Regular Article
Nanotechnology
I. Benammar; R. Salhi; J. -L. Deschanvres; R. Maalej
Abstract
This paper describes the systematic preparation of doped and undoped TiO2 with Er and/or Yb nanoparticles by hydrothermal-assisted sol-gel method using supercritical drying of ethanol followed by systematic calcination steps at 500°C, 800°C and 1000°C for 2/h. The structural study of these ...
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This paper describes the systematic preparation of doped and undoped TiO2 with Er and/or Yb nanoparticles by hydrothermal-assisted sol-gel method using supercritical drying of ethanol followed by systematic calcination steps at 500°C, 800°C and 1000°C for 2/h. The structural study of these powders with XRD reveals that our samples are crystalline with a tetragonal structure and anatase phase, which is well crystallized at 500°C. The annealing at 800°C reveals a transformation of the anatase phase to the rutile phase, which is well crystallized at 1000°C. The XRD analysis clearly indicates that the dopants are incorporated into the TiO2 network without any phase segregation-taking place in these nanoparticles. The study of the grain sizes has shown that they are nanometric in size of around 8-12 nm and that their sizes decrease with Er and/or Yb doping. The elemental analyses with micro-EDX using SEM confirmed the presence of chemical elements of TiO2 nanoparticles with expected atomic ratios. The analysis of the SEM images confirmed the XRD observations. In addition, they attest that the nanoparticles are spherical in shape. The optical analysis with excitation at 488 nm shows the presence of three emission bands in the green zone and the red zone. The heat treatment improves the optical, structural and spectroscopic properties and eliminates the contaminations that are due to the preparation conditions.
Review Article
Applied Physics
Nwar A. Yousif; Selma M. Al-Jawad; Ali A. Taha; Haralambos Stamatis
Abstract
Extensive studies were devoted to iron oxide nanoparticles (IONPs), in recent years. Iron oxides are chemical compounds that have various polymorphic forms, including maghemite (γ-Fe2O3), magnetite (Fe3O4), and Hematite (α-Fe2O3). Among them, the most important studied is magnetite (Fe3O4) ...
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Extensive studies were devoted to iron oxide nanoparticles (IONPs), in recent years. Iron oxides are chemical compounds that have various polymorphic forms, including maghemite (γ-Fe2O3), magnetite (Fe3O4), and Hematite (α-Fe2O3). Among them, the most important studied is magnetite (Fe3O4) due to its low cost and low toxicity, besides its unique magnetic and physicochemical characteristics which qualified it for use in various applications such as biomedical and technological applications. Magnetic particles should be small and have a narrow size distribution for these applications. The smaller the size of the iron oxide particles, the greater their reactivity and biodegradability. In this review, we display summary information of magnetite (Fe3O4) nanoparticles in terms of structure, characteristics, and preparation methods. Because the prepared strategy has been proven to be critical for preferable control of the particle size and shape, in addition, to producing monodispersed magnetite (Fe3O4) nanoparticles with a direct effect on their characteristics and applications, special attention will be placed on chemical preparation techniques including Hydrothermal synthesis, Co-precipitation technique, Sol-Gel process, and thermal decomposition method. This review offers specific information for selecting appropriate synthetic methods for obtaining appropriate sizes, shapes, and magnetic properties of magnetite (Fe3O4) nanoparticles (NPs) for target applications.
Regular Article
Biotechnology
Huda N. Abid; Amar Al-Keisy; Duha S. Ahmed; Sangeeta Singh
Abstract
In recent years, Bi-based photocatalysts have begun to be applied in biological applications. However, the antibacterial ability of a Bi-based photocatalyst is still unclear. In this study, Bi2MoO6 and Bi2WO6 were successfully synthesized by a hydrothermal approach. The fabricated samples were characterized ...
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In recent years, Bi-based photocatalysts have begun to be applied in biological applications. However, the antibacterial ability of a Bi-based photocatalyst is still unclear. In this study, Bi2MoO6 and Bi2WO6 were successfully synthesized by a hydrothermal approach. The fabricated samples were characterized by X-Ray diffraction, FESEM, and UV-Vis spectra. Besides, the antibacterial activity of both photocatalyst samples toward E. coli as negative and S. aureus as positive pathogens were studied. Compared with antibacterial of Bi2WO6, the resultant Bi2MoO6 exhibited high susceptible S. aureus bacterial strain revealing large zones of 24 mm to 29 mm, while Bi2WO6 exhibited less susceptible of 17.5 mm to 21.5 mm as compared with the zone of inhibition against tested bacterial E. coli. Besides, a possible mechanism suggested the effect of nanosheet structure of samples to penetrate the cell membrane which results in leakage of interior cell and complete death and these results will provide some support for the applications of Bi2MoO6 and Bi2WO6 in antibacterial materials under common environments.
Regular Article
Materials Science
Sanjeev Singh; Arti Singh; Pavagada Shaifulla
Abstract
This study aimed to compare whether Bispectral Index (BIS) reduces the consumption of the anaesthetic drug and improves recovery time in coronary artery-bypass grafting off-pump (CABG-OP) surgery without awareness during surgery (ADS). The study was a single centre, prospective, randomised, and double-blind ...
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This study aimed to compare whether Bispectral Index (BIS) reduces the consumption of the anaesthetic drug and improves recovery time in coronary artery-bypass grafting off-pump (CABG-OP) surgery without awareness during surgery (ADS). The study was a single centre, prospective, randomised, and double-blind comparative research on ASA 3 patients booked for elective CABG-OP operation under general anaesthesia (GA). Patients received either propofol or isoflurane anaesthesia, and their consumption was calculated and compared. The conventional groups CPG-1 and CIG-3 received propofol and isoflurane, and haemodynamic parameters (± 20% of initial values) were considered for anaesthesia. The groups BPG-2 and BIG-4 received propofol and isoflurane, and BIS (value 50±5) was used to maintain anaesthesia. In addition, haemodynamic parameters, awakening conditions, length of intubation, hospital stay and drug utilisation were recorded. To explicit ADS, patients were interviewed 24 hours after extubation. The quantity of propofol used was 178 ± 11 ml in CPG-1 and 117 ± 6 ml in BPG-2, with a 34.26% reduction with BIS. The isoflurane used was 39 ± 8 ml in CIG-3 and 25± 6ml in BIG-4, with a 35.89% reduction in isoflurane requirement. This difference was statistically significantly low with BIS monitored anaesthesia compared to conventional anaesthesia. The length of intubation was 2.2 ±1.27 and 2.3 ±1.49 hours in groups BPG-2 and BIG-4, respectively (p<0.05). BIS assisted CABG-OP surgeries with adequate depth of anaesthesia (BIS 50 ± 5) prevent ADS, reduce the anaesthetic agent requirement, and aid ultra‐fast‐track (UFT) extubation.
Regular Article
Applied Physics
Sarmad A. Ibrahim; Sadeq H. Lafta; Wafaa A. Hussain
Abstract
A stainless steel 316L (SS316L) wires reinforcing heat cure PMMA matrix samples were prepared for dentures applications. Mechanical scratching and electrochemical anodizing for PMMA denture base supported by wires of SS316L were used as straightforward and low-cost outside layer pretreatments. The two ...
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A stainless steel 316L (SS316L) wires reinforcing heat cure PMMA matrix samples were prepared for dentures applications. Mechanical scratching and electrochemical anodizing for PMMA denture base supported by wires of SS316L were used as straightforward and low-cost outside layer pretreatments. The two pretreatments were used to improve the flexural strength of PMMA denture bases. The mechanical scratching process acts to scratch the surface of stainless-steel wires by mixing the wires with silicon carbide powder inside a rotating Pyrex container. The pretreatment time was varied to be 60, 90, and 120min. The anodizing solution, containing ethylene glycol (EG) with HClO4 acid, was used with a 15V supply and a graphite rod as a cathode in the anodizing process. A variation in the pretreating time to be 15, 20, and 30min for the electrochemical anodizing process was included. A scanning electron microscope was utilized to examine the morphology of surfaces of the SS316L wires, which showed various morphology natures. The mechanical flexural strength test was conducted for all samples statistically to check the results. The flexural strength test results of the composite sample groups of PMMA reinforced with the scratched surface for 90 min stainless steel wire 316L presented the highest flexural strength value (113 MPa) with a 66% increment. All results proved that reinforcing PMMA by ss 316L are enhancing the flexural strength by comparing the results with previous works and pointing to the activity of the used scratching process.
Regular Article
Nanotechnology
Aseel S. Jasim; Odai N. Salman
Abstract
In this work, we reported a study on the hydrothermal process used to create TiO2 NRs films on FTO substrate utilizing two various solutions, the first one is composed of (ethanol, and titanium butoxide) while the second is composed of (HCl, DIW, and titanium butoxide). The study on the structural, morphological, ...
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In this work, we reported a study on the hydrothermal process used to create TiO2 NRs films on FTO substrate utilizing two various solutions, the first one is composed of (ethanol, and titanium butoxide) while the second is composed of (HCl, DIW, and titanium butoxide). The study on the structural, morphological, optical, and electrical properties helped to identify the characteristics of the TiO2 film which were prepared by using different solvents, the first sample (TO1) presented anatase -phase crystal structure with (3.2 eV) energy gap while the second (TO2) presented a Rutile phase with (3 eV) energy gap. The (nanorod) morphology was observed for the (TO2) sample while irregular grains were found for the (TO1) sample. Transmittance measurements have been used to investigate the optical properties, which revealed that both samples were transparent in the visible wavelength range, and absorption coefficients were higher for sample (TO2) with a rutile phase. The activation energy was (0.0226) eV and (0.0643) eV for both samples (TO1) and (TO2), respectively. The n-type conductivity was confirmed by Hall Effect measurement for both samples. The highest conductivity (300.655) (Ω-1.cm-1) and carrier consternation (1.07355 ×1017) (cm-3) were attained from sample (TO1).
Regular Article
Applied Physics
Teymur B. Taghiyev
Abstract
The study investigated the photoluminescent properties of undoped and rare-earth element erbium - doped solid solutions GaS1-xSex0.1аt% irradiated with gamma-quanta. Erbium doping reduces the photoluminescence intensity in solid solutions. After irradiation Dg= 300-1000Gy, the photoluminescence intensity ...
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The study investigated the photoluminescent properties of undoped and rare-earth element erbium - doped solid solutions GaS1-xSex0.1аt% irradiated with gamma-quanta. Erbium doping reduces the photoluminescence intensity in solid solutions. After irradiation Dg= 300-1000Gy, the photoluminescence intensity increases. An increase in the photoluminescence intensity in irradiated solid solutions is explained by a decrease in the concentration of centers responsible for the fast recombination channel and associated with lattice defects. At T=77K, due to the decay of bound Frenkel pairs, Si and Vs appear in the sulfur sublattice. The Si defects are responsible for the increase in the intensity of the green luminescence band. The redistribution of photoluminescence intensity in the range of 0.520 - 0.600 µm is due to the transfer energy to rare-earth centers in activated crystals. The performed investigations allow us to conclude that doping with erbium leads the appearance of a series of emission lines in the visible region of the spectrum.
Regular Article
Applied Physics
Ammar Mukhlif Jasim; Nathera Abass Ali
Abstract
This research investigates how activated carbon (AC) was synthesized from potato peel waste (PPW). Different ACs were synthesized under the atmosphere's conditions during carbonation via two activation methods: first, chemical activation, and second, carbon dioxide-physical activation. The influence ...
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This research investigates how activated carbon (AC) was synthesized from potato peel waste (PPW). Different ACs were synthesized under the atmosphere's conditions during carbonation via two activation methods: first, chemical activation, and second, carbon dioxide-physical activation. The influence of the drying period on the preparation of the precursor and the methods of activation were investigated. The specific surface area and pore volume of the activated carbon were estimated using the Brunauer–Emmett–Teller method. The AC produced using physical activation had a surface area as high as 1210 m2/g with a pore volume of 0.37 cm3/g, whereas the chemical activation had a surface area of 1210 m2/g with a pore volume of 0.34 cm3/g. The main aim of this research is to produce activated carbon from natural materials and to prepare and characterize the elemental analysis, surface area, and morphological properties of ACs from potato peel waste using potassium hydroxide (KOH) AC-PPK and Carbon dioxide (CO2) AC-PPC as activating agents. X-ray diffraction analysis showed the degree of crystallinity to be 35.03% in the case of AC-PPK, and AC-PPC showed a crystallinity of 35.46%. In both methods, the results showed that the crystallographic structure revealed that all the synthesized AC took on an amorphous state with low crystallinity. The atomic force microscopy (AFM) image of AC shows the presence of nanotips on the surface and shows that the maximum height was 1396 nm and 778 nm. The outer surfaces are full of cavities and highly irregular as a result of activation. The morphological analysis of the precursors was determined by scanning electron microscopy. The external surfaces are full of cavities and quite irregular as a result of activation. Also, activated carbon prepared from potato peel waste is a low-cost and effective adsorbent when compared with several activated carbon sources.
Regular Article
Applied Physics
Mariam Mohamed Abud; Mohanad Mousa Azzawi; Hawazen Fadhil Alnaqeeb
Abstract
This paper presents a novel laser pulse energy measurement method based on photoacoustic converters. The concept of paper design and built energy meters using PZT as three specimens have a diameter of (20, 24, and 25) mm, and coating SiO2 was chosen in this test because it has special properties, is ...
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This paper presents a novel laser pulse energy measurement method based on photoacoustic converters. The concept of paper design and built energy meters using PZT as three specimens have a diameter of (20, 24, and 25) mm, and coating SiO2 was chosen in this test because it has special properties, is affordable, and is compact in size. Genetic energy meters are expensive. Comparing the genetic meter (used in this study that is manufactured of pyroelectric material and PZT/SiO2). The outcomes demonstrated that within the laser pulse's energy (100-400mJ). Peak voltage values for PZT composites range from 0.48 to 0.84 volts at the voltage output as their diameter increases (PZT-S with a diameter of 20 mm). The output voltage ranges for PZT-M (diameter 24 mm) and PZT-B (diameter 25 mm) are 0.18 to 0.68 volts and 0.08 to 0.56 volts, respectively. The design has been built and characterized by measured voltage and energy meter sources. A piezoelectric actuator had been fabricated on silicon sand wafer composites by converting the light waves (the laser pulse) into shock waves. Unlike the energy meter type (pyroelectric) for genetic-, the energy meter created in (PZT/SiO2) is unaffected by Damage caused by high temperatures from laser Nd:YAG pulse energy.
