10 results on '"Elsayed HA"'
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2. UPGRADING AND SURFACE COATING OF EGYPTIAN WHITE SAND WITH POLYMERS AND SILANES
- Author
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Khaled E. Yassin, Sabreen Mourad, Mostafa Khalil, Nagui Abdel-Khalek, Abdalla Elbendari, Khaled Selim, and Elsayed Hassan
- Subjects
white sand ,RER magnetic separation ,surface modifications ,polymers ,silane ,Mining engineering. Metallurgy ,TN1-997 ,Geology ,QE1-996.5 - Abstract
Egypt is endowed with huge reserves of filler minerals, such as silica sand which form approximately 95% of the Earth's crust. The silica sand industry is used in many fields, such as pharmaceutical practices, chemicals, glass, ceramics, electronics, and photovoltaic industries. The aim of this study is to remove impurities from silica sand and apply surface modification processes to enhance its value for various industrial manufacturing applications. Various processing techniques, including classification, attrition scrubbing, magnetic separation, ultra-fine grinding and surface modification, were conducted throughout the study. The results indicated that attrition scrubbing to the classified size fraction of -0.6 + 0.1 mm was capable of reducing the iron concentration from 0.068% to 0.045%. Utilizing the Box-Behnken design, the optimal conditions for magnetic separation were identified, resulting in a decrease in iron content down to 0.012%. Simultaneously, the silica content increased from 99.05% to 99.76%. The results of ultrafine grinding using an attritor mill revealed that a grinding time of 2 hours is sufficient to reach a size suitable for the coating process. Surface modification of the produced ultrafine sand was conducted using polymers and silanes. The treated sand was characterized using SEM, zeta potential, adsorption density, and FTIR measurements. Notably, hydrophobicity increased, accompanied by an increase in particle size. Simultaneously, the surface becomes flatter, indicating the formation of a thin layer. Consequently, the coated sand proved to be a satisfactory material that met the criteria to be used as a filler in coating and paints.
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- 2024
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3. One-Dimensional Photonic Crystals Comprising Two Different Types of Metamaterials for the Simple Detection of Fat Concentrations in Milk Samples.
- Author
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Medhat M, Malek C, Tlija M, Abukhadra MR, Bellucci S, Elsayed HA, and Mehaney A
- Abstract
In this study, we demonstrate the reflectance spectrum of one-dimensional photonic crystals comprising two different types of metamaterials. In this regard, the designed structure can act as a simple and efficient detector for fat concentrations in milk samples. Here, the hyperbolic and gyroidal metamaterials represent the two types of metamaterials that are stacked together to construct the candidate structure; meanwhile, the designed 1D PCs can be simply configured as [ G ( ED )
m ]S . Here, G refers to the gyroidal metamaterial layers in which Ag is designed in a gyroidal configuration form inside a hosting medium of TiO2 . In contrast, ( ED ) defines a single unit cell of the hyperbolic metamaterials in which two layers of porous SiC ( E ) and Ag ( D ) are combined together. It is worth noting that our theoretical and simulation methodology is essentially based on the effective medium theory, characteristic matrix method, Drude model, Bruggeman's approximation, and Sellmeier formula. Accordingly, the numerical findings demonstrate the emergence of three resonant peaks at a specified wavelength between 0.8 μm and 3.5 μm. In this context, the first peak located at 1.025 μm represents the optimal one regarding the detection of fat concentrations in milk samples due to its low reflectivity and narrow full bandwidth. Accordingly, the candidate detector could provide a relatively high sensitivity of 3864 nm/RIU based on the optimal values of the different parameters. Finally, we believe that the proposed sensor may be more efficient compared to other counterparts in monitoring different concentrations of liquid, similar to fats in milk.- Published
- 2024
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4. Potential protective efficacy of biogenic silver nanoparticles synthesised from earthworm extract in a septic mice model.
- Author
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Ali SB, Mohamed AS, Abdelfattah MA, Samir AB, Abdullah FY, Elsayed HA, Abdelhalem M, Elsadek N, Osama S, Mohamed SE, and Fahmy SR
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- Animals, Mice, Male, Kidney drug effects, Kidney metabolism, Kidney pathology, Liver drug effects, Liver metabolism, Liver pathology, Sepsis drug therapy, Sepsis metabolism, Silver chemistry, Metal Nanoparticles chemistry, Oligochaeta chemistry, Disease Models, Animal
- Abstract
Sepsis is an inevitable stage of bacterial invasion characterized by an uncontrolled inflammatory response resulting in a syndrome of multiorgan dysfunction. Most conventional antibiotics used to treat sepsis are efficacious, but they have undesirable side effects. The green synthesised Ag NPs were synthesized by 5 g of the earthworm extract dissolved in a volume of 500mL of distilled water and then added to 2,500 mL aqueous solution of 1mM silver nitrate at 40 °C. After 4 h, the mixture was then allowed to dry overnight at 60 °C. Later, Ag NPs were washed and collected. They were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, and transmission electron microscopy. Sepsis model as induced by feces-intraperitoneal injection method. Eighteen male mice were assigned into three main groups: the control group, the sepsis-model group, and the Ag NPs-treated group. The control group received a single oral dose of distilled water and, after two days, intraperitoneally injected with 30% glycerol in phosphate buffer saline. The Sepsis-model group received a single oral dose of distilled water. Ag NPs - The treated group received a single oral dose of 5.5 mg/kg of Ag NPs. After two days, the sepsis-model group and Ag NPs-treated group were intraperitoneally injected with 200 µL of faecal slurry. Ag NPs treatment in septic mice significantly decreased liver enzyme activities, total protein, and serum albumin. Moreover, Ag NPs significantly enhanced kidney function, as indicated by a significant decrease in the levels of creatinine, urea, and uric acid. In addition, Ag NPs showed a powerful antioxidant effect via the considerable reduction of malondialdehyde and nitric oxide levels and the increase in antioxidant content. The histopathological investigation showed clear improvement in hepatic and kidney architecture. Our findings demonstrate the protective efficacy of biogenic Ag NPs against sepsis-induced liver and kidney damage., (© 2024. The Author(s).)
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- 2024
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5. Investigation of metronidazole resistance-associated mutations and virulence genotypes in helicobacter pylori isolates from the Egyptian population: A cross-sectional study.
- Author
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Hemeda MS, Elsayed HA, Mohamad AME, Ibrahim MM, Farahat AMA, Abdel Rahman ARZ, Salama BM, Badawy GM, Amin AI, Elyamany MI, Abdelmottaleb HAA, Ibrahim MA, Alsaid AAE, Elhagary AA, and El-Amir MI
- Abstract
Introduction: This cross-sectional study assesses the prevalence of metronidazole resistance-associated mutations and virulence genotypes in Helicobacter pylori (H. pylori) strains isolated from the Egyptian population. H. pylori infection is a significant public health concern, with antibiotic resistance challenging its eradication., Methods: Gastric biopsy samples were collected from symptomatic patients referred for upper gastrointestinal endoscopy at selected healthcare facilities. The study included 250 participants with symptoms suggestive of H. pylori infection and aged 18 years or older. Biopsy samples were obtained using standard endoscopic techniques, and H. pylori strains were isolated and identified in the laboratory. Antimicrobial susceptibility testing was conducted using standard methods. Molecular analysis, including polymerase chain reaction (PCR) and sequencing, was performed to identify metronidazole resistance-associated mutations (rdxA and frxA) and virulence genotypes (cagA and vacA)., Results: Antimicrobial susceptibility testing revealed that 43.6 % of the isolates were resistant to metronidazole, while 11.8 %, 4.5 %, and 55.4 % were resistant to clarithromycin, amoxicillin, and levofloxacin. Molecular analysis identified rdxA and frxA mutations in 36.3 % and 31.8 % of the isolates, respectively, indicating metronidazole resistance-associated mutations. Additionally, 60.0 % of the isolates were positive for the cagA gene, and 80.0 % had the vacA s1 type, both associated with increased virulence. A significant association was found between metronidazole resistance and the presence of cagA gene, vacA s1 type, rdxA mutation, and frxA mutation. Statistical analysis revealed associations between specific mutations and virulence genotypes with respective odds ratios, indicating higher likelihoods of metronidazole resistance in isolates exhibiting these genetic characteristics., Conclusions: This study highlights the prevalence of metronidazole resistance and the association between specific mutations and virulence genotypes in H. pylori strains isolated from the Egyptian population. The findings underscore the importance of monitoring antibiotic resistance patterns and understanding the genetic determinants of virulence in H. pylori for effective management and treatment strategies., Competing Interests: Declaration of competing interest There are no conflicts of interest., (Copyright © 2024 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)
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- 2024
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6. Investigating the impact of shear and bulk viscosity on the damping of confined acoustic modes in phononic crystal sensors.
- Author
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Elsayed HA, Ahmed AM, Alfassam HE, Hajjiah A, Al Zoubi W, Abukhadra MR, and Mehaney A
- Abstract
Phononic crystal (PnC) sensors are recognized for their capability to control acoustic wave propagation through periodic structures, presenting considerable potential across various applications. Despite advancements, the effects of fluid viscosity on PnC performance remain intricate and inadequately understood. This study theoretically investigates the influence of shear (dynamic) and bulk viscosity on acoustic wave damping in defective one-dimensional phononic crystal (1D PnC) sensors designed for detecting liquid analytes. Acetic acid with varying viscosities is considered to fill a cavity layer intermediated by a multilayer stack of lead and epoxy. The effects of dynamic and bulk viscosity on the resonance characteristics of the defective mode were analyzed. Numerical results reveal that increased dynamic viscosity leads to substantial broadening and decreased intensity of resonance peaks, accompanied by a shift to higher frequencies due to enhanced elastic wave attenuation and damping. At low dynamic viscosity (η = 0.2 η
d ), numerous resonance peaks with varying intensities are observed. However, at higher viscosities (η = 2.0 ηd to η = 10.0 ηd ), only one prominent peak appears in the spectrum. The intensity of this resonant peak starts at 98% for η = 2 ηd and decreases to 58.8% as the dynamic viscosity increases to η = 10 ηd . Additionally, the combined effect of dynamic and bulk viscosity introduces further damping, causing a strong shift of the resonance peak to higher frequencies, along with an increase in the full width at half maximum (FWHM) and a decrease in the quality factor (QF). These findings emphasize the necessity of incorporating both shear and bulk viscosity in the design of PnC sensors to enhance their sensitivity and accuracy in practical applications. This theoretical framework provides critical insights for optimizing sensor performance and bridging gaps between theoretical predictions and experimental observations, especially in 1D PnCs, offering potential solutions to challenges in real-world PnC sensor applications., (© 2024. The Author(s).)- Published
- 2024
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7. Improved performance of temperature sensors based on the one-dimensional topological photonic crystals comprising hyperbolic metamaterials.
- Author
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Elsayed HA, Mohamed AG, El-Sherbeeny AM, Aly AH, Abukhadra MR, Al Zoubi W, and Mehaney A
- Abstract
This paper seeks to progress the field of topological photonic crystals (TPC) as a promising tool in face of construction flaws. In particular, the structure can be used as a novel temperature sensor. In this regard, the considered TPC structure comprising two different PC designs named PC
1 and PC2 . PC1 is designed from a stack of multilayers containing Silicon (Si) and Silicon dioxide (SiO2 ), while layers of SiO2 and composite layer named hyperbolic metamaterial (HMM) are considered in designing PC2 . The HMM layer is engineered using subwavelength layers of Si and Bismuth Germinate, or BGO ( Bi 4 Ge 3 O 12 ). The mainstay of our suggested temperature sensor is mainly based on the emergence of some resonant modes inside the transmittance spectrum that provide the stability in the presence of the geometrical changes. Meanwhile, our theoretical framework has been introduced in the vicinity of transfer matrix method (TMM), effective medium theory (EMT) and the thermo-optic characteristics of the considered materials. The numerical findings have extensively introduced the role of some topological parameters such as layers' thicknesses, filling ratio through HMM layers and the periodicity of HMM on the stability or the topological features of the introduced sensor. Meanwhile, the numerical results reveal that the considered design provides some topological edge states (TESs) of a promising robustness and stability against certain disturbances or geometrical changes in the constituent materials. In addition, our sensing tool offers a relatively high sensitivity of 0.27 nm/°C., (© 2024. The Author(s).)- Published
- 2024
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8. Ultra-sensitive optimized one-dimensional phononic crystal as a fluidic sensor to enhance the measurement of acetic acid concentration.
- Author
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Heravi FJ, Hajjiah A, Elsayed HA, and Mehaney A
- Abstract
The current investigation theoretically presents a one-dimensional phononic crystal (PnC) as a fluidic sensor. The sensor under consideration aims to distinguish the concentration of acetic acid. The primary configuration of the proposed sensor is constructed with lead, epoxy, and a defect layer in the middle of the structure, that is filled with acetic acid (vinegar). As a result of the rise in density and decline in the speed of sound at a 100% concentration of acetic acid in comparison to pure water, the peak frequency of the output has shifted towards lower frequencies. Given that the maximum permissible concentration of acetic acid in water for vinegar is above 30%, sensor simulations were conducted within the concentration range of 25-35% with a step size of 1%. Interestingly, the sensitivity of the sensor exhibits a polynomial change in response to the concentration of acetic acid. Consequently, the highest level of sensitivity, which corresponds to the lowest concentration of vinegar, is recorded as 48.44 × 10
6 (Hz). The proposed system exhibits a remarkable value of the quality factor of 2802.91. Furthermore, the optimal figure of merit (FOM) is achieved when the concentration is at its lowest, with a value of 94.00. Furthermore, the temperature effects are taken into account for a wide range between 10 and 60 °C. A pronouncing sensitivity is obtained for all temperatures changes and the highest one reached the value of 1.57 × 106 (Hz/°C) at a temperature of 25 °C. Considering the present circumstances, the suggested sensor configuration has the potential to cater to a diverse array of other fluids, specifically their concentration and temperature, thereby offering a broad scope of applications., (© 2024. The Author(s).)- Published
- 2024
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9. High-performance biosensors based on angular plasmonic of a multilayer design: new materials for enhancing sensitivity of one-dimensional designs.
- Author
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Elsayed HA, Awasthi SK, Almawgani AHM, Mehaney A, Abdelrahman Ali YA, Alzahrani A, and Ahmed AM
- Abstract
In this study, a theoretical examination is conducted to investigate the biosensing capabilities of different surface plasmon resonance (SPR) based hybrid multilayer structures, which are composed of two-dimensional (2D) materials. The transfer matrix formulation is implemented to calibrate the results of this study. A He-Ne laser of wavelength = 632.8 nm is used to simulate the results. Many permutations and combinations of layers of silver (Ag), aluminum oxynitride (AlON), and 2D materials were utilized to obtain the optimized structure. Ten dielectrics and twelve 2D materials were tested for a highly sensitive multilayer hybrid sensing design, which is composed of the prism (Ohara S-FPL53)/Ag/AlON/WS
2 /AlON/sensing medium. The optimized biosensing design is capable of sensing and detecting analytes whose refractive variation is limited between 1.33 and 1.34. The maximum sensitivity, which is achieved by using the proposed design is 488.2° per RIU. Additionally, the quality factor, figure of merit, detection limit, and qualification limit values of the optimized design were also calculated to obtain a true picture of the sensing capabilities. The designing approach based on the multilayer hybrid SPR biosensors has the potential to develop various plasmonic biosensors that are related to food, chemical, and biomedical engineering fields., Competing Interests: The authors declare they have no conflicts of interests., (This journal is © The Royal Society of Chemistry.)- Published
- 2024
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10. Characteristics of multi-absorption bands in near IR based on a 1D photonic crystal comprising two composite metamaterials.
- Author
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Medhat M, Mehaney A, Al-Dossari M, Aly AH, and Elsayed HA
- Abstract
The Matlab program has been utilized in this study to examine the absorption spectral properties of a one-dimensional photonic crystal (1DPCs) comprising two composite metamaterials through near IR wavelengths. The composite metamaterials are designed from Ag of a gyroidal geometry (layer A) and hyperbolic metamaterial (layer B). Therefore, the introduced design is labeled as [Formula: see text] with n and m to define the periodicity of the hyperbolic metamaterial and the whole structure, respectively. The numerical findings have been introduced in the vicinity of the effective medium theory, transfer matrix method and the Drude model as well. In this regard, the numerical results demonstrate the appearance of some spectral absorption bands ranging from 0.7 µm to 3 µm for both TM and TE polarizations. Additionally, these bands are almost insensitive to the changes in the angle of incidence. Interestingly, we have considered the role played by some parameters such as the permittivities and thicknesses of both layers on the introduced absorption bands. Finally, we believe that the investigated results could be promising through many applications such as wavelength selective absorbers, solar energy, and smart windows as well., (© 2024. The Author(s).)
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- 2024
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