1,610 results on '"Mohamed H"'
Search Results
2. Anti-Cancer Activity, DFT and molecular docking study of new BisThiazolidine amide
- Author
-
Haider A. Omran, Ahmed A. Majed, Kawkab Hussein, Dawood S. Abid, Mostafa A. Abdel-Maksoud, Ahmed Elwahsh, Mohamed Aufy, and Mohamed H. Kotob
- Subjects
Bisthiazolidine Amide. Anticancer. Molecular Docking. DFT ,Chemistry ,QD1-999 - Abstract
In this study, a series of bis amide thiazolidine derivatives (Q1-Q6) were synthesized and their anticancer activity was evaluated against prostate (PC3) and breast (MCF7) cancer cells and normal cells line activity was evaluated against breast (MCF10), prostate (PNT1A) and living human cells (HUVEC) cancer cells. The thiazolidine rings were built from penicillamine and aromatic aldehydes (A1-A6), then converted to acetyl thiazolidines (B1-B6) using acetic anhydride, and finally linked with phenylene diamine to form the final compounds (Q1-Q6). Notably, compounds Q1 and Q3 displayed the highest activity against PC3, with IC50 values of 81 and 89 µg/ml, respectively. Docking simulations were performed for Q1, Q4, and Q5 against protein structures related to cancer (2FVD and 1SJ0). Additionally, DFT calculations were used to determine various molecular properties like HOMO/LUMO energies, band gap, and other descriptors, providing insights into the compounds’ stability and reactivity.
- Published
- 2024
- Full Text
- View/download PDF
3. Synthesis of TiO2 nanoparticles using red spinach leaf extract (Amaranthus Tricolor L.) for photocatalytic of methylene blue degradation
- Author
-
Devi Rahmawati, Muhamad Diki Permana, Diana Rakhmawaty Eddy, Norio Saito, Takahiro Takei, Suryana, Atiek Rostika Noviyanti, Iman Rahayu, Mohamed H. Helal, and Zeinhom M. El-Bahy
- Subjects
TiO2 nanoparticles ,green synthesis ,red spinach ,photocatalysis ,Science ,Chemistry ,QD1-999 - Abstract
ABSTRACTTextile industry waste such as methylene blue can pose a serious threat to health and ecosystems. One solution to overcome this problem is to utilize photocatalytic technology using TiO2 semiconductors. This research aims to make green synthetic TiO2 nanoparticles (NPs) using red spinach (Amaranthus Tricolor L.) leaf extract and used for photodegradation of methylene blue. Extraction of red spinach leaves showed that 30 min and a temperature of 95°C showed the highest phenolic content. In this research, several phenolic compounds were also identified in red spinach extract. For TiO2 NPs, the X-ray diffraction results show that TiO2 has a pure anatase phase. Electron microscope results show that TiO2 has the shape of agglomerated spherical clusters. The particle size distribution shows that TiO2 has an average size range of 77–90 nm. The methylene blue photodegradation showed that TiO2 had an efficiency of 90.36% for 180 min, higher than commercial TiO2 Evonic. This result can be attributed to the small particle size and broadband spectra so that photocatalysis is more effective.
- Published
- 2024
- Full Text
- View/download PDF
4. Geochemistry of Liquid Hydrocarbons and Natural Gases Combined with 1D Basin Modeling of the Oligocene Shale Source Rock System in the Offshore Nile Delta, Egypt
- Author
-
Mohamed M. El-Said, Ali M. A. Abd-Allah, Mohamed H. Abdel-Aal, Mohammed Hail Hakimi, Aref A. Lashin, and Ahmed Abd-El-Naby
- Subjects
Chemistry ,QD1-999 - Published
- 2024
- Full Text
- View/download PDF
5. N′-(Furan-2-ylmethylene)-2-hydroxybenzohydrazide and its metal complexes: synthesis, spectroscopic investigations, DFT calculations and cytotoxicity profiling
- Author
-
Nasser M. Hosny, Ghada Samir, and Mohamed H. Abdel-Rhman
- Subjects
Schiff’s base ,Metal complexes ,DFT computation ,Spectral studies ,Cytotoxicity ,Chemistry ,QD1-999 - Abstract
Abstract The ligand, N′-(furan-2-ylmethylene)-2-hydroxybenzohydrazide (H2L), was synthesized characterized through various spectral studies which cleared out that the free ligand existed in keto form. The ligand upon reaction with Cu(II), Co(II), Ni(II) and Zn(II) acetates yielded complexes with stoichiometric ratio 1:2 (M:L) which has been validated through the elemental and mass spectral measurements. The IR and NMR spectral studies of the isolated complexes disclosed that the ligand chelated to metal ion in mononegative bidentate fashion via the azomethine nitrogen and deprotonated enolized carbonyl oxygen. Moreover, the DFT quantum chemical calculations designated that the ligand and Ni(II) complex exhibited the highest and lowest values of HOMO, LUMO energies and HOMO-LUMO energy gap, respectively. Furthermore, the in vitro cytotoxic activity towards HePG-2 and HCT-116 cell lines of the isolated compounds was investigated and the data cleared out that the ligand was more potent than the metal complexes.
- Published
- 2024
- Full Text
- View/download PDF
6. Enhancing the Stability of Strawberry Anthocyanins Complexed to β‑Cyclodextrin and Starch toward Heat, Oxidation, and Irradiation
- Author
-
Hussein M. Ali, Mohamed H. Attia, and Eman N. Rashed
- Subjects
Chemistry ,QD1-999 - Published
- 2024
- Full Text
- View/download PDF
7. Electromagnetic Interference Shielding Analysis of Hybrid Buckypaper-Reinforced Polymer Matrix Composites: A Quantum Tunneling-Informed Equivalent Circuit Approach
- Author
-
Kartik Tripathi, Mohamed H. Hamza, Madeline A. Morales, Todd C. Henry, Asha Hall, and Aditi Chattopadhyay
- Subjects
carbon nanotubes ,buckypaper ,EMI shielding ,electrical conductivity ,quantum tunneling ,CFRPs ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A novel modeling approach is developed for investigating the effectiveness of buckypaper (BP), a porous membrane made of a highly cross-linked network of carbon nanotubes, in improving the electromagnetic interference (EMI) shielding properties of carbon fiber-reinforced polymer (CFRP) composites. The methodology uses quantum tunneling-based equivalent electrical circuits and Monte Carlo simulations to predict the frequency-dependent electrical conductivity and EMI shielding effectiveness (SE) of the hybrid BP/CFRP composites. The study examines a signal frequency range of 50 MHz to 12 GHz that includes the very high and X-band. The results show that at a frequency of 12 GHz, the transverse conductivity increases to approximately 12.67 S/m, while the longitudinal conductivity decreases to about 3300 S/m from an initial value of 40,000 S/m. These results are then integrated into the ANSYS High-Frequency Structure Simulator to predict SE by simulating the propagation of electromagnetic waves through a semi-infinite composite shield element. The numerical simulations illustrate that incorporating BP significantly improves the SE of CFRP composites beyond 2 GHz owing to its high conductivity in that frequency range. For instance, at 12 GHz signal frequency, adding a single BP interleaf enhances the SE of a [90, 0] laminate by up to ~64%.
- Published
- 2024
- Full Text
- View/download PDF
8. A Unified Seismicity Catalog Development for Saudi Arabia: Multi-Network Fusion and Machine Learning-Based Anomaly Detection
- Author
-
Sayed S. R. Moustafa, Mohamed H. Yassien, Mohamed Metwaly, Ahmad M. Faried, and Basem Elsaka
- Subjects
seismic hazard ,Red Sea ,seismicity discrepancies ,Saudi seismic networks ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This investigation concentrates on refining the accuracy of earthquake parameters as reported by various Saudi seismic networks, addressing the significant challenges arising from data discrepancies in earthquake location, depth, and magnitude estimations. The application of sophisticated machine learning techniques, particularly the Isolation Forest algorithm, has markedly enhanced the precision in the estimation of seismicity parameters by effectively identifying and eliminating outliers and discrepancies. A newly developed and refined seismicity catalog was employed to accurately determine key seismic parameters such as the magnitude of completeness (Mc), a-value, and b-value, thereby underlining their indispensable role in regional seismic hazard assessment. The research underscores the substantial impact of data inconsistencies on the evaluation of seismic hazards, thereby advocating for the advancement of research methodologies within the field of seismotectonics. The insights derived from this study significantly contribute to a more profound understanding of the seismotectonic processes in the region. These insights are crucial for the development of comprehensive seismic hazard assessments and the formulation of targeted earthquake preparedness strategies, thereby enhancing resilience against seismic risks in the region.
- Published
- 2024
- Full Text
- View/download PDF
9. Ultrasound-assisted synthesis of MSNs/PS nanocomposite membranes for effective removal of Cd2+ and Pb2+ ions from aqueous solutions
- Author
-
Khalid M. Alotaibi, Arun K. Shukla, Elham Bajuayfir, Abdullah A. Alotaibi, Mohamed H. Mrad, Fatma A. Gomaa, and Abdullah M Alswieleh
- Subjects
Mesoporous silica NPs ,Polysulfone ,Membrane ,Heavy metal ,Chemistry ,QD1-999 ,Acoustics. Sound ,QC221-246 - Abstract
Contamination of heavy metal (Cd2+ & Pb2+) ions in drinking water is producing major impacts on the environment and public health and is considered one of the greatest dangers to humanity. Membrane technology has been chosen over other processing methods due to its simplicity and high capacity for more effective removal of hazardous heavy metals. In the current study, amine, thiol, and bi-thiol functional groups were used to functionalize mesoporous silica nanoparticles (MSNs) to improve the efficiency of the silica nanoparticle. The morphology of the MSNs as well as the existence of amine and thiol on the surface of MSNs was demonstrated by a variety of characterization techniques, including FTIR, TEM, and SEM examination. The impact of surface-modified MSNs on the morphology, properties, and performance of polysulfone (PS) nanofiltration (NF) membranes was also evaluated. The membrane that incorporated amine with thiol-based MSNs (DiMP-MSNs/PS-NF membrane) had the highest pure water permeability (6.7 LMH bar−1). As a result of the functional groups, the surface-modified MSNs/PS nanofiltration are extremely effective at removing heavy metal ions from aqueous solutions. The surface-modified MSNs/PS nano-filtration membranes exhibit unprecedented Cd2+ and Pb2+ removal rates of approximately 82% and 99%, respectively. This research indicates the possible application of the surface-modified MSNs/PS nanofiltration membrane as a promising platform to remove heavy metal ions from polluted water.
- Published
- 2023
- Full Text
- View/download PDF
10. Applying Geostatistics to Understand Seismic Activity Patterns in the Northern Red Sea Boundary Zone
- Author
-
Sayed S. R. Moustafa, Mohamed H. Yassien, Mohamed Metwaly, Ahmad M. Faried, and Basem Elsaka
- Subjects
seismic hazard ,Red Sea ,spatial seismicity ,seismic networks ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A comprehensive geostatistical analysis was conducted on a dataset comprising 24,321 seismic events in the Red Sea region, spanning from 1997 to 2020. This analysis involved the creation of a new seismic activity database, incorporating data from both Egyptian and Saudi Seismic Networks. This enriched database provided a robust foundation for a detailed examination of the seismic patterns and activities in the region. Utilizing geographic information systems and various spatial analytic methods, it identifies seismic patterns and tectonic influences. The findings reveal significant seismic clustering along the Central Red Sea axis, indicative of active rifting between the Nubian and Arabian plates. The study demonstrates spatial autocorrelation in seismic activities, with high-high clusters marking zones of elevated seismicity. Kernel Density Estimator analyses highlight concentrated seismic activity in the Gulfs of Aqaba and Suez. Higher magnitude events are shown to localize in areas of greater tectonic stress, aligning with known geological features. This research provides critical insights into the seismic dynamics of the Red Sea, showcasing the effectiveness of geostatistical techniques in analyzing seismic data in tectonically active regions.
- Published
- 2024
- Full Text
- View/download PDF
11. Deep Learning-Based Metasurface Design for Smart Cooling of Spacecraft
- Author
-
Ayman Negm, Mohamed H. Bakr, Matiar M. R. Howlader, and Shirook M. Ali
- Subjects
CNN ,deep learning ,metasurface ,phase-change ,plasmonic ,radiative cooling ,Chemistry ,QD1-999 - Abstract
A reconfigurable metasurface constitutes an important block of future adaptive and smart nanophotonic applications, such as adaptive cooling in spacecraft. In this paper, we introduce a new modeling approach for the fast design of tunable and reconfigurable metasurface structures using a convolutional deep learning network. The metasurface structure is modeled as a multilayer image tensor to model material properties as image maps. We avoid the dimensionality mismatch problem using the operating wavelength as an input to the network. As a case study, we model the response of a reconfigurable absorber that employs the phase transition of vanadium dioxide in the mid-infrared spectrum. The feed-forward model is used as a surrogate model and is subsequently employed within a pattern search optimization process to design a passive adaptive cooling surface leveraging the phase transition of vanadium dioxide. The results indicate that our model delivers an accurate prediction of the metasurface response using a relatively small training dataset. The proposed patterned vanadium dioxide metasurface achieved a 28% saving in coating thickness compared to the literature while maintaining reasonable emissivity contrast at 0.43. Moreover, our design approach was able to overcome the non-uniqueness problem by generating multiple patterns that satisfy the design objectives. The proposed adaptive metasurface can potentially serve as a core block for passive spacecraft cooling applications. We also believe that our design approach can be extended to cover a wider range of applications.
- Published
- 2023
- Full Text
- View/download PDF
12. Identification and In Silico Characterization of a Conserved Peptide on Influenza Hemagglutinin Protein: A New Potential Antigen for Universal Influenza Vaccine Development
- Author
-
Atin Khalaj-Hedayati, Seyedehmaryam Moosavi, Otilia Manta, Mohamed H. Helal, Mohamed M. Ibrahim, Zeinhom M. El-Bahy, and Ganden Supriyanto
- Subjects
epitope mapping ,immunoinformatic ,hemagglutinin ,nanoparticle ,peptide-based vaccine ,universal influenza vaccine ,Chemistry ,QD1-999 - Abstract
Antigenic changes in surface proteins of the influenza virus may cause the emergence of new variants that necessitate the reformulation of influenza vaccines every year. Universal influenza vaccine that relies on conserved regions can potentially be effective against all strains regardless of any antigenic changes and as a result, it can bring enormous public health impact and economic benefit worldwide. Here, a conserved peptide (HA288–107) on the stalk domain of hemagglutinin glycoprotein is identified among highly pathogenic influenza viruses. Five top-ranked B-cell and twelve T-cell epitopes were recognized by epitope mapping approaches and the corresponding Human Leukocyte Antigen alleles to T-cell epitopes showed high population coverage (>99%) worldwide. Moreover, molecular docking analysis indicated that VLMENERTL and WTYNAELLV epitopes have high binding affinity to the antigen-binding groove of the HLA-A*02:01 and HLA-A*68:02 molecules, respectively. Theoretical physicochemical properties of the peptide were assessed to ensure its thermostability and hydrophilicity. The results suggest that the HA288–107 peptide can be a promising antigen for universal influenza vaccine design. However, in vitro and in vivo analyses are needed to support and evaluate the effectiveness of the peptide as an immunogen for vaccine development.
- Published
- 2023
- Full Text
- View/download PDF
13. Fabrication of Biohybrid Nanofibers by the Green Electrospinning Technique and Their Antibacterial Activity
- Author
-
Badr M. Thamer, Ahmed E. Al-Sabri, Abobakr Almansob, and Mohamed H. El-Newehy
- Subjects
Chemistry ,QD1-999 - Published
- 2022
- Full Text
- View/download PDF
14. Synthesis, characterization, DFT, cytotoxicity evaluation and molecular docking of a new carbothioamide ligand and its coordination compounds
- Author
-
Nasser Mohammed Hosny, Omnia Ahmed Ibrahim, Arafa Belal, Mostafa A. Hussien, and Mohamed H. Abdel-Rhman
- Subjects
Carbothioamide ,DFT ,Molecular docking ,Cytotoxicity ,Chemistry ,QD1-999 - Abstract
2-(2-hydroxybenzoyl)-N-phenylhydrazine-1-carbothioamide (H4L) and its Zn(II), Co(II), Cu(II), and Ni(II) coordination compounds have been synthesized. The results of IR, Mass spectra, UV–visible, 1H&13C-NMR, ESR, effective magnetic moments and elemental analyses suggested various structures of the synthesized coordination compounds. A square planar stereochemistry was suggested for Cu(II) and Ni(II) complexes, whereas octahedral stereochemistry was suggested for Co(II) complex. The structures were geometry optimized by DFT at exchange–correlation level (DFT/B3LYP) and 6-311++G(d,p) basis set. The electronic spectra were simulated and the optical band gap was calculated and compared with the experimental results. The determined optical band gap (Eg) represents direct electronic transitions with values in the range 4.42–4.45 eV. Molecular docking indicated the possible interactions of the compounds with the studied proteins. The cytotoxicity of the compounds were tested against HCT-116 and HePG2 cell lines and compared with Doxorubicin. H4L has a very strong cytotoxicity against the tested cell lines.
- Published
- 2023
- Full Text
- View/download PDF
15. Development of New Thiazole Complexes as Powerful Catalysts for Synthesis of Pyrazole-4-Carbonitrile Derivatives under Ultrasonic Irradiation Condition Supported by DFT Studies
- Author
-
Mahmoud Abd El Aleem Ali Ali El-Remaily, Tarek El-Dabea, Mohammed Alsawat, Mohamed H. H. Mahmoud, Alia Abdulaziz Alfi, Nashwa El-Metwaly, and Ahmed M. Abu-Dief
- Subjects
Chemistry ,QD1-999 - Published
- 2021
- Full Text
- View/download PDF
16. Titanium Dioxide/Phosphorous-Functionalized Cellulose Acetate Nanocomposite Membranes for DMFC Applications: Enhancing Properties and Performance
- Author
-
Randa E. Khalifa, Ahmed M. Omer, Mohamed H. Abd Elmageed, and Mohamed S. Mohy Eldin
- Subjects
Chemistry ,QD1-999 - Published
- 2021
- Full Text
- View/download PDF
17. Promoting Visible Light Generation of Hydrogen Using a Sol–Gel-Prepared MnCo2O4@g‑C3N4 p–n Heterojunction Photocatalyst
- Author
-
Maha Alhaddad, Reda M. Mohamed, and Mohamed H. H. Mahmoud
- Subjects
Chemistry ,QD1-999 - Published
- 2021
- Full Text
- View/download PDF
18. Molten Salts Approach of Poly(vinyl alcohol)-Derived Bimetallic Nickel–Iron Sheets Supported on Porous Carbon Nanosheet as an Effective and Durable Electrocatalyst for Methanol Oxidation
- Author
-
Badr M. Thamer, Meera Moydeen Abdul Hameed, and Mohamed H. El-Newehy
- Subjects
PVA ,bimetallic nickel–iron ,molten salt synthesis ,porous nanosheets ,electrocatalyst ,methanol oxidation ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
The preparation of metallic nanostructures supported on porous carbon materials that are facile, green, efficient, and low-cost is desirable to reduce the cost of electrocatalysts, as well as reduce environmental pollutants. In this study, a series of bimetallic nickel–iron sheets supported on porous carbon nanosheet (NiFe@PCNs) electrocatalysts were synthesized by molten salt synthesis without using any organic solvent or surfactant through controlled metal precursors. The as-prepared NiFe@PCNs were characterized by scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction, and photoelectron spectroscopy (XRD and XPS). The TEM results indicated the growth of NiFe sheets on porous carbon nanosheets. The XRD analysis confirmed that the Ni1−xFex alloy had a face-centered polycrystalline (fcc) structure with particle sizes ranging from 15.5 to 30.6 nm. The electrochemical tests showed that the catalytic activity and stability were highly dependent on the iron content. The electrocatalytic activity of catalysts for methanol oxidation demonstrated a nonlinear relationship with the iron ratio. The catalyst doped with 10% iron showed a higher activity compared to the pure nickel catalyst. The maximum current density of Ni0.9Fe0.1@PCNs (Ni/Fe ratio 9:1) was 190 mA/cm2 at 1.0 M of methanol. In addition to the high electroactivity, the Ni0.9Fe0.1@PCNs showed great improvement in stability over 1000 s at 0.5 V with a retained activity of 97%. This method can be used to prepare various bimetallic sheets supported on porous carbon nanosheet electrocatalysts.
- Published
- 2023
- Full Text
- View/download PDF
19. Biosynthesized ZnO-NPs Using Sea Cucumber (Holothuria impatiens): Antimicrobial Potential, Insecticidal Activity and In Vivo Toxicity in Nile Tilapia Fish, Oreochromis niloticus
- Author
-
Mostafa A. Elbahnasawy, Hussein A. El-Naggar, Ibrahim E. Abd-El Rahman, Mohamed H. Kalaba, Saad A. Moghannem, Fatimah Al-Otibi, Reham M. Alahmadi, Othman F. Abdelzaher, Mohamed M. Mabrouk, Ahmed G. A. Gewida, Marwa F. AbdEl-Kader, and Ahmed I. Hasaballah
- Subjects
biosynthesis ,nanoparticles ,zinc oxide ,sea cucumber ,Holothuria impatiens ,antimicrobial activity ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In this study, a sustainable and eco-friendly method was used to prepare zinc oxide nanoparticles (ZnO-NPs) using a sea cucumber aqueous extract. Then, ZnO-NPs were characterized by instrumental analysis (UV-vis, HR-TEM, XRD, FT-IR, and DLS) and evaluated for their possible antibacterial, antifungal, and insecticidal activities. Additionally, the toxicity of ZnO-NPs was evaluated in vivo against Nile Tilapia (Oreochromis niloticus). The sea cucumber was collected from the Gulf of Suez (Red Sea) at Al-Ain Al-Sokhna coast in Egypt and identified as Holothuria impatiens. The prepared Hi-ZnO-NPs peaked at 350 nm in UV–Vis spectral analysis. They showed quasi-spherical shaped particles with sizes ranging from 13 nm to 47 nm and a predominate size of 26 nm as indicated by HR-TEM. The XRD pattern of Hi-ZnO-NPs revealed a crystalline phase with an average size of 17.2 nm as calculated by Debye–Scherrer equation. FTIR analysis revealed the possible role of H. impatiens biological molecules in the biosynthesis process of ZnO-NPs. Hi-ZnO-NPs showed a negative zeta potential of −19.6 mV, demonstrating moderate stability. Biosynthesized Hi-ZnO-NPs revealed broad antimicrobial activity against Gram-positive bacteria (S. aureus ATCC 25923 and E. feacalis), Gram-negative bacteria (S. typhi, K. pneumonia and E. coli), and filamentous fungi (Aspergillus niger). Hi-ZnO-NPs demonstrated larvicidal activity against the mosquito, Culex pipiens (LC50 = 2.756 ppm and LC90 = 9.294 ppm), and adulticidal action against the housefly, Musca domestica (LD50 = 4.285 ppm and LD90 = 22.847 ppm). Interestingly, Hi-ZnO-NPs did not show mortality effects against Nile tilapia fish (Oreochromis niloticus), highlighting the potential safety of Hi-ZnO-NPs to highly exposed, non-target organisms. However, histopathological and hematological investigations provided dose-dependent impacts of Hi-ZnO-NPs to Nile tilapia. Overall, data provide an eco-friendly approach for synthesizing novel Hi-ZnO-NPs with multiple biomedical properties and potentially low toxicity to Nile tilapia fish.
- Published
- 2023
- Full Text
- View/download PDF
20. Developed Process Circuit Flowsheet of Al Amar Ore for Production of Nanocrystalline Ferrite and Improving Gold Recovery
- Author
-
Mohamed H. H. Mahmoud, Mahmoud M. Hessien, Mohammed Alsawat, Abel Santos, Nader El-Bagoury, Abdullah K. Alanazi, and Naif A. Alshanbari
- Subjects
Chemistry ,QD1-999 - Published
- 2020
- Full Text
- View/download PDF
21. Microporous Metal–Organic Framework (MOF)-Based Composite Polymer Electrolyte (CPE) Mitigating Lithium Dendrite Formation in All-Solid-State-Lithium Batteries
- Author
-
N. Angulakshmi, Yingke Zhou, Shruti Suriyakumar, R. Baby Dhanalakshmi, M. Satishrajan, Subbiah Alwarappan, Mohamed H. Alkordi, and A. Manuel Stephan
- Subjects
Chemistry ,QD1-999 - Published
- 2020
- Full Text
- View/download PDF
22. Phytotoxicity and Antimicrobial Activity of Green Synthesized Silver Nanoparticles Using Nigella sativa Seeds on Wheat Seedlings
- Author
-
Ezzat H. Elshazly, Abdel Kareem S. H. Mohamed, Hesham A. Aboelmagd, Gamal A. Gouda, Mohamed H. Abdallah, Emad A. Ewais, Mohammed A. Assiri, and Gomaa A. M. Ali
- Subjects
Chemistry ,QD1-999 - Abstract
Recently, the green synthesis of nanomaterials has grown in popularity and has become one of the most used approaches. Plant extracts are safe for the environment and could be cost-effective for nanoparticle preparation. Silver nanoparticles (AgNPs) have been synthesized using aqueous extracts of Nigella sativa (N. sativa) seeds. The formation of AgNPs was confirmed by using an X-ray diffractometer, a UV-visible spectrometer, and a transmission electron microscope. The phytotoxicity and genotoxicity of different AgNP concentrations (12.5, 25, 50, 75, and 100 μg·L−1) were evaluated by wheat (Triticum aestivum L.) seed germination. The results showed that AgNPs did not significantly affect germination, while root and coleoptile lengths decreased considerably. On the contrary, the biomass of seedlings markedly increased in response to AgNP treatments. Moreover, genotoxicity was detected, especially at high concentrations of AgNPs. DNA, RNA, and total soluble proteins of wheat seedlings significantly decreased. In addition, antimicrobial activities of biosynthesized AgNPs were detected.
- Published
- 2022
- Full Text
- View/download PDF
23. Antimycobacterial and anticancer activity of newly designed cinnamic acid hydrazides with favorable toxicity profile
- Author
-
Mohamed H. Assaleh, Snezana K. Bjelogrlic, Nevena Prlainovic, Ilija Cvijetic, Aleksandra Bozic, Irena Arandjelovic, Dragana Vukovic, and Aleksandar Marinkovic
- Subjects
Cinnamic acid hydrazides ,Mycobacterium tuberculosis ,Anti-mycobacterial ,Anti-cancer ,Hepatotoxicity ,Chemistry ,QD1-999 - Abstract
A series of twelve novel hybrids of cinnamic acid and thiocarbohydrazones were designed, synthesized in high yield using a simple coupling strategy via acid chlorides, and evaluated for their impact against Mycobacterium tuberculosis (Mtb) and cancer cells survival. Among them, compound 3 demonstrated strong anti-Mtb activity by reducing bacilli survival for>90 % in all three treated Mtb isolates, whereas isoniazid and rifampicin did not. Moreover, compound 3 didn’t affect vitality of HepG-2 cells, implying on advantageous hepatotoxicity profile compared to current therapeutic options for tuberculosis. Compounds 2a and 3b displayed as strong inducers of apoptosis in A549 cells, both activating intrinsic caspase pathway and cell cycle arrest at the G0/G1 phase. Subsequent analyses disclosed differences in their activities, where 3b has ability to induce production of mitochondrial superoxide anions, while 2a significantly inhibited cellular mobility. More importantly, 3b considerably affected viability of HepG-2 and HaCaT cells, whereas 2a had moderate impact only on the later. Molecular modeling studies indicated high permeability and good absorption through the human intestine, and moderate aqueous solubility with poor blood–brain barrier permeability. In summary, our results reveal that novel compounds 3 and 2a represent promising agents for tuberculosis and cancer treatment, respectively, indicating that further investigation needs to be performed to clarify the mechanisms of their anti-Mtb and anticancer activity.
- Published
- 2022
- Full Text
- View/download PDF
24. Chemical Profiling of Significant Antioxidant and Phytotoxic Microwave-Extracted Essential Oil from Araucaria heterophylla Resin
- Author
-
Ahmed M. Abd-ElGawad, Ibrahim Saleh, Mohamed H. Abd El-Razek, Asmaa S. Abd Elkarim, Yasser A. El-Amier, Tarik A. Mohamed, Abd El-Nasser G. El Gendy, Sherif M. Afifi, Tuba Esatbeyoglu, and Abdelsamed I. Elshamy
- Subjects
Norfolk pine ,volatile compounds ,free radical scavenging ,terpenes ,allelopathy ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Due to the various hazards of using synthetic chemical compounds in pharmaceutics, agriculture, and industry, scientists and researchers do their best to explore and assess new green natural compounds from natural resources with potent activity. The essential oil (EO) from the resin collected from Araucaria heterophylla Salisb. was extracted by the microwave technique and chemically characterized via GC-MS analysis. Furthermore, the extract EO was assessed for its antioxidant and phytotoxic activities. The EO has 33 compounds, mainly terpenes (98.23%), and the major compounds were α-pinene (62.57%), β-pinene (6.60%), germacrene D (5.88%), and β-caryophyllene (3.56%). The extracted EO showed substantial antioxidant activity, where it showed IC50 values of 142.42 and 118.03 mg L−1 for DPPH and ABTS, respectively. On the other hand, the EO revealed considerable phytotoxicity against the weed Chenopodium murale, where the EO showed IC50 values of 304.0, 230.1, and 147.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. Moreover, the EO showed the same pattern of allelopathic inhibition against the weed Sonchus oleraceus, where it showed IC50 values of 295.7, 224.5, and 106.1 mg L−1, for seed germination, seedling shoot growth, and seedling root growth, respectively. The present study showed that the extraction technique affects the constituents of the EO, particularly the quantitative composition. The EO of A. heterophylla resin also revealed considerable antioxidant and phytotoxic activity against weeds. Therefore, it can be considered a promising natural resource that could be integrated into the weed management approach. However, further study is recommended for deep characterization of their authentic compounds and evaluation of their mode of action(s) on a wide spectrum of weeds.
- Published
- 2023
- Full Text
- View/download PDF
25. Deep Learning for Predicting Traffic in V2X Networks
- Author
-
Ali R. Abdellah, Ammar Muthanna, Mohamed H. Essai, and Andrey Koucheryavy
- Subjects
5G ,V2X ,deep learning ,artificial intelligence ,LSTM ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Artificial intelligence (AI) is capable of addressing the complexities and difficulties of fifth-generation (5G) mobile networks and beyond. In this paradigm, it is important to predict network metrics to meet future network requirements. Vehicle-to-everything (V2X) networks are promising wireless communication methods where traffic information exchange in an intelligent transportation system (ITS) still faces challenges, such as V2X communication congestion when many vehicles suddenly appear in an area. In this paper, a deep learning algorithm (DL) based on the unidirectional long short-term memory (LSTM) model is proposed to predict traffic in V2X networks. The prediction problems are studied in different cases depending on the number of packets sent per second. The prediction accuracy is measured in terms of root-mean-square error (RMSE), mean absolute percentage error (MAPE), and processing time.
- Published
- 2022
- Full Text
- View/download PDF
26. Three-Dimensional Finite Element Analysis for Pressure on Flexible Wall Silos
- Author
-
Alhussein Hilal, Abdel Monem Sanad, Mohamed H. Abdelbarr, Osman M. O. Ramadan, and Hany A. Abdalla
- Subjects
finite element modeling ,three-dimensional steel silos ,square silos ,silo filling ,wall pressure ,granular material ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A 3D finite element model (FEM) for predicting the distribution of lateral pressure in a square flexible walled steel silo during the filling phase was analyzed in this study. The numerical approach, developed using Abaqus software, predicts the stress state in bulk solids, as well as the pressures exerted on the silo walls. An elasto-plastic model using the Drucker–Prager criterion was employed to simulate the behavior of the granular materials. The FEM simulates the behavior of the bulk solid and its interaction with the silo’s wall and base using a surface-to-surface discretization model. The model’s predictions were validated by previous experimental measurements. The results revealed good agreement between the FEM predictions and the experimental measurements. The research confirms that the lateral pressure distribution is not uniform at any silo level. This highlights the fact that many available theories and current design codes are not accurate for flexible steel walls. As a result of the wall’s deformability, pressure regimes on the silo wall change significantly in the horizontal direction at any level. The results showed that the horizontal variations of lateral pressure change drastically with regard to wall stiffness. The FEM has been used to investigate the effect of critical parameters on wall pressure distribution, such as properties of bulk solids, wall thickness, and silo type, whether deep or flat.
- Published
- 2022
- Full Text
- View/download PDF
27. Single- and Multilayered Perovskite Thin Films for Photovoltaic Applications
- Author
-
Nawishta Jabeen, Anum Zaidi, Ahmad Hussain, Najam Ul Hassan, Jazib Ali, Fahim Ahmed, Muhammad Usman Khan, Nimra Iqbal, Tarek A. Seaf Elnasr, and Mohamed H. Helal
- Subjects
perovskite ,thin films ,spin coating ,methylammonium lead iodide bromide ,ferroelectric ,IV measurements ,Chemistry ,QD1-999 - Abstract
Organic–inorganic lead halide perovskites materials have emerged as an innovative candidate in the development of optoelectronic and photovoltaic devices, due to their appealing electrical and optical properties. Herein, mix halide single-layer (~95 nm) and multilayer (average layer ~87 nm) CH3NH3PbIBr2 thinfilms were grown by a one-step spin coating method. In this study, both films maintained their perovskite structure along with the appearance of a pseudo-cubic phase of (200) at 30.16°. Single-layer and multilayer CH3NH3PbIBr2 thinfilms displayed leaky ferroelectric behavior, and multilayered thinfilm showed a leakage current of ~5.06 × 10−6 A and resistivity of ~1.60 × 106 Ω.cm for the applied electric field of 50 kV/cm. However, optical analysis revealed that the absorption peak of multilayered perovskite is sharper than a single layer in the visible region rather than infrared (IR) and near-infrared region (NIR). The band gap of the thinfilms was measured by Tauc plot, giving the values of 2.07 eV and 1.81 eV for single-layer and multilayer thinfilms, respectively. The structural analysis has also been performed by Fourier transform infrared spectroscopy (FTIR). Moreover, the fabricated CH3NH3PbIBr2 as an absorber layer for photoelectric cell demonstrated a power conversion efficiency of 7.87% and fill factor of 72%. Reported electrical, optical and photoelectric efficiency-based results suggest that engineered samples are suitable candidates for utilization in optoelectronic and photovoltaic devices.
- Published
- 2022
- Full Text
- View/download PDF
28. Numerical Study on the Effect of Deposit Layer on the Minimum Wall Thickness of Boiler Water Tube under Different Operating Conditions
- Author
-
Ahmed S. Aljohani, Khaled I. Ahmed, Saeed Asiri, and Mohamed H. Ahmed
- Subjects
steam boiler ,water tube ,deposit layer ,tube wall thickness ,wall tube thermal conductivity ,thermo-mechanical performance ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Water wall tube temperature is a major parameter in the steam generator design which has a significant role in keeping the steam generator available. Thus, knowing the tube average temperature in different operating conditions is very important to avoid the causes of tube failures. High temperatures are a major cause of various types of failures, such as overheating, hydrogen damage, thermal stress, etc. Furthermore, deposits on the inner tube wall contribute to such failure by changing the thermal resistance of the tube wall, which causes a significant increase in the tube wall’s average temperature, consequently lowering the allowable stress. Therefore, the model was created by using ANSYS FLUENT (Canonsburg, PA, USA) to determine the wall average water tube wall temperature considering the deposit layer thickness (magnetite). Furthermore, this model was verified. It was found that increasing tube thickness can increase the average tube temperature but combining it with increasing deposit thickness leads to higher temperatures. In other words, the effect of the deposit on the tube with higher thickness is higher than on the tube with lower thickness. By discussing the minimum thickness of the water wall tube, the suitable selection of the tube thickness and courses of action concerning the operating conditions that minimize the potential overheating of water tubes in the furnace section of the boiler can be determined.
- Published
- 2022
- Full Text
- View/download PDF
29. Functionalized electrospun carbon nanofibers for removal of cationic dye
- Author
-
Badr M. Thamer, Hany El-Hamshary, Salem S. Al-Deyab, and Mohamed H. El-Newehy
- Subjects
Chemistry ,QD1-999 - Abstract
Electrospun carbon nanofibers (ECNFs) have attracted significant attention in recent years as relatively inexpensive alternative to carbon nanotubes for adsorption organic pollutants. In this study, ECNFs were fabricated from polyacrylonitrile (PAN) using an electrospinning technique, followed by carbonization and oxidation via treatment with a H2SO4/HNO3 mixture. The prepared oxidized electrospun carbon nanofibers (O-ECNFs) were characterized using scanning and transmission electron microscopy (SEM and TEM), Fourier transform infrared (FT-IR), Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The O-ECNFs were used as nano-adsorbents for the adsorption of methylene blue (MB) from aqueous solution. The adsorption of MB by the O-ECNFs was studied as a function of pH, time, adsorbent dosage, MB concentration, and temperature. ECNF functionalization enhanced the adsorption capacity towards MB dye compared pristine ECNFs. Detailed analysis of the adsorption kinetics showed that the adsorption process followed a pseudo-second-order model. The adsorption isotherm was best fit by the Langmuir model. The thermodynamic results showed that MB adsorption onto the O-ECNFs was endothermic and spontaneous. Keywords: Electrospinning, Carbon nanofibers, Functionalization, Methylene blue, Adsorption, Kinetic
- Published
- 2019
- Full Text
- View/download PDF
30. Developing a Novel Design for a Tubular Solid Oxide Fuel Cell Current Collector
- Author
-
Khaled I. Ahmed and Mohamed H. Ahmed
- Subjects
tubular SOFC ,current collector ,optimization ,CFD ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This study presents a novel current collector design for a tubular SOFC and numerically investigates its performance. The new current collector design has a flow channel with a trapezoidal shape. Several channels, such as four, eight, and twelve, are investigated, and their effects on cell performance are reported and compared. Additionally, a traditional tubular SOFC and the newly developed design are presented. The equations of mass conservation, momentum, charge transport, and energy were considered in the numerical model, and the ANSYS Fluent SOFC module was used to solve the numerical model. The results show that the developed design performed better than the traditional design. The new design with twelve channels collected 0.384 A, higher than the other designs. Although the design with twelve channels gave a high concentration of hydrogen at the outlet compared to the designs with four and eight channels, it gave higher performance than the designs with four and eight channels. Increasing the number of channels in the developed design enhanced the cell performance significantly due to the increased contact area, leading to the efficient collection of the generated current.
- Published
- 2022
- Full Text
- View/download PDF
31. Investigation of the Heat Transfer and Pressure Drop in Tubes with Transverse Ribs of Zigzag Configurations
- Author
-
Mohamed H. Ahmed
- Subjects
ribbed tube ,zigzag configuration ,unequal ribs ,heat transfer enhancement ,pressure drop ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Heat transfer through tube walls can be promoted using a ribbed tube configuration. Most of the ribs used in previous reports have equal height along the tube length. In this numerical study, we investigate the heat transfer and pressure drop in a transverse ribbed tube where ribs of unequal heights are mounted such that the tops of the ribs form a zigzag shape. Four configurations were studied. Each configuration had a set of two neighboring ribs of different heights. The set was repeated along the tube length to form a zigzag shape. The rib height ratios, e2/e1, of the four sets were 0.25, 0.5, 0.75, and 1.0. The ratios of the height of the taller rib, pitch, and width to the tube diameter were kept constant at values of e1/d = 0.1, p/d = 1.0, and w/d = 0.05, respectively. The Reynolds number ranged from 10,000 to 60,000, while the Prandtl number ranged from 0.71 to 7.0. The results from the k-ε and k-ω models were first validated and compared with the experimental results of smooth and ribbed tubes. The two models showed comparable results, with the k-ε showing slightly better performance and was thus selected to perform the current study. It was found that the average Nusselt number increases along with increases in the rib height ratio, Prandtl number, and Reynolds number. The friction factor changed exponentially with the rib height ratio, while the Reynolds number showed a minor effect. At the same pumping power, a maximum thermal performance enhancement of approximately 8% was achieved at rib height ratios of 0.25 and 0.5. The rib height ratio of 0.5 has an advantage over that of 0.25 as it has a higher average Nusselt number. Two correlations were introduced to estimate the Nusselt number and friction factor for the current ribbed tube of zigzag configurations.
- Published
- 2022
- Full Text
- View/download PDF
32. Tragacanth Gum Hydrogel-Derived Trimetallic Nanoparticles Supported on Porous Carbon Catalyst for Urea Electrooxidation
- Author
-
Badr M. Thamer, Meera Moydeen Abdulhameed, and Mohamed H. El-Newehy
- Subjects
trimetallic nanoparticles ,hydrogel ,urea oxidation ,fuel cells ,Science ,Chemistry ,QD1-999 ,Inorganic chemistry ,QD146-197 ,General. Including alchemy ,QD1-65 - Abstract
The fabrication of electrocatalysts with high catalytic activity, high durability and low cost towards urea oxidation by a facile method is a great challenge. In this study, non-precious NiCoFe trimetallic supported on porous carbon (NiCoFe@PC) was prepared via gelation and pyrolysis method, presenting a remarkable electrocatalytic activity with low onset potential for urea oxidation in an alkaline medium. Field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were used to clarify the morphology of the NiCoFe@PC nanostructure and its nanoparticle size of 17.77 nm. The prepared catalyst with the composition ratio of 24.67, 5.92 and 5.11% for Ni, Fe and Co, respectively, with highly crystalline nanoparticles, fixed on porous carbon, according to energy-dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis. The FeCoNi@PC catalyst showed a catalytic activity of 44.65 mA/cm2 at 0.57 V vs. Ag/AgCl and a low onset potential of 218 mV, which is superior to many other transition bi/trimetallic-based catalysts previously reported.
- Published
- 2022
- Full Text
- View/download PDF
33. Antidepressant-Like Effect of Traditional Medicinal Plant Carthamus Tinctorius in Mice Model through Neuro-Behavioral Tests and Transcriptomic Approach
- Author
-
Mohamed H. Alegiry, Abdelfatteh El Omri, Ahmed Atef Bayoumi, Mohammed Y. Alomar, Irfan A. Rather, and Jamal S. M. Sabir
- Subjects
safflower ,oleamide ,depression ,transcriptome ,neuro-behavioral test ,grik1 ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Major depression disorder (MDD) has become a common life-threatening disorder. Despite the number of studies and the introduced antidepressants, MDD remains a major global health issue. Carthamus tinctorius (safflower) is traditionally used for food and medical purposes. This study investigated the chemical profile and the antidepressant-like effect of the Carthamus tincto-rius hot water extract in male mice and its mechanism using a transcriptomic analysis. The antidepressant effect of hot water extract (50 mg/kg and 150 mg/kg) was investigated in mice versus the untreated group (saline) and positive control group (fluoxetine 10 mg/kg). Hippocampus transcriptome changes were investigated to understand the Carthamus tinctorius mechanism of action. The GC-MS analysis of Carthamus tinctorius showed that hot water extract yielded the highest amount of oleamide as the most active ingredient. Neuro-behavioral tests demonstrated that the safflower treatment significantly reduced immobility time in TST and FST and improved performance in the YMSAT compared to the control group. RNA-seq analysis revealed a significant differential gene expression pattern in several genes such as Ube2j2, Ncor1, Tuba1c, Grik1, Msmo1, and Casp9 related to MDD regulation in 50 mg/kg safflower treatment as compared to untreated and fluoxetine-treated groups. Our findings demonstrated the antidepressant-like effect of safflower hot water extract and its bioactive ingredient oleamide on mice, validated by a significantly shortened immobility time in TST and FST and an increase in the percentage of spontaneous alternation.
- Published
- 2022
- Full Text
- View/download PDF
34. Imide-Based Polymers of Intrinsic Microporosity: Probing the Microstructure in Relation to CO2 Sorption Characteristics
- Author
-
Worood A. Elmehalmey, Rasha A. Azzam, Youssef S. Hassan, Mohamed H. Alkordi, and Tarek M. Madkour
- Subjects
Chemistry ,QD1-999 - Published
- 2018
- Full Text
- View/download PDF
35. Theoretical Study on the Flexural Behavior of Structural Elements Strengthened with External Pre-Stressing Methods
- Author
-
Gouda A. Mohamed, Ahmed S. Eisa, Pavol Purcz, and Mohamed H. El-Feky
- Subjects
strengthening ,pre-stressing ,external tendon ,frames ,load capacity ,finite element ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This study aims to strengthen the flexural behavior of structural elements with external pre-stressing tendons, thereby improving their load-carrying capacity and increasing their resistance against the external load. Different techniques were used to apply external pre-stressed strengthening to RC beams and RC frames. Seven identical RC frames were analyzed: an original sample without an external tendon, two strengthened samples with external tendons at the positive bending zone, two strengthened samples with external tendons at the beam–column connection zone, a strengthened sample with external straight line tendons along the beam and, finally, a strengthened sample with external U-shape tendons along the beam of the frame. The analysis and the results were obtained using ANSYS WORKBENCH finite element (FE) program. Comparisons were performed between these techniques to determine which technique is better for strengthening. The failure mode, vertical deflection, column stress, load-carrying capacity, and ductility of the samples were listed and analyzed under four-point vertical loading. The results show that using external tendons significantly increases the load capacity and the stiffness of structural frames. Moreover, the tendon in the beam zone is more effective than the tendon in the column zone.
- Published
- 2021
- Full Text
- View/download PDF
36. Biocompatibility Computation of Muscle Cells on Polyhedral Oligomeric Silsesquioxane-Grafted Polyurethane Nanomatrix
- Author
-
Touseef Amna, Mallick Shamshi Hassan, Mohamed H. El-Newehy, Tariq Alghamdi, Meera Moydeen Abdulhameed, and Myung-Seob Khil
- Subjects
polyhedral oligomeric silsesquioxanes ,polyurethane ,muscle cells ,nanofibers ,Chemistry ,QD1-999 - Abstract
This study was performed to appraise the biocompatibility of polyhedral oligomeric silsesquioxane (POSS)-grafted polyurethane (PU) nanocomposites as potential materials for muscle tissue renewal. POSS nanoparticles demonstrate effectual nucleation and cause noteworthy enhancement in mechanical and thermal steadiness as well as biocompatibility of resultant composites. Electrospun, well-aligned, POSS-grafted PU nanofibers were prepared. Physicochemical investigation was conducted using several experimental techniques, including scanning electron microscopy, energy dispersive X-ray spectroscopy, electron probe microanalysis, Fourier transform infrared spectroscopy, and X-ray diffraction pattern. Adding POSS molecules to PU did not influence the processability and morphology of the nanocomposite; however, we observed an obvious mean reduction in fiber diameter, which amplified specific areas of the POSS-grafted PU. Prospective biomedical uses of nanocomposite were also appraised for myoblast cell differentiation in vitro. Little is known about C2C12 cellular responses to PU, and there is no information regarding their interaction with POSS-grafted PU. The antimicrobial potential, anchorage, proliferation, communication, and differentiation of C2C12 on PU and POSS-grafted PU were investigated in this study. In conclusion, preliminary nanocomposites depicted superior cell adhesion due to the elevated free energy of POSS molecules and anti-inflammatory potential. These nanofibers were non-hazardous, and, as such, biomimetic scaffolds show high potential for cellular studies and muscle regeneration.
- Published
- 2021
- Full Text
- View/download PDF
37. Seawater Absorption and Adhesion Properties of Hydrophobic and Superhydrophobic Thermoset Epoxy Nanocomposite Coatings
- Author
-
Ayman M. Atta, Mohamed H. El-Newehy, Meera Moydeen Abdulhameed, Mohamed H. Wahby, and Ahmed I. Hashem
- Subjects
epoxy coating ,proper superhyrophobicity ,nanoparticles ,rather-exothermic curing ,coating durability ,Chemistry ,QD1-999 - Abstract
The enhancement of both thermal and mechanical properties of epoxy materials using nanomaterials becomes a target in coating of the steel to protect it from aggressive environmental conditions for a long time, with reducing the cost. In this respect, the adhesion properties of the epoxy with the steel surfaces, and its proper superhyrophobicity to repel the seawater humidity, can be optimized via addition of green nanoparticles (NPs). In-situ modification of silver (Ag) and calcium carbonate (CaCO3) NPs with oleic acid (OA) was carried out during the formation of Ag−OA and CaCO3−OA, respectively. The epoxide oleic acid (EOA) was also used as capping for Ca−O3 NPs by in-situ method and epoxidation of Ag−OA NPs, too. The morphology, thermal stability, and the diameters of NPs, as well as their dispersion in organic solvent, were investigated. The effects of the prepared NPs on the exothermic curing of the epoxy resins in the presence of polyamines, flexibility or rigidity of epoxy coatings, wettability, and coatings durability in aggressive seawater environment were studied. The obtained results confirmed that the proper superhyrophobicity, coating adhesion, and thermal stability of the epoxy were improved after exposure to salt spray fog for 2000 h at 36 °C.
- Published
- 2021
- Full Text
- View/download PDF
38. Facile synthesis of Ni-decorated multi-layers graphene sheets as effective anode for direct urea fuel cells
- Author
-
Ahmed Yousef, Mohamed H. El-Newehy, Salem S. Al-Deyab, and Nasser A.M. Barakat
- Subjects
Graphene ,Nickel ,Nanocomposites ,Urea electrooxidation ,Fuel cell ,Chemistry ,QD1-999 - Abstract
A large amount of urea-containing wastewater is produced as a by-product in the fertilizer industry, requiring costly and complicated treatment strategies. Considering that urea can be exploited as fuel, this wastewater can be treated and simultaneously exploited as a renewable energy source in a direct urea fuel cell. In this study, multi-layers graphene/nickel nanocomposites were prepared by a one-step green method for use as an anode in the direct urea fuel cell. Typically, commercial sugar was mixed with nickel(II) acetate tetrahydrate in distilled water and then calcined at 800 °C for 1 h. Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS) were employed to characterize the final product. The results confirmed the formation of multi-layers graphene sheets decorated by nickel nanoparticles. To investigate the influence of metal nanoparticles content, samples were prepared using different amounts of the metal precursor; nickel acetate content was changed from 0 to 5 wt.%. Investigation of the electrochemical characterizations indicated that the sample prepared using the original solution with 3 wt.% nickel acetate had the best current density, 81.65 mA/cm2 in a 0.33 M urea solution (in 1 M KOH) at an applied voltage 0.9 V vs Ag/AgCl. In a passive direct urea fuel cell based on the optimal composition, the observed maximum power density was 4.06 × 10−3 mW/cm2 with an open circuit voltage of 0.197 V at room temperature in an actual electric circuit. Overall, this study introduces a cheap and beneficial methodology to prepare effective anode materials for direct urea fuel cells.
- Published
- 2017
- Full Text
- View/download PDF
39. Microwave synthesis and fluorescence properties of homo- and heterodimeric monomethine cyanine dyes TOTO and their precursors
- Author
-
Hussein H. Alganzory, Wael A. El-Sayed, Mohamed H. Arief, Mahasen S. Amine, and El-Zeiny M. Ebeid
- Subjects
Microwave ,monomethine cyanine dyes ,TOTO’s analogues ,singlet oxygen ,Science ,Chemistry ,QD1-999 - Abstract
A series of monomeric and dimeric cyanine dyes belonging to the thiazole orange family have been prepared via an improved synthetic procedure, by the reaction of the monomethine dye containing an iodoalkyl group with tertiary diamine linkers under microwave irradiation. The effects of microwave power and irradiation time on yield were examined. The electronic absorption and steady-state fluorescence spectra of prepared dyes have been investigated. Fluorescence properties indicate significance in singlet oxygen sensitization and make the present compounds potential candidates in the area of photodynamic therapy.
- Published
- 2017
- Full Text
- View/download PDF
40. Nano-engineered ZnO/CeO2 dots@CNFs for fuel cell application
- Author
-
Zafar Khan Ghouri, Nasser A.M. Barakat, Hak Yong Kim, Mira Park, Khalil Abdelrazek Khalil, Mohamed H. El-Newehy, and Salem S. Al-Deyab
- Subjects
Carbon nanofibers ,Nanodots ,Electrospinning ,Direct methanol fuel cells ,Negative onset potential ,Chemistry ,QD1-999 - Abstract
Well-dispersed ZnO(x)CeO2(1−x) nanodots@carbon nanofibers as anode catalysts for the electrooxidation of methanol were synthesized by an easy-controlled template-free method. Their structure and morphology were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy (FESEM) equipped with rapid EDX (energy dispersive analysis of X-ray). The appealed characterization techniques specified that the obtained material is carbon nanofibers decorated by ZnO and CeO2 nanodots. The electrochemical oxidation of methanol on ZnO(x)CeO2(1−x) nanodots@CNFs modified glassy carbon electrode in alkaline solutions was systematically evaluated by cyclic voltammetry (CV) method. A detailed investigation is made for the electrocatalytic oxidation of methanol by varying methanol concentration. The corresponding current densities of ZnO(60%)CeO2(40%) nanodots@CNFs and ZnO(40%)CeO2(60%) nanodots@CNFs were 5.3 and 16.3 mA/cm2, respectively. Moreover, negative onset potential (−50 mV vs. Ag/AgCl) was observed when ZnO(40%)CeO2(60%) nanodots@CNFs were utilized, which is a superior value among the reported non-precious electrocatalysts. These results suggested cheap and effective nanomaterials as non-precious catalyst for DMFCs application and pave the way to further improve the performance in energy and environmental applications.
- Published
- 2016
- Full Text
- View/download PDF
41. Development of Advanced Computer Aid Model for Shear Strength of Concrete Slender Beam Prediction
- Author
-
Ahmad Sharafati, Masoud Haghbin, Mohammed Suleman Aldlemy, Mohamed H. Mussa, Ahmed W. Al Zand, Mumtaz Ali, Suraj Kumar Bhagat, Nadhir Al-Ansari, and Zaher Mundher Yaseen
- Subjects
structure monitoring ,shear strength prediction ,machine learning ,hybrid ANFIS model ,high-strength concrete ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
High-strength concrete (HSC) is highly applicable to the construction of heavy structures. However, shear strength (Ss) determination of HSC is a crucial concern for structure designers and decision makers. The current research proposes the novel models based on the combination of adaptive neuro-fuzzy inference system (ANFIS) with several meta-heuristic optimization algorithms, including ant colony optimizer (ACO), differential evolution (DE), genetic algorithm (GA), and particle swarm optimization (PSO), to predict the Ss of HSC slender beam. The proposed models were constructed using several input combinations incorporating several related dimensional parameters such as effective depth of beam (d), shear span (a), maximum size of aggregate (ag), compressive strength of concrete (fc), and percentage of tension reinforcement (ρ). To assess the impact of the non-homogeneity of the dataset on the prediction result accuracy, two possible modeling scenarios, (i) non-processed (initial) dataset (NP) and (ii) pre-processed dataset (PP), are inspected by several performance indices. The modeling results demonstrated that ANFIS-PSO hybrid model attained the best prediction accuracy over the other models and for the pre-processed input parameters. Several uncertainty analyses were examined (i.e., model, variables, and data), and results indicated predicting the HSC shear strength was more sensitive to the model structure uncertainty than the input parameters.
- Published
- 2020
- Full Text
- View/download PDF
42. Kinetic Uptake Studies of Powdered Materials in Solution
- Author
-
Mohamed H. Mohamed and Lee D. Wilson
- Subjects
kinetics ,dye adsorption ,cyclodextrin ,polyurethane ,p-nitrophenol ,phenolphthalein ,nanomaterials ,Chemistry ,QD1-999 - Abstract
Challenges exist for the study of time dependent sorption processes for heterogeneous systems, especially in the case of dispersed nanomaterials in solvents or solutions because they are not well suited to conventional batch kinetic experiments. In this study, a comparison of batch versus a one-pot setup in two variable configurations was evaluated for the study of uptake kinetics in heterogeneous (solid/solution) systems: (i) conventional batch method; (ii) one-pot system with dispersed adsorbent in solution with a semi-permeable barrier (filter paper or dialysis tubing) for in situ sampling; and (iii) one-pot system with an adsorbent confined in a semi-permeable barrier (dialysis tubing or filter paper barrier) with ex situ sampling. The sorbent systems evaluated herein include several cyclodextrin-based polyurethane materials with two types of phenolic dyes: p-nitrophenol and phenolphthalein. The one-pot kinetics method with in situ (Method ii) or ex situ (Method iii) sampling described herein offers significant advantages for the study of heterogeneous sorption kinetics of highly dispersed sorbent materials with particles sizes across a range of dimensions from the micron to nanometer scale. The method described herein will contribute positively to the development of advanced studies for heterogeneous sorption processes where an assessment of the relative uptake properties is required at different experimental conditions. The results of this study will be advantageous for the study of nanomaterials with significant benefits over batch kinetic studies for a wide range of heterogeneous sorption processes.
- Published
- 2015
- Full Text
- View/download PDF
43. An expeditious and green synthesis of new enaminones and study their chemical reactivity toward some different amines and binucleophiles under environmentally friendly conditions
- Author
-
Khadijah M. Al-Zaydi, Ramadan A. Mekheimer, Sameera M. Mousally, Rita M. Borik, and Mohamed H. Elnagdi
- Subjects
Green synthesis ,Enaminones ,Ultrasound irradiations ,Ionic liquids ,Nucleophilic substitution ,Binucleophiles ,Chemistry ,QD1-999 - Abstract
The condensation reaction of 3-heteroaromatic-3-oxopropanenitriles 3, 4 and 7 with dimethylformamide–dimethylacetal (DMF–DMA) gave the corresponding enaminones 8, 9 and 10, respectively. Nucleophilic substitution of 8 and 9 with different amines resulted in a new derivatives of enaminones 11–18. The reactivity of enaminones 8 and 9 toward some nitrogen nucleophiles was investigated with a view to synthesize new heterocyclic systems. Thus, treatment of compounds 8 and 9 with phenylhydrazine afforded the pyrazole derivatives 19 and 20, respectively. On the other hand, reacting 8 and 9 with guanidine gave the pyrimidines 21 and 22, respectively. Treatment of compound 9 with hydroxylamine hydrochloride afforded the aminoisoxazoles 23. The foregoing reactions were carried out with conventional heating and under green conditions [ultrasound (US) irradiations or ionic liquids (ILs)] and a comparative study was employed. All the new structures are fully characterized.
- Published
- 2017
- Full Text
- View/download PDF
44. A Stability-Indicating RP-HPLC-UV Method for Determination and Chemical Hydrolysis Study of a Novel Naproxen Prodrug
- Author
-
Mohamed H. M. Hamid and Tilal Elsaman
- Subjects
Chemistry ,QD1-999 - Abstract
A new naproxen amide prodrug was synthesized and spectrally characterized and a simple, precise, and accurate stability-indicating RP-HPLC method was developed and validated for determination and chemical hydrolysis study of the prodrug. Forced degradation studies were conducted as per the International Conference on Harmonization (ICH) guidelines to establish the stability-indicating power of the method. Separations were performed on a C18 column (150 × 4.6 mm i.d., 5 μm p.s.). The mobile phase consisted of acetonitrile and phosphate buffer pH 4.0 in the ratio 60 : 40. The flow rate and injection volume were 1.0 mL/min and 15 μL, respectively. The peaks were monitored at 272 nm. The average retention time is 5.136 min. The linearity of the method was investigated in the range of 10–50 μg/mL and r2 was found to be larger than 0.9987. The LOD and LOQ were found to be 1.853 and 5.615 μg/mL, respectively. Results indicated that the degradants are well resolved and separated from the prodrug. Hydrolysis kinetics studies were carried out in buffer solutions (pH 1.2, 5.5 and 7.4) to establish the fate of the prodrug. The half-lives in the respective buffers were 23.5, 262, and 334 hours indicating sufficient stability to attain the goal of oral delivery.
- Published
- 2017
- Full Text
- View/download PDF
45. Synthesis and biocidal activity of modified poly(vinyl alcohol)
- Author
-
El-Refaie Kenawy, Mohamed H. El-Newehy, Fouad I. Abdel-Hay, and Abd El-Raheem R. El-Shanshoury
- Subjects
Onium salts ,Polycationic biocides ,Antimicrobial activity ,Poly(vinyl alcohol) ,Chemistry ,QD1-999 - Abstract
Functionalized polymers and their polymer nature give them more advantages than the corresponding small molecules. In this respect, polymeric ammonium and phosphonium salts were prepared by chemical modifications of poly(vinyl alcohol) (PVA) aiming to explore their antimicrobial activities against pathogenic bacteria and fungi. The modifications were performed by chloroacetylation with chloroacetyl chloride. Incorporation of the ammonium and phosphonium salts was conducted by the reaction of chloroacetylated poly(vinyl alcohol) (CPVA) with triethylamine (TEA), triphenylphosphine (TPP), and tributylphosphine (TBP). The antimicrobial activity of the polymers against variety of test microorganisms was examined by the cut plug and viable cell counting methods of shake cultures of 10 times dilute nutrient broth and Sabouraud’s media, seeded with the test microorganisms. It was found that the immobilized polymers exhibited antimicrobial activity against the Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Shigella sp. and Salmonella typhi) and Gram positive bacteria (Bacillus subtilis and B. cereus) and the dermatophyte fungus (Trichophyton rubrum). The growth inhibition of the test microorganisms (ratio of surviving cell number, M/C) varied according to the composition of the active group in the polymer and the test organism. It increased by increasing the concentration of the polymer. Triphenyl phosphonium salt of the modified poly(vinyl alcohol) exhibited the most biocidal activity against both Gram-negative and Gram-positive bacteria after 24 h.
- Published
- 2014
- Full Text
- View/download PDF
46. Optimization of amine-terminated polyacrylonitrile synthesis and characterization
- Author
-
Mohamed H. El-Newehy, Abdullah Alamri, and Salem S. Al-Deyab
- Subjects
Polyacrylonitrile ,Diamines ,Functional polymers ,Biomedical applications ,Chemistry ,QD1-999 - Abstract
Amine-terminated PANs were prepared in two steps. The first step includes free radical polymerization of acrylonitrile (AN) using initiator pair of ammonium persulfate and sodium thiosulfate as redox system. In the second step, the amino groups were introduced through the reaction of polyacrylonitrile with excess of different diamines (10-fold) including ethylenediamine (EDA), hexamethylenediamine (HMDA) and octamethylenediamine (OMDA), to yield PAN–EDA, PAN–HMDA and PAN–OMDA, respectively. Optimization of the amine-terminated PANs synthesis was carried out at different temperatures (30–90 °C) and different time intervals (4–24 h). In addition, the introduction of the amino group was followed by the piperidine test and recording of the FT-IR spectra. All polymers were characterized by, 1H NMR spectra, thermogravimetric analysis (TGA), and FT-IR spectra.
- Published
- 2014
- Full Text
- View/download PDF
47. Application of FTIR and LA-ICPMS Spectroscopies as a Possible Approach for Biochemical Analyses of Different Rat Brain Regions
- Author
-
Mohamed H. M. Ali, Fazle Rakib, Volker Nischwitz, Ehsan Ullah, Raghvendra Mall, Amjad M. Shraim, M. I. Ahmad, Zafar Khan Ghouri, Donald McNaughton, Stephan Küppers, Tariq Ahmed, and Khalid Al-Saad
- Subjects
FTIR imaging spectroscopy ,biochemical analysis ,brain ,LA-ICP-MS ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Fourier Transform Infrared Spectroscopy (FTIR) is a non-destructive analytical technique that has been employed in this research to characterize the biochemical make-up of various rat brain regions. The sensorimotor cortex, caudate putamen, thalamus, and the hippocampus were found to have higher olefinic content—an indicator of a higher degree of unsaturated fatty acids—rich in short-chain fatty acids, and low in ester and lipid contents. While the regions of the corpus callosum, internal, and external capsule were found to contain long-chained and higher-esterified saturated fatty acids. These molecular differences may reflect the roles of the specific regions in information processing and can provide a unique biochemical platform for future studies on the earlier detection of pathology development in the brain, as a consequence of disease or injury. Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS) is another vital analytical technique that was used in this work to analyze the elements’ distribution patterns in various regions of the brain. The complementary data sets allowed the characterization of the brain regions, the chemical dominating groups, and the elemental composition. This set-up may be used for the investigation of changes in the brain caused by diseases and help create a deeper understanding of the interactions between the organic and elemental composition.
- Published
- 2018
- Full Text
- View/download PDF
48. Porous Copolymer Resins: Tuning Pore Structure and Surface Area with Non Reactive Porogens
- Author
-
Lee D. Wilson and Mohamed H. Mohamed
- Subjects
porous copolymer resins ,porogen ,suspension polymerization ,porosity ,surface area ,Chemistry ,QD1-999 - Abstract
In this review, the preparation of porous copolymer resin (PCR) materials via suspension polymerization with variable properties are described by tuning the polymerization reaction, using solvents which act as porogens, to yield microporous, mesoporous, and macroporous materials. The porogenic properties of solvents are related to traditional solubility parameters which yield significant changes in the surface area, porosity, pore volume, and morphology of the polymeric materials. The mutual solubility characteristics of the solvents, monomer units, and the polymeric resins contribute to the formation of porous materials with tunable pore structures and surface areas. The importance of the initiator solubility, surface effects, the temporal variation of solvent composition during polymerization, and temperature effects contribute to the variable physicochemical properties of the PCR materials. An improved understanding of the factors governing the mechanism of formation for PCR materials will contribute to the development and design of versatile materials with tunable properties for a wide range of technical applications.
- Published
- 2012
- Full Text
- View/download PDF
49. Surface Improvement of Halloysite Nanotubes
- Author
-
Tayser Sumer Gaaz, Abu Bakar Sulong, Abdul Amir H. Kadhum, Mohamed H. Nassir, and Ahmed A. Al-Amiery
- Subjects
halloysite ,nanotubes ,polyvinyl ,malonic acid ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A novel development on halloysite-polyvinyl alcohol (HNTs-PVA) nanocomposites has been conducted using malonic acid (MA) by crosslinking PVA and HNTs. PVA-MA crosslinking produces smooth surfaces, which play an important role in enhancing the properties of HNTs-PVA nanocomposite. The crystallographic structures of crosslinked HNTs-PVA show almost no change as depicted by the X-ray diffraction (XRD)-2θ-peak, suggesting that MA has no or little influence on the crystallographic structure of the HNTs-PVA. Images taken by field emission scanning electron microscope (FESEM) suggest possible effects of MA on the morphology and internal features of HNTs-PVA by reducing the agglomeration of HNTs, which is considered a decisive step in improving the surface qualities of HNTs. Investigating the samples using the Brunauer–Emmelt–Teller (BET) technique showed that the surface area was increased by about 10 times, reaching the second highest recorded results compared to the HNTs, which could be considered a breakthrough step in enhancing the properties of HNTs-PVA due to MA crosslinking.
- Published
- 2017
- Full Text
- View/download PDF
50. Utility of 1-(4-Substituted Aminophenyl)Ethanones in Heterocyclic Synthesis Part (II)
- Author
-
Abdullah Y. A. Alzahrani, Moustafa A. Gouda, M. A. Salem, and Mohamed H. Helal
- Subjects
Chemistry ,Organic Chemistry ,Combinatorial chemistry - Abstract
Abstract: The improvement of new synthetic routes towards thiophene, oxazole, triazole, pyrimidine, pyridine, quinolone, coumarin, imidazopyrimidine, pyridoimidazole and triazolo[1,5-a] pyridine for their biological and medicinal exploration is an appealing vicinity for researchers. This review focuses on the utility of 1-(4-substituted-aminophenyl) ethanones and their derivatives as critical intermediates for the synthesis of these systems developed within the closing decade.
- Published
- 2022
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.