<abstract><title style='display:none'>Abstract</title> Graphene has achieved a great amount of popularity and interest from the science world because of its extraordinary physical, mechanical and thermal properties. Graphene is an allotrope of carbon, having one-atom-thick planar sheets of sp2 bonded carbon atoms densely packed in a honeycomb crystal lattice. Many methods to synthesize graphene have been developed over a short period and we believe it is necessary to create a list of the most notable approaches. This article focuses on the methods to synthesize graphene in an attempt to summarize and document advancements in the synthesis of graphene research and future prospects.</abstract>

Graphene synthesis: a Review

<abstract><title style='display:none'>Abstract</title>Thin films of manganese-doped cadmium oxide (CdO:Mn) with different Mn-doping levels (0, 1, 2, 3 and 4 at.%) were deposited on glass substrates by employing an inexpensive, simplified spray technique using a perfume atomizer at 375 °C. The influence of Mn incorporation on the structural, morphological, optical and electrical properties of CdO films has been studied. All the films exhibit cubic crystal structure with a (1 1 1) preferential orientation. Mn-doping causes a slight shift of the (1 1 1) diffraction peak towards higher angle. The crystallite size of the films is found to decrease from 34.63 nm to 17.68 nm with an increase in Mn doping concentration. The CdO:Mn film coated with 1 at.% Mn exhibit a high transparency of nearly 90 % which decreases for higher doping concentration. The optical band gap decreases with an increase in Mn doping concentration. All the films have electrical resistivity of the order of 10−4 Ω·cm.</abstract>

Effect of doping concentration on the structural, morphological, optical and electrical properties of Mn-doped CdO thin films

<abstract xml:lang="en"><title style='display:none'>Abstract</title>The present study illustrates the characteristics and co-precipitation method for synthesis of tin oxide nanoparticles. The tin oxide nanoparticles were produced using tin chloride, Triton X-100 and ammonia precipitators. Structure, size and surface morphology of the tin oxide was studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results show sphere shaped tin oxide nanoparticles without chlorine contamination. The crystallite size determined by the Scherrer formula is about 23 nm. Lattice parameters calculated by Nelson-Riley equation show high quality of crystallization.</abstract>

Department of Technical Faculty, Shahrood Branch, Islamic Azad University, Shahrood, Iran

Department of Engineering Oil and Gas Petro Tadbir Pars Company, Tehran, Iran

Synthesis and characterization of tin oxide nanoparticles via the Co-precipitation method

<abstract xml:lang="en"><title style='display:none'>Abstract</title>Duck eggs are one of the most versatile cooking ingredients in which residue eggshells are discarded. Raw duck eggshells were calcined at temperatures between 300 to 900 °C, for 1, 3, and 5 h. Both the raw and calcined duck eggshells were characterized by FTIR, STA, XRD, XRF, TEM, BET, a particle size analyzer, and an impedance analyzer. The proper calcination conditions are: 900 °C and 1 h, yielding calcium oxide with a purity of 99.06 % w/w. The calcium carbonate of the rhombohedral form (CaCO3) transforms completely into the calcium oxide or lime of the face centered cubic form (CaO) at 900 °C, as shown by XRD diffraction patterns. The transmission electron microscopy (TEM) images of the calcium oxide reveal a moderately good dispersion of nearly uniform particles. The calcium oxide has a white color, a spherical shape, high porosity, and narrow particles size distribution. The percentage of ceramic yield of the calcium oxide is 53.53, as measured by STA (TG-DTA-DTG). The calcium oxide has a N2 adsorption-desorption isotherm indicating the meso-porosity range. The dielectric constant and the electrical conductivity of the calcined calcium oxide are 35 and 1:0×10−6(Ω·m)−1, respectively, at the frequency of 500 Hz.</abstract>

Center for Advanced Studies in Industrial Technology and The Materials Engineering Department, Faculty of Engineering, Kasetsart University, Bangkok, 10900, Thailand

The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, 10330, Thailand

Preparation and properties of calcium oxide from eggshells via calcination

<abstract><title style='display:none'>Abstract</title>The SiN/SiO2 stack is widely used to passivate the surface of n-type monocrystalline silicon solar cells. In this work, we have undertaken a study to compare the stack layer obtained with SiO2 grown by both rapid thermal and chemical ways to passivate n-type monocrystalline silicon surface. By varying the plateau time and the plateau temperature of the rapid thermal oxidation, we determined the parameters to grow 10 nm thick oxide. Two-step nitric acid oxidation was used to grow 2 nm thick silicon oxide. Silicon nitride films with three refractive indices were used to produce the SiN/SiO2 stack. Regarding this parameter, the minority carrier lifetime measured by means of QSSPC revealed that the refractive index of 1.9 ensured the best passivation quality of silicon wafer surface. We also found that stacks with nitric acid oxidation showed definitely the best passivation quality. In addition to produce the most efficient passivation, this technique has the lowest thermal budget.</abstract>

SiN/SiO2 passivation stack of n-type silicon surface

<abstract><title style='display:none'>Abstract</title>Pure CdO nanopowder and CdO-Fe3O4 nanocomposite were synthesized by a cost effective chemical method, and the samples were characterized by XRD, SEM, TEM, FT-IR, UV-Vis-NIR and PL. Also, magnetic and photocatalytic properties of the synthesized samples were studied. XRD patterns of the composite confirm the presence of diffraction peaks related to both CdO and Fe3O4. EDX spectrum confirms the presence of the elements Cd, O and Fe in the composite. Peaks related to Cd–O and Fe–O bonds were observed respectively at 688 cm−1 and 592 cm−1 in the FT-IR spectrum. The paramagnetic behavior of pure CdO becomes ferromagnetic when coupled with Fe3O4. The composite exhibited a high photodegradation efficiency of 92.85 % against the degradation of methylene blue dye under visible light radiation.</abstract>

CdO-Fe3O4 nanocomposite with enhanced magnetic and photocatalytic properties

<abstract>
<title style='display:none'>Abstract</title>
Rheumatoid arthritis is a chronic autoimmune-disease-causing inflammation, joint pain, and joint destruction, severely affecting the quality of life of millions worldwide. In the current research, a nanocarrier system was developed for the delivery of resveratrol and prednisolone to treat rheumatoid arthritis. The drug delivery system was characterized in vitro using scanning electron microscopy and various cell culture studies. Finally, the alleviative symptoms of the developed treatment strategy were investigated in a rat model of rheumatoid arthritis. In vitro studies showed that the carrier system released the drugs in a sustained manner and possessed strong immunomodulatory functions. Nanocarriers loaded with prednisolone, resveratrol, and drug-free carriers had 396.88 ± 76.41 nm, 392.49 ± 97.31 nm, and 338.02 ± 77.75 nm of mean particle size, respectively. In vivo studies revealed that local injection of the carrier system could alleviate the degenerative effects of rheumatoid arthritis. ELISA assays showed that the co-injection of resveratrol and prednisolone-loaded albumin nanoparticles could significantly modulate inflammatory responses. The developed treatment modality may potentially be used to treat rheumatoid arthritis.
</abstract>

Resveratrol and prednisolone loaded into human serum albumin nanoparticles for the alleviation of rheumatoid arthritis symptoms: an in vitro and in vivo study

<abstract>
<title style='display:none'>Abstract</title>
18Ni300 is widely used in precision moulds, national defence, and other engineering fields due to its high strength and toughness, and because its properties can be greatly changed after heat treatment. In this research, the 18Ni300 cladding layer was fabricated on 18Ni300 substrate using the laser cladding method and a solid solution artificial aging treatment was carried out to analyse its macro morphology and metallographic organization. Comparison of hardness, friction, and wear of cladding layers manufactured by laser cladding and of materials produced by rolling was performed before and after heat treatment. The results show that the solution and artificial aging heat treatment has a significant effect on the microstructure of the cladding layer fabricated by laser cladding. There are obvious differences in the organization and morphology of different parts of the cladding layer before heat treatment; the metallographic organization and morphology of different parts of the cladding layer after heat treatment are the same. The trend of change of material hardness before and after heat treatment is the same in that the cladding layer is greater than the rolled material and the hardness of the material after heat treatment is much greater than the hardness of the material before heat treatment. The hardness and wear resistance of the material after solution and artificial aging heat treatment has been significantly improved, and the impact on the rolled production material of the melted cladding layer manufactured by laser cladding is even greater.
</abstract>

Effect of solution and artificial aging heat treatment on the hardness, friction and wear properties of laser cladding and roll-formed 18Ni300 materials

<abstract>
<title style='display:none'>Abstract</title>
This research aims to develop sustainable high-strength concrete (SHSC) by replacing 100% fine and/or coarse aggregates with fine recycled aggregate (RA) and/or coarse RA. Due to the high surface water absorption of coarse RA, a surface treatment method was adopted, consisting of immersing it in a cement and silica fume slurry. Moreover, to improve the performance of the produced SHSC, steel fibers were employed at a relatively low volume fraction (0.5%). Eleven blends were cast and tested in this experimental study. A control SHSC mix (without RA) and ten other mixtures, including fine natural and RA, treated and untreated coarse RA, with and without steel fibers, were prepared. Compressive, splitting, and flexural strengths, water absorption, density, and ultrasonic pulse velocity (UPV) of the resulting SHSC were conducted. The results indicated that the use of RA in SHSC resulted in an average drop of 25% in its mechanical properties and an increase of about 30% in water absorption. However, using treated RA compensated the compressive and tensile strength reductions in SHSC by 9% and 7%, respectively, compared to mixes containing untreated RA. On the other hand, adding fibers helped improve compressive, flexural, and splitting tensile strengths by about 8%, 23%, and 31%, respectively, compared to the corresponding control mix. Consequently, the results showed that it is possible to produce durable SHSC made from 100% RA and 0.5% steel fibers with a reduced density and improved mechanical performance to a comparable level or even superior to high-strength concrete (HSC) with only natural aggregates (NAs).
</abstract>

Development of treated coarse recycled aggregate-based sustainable fibrous high-strength concrete with fine recycled aggregates

<abstract>
<title style='display:none'>Abstract</title>
In this work, NiO–ZnOnanocomposite (NC)was prepared through a facile, low-temperature,sol–gel route. Zinc acetate dihydrate, nickel chloride hexahydrate, cetyltrimethyl ammonium bromide (CTAB), and citric acid were used in the synthesis of the material. Then, the sample was kept in the muffle furnace at a temperature of 600°C for 2 h. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), UV–Visible spectroscopy, and photocatalytic and antifungal investigations were used to characterize the synthesized nanocrystallites. The XRD data showedthe polycrystalline hexagonal ZnO nanoparticles and cubic NiO crystallites. FTIR studies confirmed the presence of Zn-O and Ni-O bonds in the sample. The FESEM analysis showed the morphology of nanocrystallitescharacterized by their homogeneous shape and size. The absorbance curves from the UV–Visible spectroscopy investigation revealed the bandgap of 3.17 eV. The research findings demonstrate that the NiO–ZnO NC possesses the significant level of selected microbial pathogens. Industrial dyesmake water unhealthy for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable, and causes a severe threat to human health and environmental safety. Hence, it is necessary to develop efficient and environmentally friendly technology to remove MB from wastewater. The ZnO–NiO NC degraded the MB dye pollutant under visible irradiation (125 W), according to photocatalytic tests. After 120 min of exposure, the photocatalytic investigations demonstrated 75% degradation efficiency.
</abstract>

Microstructural, antifungal and photocatalytic activity of NiO–ZnO nanocomposite

<abstract>
<title style='display:none'>Abstract</title>
Nanobainitic steels exhibit an exceptional combination of high strength, good plasticity, impact toughness, and wear resistance. They are suitable for the production of large mass components through the open-die forging process. Subsequently, the forgings are air-cooled. An obstacle of this method is the extended time required for the large forgings to undergo a bainitic transformation, making the industrial implementation of this process economically unjustifiable. Nevertheless, nanobainitic steels also allow for the open-die forging of small batches of structural elements with high property requirements. A technological limitation lies in the necessity of performing a series of operations, leading to a prolonged processing time dependent on the shape of the product and the degree of deformation. Therefore, inter-operational reheating is often necessary, incurring costs and time consumption. This is particularly relevant to forgings with a mass ranging from a few to several dozen kilograms, which, due to their low thermal capacity, rapidly dissipate heat to the surroundings and tools. Designing an economical process with a limited number of reheating cycles requires advanced knowledge of material behavior under thermo-mechanical deformation parameters, including boundary conditions where a significant decrease in plasticity occurs and the risk of crack initiation. To obtain this information, a comprehensive analysis of the influence of thermo-mechanical parameters applied during the deformation of nanobainitic steel at relatively low temperatures on the flow characteristics and crack formation was conducted. To achieve this goal, the Digital Image Correlation method, the finite element method modeling considering damage criteria, and the macrostructural evaluation of deformed specimens were employed.
</abstract>

Evaluation of cracking risk of 80MnSi8-6 nanobainitic steel during hot forging in the range of lower temperature limits

<abstract>
<title style='display:none'>Abstract</title>
It is essential to retrofit deep beams with shear inadequacies because these beams, although they have the same shear and flexural reinforcements as ordinary beams, are more susceptible to shear failure. Hence, it is of great significance to overcome the shear weaknesses in deep beams. This research paper aims to experimentally examine the effectiveness of near-surface mounted (NSM) carbon fiber reinforced polymer (CFRP) for retrofitting reinforced concrete (RC) deep beams subjected to shear forces. The study involved three different types of specimens. The first specimen was constructed with concrete throughout its span and included shear stirrups. The second specimen was divided into two halves, with one half lacking shear reinforcements and the other half having them. The third specimen had steel web reinforcement in one half of the span, while the other half was strengthened using NSM CFRP U-wrap strips and externally bonded horizontal CFRP strips. The proposed strengthening method significantly increased the shear strength of the deep beams, surpassing that provided by steel web reinforcement alone. Furthermore, the NSM CFRP strengthened specimen exhibited a change in failure mode from shear to flexural failure. In comparison to the control beam without stirrups, the beams strengthened with NSM CFRP U-wrap strips demonstrated an impressive 82% improvement in shear strength, while the beam with shear reinforcement showed a 23 % enhancement in load capacity. The proposed strengthened scheme is capable of enhancing the structural performance and load-carrying capacity effectively. A finite element model was generated utilizing ABAQUS software to simulate the behavior of the tested deep beams and verified against the experimental outcomes. The numerical models successfully predicted the behavior of the RC deep beams strengthened with NSM CFRP when compared to the experimental data.
</abstract>

Shear strengthening of deficient RC deep beams using NSM FRP system: Experimental and numerical investigation

<abstract xml:lang="en"><title style='display:none'>Abstract</title>Auxetic materials are endowed with a behavior that contradicts common sense, when subjected to an axial tensile load they increase their transverse dimension. In case of a compression load, they reduce their transverse dimension. Consequently, these materials have a negative Poisson’s ratio in such direction. This paper reviews research related to these materials. It presents the theories that explain their deformation behavior and reveals the important role represented by the internal structure. Their mechanical properties are explored and some potential applications for these materials are shown.</abstract>

Auxetic materials — A review

<abstract xml:lang="en"><title style='display:none'>Abstract</title>Silver colloidal nanoparticles were prepared according to the chemical reduction method in which the ascorbic acid was used as a reducing agent and sodium citrate as a stabilizing agent. The absorption spectra of all prepared samples obtained using the UV-Vis spectrophotometer showed a surface plasmon peak at a wavelength of about 420 nm. The size of the silver nanoparticles was controlled by changing the pH values of the reaction system. At high pH, smaller size silver nanoparticles were obtained compared to low pH values. This difference can be attributed to the difference in the reduction rate of the precursor. In addition to the inverse proportionality between the size and the pH value it is clear that increasing the pH value enables us to obtain spherical nanoparticles while at low pH, rods and triangular particle shapes were formed. Poor balance between nucleation and growth processes could be the cause of this result.</abstract>

Physics Department, Jordan University of Science and Technology, Irbid, Jordan

Al-Huson University College, Al-Balqa applied University, Huson-Irbid, Jordan

pH effect on the aggregation of silver nanoparticles synthesized by chemical reduction

<abstract xml:lang="en"><title style='display:none'>Abstract</title>In this research work, we prepared γ-Fe2O3 nanoparticles by thermal-decomposition of Fe3O4. The Fe3O4 nanoparticles were synthesized via co-precipitation method at room temperature. This simple, soft and cheap method is suitable for preparation of iron oxide nanoparticles (γ-Fe2O3; Fe3O4). The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), vibrating sample magnetometer and differential scanning calorimeter (DSC). The XRD and FT-IR results indicated the formation of γ-Fe2O3 and Fe3O4 nanoparticles. The TEM images showed that the γ-Fe2O3 and Fe3O4 were spherical, and their size was 18 and 22 nm respectively. Magnetic properties have been measured by VSM at room temperature. Hysteresis loops showed that the γ-Fe2O3 and Fe3O4 nanoparticles were super-paramagnetic.</abstract>

Synthesis of maghemite (γ-Fe2O3) nanoparticles by thermal-decomposition of magnetite (Fe3O4) nanoparticles

<abstract><title style='display:none'>Abstract</title>Raman spectroscopy is a most often used standard technique for characterization of different carbon materials. In this work we present the Raman spectra of polycrystalline diamond layers of different quality, synthesized by Hot Filament Chemical Vapor Deposition method (HF CVD). We show how to use Raman spectroscopy for the analysis of the Raman bands to determine the structure of diamond films as well as the structure of amorphous carbon admixture. Raman spectroscopy has become an important technique for the analysis of CVD diamond films. The first-order diamond Raman peak at ca. 1332 cm−1 is an unambiguous evidence for the presence of diamond phase in the deposited layer. However, the existence of non-diamond carbon components in a CVD diamond layer produces several overlapping peaks in the same wavenumber region as the first order diamond peak. The intensities, wavenumber, full width at half maximum (FWHM) of these bands are dependent on quality of diamond layer which is dependent on the deposition conditions. The aim of the present work is to relate the features of diamond Raman spectra to the features of Raman spectra of non-diamond phase admixture and occurrence of other carbon structures in the obtained diamond thin films.</abstract>

Study of CVD diamond layers with amorphous carbon admixture by Raman scattering spectroscopy

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