Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
59 result(s) for "Allam, Nageh K."
Sort by:
Computational and experimental elucidation of the boosted stability and antibacterial activity of ZIF-67 upon optimized encapsulation with polyoxometalates
Water microbial purification is one of the hottest topics that threats human morbidity and mortality. It is indispensable to purify water using antimicrobial agents combined with several technologies and systems. Herein, we introduce a class of nanosized metal organic framework; Zeolitic imidazolate framework (ZIF-67) cages encapsulated with polyoxometalates synthesized via facile one-step co-precipitation method. We employed two types of polyoxometalates bioactive agents; phosphotungstic acid (PTA) and phosphomolybdic acid (PMA) that act as novel antibacterial purification agents. Several characterization techniques were utilized to investigate the morphological, structural, chemical, and physical properties such as FESEM, EDS, FTIR, XRD, and N 2 adsorption/desorption isotherms techniques. The antibacterial assessment was evaluated using colony forming unit (CFU) against both Escherichia coli and  Staphylococcus aureus as models of Gram-negative and Gram-positive bacteria, respectively. The PTA@ZIF-67 showed higher microbial inhibition against both Gram-positive and Gram-negative bacteria by 98.8% and 84.6%, respectively. Furthermore, computational modeling using density functional theory was conducted to evaluate the antibacterial efficacy of PTA when compared to PMA. The computational and experimental findings demonstrate that the fabricated POM@ZIF-67 materials exhibited outstanding bactericidal effect against both Gram-negative and Gram-positive bacteria and effectively purify contaminated water.
A novel machine learning approach for surface roughness quantification and optimization of cast-on-strap lead-antimony alloy via two-point correlation function
Surface roughness has a negative impact on the materials’ lifetime. It accelerates pitting corrosion, increases effective heat transfer, and increases the rate of effective charge loss. However, controlled surface roughness is desirable in many applications. The automotive lead-acid battery is very sensitive to such effects. In our case study, the cast-on-strap machine has the largest effect on the surface roughness of the lead-antimony alloy. In this regard, statistical correlation functions are commonly used as statistical morphological descriptors for heterogeneous correlation functions. Two-point correlation functions are fruitful tools to quantify the microstructure of two-phase material structures. Herein, we demonstrate the use of the two-point correlation function to quantify surface roughness and optimize lead-antimony poles and straps used in the lead-acid battery as a solution to reduce their electrochemical corrosion when used in highly corrosive media. However, we infer that this method can be used in surface roughness mapping in a wide range of applications, such as pipes submerged in seawater as well as laser cutting. The possibility of using information obtained from the two-point correlation function and applying the simulated annealing procedure to optimize the surface micro-irregularities is investigated. The results showed successful surface representation and optimization that agree with the initially proposed hypothesis.
An alternative, low-dissolution counter electrode to prevent deceptive enhancement of HER overpotential
Electrochemical hydrogen evolution reaction (HER) is typically studied in three-electrode system. In this system, several counter electrodes are commonly used to ensure fast kinetics, including Pt, gold, and glassy carbon. However, the extensive application of such electrodes has raised caveats on the contribution of the redox-active species dissolving from such electrodes and redepositing on the surface of the working electrode to the measured overpotential. Consequently, this has been frequently confused with the actual electrochemical signature of the working electrode catalyst, resulting in a deceptive enhancement in the recorded overpotential. This issue becomes more critical when the electrolysis measurements involve an activation step, necessitating the need for alternative counter electrodes that are stable, especially in acidic medium, which is commonly used as the electrolyte in HER studies. Herein, while we systematically unveil such problems, an alternative counter electrode that overcomes those problems is demonstrated. Specifically, the correlation between the working electrode area to that of the counter electrode, the dissolution rate of the counter electrode, and the potential range used in the activation/cleaning of the surface on accelerating the dissolution rate is explored and discussed in detail. Finally, commercial Ti mesh is demonstrated as an alternative emerging counter electrode, which is proven to be very stable and convenient to study the HER in acidic media.
Fabrication of polyhedral Cu–Zn oxide nanoparticles by dealloying and anodic oxidation of German silver alloy for photoelectrochemical water splitting
A significant effort has been dedicated to the synthesis of Cu–Zn oxide nanoparticles as a robust photocathode material for photoelectrochemical water splitting. Cu–Zn oxide nanoparticles were formed by controlled anodization of German silver (Cu–Zn–Ni) alloy in an aqueous electrolyte. Scanning electron microscopy (SEM) demonstrates the dependence of the obtained nanostructures on the anodization time. The X-ray diffraction (XRD) patterns showed the formation of copper oxide (CuO) and zinc oxide (ZnO) nanoparticles with good stability. This was also confirmed by the compositional X-ray photoelectron spectroscopy (XPS) analysis. The obtained polyhedral nanoparticles showed high optical activity with adequate bandgap energy. These optimized nanoparticles achieved boosted photocurrent of − 0.55 mA/cm 2 at − 0.6 V vs. SCE under AM 1.5 illumination, confirming the role of the optimized dealloying and thermal treatment in tuning the photoelectrochemical performance of the material.
Selective electrochemical reduction of CO2 on compositionally variant bimetallic Cu–Zn electrocatalysts derived from scrap brass alloys
The electrocatalytic reduction of carbon dioxide (CO 2 RR) into value-added fuels is a promising initiative to overcome the adverse effects of CO 2 on climate change. Most electrocatalysts studied, however, overlook the harmful mining practices used to extract these catalysts in pursuit of achieving high-performance. Repurposing scrap metals to use as alternative electrocatalysts would thus hold high privilege even at the compromise of high performance. In this work, we demonstrated the repurposing of scrap brass alloys with different Zn content for the conversion of CO 2 into carbon monoxide and formate. The scrap alloys were activated towards CO 2 RR via simple annealing in air and made more selective towards CO production through galvanic replacement with Ag. Upon galvanic replacement with Ag, the scrap brass-based electrocatalysts showed enhanced current density for CO production with better selectivity towards the formation of CO. The density functional theory (DFT) calculations were used to elucidate the potential mechanism and selectivity of the scrap brass catalysts towards CO 2 RR. The d-band center in the different brass samples with different Zn content was elucidated.
Superior visible light antimicrobial performance of facet engineered cobalt doped TiO2 mesocrystals in pathogenic bacterium and fungi
Pristine and Co-doped TiO 2 mesocrystals have been synthesized via a simple sol–gel method and their antimicrobial activity has been investigated. The antimicrobial performance was evaluated in terms of zone of inhibition, minimum inhibitory concentration (MIC), antibiofilm activity, and effect of UV illumination in liquid media. The Co-doped TiO 2 mesocrystals showed very promising MIC of 0.390 μg/mL and 0.781 μg/mL for P. mirabilis and P. mirabilis , respectively . Additionally, the material showed an MIC of 12.5 μg/mL against  C. albicans , suggesting its use as antifungal agent. Upon the addition of 10.0 µg/mL of Co-doped TiO 2 mesocrystals, the biofilm inhibition% reaches 84.43% for  P. aeruginosa , 78.58% for P. mirabilis , and 77.81% for S. typhi , which can be ascribed to the created active oxygen species that decompose the tested microbial cells upon illumination. Thus the fabricated Co-doped TiO 2 mesocrystals exhibit sufficient antimicrobial features under visible light, qualifying them for use as antimicrobial agents against pathogenic bacteria and fungi and subsequently inhibit their hazardous effects.
A comprehensive review on targeted therapies for triple negative breast cancer: an evidence-based treatment guideline
Triple-negative breast cancer (TNBC) is an aggressive malignancy characterized by limited therapeutic options and poor prognosis. Despite advancements in precision oncology, conventional chemotherapy remains the cornerstone of TNBC treatment, often accompanied by debilitating side effects and suboptimal outcomes. This review presents a comprehensive analysis of clinical trials on targeted therapies, aiming to establish a novel, evidence-based treatment strategy exclusively leveraging molecularly targeted agents. By integrating patient-specific genetic profiles with therapeutic responses observed across various clinical trial phases, this approach seeks to optimize efficacy while minimizing toxicity. The proposed targeted therapy combinations hold significant potential to revolutionize TNBC treatment, offering a paradigm shift toward precision medicine and improved patient outcomes.
Nitrogen-Passivated germanium carbide nanomeshes as potential catalysts for photocatalytic water splitting
Nitrogen-passivated germanium carbide (GeC) nanomeshes have been systematically investigated as efficient photocatalysts for water splitting. The nanomesh, characterized by a lattice constant of 19.3 Å and a pore diameter of 7.3 Å, maintains a planar architecture with optimized N-Ge and N-C bond lengths of 1.8 Å and 1.3 Å, respectively. Partial density of states (PDOS) analysis indicates that the conduction band is predominantly governed by Ge states, while C states dominate the valence band. Nitrogen incorporation critically alters the electronic structure near the band edges, significantly influencing photocatalytic behavior. Notably, introducing porosity reduces the bandgap from 2.04 eV (pristine GeC) to 1.33 eV in the N-passivated configuration. The calculated band edge positions straddle the redox potentials of water, indicating thermodynamic feasibility for overall water splitting. Several favorable sites were identified for the hydrogen evolution reaction (HER), with nearly thermoneutral ΔG values, suggesting high catalytic efficiency. For the oxygen evolution reaction (OER), the formation of OH* was determined to be the rate-limiting step with a ΔG 1  = 1.84 eV. Bader charge analysis confirmed electron transfer from the OH* species to the adjacent Ge atom, resulting in a net gain of 0.39 |e| by Ge. These findings demonstrate that N-passivated GeC nanomeshes exhibit a favorable electronic structure and catalytic surface characteristics for photocatalytic water splitting.
Adenine-functionalized Spongy Graphene for Green and High-Performance Supercapacitors
A simple method is demonstrated to prepare spongy adenine-functionalized graphene (SFG) as interconnected, porous 3-dimensional (3D) network crinkly sheets. Such 3D network structure provides better contact at the electrode/electrolyte interface and facilitates the charge transfer kinetics. The fabricated SFG was characterized by X-ray diffraction (XRD), FTIR, scanning electron microscopy (FESEM), Raman spectroscopy, thermogravimetric analysis (TGA), UV−vis absorption spectroscopy, and transmission electron microscopy (TEM). The synthesized materials have been evaluated as supercapacitor materials in 0.5 M H 2 SO 4 using cyclic voltammetry (CV) at different potential scan rates, and galvanostatic charge/discharge tests at different current densities. The SFG electrodes showed a maximum specific capacitance of 333 F/g at scan rate of 1 mV/s and exhibited excellent cycling retention of 102% after 1000 cycles at 200 mV/s. The energy density was 64.42 Wh/kg with a power density of 599.8 W/kg at 1.0 A/g. Those figures of merit are much higher than those reported for graphene-based materials tested under similar conditions. The observed high performance can be related to the synergistic effects of the spongy structure and the adenine functionalization.
Refractory plasmonics enabling 20% efficient lead-free perovskite solar cells
Core-shell refractory plasmonic nanoparticles are used as excellent nanoantennas to improve the efficiency of lead-free perovskite solar cells (PSCs). SiO 2 is used as the shell coating due to its high refractive index and low extinction coefficient, enabling the control over the sunlight directivity. An optoelectronic model is developed using 3D finite element method (FEM) as implemented in COMSOL Multiphysics to calculate the optical and electrical parameters of plain and ZrN/SiO 2 -modified PSCs. For a fair comparison, ZrN-decorated PSCs are also simulated. While the decoration with ZrN nanoparticles boosts the power conversion efficiency (PCE) of the PSC from 12.9% to 17%, the use of ZrN/SiO 2 core/shell nanoparticles shows an unprecedented enhancement in the PCE to reach 20%. The enhancement in the PCE is discussed in details.