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In this paper, a new model for estimation of the electrical conductivity of polymer carbon nanotube (CNT) nanocomposites based on the conventional power-law model and Halpin-Tsai formulation has been proposed. Halpin-Tsai model was originally presented to calculate the tensile modulus of composites, which can be modified for estimation of the electrical conductivity by replacing the electrical parameters. The nature of “b” exponent in power-law model is defined according to CNT dimensions, CNT electrical conductivity and the interphase thickness and also the impacts of these parameters on the “b” and the electrical conductivity of nanocomposite are taken into consideration. The developed model interprets that the electrical conductivity of polymer-CNT nanocomposite increases as the concentration, length and electrical conductivity of CNT and the interphase thickness increase. Furthermore, reduction in CNT diameter and waviness results in growth of nanocomposite electrical conductivity. In order to validate the developed model, nanocomposite samples with different volume fractions were produced by solid-state technique of the melt-blending method. The results of calculations and experimental procedure show good agreement.

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Today, in order to reduce the harmful effects of the environment and increase the mechanical properties and durability of concrete, particles with high pozzolanic properties are used as a suitable alternative to ordinary cement in concrete. And filler, as an alternative to cement, has attracted the attention of researchers. In this laboratory study to investigate the effects of slag and nanosilica slag consumption on the microstructure of geopolymer concrete and compare it with the characteristics of control concrete containing Portland cement, 1 mixing design of control concrete and 3 mixing designs of geopolymer concrete containing 92, 96 and 100% composite kiln slag was fabricated with 0, 4 and 8% nanosilica, respectively. X-ray fluorescence (XRF) was performed. In order to investigate the effect of microstructural changes on the macro structure of concrete, compressive strength and tensile strength tests were performed on concrete samples at 90 days of age. Examination of the images obtained from the SEM test shows the superiority of the microstructure of the geopolymer cement matrix in all designs, compared to the microstructure of the control concrete containing Portland cement. Celsius), the effects of improvement and cohesion in the microstructure of geopolymer concrete are evident due to the presence of silica nanoparticles, in this regard, the presence of 8% nanosilica in mixture 4 (geopolymer concrete), accelerates the reactivity process and increases the volume of hydrated gels Geopolymerization was compared to other geopolymer concrete mixtures (containing 0 and 4% nanosilica). Images of concrete samples heated to 500 ° C show signs of weakening of the concrete microstructure compared to images taken of concrete at room temperature. The results of XRF test indicate the presence of the highest amount of oxidilica and aluminum oxide (the main factors in improving the density in the microstructure of concrete), in the combination of designs 4 and 2 by 36 and 8%, respectively. The high peaks created in the XRD spectrum diagram often occur in areas with angles (θ2) of 28 °, and their height varies according to the presence of aluminosilicate particles in the concrete mix. The application of high heat to the concrete specimens caused a decrease in the results of the XRD test. Evaluations performed on the results of the test to determine the compressive strength and tensile strength in concrete, showed coordination and overlap with the results of microstructural tests in this study.

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ABSTRACT
Equal Channel Angular Pressing (ECAP) is one of the methods of refining and fine-graining metal materials. In this research, ECAP operation was performed on samples of 5182 alloy in 1 to 4 passes at ambient temperature. After implementation of the specimens through ECAP, prepared to obtain mechanical properties such as hardness, tensile and metallography. The results of these experiments showed that the mechanical properties of the packed materials through ECAP have improved compared to the normal state. Using a scanning microscope, it was observed that the average grain size decreased from 131 μm in the initial state to 745 nm after the ECAP process after the fourth pass. The results of hardness test also showed a 213% increase compared to normal.  The increase in yield stress after 4 passes is about 3 times. Finally, the crack growth of these materials under fatigue loading was compared with the non-ECAP mode by creating a suitable pre-crack. It was observed that crack growth is faster in ECAP materials and the failure surface is smoother compared to normal. Also, the deviation of the crack from its path in microstructure materials is less than normal. Finally, by comparing the Experimental results of crack growth with the results of numerical analysis, the accuracy of the numerical results is validated and confirmed.

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Cementitious composites are mainly used in the construction industry due to their good characteristics such as low cost, acceptable compressive strength, and easy access. However, there are many weaknesses in these materials, including low tensile strength, brittle behavior, and unacceptable durability (service life), which need to be improved to achieve more sustainable constructions. Nowadays, the using of nanotechnology have been growing and nanomaterials have been widely used in compound with a multitude of conventional materials. The outstanding chemical and physical properties of nanomaterials enable them to play a key role in various applications, such as modifying the material structure, ameliorating the properties of the material, and manufacturing modern multifunctional products. Recent advances in nanotechnology have led to produce nano-sized particles that can improve the durability performance of construction materials. Nanoparticles such as nano-silica, nano-Fe₂O₃, nano-clay, carbon nanotube (CNT), nano-Al₂O₃, nano-TiO₂, and graphene oxide have been used to enhance the properties of cementitious composites. The performance of halloysite nanotube on the characteristics of cementitious composites has been studied less than other nanomaterials. Although the positive effects of nanomaterials such as halloysite nanotube (HNT) on the properties of cementitious composites have been proven, the very important issue of the correct and proper dispersion of nanomaterials in the cementitious environment has not been studied acceptably. The high surface energy and interparticle forces, including van der Waals, hydrogen bonding, and electrostatic interactions, make the nanomaterials highly susceptible to agglomeration. The aggregates of nanomaterials not only decrease their benefit but also act as potential weak spots in cementitious composites that can cause stress concentration, therewith diminishing the mechanical properties of cementitious composites. In this regard, the current paper investigated the effective factors on the agglomeration of halloysite nanotube (HNT) in the cementitious alkaline environment. Finally, this paper presented an approach for solving the problem of HNT agglomeration. Results showed that Ca²⁺, K⁺, and Na⁺ ions as alkaline agents of cement environment are the main factors to provide a state for HNT agglomeration. Among them, Ca²⁺ has more effect in agglomeration of halloysite nanotube due to the bridging effect between halloysite particles. From the results, the dispersion of HNT made better with increasing the alkalinity of cement environment until pH=11, while after this pH, the agglomeration of HNT started and the intense of agglomeration raised with the increase of pH, where it reached a maximum value at pH=13.5. Common approaches to nanoparticle dispersion are through physical methods (e.g., ultrasonic, high shear mixing, ball milling, etc.) and chemical methods (e.g., chemical modification of nanoparticle surfaces, use of dispersants such as surfactants, etc.). For the cementitious systems, a combination of ultrasonic and surfactant is mostly suggested. In this research, the effect of various surfactants on overcoming the agglomeration of halloysite nanotube in the cementitious environment was studied. The results indicated that the Polycarboxylate-based surfactant has better performance on improving the dispersion of HNT compared to that of other surfactants. Furthermore, incorporation of 3 wt% HNT enhanced the compressive, flexural and sorptivity of plain mortar up to 26, 22, and approximately 28%, respectively. The outcomes of the current paper display the fact that it is necessary to have special attention on the subject of the proper dispersion of nanomaterials in the cementitious environment for achieving the maximum efficiency of nanomaterials.

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 Micro-milling process as one of the most widely used methods of making parts due to the small size and their delicate properties in the process. In this study, micro-milling operations were performed on a titanium piece made of Ti6Al4V alloy using a tool with a diameter of 0.5 mm. The effect of nanoparticles used in lubricants on the surface roughness of the micro-milled workpiece is the most important characteristic studied in this research. In this research, experimental test methods and design and analysis of experiments by Taguchi method have been used to study the surface roughness during the process. Experimental tests to compare the role of lubrication in dry, wet and Minimum Quantity Lubrication (MQL) in different machining environments with lubricants containing nanoparticles and without nanoparticles and the effect of shear parameters on different characteristics of micro-milling of Ti6Al4V alloy is done. The results show that the use of Minimum Quantity Lubrication (MQL), especially with lubricants containing nanoparticles, increased the surface quality and had a more effective role in lubrication during micro-milling of Ti6Al4V alloy. Spindle speed and type of lubrication are the most effective parameters in Ti6Al4V alloy micro-milling.
 

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This study has experimentally investigated the effect of Fe₃O₄ and secondary flow injection on convection heat transfer and friction coefficient on a horizontal pipe. Secondary flow injected to main flow to make more turbulence to five different models. Water and Fe₃O₄ have been considered in5865 to 18800 Reynolds range and three0.01%,0.03% and0.06% volume concentrations. Length and diameter of test tube considered 65 cm and 1.7 cm, respectively, the diameter of secondary flow injection holes considered 3 mm and 4.5 mm, the ratio of volumetric flow rate to total flow considered 10% and 20% and distance between secondary flow injection holes considered 4 and 2. The results show that the increase of diameter of secondary flow injections holes, the ratio of secondary flow volumetric flow rate to total flow and the decrease of distance between secondary flow injection holes are effective on coefficient of utilization increase. The highest coefficient of utilization achieved   =20%,  =2 in each model using water fluid in d=4.5 state. In this state, the mean of coefficient of utilization achieved 1.256, 1.266, 1.31, 1.45 and 1.52 for first, second, third, fourth and fifth models in all Reynolds, respectably. The above state has the highest thermal performance in the fourth and fifth models. The mean of coefficient of utilization in all Reynolds increased 0.91%, 3.97% and 4.98% for the above state in the fourth model using Fe₃O₄ with three0.01%,0.03% and0.06% volume concentrations to water fluid, respectively. Similarly, this increase achieved 1.58%, 4.56% and 5.66% in the fifth model, respectively.

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Advancement in the production processes of nanostructures with appropriate formula characteristics provides the production of stable nanoparticles with the ability to be used in the food industry. Microencapsulated bioactive compounds can be integrated into electrospun fibers to achieve greater stability of nanoparticles against heat and light, which leads to increased storage time. In the present study, composite nanofiber layers were made from mucilage extracted from Salvia macrosiphon L. seeds using electrospinning. The nanocomposite of nanofibers was prepared from polyvinyl alcohol/rice bran protein isolate/ Salvia macrosiphon L. seed mucilage in different ratios. Then the morphology and FTIR spectroscopy were investigated. The average diameter of the produced nanofibers is about 40 nm and the coefficient of variance is 13%, which showed that the diameter of the fibers is relatively uniform. Increasing the concentration of the mucilage solution and the constant percentage of polyvinyl alcohol significantly increased the diameter of the nanofibers. In the next step, vitamin D3 was encapsulated in polyvinyl alcohol nanofibers and rice bran protein concentrate. FTIR results confirmed the presence of vitamin D3 in the prepared nanofibers. At higher concentrations of phenolic compounds, with the increase in the number of hydroxyl groups of aromatic rings in the reaction medium, the inhibitory power of mucilage free radicals increased. The composition of nanofibers in the spectroscopic graphs showed that there are two strong peaks in the range of 1454 and 1743 CM-1 from vitamin D3 in the nanocomposite and microcoated samples which show the stretching vibrations related to the C=C group in the aromatic rings of phenolic compounds. Based on the findings, bioactive compounds to increase access to vitamin D3 can be enclosed in electrospun nanofibers of Salvia macrosiphon L. mucilage/polyvinyl alcohol/rice bran protein concentrate.

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This study was done as a response to recent demands for developing and introducing new natural preservatives and quality enhancers for application in food industry. The emulsion produced by ultrasonic method, was consisted of coriander essential oil nano-droplets dispersed in Aloe vera extract. The two ingredients were tested individually and proved to have antioxidant and antibacterial activities. Total phenolic and flavonoid content of nanoemulsion estimated 33.53 mg GAE/g and 657.33 mg QE/g nanoemulsion respectively. DPPH and ABTS radical scavenging evaluated about 73.70 and 71.30 percent at 300 mg/mL concentration of nanoemulsion. Four methods (disk diffusion agar, well diffusion agar, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)) were used to evaluating antimicrobial effect of prepared nanoemulsion. Similar to disk diffusion agar method, the results of well diffusion agar method showed the inhibition zones with diameters less than 10 mm. Based on MIC and MBC results, the nanoemulsion had an inhibitory effect on all subjected pathogens with MBC of 512 mg/ml against Staphylococcus aureus and Bacillus cereus while higher concentrations than 512 mg/mL were required for other pathogens. Overall results of four antibacterial tests indicated a stronger effect of nanoemulsion on the Gram-positive pathogens than the Gram-negative bacteria used in this study. Prepared coriander essential oil nanoemulsion in Aloe vera extract can be used as an antioxidant preservative with high performance in the food industry yet it is required to do more tests on this nanoemulsion to reach the valid effective concentrations.
 

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The electrical properties of nanostructured piezoelectric materials have attracted the attention of many researchers in the last decade. These features are used in piezoelectric micro-sensors. Mechanical propulsion is usually the result of contact between a piezoelectric surface and a foreign object. In this paper, the effect of mechanical propulsion using an air wave (sound) or vacuum on a silicon diaphragm is investigated. The local stresses created on the diaphragm due to the impact of an air wave have a significant effect on the peak-to-peak voltage of the piezoelectric sensor, which can be measured by measuring changes in this parameter. To investigate this, a micromachined diaphragm of silicon was examined and it was found that fabricating a piezoelectric sensor on a thin and patterned diaphragm could increase the peak-to-peak voltage by about 1.3 times. Detection of these stresses using piezoelectric material layered on the thin and formable diaphragm can act as a piezoelectric microphone or a barometer that the presence of microstructures on the diaphragm will increase their sensitivity.

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This study aimed to convert sweet and bitter lupine protein isolates to nano-emulsions and to develop products with the nano-emulsion and examine the stability; develop emulsification with ultrasonication; develop and characterize food protein-stabilized nanoemulsions; and to modify lupine protein properties with pH shifting and ultrasonication. The antioxidant activity of sweet and bitter isolates was decreased in the nano-particle sized samples when compared to non-nano particle-sized samples, as well as the inhibitory activity of both angiotensin-converting enzyme and alpha-amylase, while it increased in sweet and bitter lupine isolates. For both types of lupine, water holding capacity was increased, and foaming stability of nano treatment was increased in protein isolate samples. In lupine, albumins and three globulins fractions, namely, β-conglutin, α-conglutin, and γ-conglutin, were characterized as the main storage proteins. No clear differences were observed between nano and non-nano samples regarding albumins and three globulins fractions. The results of microstructure characterization showed that sonication leads to distortion/breakage of protein particles shape, which results in smaller proteins that can be used as a top-down approach for the formation of nano-sized protein particles. In this regard, sonication can be considered as a heterogeneous approach that may lead to de-aggregation, breaking of protein particles, and distortion of their shape.

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Self-compacting concrete (SCC) is known for its outstanding characteristics such as superior mechanical and durability properties. Corrosion of rebar due to penetration of chloride ions in the reinforced concrete elements is of particular importance. Therefore, this issue in the SCC must be investigated. Pozzolanic materials could be used in the SCC to increase the resistance of concrete against chlorine ion penetration. In this research, effects of pozzolanic materials including micro silica, nano silica, fly ash, rice husk ash, as well as limestone powder on the mechanical and durability characteristics of self-compacting concrete placed in chloride environment have been studied. The results show that nano-silica increases the mechanical and durability characteristics of self-compacting concrete. Moreover, the SCC containing combination of nano-silica and pozzolanic materials has better properties than the one containing nano-silica.

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Aims Using nanomaterials in cancer therapy has shown that this kind of treatment is more efficient with fewer side effects. A considerable number of nanomaterials that can be used in cancer therapy are introduced; among them, graphene attracts most of the scientist's attention due to its unique features. In this study, the graphene oxide (GO) was synthesized and reduced by gelatin for cellular delivery of an anticancer drug, curcumin, .
Materials and Methods GO was synthesized by hummer method and reduced by gelatin. Curcumin anticancer drug was loaded on the synthesized nanocarriers via hydrophobe-hydrophobe interaction.
Findings Chemical, physical and biological assays have been done to evaluate the synthesis and surface modification. In the next step, the drug loading efficiency was obtained by the UV-Vis  spectroscopy method.
Conclusion: GO is successfully synthesized, with the average size of 300nm. AFM pictures of GO before and after reduction show an increase in thickness that proves the presence of gelatin on the surface. From the cytotoxicity assay on L292 cell line, it can be concluded that surface modification was effective because GO showed remarkable toxicity while gelatin-rGO does not show any toxicity even at a concentration of 200 μgml^-1. Also, the drug loading efficiency is obtained at 78%. Therefore, the gelatin-rGO with excellent stability and biocompatibility can be suggested as a drug carrier applicable in biomedical studies.

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Surface quality and roughness are major effective parameters on the function of optic components. This study developed a new design of the Ball-End Magnetorheological finishing tool with the ability to mount on a three-axis CNC milling. In the new design, a new concept of the cooling system was used for cooling the internal and external surfaces of the electromagnetic coil, and optimizations on magnetic flux distribution were performed. With the aid of magnetostatic simulation in Ansys Maxwell software, the tool’s capability for producing magnetic flux density was tested. The capability of a new tool for polishing non-ferromagnetic BK7 glass was tested by selecting optimized process parameters like working gap and magnetizing current. An experimental magnetic flux density test with the gauss meter showed that the newly designed BEMRF tool can generate enough magnetic flux density for polishing BK7 glass. The finishing test showed the tool’s ability to create enough indentation force on the workpiece’s surface and reduce surface roughness.
 

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In the present research, classic micromechanical methods and their application as constitutive models in conjugation with incremental theory were developed. Using the modified Eshelby model, the Eigen strain concept in polymeric composite, and a modified form of self-consistent model the elastic properties of nanocomposites were predicted. Also, the stress-strain behavior of elastomer nanocomposites was calculated and validated by the experimentally determined ones. The results showed that the new model can predict the stress-strain behavior of elastomer nanocomposite at different particle volume fractions.
 

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In this research, processing and 3D printing of PETG-ABS- Fe 3 O 4  nanocomposites reinforced with iron oxide nanoparticles in three different weight percentages of iron oxide nanoparticles with PETG70-ABS30 polymer matrix was done. This research was carried out with the aim of strengthening the shape memory properties, thermal properties, mechanical properties and adding the ability to indirectly stimulate the background matrix through the addition of iron oxide nanoparticles. SEM images confirmed that the mixture of PETG-ABS is immiscible and adding nanoparticles does not change the compatibility and miscibility of the base polymer, and this result is consistent with the DMTA analysis was also checked and confirmed. With increasing amount of iron oxide, the tensile strength and elongation decrease, and this decrease in mechanical properties is more pronounced in the sample of 20% by weight of iron oxide compared to the sample of 10% by weight. Nevertheless, the final strength of the samples is around 25 to 32 MPa, which indicates a suitable and acceptable distribution of nanoparticles up to 15% by weight in the polymer field. By increasing the amount of iron oxide nanoparticles, the amount of shape recovery increases and the nanocomposites containing 10, 15 and 20% by weight show shape recovery of 63.77%, 88.48 and 93.33%, respectively.

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In orthopedics, the drilling process is one of the most important steps in the preparation of medical tools and implants. Improving the performance of medical tools and implants is of great importance, because these tools and implants are used in the repair of bone and joint injuries. One of the ways to improve the efficiency of these tools and implants is to use titanium nitride nano coatings on drilling tools. This article is presented with the aim of experimental analysis and optimization of axial force in the orthopedic drilling process using a tool coated with titanium nitride nano coating by physical deposition method. The purpose of this research is to improve the performance and efficiency of this process by optimizing various parameters such as tool rotation speed, cutting depth and titanium nitride coating. For this purpose, experimental tests were conducted using the response surface method. the sensitivity analysis was also performed. The results have shown that the rotational speed, as the most effective parameter, has a lesser effect (45% effect) on the axial force in the case without nanocoating, while it shows a greater effect (73% effect) in the case with nanocoating.