Diaa Atta

National Research Center, Egypt | NRC · Division of Physics

The focus of the current work is the study of the effect of the photo-catalytic activity of ZnO nanoparticles. The photocatalytic destruction of methylene blue dye, a common water contaminant, was used to assess the photocatalytic efficiency of the ZnO nanoparticles from its aqueous solution by using ZnO nanoparticles thin film under UV light and l...

In this study, a new approach methodology is employed to modify the structural, optical, and photoluminescence properties of Ni2O3/SnO2(NO/TO) nanocomposites. The effects of temperature and laser irradiation on a specific system were analyzed and described using XRD, XPS, and TEM. The diffraction patterns indicate the presence of two distinct phase...

Green fluorite samples from Homret Akarem, eastern desert Egypt, were investigated by laser-based Raman spectroscopy to study the effect of rare earth elements (REEs) and natural radiation from the surrounding environment on their physico-chemical properties, taking into consideration the geological setting. Geochemical data of trace elements displ...

Chemotaxis is the biologically intrinsic navigation towards or away from chemical stimuli; it is a crucial behavioral response for animals when interacting with their environment. It facilitates the location of sustenance, hosts, and other vital environmental signals. While prior research has predominantly concentrated on the chemotactic behaviors...

Applications of lasers in phototherapy have been the trend for the last few decades. The photodynamic therapy process normally depends on photosensitizers and laser beams. Through this study, indocyanine green has been used as a photosensitizer, which is normally activated using laser lines between 750 and 805 nm. The activity of the indocyanine gr...

Volume 49, Issue 15, 1 August 2023, Pages 25333-25343

The purpose of this work was to examine the photocatalytic activity of Chitosan/Zn- gel blend film. It is well known that Chitosan can do photo-degradation; Zinc gel was added as a blend to enhance the photo-catalytic behavior of chitosan. Their photocatalytic activities were estimated by the degradation of the used dye from its solution by using t...

Giza plateau in Egypt is famous for its pyramids and tombs which were built and carved into the rock. The pyramid of Queen Hetep Heres, the mother of King Khufu, encountered several erosion factors. From a simple visual examination, it is noted that Hetep Heres' pyramid has many problems that affect its sustainability. Different samples have been t...

Selected four gilt-bronze statuettes have been studied after excavation from the burial environment. Soil deposits and corrosion forms were observed on the surface disfiguring the gold layer. Confocal micro-Raman spectroscopy and Portable X-ray fluorescence (pXRF) were used to identify the molecular structure and elements distribution over the stat...

Background: This study was designed to investigate the in vitro bioactivity of a new dual cured calcium silicate cement (TheraCal PT) compared to its light cured (TheraCal LC) and chemically set (Biodentine) counterparts. Materials and Methods: The study is an in vitro original research article. Prepared cements discs were immersed in deionized wat...

Phosphosilicate thin film and monolith co-doped with Er³⁺-Yb³⁺ were prepared by self-modified Sol-Gel. Spin coating was used to deposit the prepared samples. The calculated crystallite sizes were found to be 26 and 28 nm for (S22P0.5E0.5YM) sintered at 500 and 1000 °C, respectively. A thickness of 1.6 μm was obtained for (S22P0.5E0.5YM). Laser-base...

Three wooden Coptic icons located at Saint Mercurius Monastery in Tamooh, Giza, Egypt were comprehensively investigated in order to determine the possible causes of their deterioration. Samples from every paint used in each icon were collected spanning from the outermost varnish layer down to the ground layer. Investigation was carried out using Fo...

Quantum mechanical calculations at density functional theory (DFT) level: B3LYP/6-31g(d,p) was used to study PVC. The effect of solvents upon PVC was investigated including: acetonitrile, CCl 4 , ethanol, toluene and DMSO respectively. Radiation is also studied at the same level of theory. The results are discussed in terms total dipole moment; HOM...

According to the enormous application of fullerene as well as fullerene based systems the present work is conducted to evaluate the effect of Na upon the physical properties of fullerene. So that Hartree-Fock method is employed with 3-21 g∗ basis set to calculate both HOMO/LUMO band gap energy and total dipole moment for C60-XXNa where X is varying...

Dioxin, which is hardly hydrated is supposed to hydrate with four water molecules at HF/3-21G∗ ∗ ab initio level of theory, then supposed to interact with aspartic acid at the same level of theory. The changes in the total dipole moment, HOMO/LUMO band gap energy and geometrical parameters were calculated and recorded. Results indicated that slight...

Hydrogen bonding plays an important role in the coordination of metals with organic acids. Density Functional Theory (DFT) at B3LYP/6-31g(d,p) level is conducted to evaluate total dipole moment, HOMO/LUMO band gap energy and geometrical parameters of COOH. Na, Mg, Ca, Fe, Ni, and Zn were coordinated with COOH of acetic and benzoic acid in the prese...

The acetic acid and benzoic acids are chosen as model molecules to study their possible interactions with aluminium hydroxide. Three schemes have been examined for interaction, namely Van der Waal, unidentate complex and bidentate complex interactions. B3LYP/6-31g(d, p) is used to calculate optimized structure, total dipole moment, HOMO/LUMO band g...

Dioxins are classes of compounds that find their ways to the environment as by-products of industrial activities. The existence of dioxin in hydrated form is tried through the present computational study. The effect of tetrahydrated dioxin is studied upon acetic and benzoic acids as model molecules for organic acids. HF/3-21G** ab initio quantum me...

In this paper, we introduce low frequency deformation of thin metal sheet. Spectroscopic analysis of low frequency plastic deformation of Al cold rolled sheets was done. We used commercial Aluminum sheets with low silicon contents, cold rolled. Al sheets were severe plastically deformed (SPD) in air using a homemade system at low frequency 20.3 Hz,...

Single molecule spectroscopy is considered among the most important spectroscopic and microscopic analytical tools especially that follow the biological reactions. The usage of wide field microscope in single molecule spectroscopy is not something new but what we introduce is a simultaneous dual color imaging wide field microscope setup. The setup...

Amino acids are considered as the building units of protein structures. The amino acid glycine was subjected to ab initio quantum mechanical calculations at HF/3-21g** level of theory. Glycine is optimized in gas phase then different solvents were applied using Polarizable Continuum Model (PCM) and the integral equation formalism variant (IEFPCM) w...

Chitosan is loaded with olive oil and then subjected to Fourier transform infrared spectroscopic study. FTIR spectra of chitosan as well as the loaded chitosan show that olive oil is weakly bonded with chitosan. Both spectra are nearly identical which could be an indication that, chitosan is an ideal structure for loading olive oil. Molecular model...

Single molecule measurements are considered among the most challenging points of research in recent trends of spectroscopy. Time resolved confocal microscope was presented as a successful tool for the molecular dynamics detection. Confocal volume is one from the most important parameters, which must be well defined before measuring using Fluorescen...

Blending natural polymers are considered as important approach towards the production of new biopolymers with unique properties. Blending could enhance surface reactivity and produce unique hydrogen bonding which could produce a new composite with new physical as well as chemical properties. Spectral recognition of such materials could be achieved...

It's not easy being green: Real-time visualization of labeled ribosomes and de novo synthesized green fluorescent protein molecules using single-molecule-sensitive fluorescence microscopy demonstrates that the mutant GFPem is produced with a characteristic time of five minutes. Fluorescence of the fastest GFP molecules appears within one minute (se...

Due to their high sensitivity and specificity fluorescence based single molecule techniques offer the possibility to study individual molecules (e.g., proteins or protein complexes) in situ in their cellular context. Recent progress in instrumentation and in sample preparation provides an increasingly better accessibility to more complex molecular...

In the present work both FTIR and Flame AAS were jointly used to investigate the uptake of pollutants by the aquatic plant water hyacinth. The plant was immersed alive in synthetic standard solutions containing acetic acid up to 0.40 M for 19.0 h. Then it was immersed in 0.10 M acetic acid for different periods of time up to 210.0 h. Later on, both...

Protein unfolding inside immobilized polymerosomes: One of the most interesting properties of polymeric vesicles is their remarkable stability against extreme temperatures and osmotic stress, and their longevity even under harsh environmental conditions. We have demonstrated, in an application on protein folding, that surface-tethered polymerosomes...

Both molecular modelling and PTIR have been used to study carboxyl group among acetic acid, potassium and sodium acetate, glycine, sodium salicylate, salicylic acid and cellulose acetate. Molecular modelling was used to study formic acid, carboxylic acids R-COOH, monovalent alkali carboxylate CH 3COO-M, alanine, benzoic acid as well as naphthalene....