175 results on '"Semnani, Dariush"'
Search Results
152. Performance prediction of a specific wear rate in epoxy nanocomposites with various composition content of polytetrafluoroethylen (PTFE), graphite, short carbon fibers (CF) and nano-TiO2 using adaptive neuro-fuzzy inference system (ANFIS)
- Author
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Haghighat Mesbahi, Ali, Semnani, Dariush, and Nouri Khorasani, Saeid
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PERFORMANCE evaluation , *MECHANICAL wear , *EPOXY resins , *NANOCOMPOSITE materials , *PREDICTION models , *ARTIFICIAL neural networks , *FUZZY systems - Abstract
Abstract: Specific wear rate of composite materials plays a significant role in industry. The processes to measure it are both time and cost consuming. It is essential to suggest a modeling method to predict and analyze the effectiveness of parameters of specific wear rate. Nowadays, computational methods such as Artificial Neural Network (ANN), Fuzzy Inference System (FIS) and adaptive neuro-fuzzy inference system (ANFIS) are mainly considered as applicable tools from modeling point of view. ANFIS present integrate performance of neural network (NN) and fuzzy system (FS). Present paper investigates performance prediction of a specific wear rate of epoxy composites with various composition using ANFIS. The obtained results showed that ANFIS is a powerful tool in modeling specific wear rate. The obtained mean of squared error (MSE) for testing sets in present paper obtained 0.0071. [Copyright &y& Elsevier]
- Published
- 2012
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153. Study of structural parameters of weft knitted fabrics on luster and gloss via image processing.
- Author
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Semnani, Dariush, Sheikhzadeh, Mohammad, Hadjian, Mehdi, and Reyhani, Farzary
- Subjects
WEFT knit textiles ,STITCH-bonded textiles ,TEXTILES ,TEXTURE analysis (Image processing) ,IMAGE processing - Abstract
Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2012
154. Fuzzy classification of luster of textile fabrics.
- Author
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Hadjianfar, Mehdi and Semnani, Dariush
- Subjects
FUZZY systems ,TEXTILES ,IMAGE processing ,FUZZY logic ,NUMERICAL analysis - Abstract
The appearance of fabric is very important when a customer makes a choice for outer apparel. One of the factors that has an effect on the users’ judgment and on the appearance of the fabric is the luster of textiles. The luster can be considered as one of the most effective and essential factors of investigating the appearance of a fabric that is used by a consumer. In order to determine textile luster, there are different methods based on classic definitions; the ones based on image processing have results closer to human impressions of the fabric. Nevertheless, all the determining methods give numerical luster indexes which are far from the reality of a human’s impression, which is a qualitative one for luster. One method that can be used to transform numerical data to qualitative data is fuzzy logic for the classification of data for the luster index.In the presented method, after indicating luster index by the use of image processing, different fabric samples are classified in six different classes based on the luster determined by judgment of ten different inspectors. The luster index is finally classified in six fuzzy classes based on fuzzy logic theory. Results show that fuzzy classification is confirmed by viewers’ judgments. [ABSTRACT FROM PUBLISHER]
- Published
- 2011
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155. Investigating the Performance of Various Relaxation Processes on the Surface Regularity and Dimensional Properties of Plain Knitted Fabrics Using the Image Processing Technique.
- Author
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Sanjari, Hamid Reza, Semnani, Dariush, and Sheikhzadeh, Mohammad
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TEXTILES ,NUMERICAL analysis ,RADON ,RELAXATION phenomena ,IMAGE processing - Abstract
The main objective of this paper was to develop a more advanced finishing treatment for the stitch shape regularity and dimensional properties of knitted fabrics. In our previous work, we presented a novel definition of knitted fabric regularity. In the present study we utilised our pervious approach based on Radon transformation analysis to study the effect of different relaxation regimes on the above properties of plain fabrics. We applied various relaxation methods to plain fabrics to make the stitch shape closer to the ideal. The rhythm of stitch shape improvement was evaluated by measuring the deviation of the direction angle of the stitches against the ideal state. The results show that the average fabric irregularity index after ultrasonic-chemical relaxation treatment is better than other relaxation method indices. Moreover the average fabric constant dimensional parameter (Ks) after the above treatment is higher than values reported by pervious workers. Therefore we propose this relaxation treatment as a new relaxation method that is more effective with respect to plain fabric regularity and stability during usage. [ABSTRACT FROM AUTHOR]
- Published
- 2011
156. Study on hybrid yarns integrity through image processing and artificial intelligence techniques.
- Author
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Baradari, Mehdi Gholipour, Semnani, Dariush, and Sheikhzadeh, Mohammad
- Abstract
The commingled hybrid yarns of different structures have been used to investigate the variation in their abrasion resistance over those of simple yarns by calculating the abrasion destruction index. The cotton yarns of the counts 20Ne and 30Ne and cotton-polyester yarns of the same counts (20Ne and 30Ne) at 20, 40 and 60 bar pressure, have been commingled using flat and textured polyester yarns of 150 den. The produced samples are then abraded by a standard metallic object at four different stages including 150 abrasion cycles in each stage. Through image analyzing technique, the abrasive damage of the samples has been investigated and the abrasion indexes are calculated. The Kohonen neural network is used to cluster the samples in 5 classes as per their abrasion resistance. The cotton-polyester yarn (30Ne), hybrid samples from cotton (30Ne) and textured polyester at 20, 40 and 60 bar; and the hybrid yarn made from cotton-polyester (30Ne) and flat polyester at 60 bar are found to be the best. Furthermore, the abrasion resistance of samples improves on increasing the pressure of commingling process. Generally, cotton yarn and textured polyester yarn show the better abrasion resistance in comparison with the other samples. [ABSTRACT FROM AUTHOR]
- Published
- 2010
157. A New Method for Measuring Luster Index Based on Image Processing.
- Author
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Hadjianfar, Mehdi, Semnani, Dariush, and Sheikhzadeh, Mohammad
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LUSTER ,TEXTILES ,APPEARANCE of materials ,IMAGE processing ,IMAGE analysis ,METHODOLOGY - Abstract
Appearance is an important property of textiles, and in specifying textile appearance luster should be taken into account. There are many problems involved in defining and measuring the luster of textile surfaces, so luster and its measurement have been the subject of extensive investigation, in both theoretical and practical aspects. Many types of surface have been studied and many methods of assessing luster have been devised. There are several devices which are designed to measure luster and gloss, some designed specifically for textiles. However, there is still a lack of information regarding measurement and evaluation of luster of textile surfaces. Current methods investigate fabric via one or more directions and are not capable of providing a general view of fabric luster with regard to appearance, in particular for uneven fabrics. This study reports on a new methodology to obtain an index for the luster of fabric, which compares the luster of fabrics via image analysis. The method produces results consistent with human evaluation of luster, whereas in previous methods the lighting and procedures used in luster calculation have differed from the real-world situations of fabric usage. The method presented in this research, for all samples, takes photographs of fabrics in various directions under constant conditions, and derives the luminance of images. An index is obtained for the luster of fabrics by analyzing the luminance of fabrics. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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158. A sharp technique for identification of defective points in false twist textured yarns.
- Author
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Semnani, Dariush and Gholami, Ali
- Abstract
Fast Fourier Transformation technique has been used to classify the defective points in the yarn surface into three classes, namely less important defective points of textured yarn containing surface fibres and broken filaments; medium defective points; and large and unusual defective points. The results obtained from textured yarn with 300 Nm show that this method can be considered for commonly used yarns in acceptable accuracy. This method can detect the defects in a fraction of seconds and can be installed on machines. [ABSTRACT FROM AUTHOR]
- Published
- 2009
159. Silk Fibroin Nano-Coated Textured Silk Yarn by Electrospinning Method for Tendon and Ligament Scaffold Application
- Author
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Ghiasi, Mostafa, Naghashzargar, Elham, and Semnani, Dariush
- Abstract
In recent years, the use of combined nanofibers with textile structures for various applications such as tissue engineering has been highly regarded. Among the different methods, electrospinning mechanism is more important to produce polymeric nanofibers in extensive diameters that has been used to fabricate silk fibroin nanofibers in this research. On the basis of the statistical analysis and analytic hierarchy process optimization method, the optimum electrospinning parameters to produce good morphology of nanofibers and the best conditions of texturing process to fabricate suitable structure of textured silk yarn have been obtained, respectively. The following step to produce nanocoated textured yarn was defined as a nanocoating process on the surface of textured silk yarn. Finally, the morphological and mechanical properties of these samples including no-textured silk yarn, textured silk yarn and nanocoated textured silk yarn analyzed and compared. Based on the finding of this study, the nanocoated textured silk yarn was found to be a promising construct for engineered scaffolds in tendon and ligament tissue engineering.
- Published
- 2012
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160. Gaining insight into electrolyte solution effects on the electrochemomechanical behavior of electroactive PU/PPy nanofibers: Introducing a high-performance artificial muscle.
- Author
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Ebadi, Seyed Vahid, Semnani, Dariush, Fashandi, Hossein, Rezaei, Behzad, and Fakhrali, Aref
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ELECTROLYTE solutions , *ARTIFICIAL muscles , *ION exchange (Chemistry) , *NANOFIBERS , *CONDUCTING polymers - Abstract
• The high-performance PU/PPy nanofibrous actuators was fabricated. • The influence of electrolyte specifications on the actuation behavior was studied. • The larger anions markedly increase the magnitude of bending movement of actuator. • The nanofibrous actuator showed a remarkable bending displacement more than 720°. The unique properties of nanofibrous artificial muscles including high specific surface area, high porosity, and flexibility as well as similarity to natural muscle structures make them a promising option for use in advanced technologies. In this study, a polyurethane/polypyrrole (PU/PPy) nanofibrous bending artificial muscle was produced and contribution of important electrolyte specifications including concentration and type and size of ions on the electrochemomechanical performance was evaluated. The bending actuation of the produced muscles increased with the concentration of electrolyte solution and this increase was observed at a higher rate in lower concentrations. It was found that the nature of electrolyte ions is a key determinant of the mechanism of ion exchange with the conductive polymer. The using of larger anions in the anion exchange mechanism results in greater bending movements. For example, using LiTFSI electrolyte solution instead of LiCl, in the same potential range, increased the bending displacement from 31° to more than 250°. Immersing in the 0.1 M LiTFSI electrolyte solution, the produced nanofibrous artificial muscle showed a remarkable bending displacement more than 720° in a cycle potential between -0.8 V and 0.8 V. This amazing actuation performance demonstrates the high potential of the produced electrochemomechanical artificial muscles in practical applications. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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161. Electrochromic Self-Electrostabilized Polypyrrole Films Doped with Surfactant and Azo Dye.
- Author
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Bayat, Maryam, Izadan, Hossein, Molina, Brenda G., Sánchez, Margarita, Santiago, Sara, Semnani, Dariush, Dinari, Mohammad, Guirado, Gonzalo, Estrany, Francesc, and Alemán, Carlos
- Subjects
SODIUM dodecyl sulfate ,CONDUCTING polymers ,SURFACE active agents ,POLYPYRROLE ,AZO dyes ,SCANNING electron microscopy ,X-ray microscopy - Abstract
Two azo dyes, acid red 1 (AR1) and acid red 18 (AR18), were used alone or in combination with sodium dodecyl sulfate (SDS) for the electropolymerization of a pyrrole monomer. Polypyrrole (PPy) showed higher redox capacity when SDS and AR18 were used simultaneously as dopant agents (PPy/AR18-SDS) than when the conducting polymer was produced in the presence of SDS, AR18, AR1, or an AR1/SDS mixture. Moreover, PPy/AR18-SDS is a self-stabilizing material that exhibits increasing electrochemical activity with the number of oxidation–reduction cycles. A mechanism supported by scanning electron microscopy and X-ray diffraction structural observations was proposed to explain the synergy between the SDS surfactant and the AR18 dye. On the other hand, the Bordeaux red color of PPy/AR18-SDS, which exhibits an optical band gap of 1.9 eV, rapidly changed to orange-yellow and blue colors when films were reduced and oxidized, respectively, by applying linear or step potential ramps. Overall, the results indicate that the synergistic utilization of AR18 and SDS as dopant agents in the same polymerization reaction is a very successful and advantageous strategy for the preparation of PPy films with cutting-edge electrochemical and electrochromic properties. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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162. Comparison of the antifungal activity of fluconazole- and ketoconazole-loaded PCL/PVP nanofibrous mat.
- Author
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Afrashi, Mehran, Nasari, Mina, Semnani, Dariush, Dehghan, Parvin, and Maheronnaghsh, Mehrnoush
- Abstract
In this study, the antifungal activity of both fluconazole and ketoconazole was compared. The drugs were loaded into the polycaprolactone (PCL)/polyvinylpyrrolidone (PVP) nanofibrous mats and the effect of the drug-loaded samples on Candida albicans (Ca) were investigated by disc diffusion method. Furthermore, the characterization of nanofibrous mats was performed by field emission scanning electron microscopy, Fourier transform infrared (FT-IR) and contact angle tests. The mean diameter of nanofibres was 656 nm and it decreased with the addition of drugs into the electrospinning solutions, because the viscosity of solutions were decreased while electron conductivity of solutions was increased. With increase in the amount of the drug from 5 to 15%, the hydrophilicity increased. FT-IR revealed both drugs were physically embedded in the nanofibres and confirmed their presence in the composition. In addition, the degradation behaviour of samples was significant due to by the amount and the dissolution of PVP and approximately 40% loss weight occurred after 22 days. In the disc diffusion tests, both drug-loaded samples had antifungal effect on sensitive isolates of Ca, while for resistant of isolate the ketoconazole had more effective than fluconazole. Overall, the study highlights the ability of antifungal drug-loaded PVP/PCL nanofibrous mats as potential wound dressing materials and local delivery systems. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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163. Investigation and comparison of new galactosylation methods on PCL/chitosan scaffolds for enhanced liver tissue engineering.
- Author
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Ghahremanzadeh, Fatemeh, Alihosseini, Farzaneh, and Semnani, Dariush
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TISSUE engineering , *CHITOSAN , *LIVER cells , *LIVER , *CONTACT angle - Abstract
In liver tissue engineering, improving the ability of the scaffold to increase the tendency of cells to grow and proliferate is very important. In this study, new methods for modifying the surface of Polycaprolactone (PCL)/Chitosan (Cs) nanofiber for use in liver tissue engineering have been proposed. Galactosylation of chitosan was performed in three ways. According to the FE-SEM, FTIR, NMR and DSC analysis, presence of galactose in uniform nanofibers confirmed and led to a decrease in crystallinity. The hydrophobicity of the scaffolds by contact angle showed that the scaffold with galactosylated after electrospinning, had the highest contact angle of 82.22 ± 2° compared to raw scaffold with 98.52 ± 4°. According to the results of degradation in PBS, the highest rate of degradation was observed in scaffolds that were galactosylated after electrospinning. By culturing HepG2 cells on and based on the results of SEM and MTT analysis, found that the presence of galactose in the scaffolds significantly increased cell growth and proliferation without any toxicity. The immersion method shows a greater ability to improve the growth of liver cells. Also, using in-situ way due to the roughness created in this method may lead to better results especially for in-vivo tests. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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164. An investigation on quilled nozzle-less electrospinning in comparison with conventional methods for producing PAN nanofibers.
- Author
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Rezazadeh Tehrani, Sayed Pedram, Hadjianfar, Mehdi, Afrashi, Mehran, and Semnani, Dariush
- Subjects
NOZZLES ,ELECTROSPINNING ,NANOFIBERS ,NANOTECHNOLOGY ,ENERGY consumption - Abstract
Over the last decades by appearing nanotechnology electrospinning has been reconsidered as a significant method. However, electrospinning production rate is limited by the rate at which the polymer solution or melt is fed to a single jet. Feeding rate can be increased through implementing a wide range of methods such as multiple nozzle electrospinning. In the present work, an innovative “quilled” drum with a peculiar design was rotated in a PAN polymer solution in an electrical field to optimize energy consumption, uniform nanofiber distribution on the collector, and increase production rate. The produced nanofibers were compared with those produced from modified multi-nozzle and single-nozzle electrospinning methods. The mean diameters of nanofibers produced from the quilled drum was 32% greater than that of single-nozzle and 28% less than multi-nozzle electrospinning. The CV% of thickness of the webs were 7.9, 11.2, and 12.5% for the quilled, single nozzle and multi-nozzle methods, respectively which showed the presented method produced more uniform webs. The production rate of this electrospinning was 60 and 17 times more than single and multi-nozzle methods, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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165. Electrospun polyvinylidene pyrolidone/gelatin membrane impregnated with silver sulfadiazine as wound dressing for burn treatment.
- Author
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Semnani, Dariush, Poursharifi, Nazanin, Banitaba, Nooshin, and Fakhrali, Aref
- Subjects
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ELECTROSPINNING , *VINYLIDENE compounds , *SULFADIAZINE , *SURFACE area , *MECHANICAL behavior of materials , *FOURIER transform infrared spectroscopy - Abstract
Nanofibrous membranes used for burn treatment have become widely popular due to their large surface area and high porous structure. In this study, electrospinning was used to fabricate a blended nanofibrous membrane of polyvinylidene pyrolidone (PVP) and gelatin, to use as wound dressing. The physical and mechanical properties of this novel membrane were investigated using SEM, FTIR and tensile tests. Results showed that poor mechanical properties of gelatin, which are preferred in medical applications for curing burns as they allow for antigen activity and skin repair, can be enhanced by adding PVP in the solution. Silver sulfadiazine (AgSD), an antibacterial agent, was also impregnated into the PVP/gelatin nanofibrous structure during electrospinning. The membrane thus fabricated showed antibacterial activities against both the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. AgSD release behaviour of fabricated samples indicated short-term drug delivery. It was concluded that the proposed drug-loaded membrane can be used as wound dressing, specifically, in treating skin burns. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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166. Fabrication of novel PCL/PGS fibrous scaffold containing HA and GO through simultaneous electrospinning-electrospray technique.
- Author
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Nasari, Mina, Poursharifi, Nazanin, Fakhrali, Aref, Banitaba, Seyedeh Nooshin, Mohammadi, Sajjad, and Semnani, Dariush
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POLYCAPROLACTONE , *TISSUE scaffolds , *GRAPHENE oxide , *CELL survival , *HYDROXYAPATITE , *ELECTROSPINNING - Abstract
Herein, poly(caprolactone)/poly (glycerol sebacate) (PCL/PGS) fibrous structures incorporating hydroxyapatite (HA) and graphene oxide (GO) nanofillers were prepared through two procedures, including electrospinning and simultaneous electrospinning/electrospray procedures. Accordingly, introducing nanofillers into the structures through the simultaneous method led to improving the mechanical strength from 3.69 to 4.95 MPa. The electrospray nanofillers caused improvement of the amorphous regions (up to 83.4%) and increased the degradation rate. Furthermore, the filler-filled electrospun/electrospray sample illustrated the highest cell viability of 94.81 ± 0.5%. The results implied that the simultaneous procedure is promising for fabricating filler-loaded membranes as bone tissue scaffolds. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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167. Systematic investigation of parameters of an electrospinning process of poly(acrylic acid) nanofibres using response surface methodology.
- Author
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Ebadi, Seyed Vahid, Fakhrali, Aref, and Semnani, Dariush
- Subjects
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POLYACRYLIC acid , *POLYMER solutions , *SCANNING electron microscopy , *SURFACE morphology , *HEAVY metals - Abstract
In this study, response surface methodology (RSM) based on the central composite design (CCD) was used for modelling the electrospinning process of polyacrylic acid (PAA) nanofibres, so as to assess simultaneously the effect of the most important electrospinning parameters (concentration of polymer solution, applied voltage, distance between the nozzle and collector and flow rate of solution) on the diameter of electrospun PAA nanofibres. The surface morphology was studied by scanning electron microscopy (SEM). The average diameter of PAA nanofibres obtained was from 233 to 1210 nm from SEM images with different process parameters. The results showed that the solution concentration, the applied voltage and the distance between the nozzle and collector are, in that order, the most important parameters affecting the diameter of nanofibres. The flow rate, however, showed no significant effect on the nanofiber diameter. The RSM model predicted that under optimal electrospinning conditions (solution concentration of 3 w/v%, voltage of 16 kV, electrospinning distance of 15 cm and flow rate of 1.75 ml h–1), the nanofibres would be 262 nm in diameter, which was proved to be very close to the actual measured value. Therefore, the obtained results demonstrated the good performance of the RSM model in investigating the effect of electrospinning variables and predicting the diameter of PAA nanofibres. PAA nanofibres have great potential in applications such as sensors and biosensors, removal of heavy metals and contaminants, muscle tissue engineering, etc. and the use of thinner nanofibres leads to their improved performance in these applications. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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168. Grading of Yarn Appearance Using Image Analysis and an Artificial Intelligence Technique.
- Author
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Semnani, Dariush, Latifi, Masoud, Tehran, Mohammad Amani, Pourdehimi, Behnam, and Merati, Ali Akbar
- Abstract
In this research, a new method is used for grading of yarn appearance based on yam images of ASTM standard (section D 2255), by using an image processing technique and an artificial intelligence technique. In this method, grading of yarn appearance is based on computer vision and analyzing the images of standard pictorial boards of yarn. Therefore this method is very similar to human vision. The logic of the classification by ASTM is considered and then a new definition for classification of yarn appearance grade is presented. In this method of classification, the grading procedure is not dependent on yarn structure and raw materials. Thus it is possible to use this method for grading of any type of yarn based on apparent features. [ABSTRACT FROM AUTHOR]
- Published
- 2006
169. Evaluation of the effects of zein incorporation on physical, mechanical, and biological properties of polyhydroxybutyrate electrospun scaffold for bone tissue engineering applications.
- Author
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Ghasemi, Saeid, Alibabaie, Afshin, Saberi, Reyhane, Esmaeili, Mahdie, Semnani, Dariush, and Karbasi, Saeed
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TISSUE scaffolds , *TISSUE engineering , *POLYHYDROXYBUTYRATE , *POLYCAPROLACTONE , *POLY-beta-hydroxybutyrate , *TENSILE strength , *HYDROPHOBIC surfaces , *HYDROGEN bonding - Abstract
Materials and fabrication methods significantly influence the scaffold's final features in tissue engineering. This study aimed to blend zein with polyhydroxybutyrate (PHB) at 5, 10, and 15 wt%, fabricate scaffolds using electrospinning, and then characterize them. SEM and mechanical analyses identified the scaffold with 10 wt% zein (PHB-10Z) as the optimal sample. Incorporating 10 wt% zein reduced fiber diameter from 894 ± 122 to 531 ± 42 nm while increasing ultimate tensile strength and elongation at break by approximately 53 % and 70 %, respectively. FTIR proved zein's presence in the scaffolds and possible hydrogen bonding with PHB. TGA confirmed the miscibility of polymers. DSC and XRD analyses indicated lower crystallinity for the PHB-10Z than for PHB. AFM evaluation indicated a rougher surface for the PHB-10Z in comparison to PHB. The PHB-10Z demonstrated a more hydrophobic surface and less weight loss after 100 days of degradation in PBS than PHB. The free radical scavenging assay exhibited antioxidant activity for the zein-containing scaffold. Eventually, enhanced cell attachment, viability, and differentiation in the PHB-10Z scaffold drawn from SEM, MTT, ALP activity, and Alizarin red staining of MG-63 cells confirmed that PHB-zein electrospun scaffold is a potent candidate for bone tissue engineering applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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170. Nano/micro hybrid scaffold of PCL or P3HB nanofibers combined with silk fibroin for tendon and ligament tissue engineering.
- Author
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Naghashzargar, Elham, Farè, Silvia, Catto, Valentina, Bertoldi, Serena, Semnani, Dariush, Karbasi, Saeed, and Tanzi, Maria Cristina
- Subjects
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TISSUE engineering , *TENDONS , *LIGAMENTS , *NANOFIBERS , *SILK fibroin , *ELECTROSPINNING - Abstract
A novel biodegradable nano/micro hybrid structure was obtained by electrospinning P3HB or PCL nanofibers onto a twisted silk fibroin (SF) structure, with the aim of fabricating a suitable scaffold for tendon and ligament tissue engineering. The electrospinning (ES) processing parameters for P3HB and PCL were optimized on 2D samples, and applied to produce two different nano/micro hybrid constructs (SF/ES-PCL and SF/ES-P3HB). Morphological, chemico-physical and mechanical properties of the novel hybrid scaffolds were evaluated by SEM, ATR FT-IR, DSC, tensile and thermodynamic mechanical tests. The results demonstrated that the nanofibers were tightly wrapped around the silk filaments, and the crystallinity of the SF twisted yarns was not influenced by the presence of the electrospun polymers. The slightly higher mechanical properties of the hybrid constructs confirmed an increase of internal forces due to the interaction between nano and micro components. Cell culture tests with L929 fibroblasts, in the presence of the sample eluates or in direct contact with the hybrid structures, showed no cytotoxic effects and a good level of cytocompatibility of the nano/micro hybrid structures in term of cell viability, particularly at day 1. Cell viability onto the nano/micro hybrid structures decreased from the first to the third day of culture when compared with the control culture plastic, but appeared to be higher when compared with the uncoated SF yarns. Although additional in vitro and in vivo tests are needed, the original fabrication method here described appears promising for scaffolds suitable for tendon and ligament tissue engineering. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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171. Study on the electrochromic properties of polypyrrole layers doped with different dye molecules.
- Author
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Bayat, Maryam, Izadan, Hossein, Santiago, Sara, Estrany, Francesc, Dinari, Mohammad, Semnani, Dariush, Alemán, Carlos, and Guirado, Gonzalo
- Subjects
- *
POLYPYRROLE , *SODIUM dodecyl sulfate , *ATOMIC force microscopy , *INDIUM tin oxide , *POLYETHYLENE terephthalate , *MOLECULES - Abstract
[Display omitted] • Design of a simple methodology to tune the color and increase the contrast of polypyrrole (PPy) electrochromic films with dyes. • Establishment of the effect of dopants (dyes and surfactants) on the electrochromic PPy films. • Production of the PPy electrochromic films with high coloration. Three dye molecules (Dye) of Acid Brilliant Scarlet 3R (AR18), Amido Naphthol Red G (AR1), Indigo Carmine (IC), as well as sodium dodecyl sulfate (SDS) as dopant agents were used for electrochemical synthesis of polypyrrole (PPy) layers onto indium doped tin oxide (ITO) coated polyethylene terephthalate (PET) electrode. The morphology, electrochemical, optical, and spectroelectrochemical properties of the layers were investigated. The study of the electrochemical behavior showed that the presence of each AR18, AR1, or IC with SDS, had shown an excellent synergistic effect on the electrochemical stability of layers. The morphological characterization of the PPy/dopant(s) using atomic force microscopy (AFM) showed that the surface roughness in the PPy/IC-SDS layer was 39% and 32% less than the PPy/AR18-SDS and PPy/AR1-SDS, respectively. The absorption spectrum of PPy/dopant(s) in the UV–Vis-NIR wavelength range showed the formation of polaron and bipolaron in PPy chains. Also, the optical bandgap energy of PPy/dopant(s) decreased, and the fully doped state in all PPy films was observed. Spectroelectrochemical properties of the films showed that the simultaneous use of each dye molecule and the surfactant as dopant in PPy layers demonstrated proper electrochemical and optical stability and satisfactory electrochromic parameters. For example, the color contrast of PPy/AR18-SDS was 50%, while this parameter in control sample (PPy doped with lithium perchlorate) was 21%. Also, the cathodic and anodic coloration efficiency showed a 6-fold increase in PPy/Dye-SDS compared to PPy/ClO 4 -. In general, according to the results it is likely that by increasing the number of anion groups in the dye molecules and decreasing their dimensions as dopant agents, the electrochemical and electrochromic properties of the resultant layer would be improved. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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172. 5FU-loaded PCL/Chitosan/Fe 3 O 4 Core-Shell Nanofibers Structure: An Approach to Multi-Mode Anticancer System.
- Author
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Hadjianfar M, Semnani D, Varshosaz J, Mohammadi S, and Rezazadeh Tehrani SP
- Abstract
Purpose: 5-Fluorouracil (5FU) and Fe
3 O4 nanoparticles were encapsulated in core-shell polycaprolactone (PCL)/chitosan (CS) nanofibers as a multi-mode anticancer system to study drug release sustainability. The structure of the core-shell drug delivery system was also optimized according to drug release behavior by artificial intelligence. Methods: The core-shell nanofibers were electrospun by a coaxial syringe. Artificial neural network (ANN) was used for function approximation to estimate release parameters. A genetic algorithm was then used for optimizing the structure. Chemical assay of the optimized sample was performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). vibration sample magnetometer (VSM) test was conducted to measure the real amount of loaded magnetic nanoparticles. HepG2 cell cytotoxicity was studied and the results for the optimized samples with and without Fe3 O4 after 72 hours were reported. Results: Feeding ratio of sheath to core and the amount of CS, Fe3 O4 , and 5FU had a statistical effect on nanofibers diameters, which were 300-450 nm. The drug loading efficiency of these nanofibers was 65-86%. ANN estimated the release parameters with an error of 10%. The temperature increased about 5.6°C in the alternative magnetic field (AMF) of 216 kA.m-1 ~300 kHz and 4.8°C in the AMF of 154 kA.m-1 ~400 kHz after 20 minutes. HepG2 cell cytotoxicity for the optimized samples with and without Fe3 O4 after 72 hours were 39.7% and 38.8%, respectively. Conclusion: Since this core-shell drug release system was more sustainable compared to the blend structure despite the low half-life of 5FU, it is suggested to utilize it as post-surgical implants for various cancer treatments such as liver or colorectal cancer in the future. This system is capable of providing chemotherapy and hyperthermia simultaneously., (©2022 The Authors.)- Published
- 2022
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173. Improved performance of Bis-GMA dental composites reinforced with surface-modified PAN nanofibers.
- Author
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Amiri P, Talebi Z, Semnani D, Bagheri R, and Fashandi H
- Subjects
- Acrylic Resins, Compressive Strength, Elastic Modulus, Methacrylates, Polyethylene Glycols, Polymerization, Polymers chemistry, Polymethacrylic Acids, Polyurethanes chemistry, Powders, Stress, Mechanical, Surface Properties, Bisphenol A-Glycidyl Methacrylate chemistry, Composite Resins chemistry, Nanofibers chemistry
- Abstract
In the present work, polyacrylonitrile (PAN) nanofibers reinforced dental composites were investigated to achieve the improved interfacial adhesion between the PAN nanofiber and resin matrix using surface modification of nanofibers. PAN nanofibers mat were prepared by electrospinning and then, surface treated with the activated bisphenol A glycidyl methacrylate (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA) (50/50 mass ratio) dental resin followed by photo-curing. Also, the treated nanofibers mat was milled into a powder to achieve the uniform distribution of nanofibers in the matrix resin. The reinforced dental composite were prepared by mixing the various mass fraction of the powder (0.5-15 wt%) with the Bis-GMA/TEGDMA dental monomers. The effect of weight ratio of surface-modified nanofibers to blend resin on the chemical structure, morphology, compression and flexural properties, color and polymerization shrinkage of dental composites was evaluated. The results showed that using surface-treated nanofibers with content of 5 wt% enhanced the compression strength, flexural strength, flexural modulus and work of rupture of the resultant dental composite by factors of 23%, 7%, 80%, and 145%, respectively, comparing to the unreinforced neat resin. Also, the polymerization shrinkage reduces by 37%. These significant improved properties of the dental composite could be due to the semi-interpenetration network formation between surface-modified nanofibers and resin matrix and well distribution of nanofibers in the dental resin. Further increasing the nanofiber content led to poor mechanical properties of obtained dental composites. The results also, revealed that the color of resin composite could be whiter using modified PAN nanofibers as the filler.
- Published
- 2021
- Full Text
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174. Nanofibrous Tubular Membrane for Blood Hemodialysis.
- Author
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Mohammadi F, Valipouri A, Semnani D, and Alsahebfosoul F
- Subjects
- Creatinine blood, Creatinine isolation & purification, Creatinine urine, Dimethylformamide chemistry, Furans chemistry, Humans, Kidney Tubules metabolism, Microscopy, Electron, Scanning, Polymers chemistry, Sulfones chemistry, Urea blood, Urea isolation & purification, Urea urine, Membranes, Artificial, Nanofibers, Renal Dialysis instrumentation
- Abstract
As the most important components of a hemodialysis device, nanofibrous membranes enjoy high interconnected porosity and specific surface area as well as excellect permeability. In this study, a tubular nanofibrous membrane of polysulfone nanofibers was produced via electrospinning method to remove urea and creatinine from urine and blood serums of dialysis patients. Nanofibrous membranes were electrospun at a concentration of 11.5 wt% of polysulfone (PS) and dimethylformamide (DMF)/tetrahydrofuran (THF) with a ratio of 70/30. The effects of the rotational speed of collectors, electrospinning duration, and inner diameter of the tubular nanofibrous membrane on the urea and creatinine removal efficiency of the tubular membrane were investigated through the hemodialysis simulation experiments. It was found that the tubular membrane with an inner diameter of 3 mm elecrospun at shorter duration with lower collecting speed had the highest urea and creatinine removal efficiency. The hemodialysis simulation experiment showed that the urea and creatinine removal efficiency of the tubular membrane with a diameter of 3 mm were 90.4 and 100%, respectively. Also, three patients' blood serums were tested with the nanofibrous membrane. The results showed that the creatinine and urea removal rates were 93.2 and 90.3%, respectively.
- Published
- 2018
- Full Text
- View/download PDF
175. Artificial neural network for modeling the elastic modulus of electrospun polycaprolactone/gelatin scaffolds.
- Author
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Vatankhah E, Semnani D, Prabhakaran MP, Tadayon M, Razavi S, and Ramakrishna S
- Subjects
- Algorithms, Animals, Polymers chemistry, Regression Analysis, Sus scrofa, Elastic Modulus, Gelatin chemistry, Neural Networks, Computer, Polyesters chemistry, Tissue Engineering methods, Tissue Scaffolds chemistry
- Abstract
Scaffolds for tissue engineering (TE) require the consideration of multiple aspects, including polymeric composition and the structure and mechanical properties of the scaffolds, in order to mimic the native extracellular matrix of the tissue. Electrospun fibers are frequently utilized in TE due to their tunable physical, chemical, and mechanical properties and porosity. The mechanical properties of electrospun scaffolds made from specific polymers are highly dependent on the processing parameters, which can therefore be tuned for particular applications. Fiber diameter and orientation along with polymeric composition are the major factors that determine the elastic modulus of electrospun nano- and microfibers. Here we have developed a neural network model to investigate the simultaneous effects of composition, fiber diameter and fiber orientation of electrospun polycaprolactone/gelatin mats on the elastic modulus of the scaffolds under ambient and simulated physiological conditions. The model generated might assist bioengineers to fabricate electrospun scaffolds with defined fiber diameters, orientations and constituents, thereby replicating the mechanical properties of the native target tissue., (Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
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