40 (SV40)'s large T antigen with its replication origin is commonly used in molecular studies to enhance the expression of heterogeneous genes through multiplying the plasmid copy number. There are no reports related to the impact of the SV40 T antigen on plant, multiple fissional, cell-type. This study explores the response of two multiple-fission microalgal cells, Scenedesmus quadricauda and Chlorella vulgaris, to the expression of the T-antigen, with aim of applying SV40 T-antigen to increase the expression efficiency of foreign genes in the two species. Different levels of low-expression have been constructed to control the expression of SV40 T antigen using three heterogenous promoters (NOS, CaMV35S, and CMV). Chlorella cultures showed slowdown in the growth rate for samples harboring the T antigen under the control of CaMV35S and CMV promoters, unlike Scenedesmus cultures which showed no significant difference between samples and could have silenced the expression.

Identification of Green Alga Chlorella vulgaris Isolated from Freshwater and Improvement Biodiesel Productivity via UV Irradiation

Gomaa, Mohamed A.,Refaat, Mohamed H.,Salim, Tamer M.,El-Sayed, Abo El-Khair B.,Bekhit, Makhlouf M. The Korean Society for Microbiology and Biotechnol 2019 한국미생물·생명공학회지 Vol.47 No.3

Chlorella vulgaris was isolated from the Nile River, Qalubia Governorate, Egypt, for possible use in biodiesel production. BG-II nutrient growth media was used for isolation and laboratory growth. Identification was performed via 18S rRNA gene amplification, followed by sequencing. The alga was exposed to UV-C (254 nm) for 15, 30, and 45 s to improve dry weight accumulation and to increase the oil production. Daily measurements of dry weight ($g{\cdot}l^{-1}$) were performed; oil content and volumetric lipid productivity were also determined. UV-C exposure led to an increase in the volumetric lipid productivity by 27, 27.3, and $32.4mg{\cdot}l^{-1}{\cdot}d^{-1}$ with 15, 30, and 45 s, respectively, as compared with the control, which resulted in $18mg{\cdot}l^{-1}{\cdot}d^{-1}$. Of the examined mutants, the one with the highest productivity was re-irradiated by UV-C (254 nm) for 15, 30, 45, and 60 s. For 15 s of exposure time, the oil content increased to 34%, while it was 31% at 30 s; further, it decreased to 22% at 45 and 60 s exposures. The fatty acid methyl ester profile was 82.22% in the first mutant at 45 s, compared with the wild strain that contained a total of 66.01% of FAs. Furthermore, the highest levels of polyunsaturated fatty acid methyl ester were observed in the mutant exposed for 45 s, and it reached 11.41%, which reduced the cetane number to 71.3.

Potentiostatic and galvanostatic electrodeposition of manganese oxide for supercapacitor application: A comparison study

Gomaa A.M. Ali,Mashitah M. Yusoff,Yun Hau Ng,Hong Ngee Lim,Kwok Feng Chong 한국물리학회 2015 Current Applied Physics Vol.15 No.10

The structural and electrochemical properties of manganese oxide (MnO2) electrodeposited by potentiostatic and galvanostatic conditions are studied. X‒ray diffraction analyses confirm identical MnO2 phase (ramsdellite) are deposited under potentiostatic and galvanostatic conditions. Under comparable current density during electrodeposition, MnO2 deposited by galvanostatic condition shows smaller crystallite size, less compact layered structure, higher surface area and wider band gap, in comparison to the potentiostatic deposition. The MnO2 morphology difference under different electrodeposition conditions contributes to different capacitive behaviors. The lower compactness of MnO2 deposited galvanostatically renders facile ions diffusion, leading to higher specific capacitance with low equivalent series resistance. The findings suggest galvanostatic electrodeposition is suitable to produce MnO2 nanostructure for supercapacitor application.

Re-centering Capability of Inverted-Y Dual Eccentrically Braced Frame

Amir Gomaa,Ashraf Osman 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.4

Repair process of structures after a strong earthquake is often governed by the level of permanent deformation experienced by these structures during the shaking event. These phenomena drastically aff ect the repair cost in addition to the prolonged time needed to accomplish this complex process. In this research the feasibility of utilizing the Re-centering capability of a dual system consisting of steel special moment resisting frame ‘SMRF’ and Inverted-Y geometric confi guration eccentric braced frame ‘EBF’ to create an easy-repairable structure after a severe earthquake was examined. In this structural system a removable vertical shear link (i.e. using bolted connection) which is part of the EBF will act as a fuse to dissipate the earthquake input energy while the SMRF will act as a Re-centering system that will force the structure to return to its original position after removing the shear links by intentionally keeping it in the region of elastic behavior. The proposed system’s seismic performance was evaluated through performing series of pushover analyses under diff erent loading patterns, and time history analyses under the action of seven earthquakes. Furthermore, the design provisions provided in the American Code “ Seismic Provisions for Structural Steel Buildings ” ANSI/AISC 341-10 were verifi ed against the required response and extra recommendations for designing and detailing such structural system were introduced in order to achieve the required behavior. The performed study showed that during severe earthquakes the majority of the inelastic actions were localized within the shear links only while the SMRF behaved almost elastically with few exceptions. In addition, the study provided design and detailing recommendations to create an easy repairable structure after severe earthquakes.

An intrinsic proof of Numata's theorem on Landsberg spaces

Salah Gomaa Elgendi,Amr Soleiman 대한수학회 2024 대한수학회지 Vol.61 No.1

In this paper, we study the unicorn's Landsberg problem from an intrinsic point of view. Precisely, we investigate a coordinate-free proof of Numata's theorem on Landsberg spaces of scalar curvature. In other words, following the pullback approach to Finsler geometry, we prove that all Landsberg spaces of dimension $n\geq 3$ of non-zero scalar curvature are Riemannian spaces of constant curvature.

Intrinsic theory of $C^v$-reducibility in Finsler Geometry

Salah Gomaa Elgendi,Amr Soleiman 대한수학회 2024 대한수학회논문집 Vol.39 No.1

In the present paper, following the pullback approach to Finsler geometry, we study intrinsically the $C^v$-reducible and generalized $C^v$-reducible Finsler spaces. Precisely, we introduce a coordinate-free formulation of these manifolds. Then, we prove that a Finsler manifold is $C^v$-reducible if and only if it is $C$-reducible and satisfies the $\mathbb{T}$-condition. We study the generalized $C^v$-reducible Finsler manifold with a scalar $\pi$-form $\mathbb{A}$. We show that a Finsler manifold $(M,L)$ is generalized $C^v$-reducible with $\mathbb{A}$ if and only if it is $C$-reducible and $\mathbb{T}=\mathbb{A}$. Moreover, we prove that a Landsberg generalized $C^v$-reducible Finsler manifold with a scalar $\pi$-form $\mathbb{A}$ is Berwaldian. Finally, we consider a special $C^v$-reducible Finsler manifold and conclude that a Finsler manifold is a special $C^v$-reducible if and only if it is special semi-$C$-reducible with vanishing $\mathbb{T}$-tensor.

Cylindrical Shock Waves in Space Superthermal Fluids

Hesham Gomaa Abdelwahed,Emad Kheder El-Shewy,Ali Abd El-Rahman,Noura Fakhry Abdo 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.75 No.9

The three-dimensional Burgers equation is used to count the effects of the spectral index param- eter , the ion, the negative (positive) kinematics viscosity coefficients of negatively (positively) charged grains on the dissipation of cylindrical shocks. The obtained results may useful for both laboratory and space applications of plasmas.

Economic Evaluation of Coupling APR1400 with a Desalination Plant in Saudi Arabia

Abdoelatef, M. Gomaa,Field, Robert M.,Lee, YongKwan The Korean Society of Systems Engineering 2016 시스템엔지니어링학술지 Vol.12 No.1

Combining power generation and water production by desalination is economically advantageous. Most desalination projects use fossil fuels as an energy source, and thus contribute to increased levels of greenhouse gases. Environmental concerns have spurred researchers to find new sources of energy for desalination plants. The coupling of nuclear power production with desalination is one of the best options to achieve growth with lower environmental impact. In this paper, we will per-form a sensitivity study of coupling nuclear power to various combinations of desalination technology: {1} thermal (MSF [Multi-Stage Flashing], MED [Multi-Effect Distillation], and MED-TVC [Multi-Effect Distillation with Thermal Vapour Compression]); {2} membrane RO [Reverse Osmosis]; and {3} hybrid (MSF-RO [Multi-Stage Flashing & Reverse Osmosis] and MED-RO [Multi-Effect Distillation & Reverse Osmosis]). The Korean designed reactor plant, the APR1400 will be modeled as the energy production facility. The economical evaluation will then be executed using the computer program DEEP (Desalination Economic Evaluation Program) as developed by the IAEA. The program has capabilities to model several types of nuclear and fossil power plants, nuclear and fossil heat sources, and thermal distillation and membrane desalination technologies. The output of DEEP includes levelized water and power costs, breakdowns of cost components, energy consumption, and net saleable power for any selected option. In this study, we will examine the APR1400 coupled with a desalination power plant in the Kingdom of Saudi Arabia (KSA) as a prototypical example. The KSA currently has approximately 20% of the installed worldwide capacity for seawater desalination. Utilities such as power and water are constructed and run by the government. Per state practice, economic evaluation for these utilities do not consider or apply interest or carrying cost. Therefore, in this paper the evaluation results will be based on two scenarios. The first one assumes the water utility is under direct government control and in this case the interest and discount rate will be set to zero. The second scenario will assume that the water utility is controlled by a private enterprise and in this case we will consider different values of interest and discount rates (4%, 8%, & 12%).

Synergistic impact of multiwalled carbon nanotubes on the properties of Ni-Mo thin-film via electrodeposition technique

Mona Hasan Gomaa,Zeinab Abdel Hamid,Magdy Ahmed Mahmoud Ibrahim,Rania Abd El Sttar,El-Said Helmy El- Mosallamy 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.5

Carbon nanotubes (CNTs) are the hardest and strongest materials due to their perfect mechanical properties and excellent chemical, electrical, and thermal characteristics. Therefore, CNTs are attractive candidates for the development of innovative multifunctional nanocomposites. The goal of the study was to synthesize and characterize NiMoCNT nanocomposite coatings onto steel substrates by electrodeposition technique to enhance the properties of the NiMo layer coating. The electrodeposition was carried out galvanostatically, and the percentage of MWCNT (wt%) in the composites was investigated under various working circumstances, including current density, pH, temperature, and CNTs concentration in the electroplating bath. Different techniques, such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray analysis (EDS), were used for the composite characterization. Moreover, the corrosion resistance and the nanocomposites’ mechanical characteristics were investigated. The results of the NiMo alloy show that the enhancement in current density decreases the Mo content from 41.8 wt% (at 3.5×10−2 Acm−2) to 31.06 wt% (at 6.5×10−2 Acm−2). On the other hand, the results proved that as the concentration of CNTs in the bath increases, the wt% of CNTs co-deposited in the NiMo matrix enhances, peaking at 22.36 wt% at 0.03 gL−1. Furthermore, the findings show that the Mo content of the coating is reduced when CNTs are present. In comparison to a NiMo coating without CNTs, the composite incorporating CNTs exhibits better corrosion resistance. In addition, the mechanical properties show that the microhardness of NiMoCNT composite-coated steel is better than that of NiMo, and the highest microhardness of NiMoCNT composite coated steel was 4.69 GPa, while pure NiMo coated steel had a microhardness of 2.37 GPa.

Impact of SV40 T antigen on two multiple fission microalgae species Scenedesmus quadricauda and Chlorella vulgaris

Ahmed E. Gomaa,Seung Hwan Yang 한국인터넷방송통신학회 2018 Journal of Advanced Smart Convergence Vol.7 No.1

The combination of Simian Virus40 (SV40)’s large T antigen with its replication origin is commonly used in molecular studies to enhance the expression of heterogeneous genes through multiplying the plasmid copy number. There are no reports related to the impact of the SV40 T antigen on plant, multiple fissional, cell-type. This study explores the response of two multiple-fission microalgal cells, Scenedesmus quadricauda and Chlorella vulgaris, to the expression of the T-antigen, with aim of applying SV40 T-antigen to increase the expression efficiency of foreign genes in the two species. Different levels of low-expression have been constructed to control the expression of SV40 T antigen using three heterogenous promoters (NOS, CaMV35S, and CMV). Chlorella cultures showed slowdown in the growth rate for samples harboring the T antigen under the control of CaMV35S and CMV promoters, unlike Scenedesmus cultures which showed no significant difference between samples and could have silenced the expression.