Comparative toxicity, growth inhibitory and biochemical effects of terpenes and phenylpropenes on Spodoptera littoralis (Boisd.)

Nagwa M.A. Al-Nagar,Hamdy K. Abou-Taleb,Mohamed S. Shawir,Samir A.M. Abdelgaleil 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.1

Eleven monoterpenes, phenylpropenes and sesquiterpenes were evaluated for their insecticidal and growth inhibitory activities against the second and fourth larval instars of Spodoptera littoralis. Among the tested compounds, 1,8-cineole revealed the highest fumigant toxicity against the 2nd and 4th larval instars with LC 50 values of 2.32 and 3.13 mg/L air, respectively. The monoterpenes, p-cymene, α-terpinene, (−)α-pinene and (−)-carvone were highly toxic to both larval stages as their LC 50 values ranged between 7.35 and 13.79 mg/L air against 2nd larval instar and between 14.66 and 32.02 mg/L air against 4th larval instar. In topical application assay against the 4th larval instar, (−)-carvone (LD 50 = 0.15 mg/larva) and cuminaldehyde (LD 50 = 0.27 mg/larva) were the most potent contact toxicants. In residual film assay, trans-cinnamaldehyde, (−)-citronellal and pcymene showed the highest insecticidal activity against the 2nd larval instar, while α-terpinene and (−)-carvone were most effective compounds against the 4th larval instar. Moreover, the tested compounds caused strong growth reduction of both larval stages with growth inhibition higher than 80% in the 2nd larval instar and higher than 70% in the 4th larval instar. On the other hand, (−)-carvone, cuminaldehyde and (Z,E)-nerolidol showed pronounced inhibitory effects on acetylcholinesterase (AChE) and adenosine triphosphatases (ATPases) activity of S. littoralis larvae. Cuminaldehyde (IC 50 = 1.04 mM) and (Z,E)-nerolidol (IC 50 = 0.02 mM) caused the highest inhibition of AChE and ATPases, respectively. Taken together, the results indicate that monoterpenes, phenylpropenes and phenylpropenes could be used to develop new botanical insecticides for S. littoralis management.

Nonlinear analysis of contemporary and historic masonry vaulted elements externally strengthened by FRP

Hamdy, Gehan A.,Kamal, Osama A.,El-Hariri, Mohamed O.R.,El-Salakawy, Tarik S. Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.5

This paper addresses numerical modeling and nonlinear analysis of unreinforced masonry walls and vaults externally strengthened using fiber reinforced polymers (FRP). The aim of the research is to provide a simple method for design of strengthening interventions for masonry arched structures while considering the nonlinear behavior. Several brick masonry walls and vaults externally strengthened by FRP which have been previously tested experimentally are modeled using finite elements. Numerical modeling and nonlinear analysis are performed using commercial software. Description of the modeling, material characterization and solution parameters are given. The obtained numerical results demonstrate that externally applied FRP strengthening increased the ultimate capacity of the walls and vaults and improved their failure mode. The numerical results are in good agreement with the experimentally obtained ultimate failure load, maximum displacement and crack pattern; which demonstrates the capability of the proposed modeling scheme to simulate efficiently the actual behavior of FRP-strengthened masonry elements. Application is made on a historic masonry dome and the numerical analysis managed to explain its structural behavior before and after strengthening. The modeling approach may thus be regarded a practical and valid tool for design of strengthening interventions for contemporary or historic unreinforced masonry elements using externally bonded FRP.

Synthesis and Cycloaddition Reaction of C-(2-naphthoyl)-N-arylmethanohydrazonoylpyridinium Bromides

Hassaneen, Hamdi M.,Shawali, Ahmad S.,Elwan, Nehal M.,Abounada, Nada M.,Algharib, Mohammed S. The Pharmaceutical Society of Korea 1992 Archives of Pharmacal Research Vol.15 No.4

Coupling of naphthacylpyridinium bromide 2 [1-(2-naphthyl) ethanone-2-pyridinium bromide] with N-nitrosoacetarylamides afforded C-(2-naphthoyl)-N-arylmethanohydrazonoylpyridinium bromides 3A-C. Treatment of 3A-C with base afforded the corresponding tetrazines 6A-C. Cycloaddition of nitrilimines 5A-C to N-arylmaleimides, acrylonitrile, ethyl acrylate, acrylamide, fumaronitrile, $\alpha$-cyanocinnamonitriles, ethyl $\alpha$-cyano-p-nitrocinnamates and $\alpha$-cyano-p-nitrocinnamamide afforded the corresponding cycloadducts 7-14, respectively. The cycloadducts 11-14 undergo a facile thermal elimination of hydrogen cyanide to give the corresponding pyrazoles 18-21 respectively.

The effects of the surrounding viscoelastic media on the buckling behavior of single microfilament within the cell: A mechanical model

Khadimallah, Mohamed A.,Safeer, Muhammad,Taj, Muhammad,Ayed, Hamdi,Hussain, Muzamal,Bouzgarrou, Souhail Mohamed,Mahmoud, S.R.,Ahmad, Manzoor,Tounsi, Abdelouahed Techno-Press 2020 Advances in concrete construction Vol.10 No.2

In the present study, a mechanical model is applied to account the effects of the surrounding viscoelastic media on the buckling behavior of single microfilament within the cell. The model immeasurably associates filament's bending rigidity, neighboring system elasticity, and cytosol viscosity with buckling wavelengths, buckling growth rates and buckling amplitudes of the filament. Cytoskeleton components in living cell bear large compressive force and are responsible in maintaining the cell shape. Actually these filaments are surrounded by viscoelastic media consisting of other filaments network and viscous cytosole within the cell. This surrounding, viscoelastic media affects the buckling behavior of these filaments when external force is applied on these filaments. The obtained results, indicate that the coupling of viscoelastic media with the viscous cytosol greatly affect the buckling behavior of microfilament. The buckling forces increased with the increase in the intensity of surrounding viscoelastic media.

Nonlinear analysis of contemporary and historic masonry vaulted elements externally strengthened by FRP

Gehan A. Hamdy,Osama A. Kamal,Mohamed O.R. El-Hariri,Tarik S. El-Salakawy 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.5

This paper addresses numerical modeling and nonlinear analysis of unreinforced masonry walls and vaults externally strengthened using fiber reinforced polymers (FRP). The aim of the research is to provide a simple method for design of strengthening interventions for masonry arched structures while considering the nonlinear behavior. Several brick masonry walls and vaults externally strengthened by FRP which have been previously tested experimentally are modeled using finite elements. Numerical modeling and nonlinear analysis are performed using commercial software. Description of the modeling, material characterization and solution parameters are given. The obtained numerical results demonstrate that externally applied FRP strengthening increased the ultimate capacity of the walls and vaults and improved their failure mode. The numerical results are in good agreement with the experimentally obtained ultimate failure load, maximum displacement and crack pattern; which demonstrates the capability of the proposed modeling scheme to simulate efficiently the actual behavior of FRP-strengthened masonry elements. Application is made on a historic masonry dome and the numerical analysis managed to explain its structural behavior before and after strengthening. The modeling approach may thus be regarded a practical and valid tool for design of strengthening interventions for contemporary or historic unreinforced masonry elements using externally bonded FRP.

Highly efficient and reusable superhydrophobic/superoleophilic polystyrene@ Fe₃O₄ nanofiber membrane for high-performance oil/water separation

Moatmed, Sara M.,Khedr, Mohamed Hamdy,El-dek, S.I.,Kim, Hak-Yong,El-Deen, Ahmed G. Elsevier 2019 Journal of environmental chemical engineering Vol.7 No.6

<P><B>Abstract</B></P> <P>Due to increasing of oil spills and high organic contamination of marine environment, developing of cost-effective and rapid oil/water separation technique has become inevitable. Herein, freestanding and flexible hybrid polystyrene nanofibers are introduced as highly efficient hybrid membrane for ultrafast oil/water separation without external pressure. Typically, different loading of Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles embedded into polystyrene nanofibers using electrospinning to fabricate superhydrophobic/super-oleophilic membrane. The morphological shape, crystal structure and surface wettability behavior were elucidated by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and contact angel, respectively. The optimum loading of magnetite nanoparticles into the nanofiber membranes was investigated to achieve best separation performance. The obtained results demonstrated that the incorporation of (Fe<SUB>3</SUB>O<SUB>4</SUB>) nanoparticles into membrane has a significant impact for enhancing superhydrophobic properties and the separation efficiency against light and heavy oils. Among all formulations, the fabricated (PS@Fe<SUB>3</SUB>O<SUB>4</SUB>10 wt.%) membrane revealed ultrahigh flux (5000 L m<SUP>−2</SUP> h<SUP>−1</SUP>) with separation efficiency of 99.8 % for hexane under gravity driven process and excellent superhydrophobicity with water contact angle 162° moreover excellent reusability 98.5 % for 50 consecutive cycles. Interestingly, the proposed hybrid nanofiber membrane achieved distinct separation efficiencies 95 % and 92 % for food oils such as olive oil and sesame oil. Overall, the current study provides cost-effective and facile approach to distinctly improve the membrane performance for durable oil/water separation technique.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Runge-Kutta method for flow of dusty fluid along exponentially stretching cylinder

Waheed Iqbal,Mudassar Jalil,Mohamed A. Khadimallah,Hamdi Ayed,Muhammad N. Naeem,Muzamal Hussain,Souhail Mohamed Bouzgarrou,S.R. Mahmoud,E. Ghandourah,Muhammad Taj,Abdelouahed Tounsi 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.5

The present manuscript focuses on the flow and heat transfer of the dusty fluid along exponentially stretching cylinder. Enormous attempts are made for fluid flow along cylinder but the study of fluid behavior along exponentially stretching cylinder is discussed lately. Using appropriate transformations, the governing partial differential equations are converted to non-dimensional ordinary differential equations. The transformed equations are solved numerically using Shooting technique with Runge-Kutta method. The influence of the physical parameters on the velocity and temperature profiles as well as the skin fraction coefficient and the local Nusselt number are examined in detail. The essential observations are as the fluid velocity decreases but temperature grows with rise in particle interaction parameter, and both the fluid velocity and temperature fall with increase in mass concentration parameter, Reynold number, Particle interaction parameter for temperature and the Prandtl number.

Buckling and bending of coated FG graphene-reinforced composite plates and shells

Ahmed Amine Daikh,Amin Hamdi,Hani M. Ahmed,Mohamed S. Abdelwahed,Alaa A. Abdelrahman,Mohamed A. Eltaher Techno-Press 2023 Advances in nano research Vol.15 No.2

The advancement of theoretical research has numerous challenges, particularly with regard to the modeling of structures, in contrast to experimental investigation of the mechanical behavior of complex systems. The main objective of this investigation is to provide an analytical analysis of the static problem of a new generation of composite structure, namely, functionally graded FG graphene reinforced composite GRC coated plates/shells. A complex power law function is used to define the material's graduation. Investigations are conducted on Hardcore and Softcore coated FG plates/shells. The virtual work approach is used to perform the equilibrium equations, which are then solved using the Galerkin technique to account for various boundary conditions. With reliable published articles, the presented solution is validated. The effects of hardcore and softcore distributions, gradation indexes, and boundary conditions on the buckling, bending deflection and stresses of FG GRC-coated shells are presented in detail. Obtained results and the developed procedure are supportive for design and manufacturing of FG-GRC coated plates/shells in several fields and industries e.g., aerospace, automotive, marine, and biomedical implants.

Theoretical fabrication of Williamson nanoliquid over a stretchable surface

Sharif, Humaira,Hussain, Muzamal,Khadimallah, Mohamed Amine,Ayed, Hamdi,Taj, Muhammad,Bhutto, Javed Khan,Mahmoud, S.R.,Iqbal, Zafer,Ahmad, Shabbir,Tounsi, Abdelouahed Techno-Press 2022 Advances in concrete construction Vol.14 No.2

On the basis of fabrication, the utilization of nano material in numerous industrial and technological system, obtained the utmost significance in current decade. Therefore, the current investigation presents a theoretical disposition regarding the flow of electric conducting Williamson nanoliquid over a stretchable surface in the presence of the motile microorganism. The impact of thermal radiation and magnetic parameter are incorporated in the energy equation. The concentration field is modified by adding the influence of chemical reaction. Moreover, the splendid features of nanofluid are displayed by utilizing the thermophoresis and Brownian motion aspects. Compatible similarity transformation is imposed on the equations governing the problem to derive the dimensionless ordinary differential equations. The Homotopy analysis method has been implemented to find the analytic solution of the obtained differential equations. The implications of specific parameters on profiles of velocity, temperature, concentration and motile microorganism density are investigated graphically. Moreover, coefficient of skin friction, Nusselt number, Sherwood number and density of motile number are clarified in tabular forms. It is revealed that thermal radiation, thermophoresis and Brownian motion parameters are very effective for improvement of heat transfer. The reported investigation can be used in improving the heat transfer appliances and systems of solar energy.

Elastic shell model: Effect of Young's Modulus on the vibration of double-walled CNTs

Hussain, Muzamal,Asghar, Sehar,Khadimallah, Mohamed Amine,Ayed, Hamdi,Banoqitah, Essam Mohammed,Loukil, Hassen,Ali, Imam,Mahmoud, S.R.,Tounsi, Abdelouahed Techno-Press 2022 Advances in concrete construction Vol.13 No.6

In this paper, vibrational attributes of double-walled carbon nanotubes (CNTs) has been studied based upon nonlocal elastic shell theory. The implication of small scale is being perceived by establishing nonlocal Love shell model. The wave propagation approach has been operated to frame the governing equations as eigen value system. The comparison of local and nonlocal model has been overtly explored by means of scaling parameter. An appropriate selection of material properties and nonlocal parameter has been considered. The influence of changing mechanical parameter Young's modulus has been studied in detail. The dominance of end condition via nonlocal parameter is explained graphically. The results generated furnish the evidence regarding applicability of nonlocal shell model and also verified by earlier published literature.