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Efficient geometry of surface plasmon resonance based fiber optic sensor
, Article 2018 IEEE 38th International Conference on Electronics and Nanotechnology, ELNANO 2018 - Proceedings, 24 April 2018 through 26 April 2018 ; 2018 , Pages 351-354 ; 9781538663837 (ISBN) ; Ahmadi, M ; Mohammadpour, R ; Sasanpour, P ; Sharif University of Technology
Abstract
The efficient structure for optical fiber based surface Plasmon resonance sensor has been investigated. The sensor structure is based on removing the cladding of a multimode optical fiber and replacing it with thin film of gold. The incident light inside the fiber will excite surface plasmons which will be resulted in the absorption in specific wavelengths. The absorption behavior is dependent on the dielectric constants at the vicinity of the metallic thin film. Based on the amount of removed cladding and deposition regions on the core structure of the fiber, different configurations can be considered. Based on the computational analysis, we have studied performance of sensor for three...
Preparation of poly(vinyl chloride) (PVC) ultrafiltration membranes from PVC/additive/solvent and application of UF membranes as substrate for fabrication of reverse osmosis membranes
, Article Journal of Applied Polymer Science ; Volume 135, Issue 21 , 2018 ; 00218995 (ISSN) ; Asadollahi, M ; Musavi, A ; Bastani, D ; Sharif University of Technology
John Wiley and Sons Inc
2018
Abstract
Ultrafiltration (UF) membranes were prepared from poly(vinyl chloride) (PVC) as main polymer, poly(vinyl pyrrolidone) (PVP) as additive, and 1-methyl-2-pyrrolidone (NMP) as solvent using Design Expert software for designing the experiments. The membranes were characterized by SEM, contact angle measurement, and atomic force microscopy. The performance of UF membranes was evaluated by pure water flux (PWF) and blue indigo dye particle rejection. In addition, the molecular weight cutoff of UF membranes was determined by poly(ethylene glycol) (PEG) rejection. The UF membranes were used as substrates for fabrication of polyamide thin film composite (TFC) reverse osmosis (RO) membranes. The...
A liquid film motor
, Article Microfluidics and Nanofluidics ; Volume 6, Issue 5 , 2009 , Pages 711-715 ; 16134982 (ISSN) ; Shirsavar, R ; Hamedani Radja, N ; Ejtehadi, M. R ; Sharif University of Technology
2009
Abstract
It is well known that electro-hydrodynamical effects in freely suspended liquid films can force liquids to flow. Here, we report a purely electrically driven rotation in water and some other liquid suspended films with full control on the velocity and the chirality of the rotating vortices. The device, which is called "film motor", consists of a quasi two-dimensional electrolysis cell in an external in-plane electric field, crossing the mean electrolysis current density. If either the external field or the electrolysis voltage exceeds some threshold (while the other does not vanish), the liquid film begins to rotate. The device works perfectly with both DC and AC fields. © Springer-Verlag...
Effect of mineral fillers on the performance, rheological and dynamic viscosity measurements of asphalt mastic
, Article Construction and Building Materials ; Volume 222 , 2019 , Pages 390-399 ; 09500618 (ISSN) ; ur Rehman, Z ; Hassan Khan, A ; Qamar, S ; Niaz Akhtar, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
The principal objective involved in this research is to explore the mechanical behaviour of the binder using different mineral fillers such as stone dust (SD), brick dust (BD) and fly ash Class F (FA). Currently, a large quantity of roads is being constructed under the China-Pakistan Economic Corridor (CPEC) project. It is a major concern for quality of road to with stand heavy loads. For the investigation of the quality of roads, it is mandatory to evaluate the behaviour of mineral fillers addition in asphalt mastic. Fatigue cracking, thermal cracking and permanent deformation have been found a major common distress in the construction of road networks. In this study, the behaviour of...
A combined experimental and numerical study of the effect of surface roughness on nanoindentation
, Article International Journal of Applied Mechanics ; Volume 11, Issue 7 , 2019 ; 17588251 (ISSN) ; Chamani, M ; Baghani, M ; Sharif University of Technology
World Scientific Publishing Co. Pte Ltd
2019
Abstract
Gold and copper thin films are widely used in microelectromechanical system (MEMS) and nanoelectromechanical system (NEMS) devices. Nanoindentation has been developed in mechanical characterization of thin films in recent years. Several researchers have examined the effect of surface roughness on nanoindentation results. It is proved that the surface roughness has great importance in nanoindentation of thin films. In this paper, the surface topography of thin films is simulated using the extracted data from the atomic force microscopy (AFM) images. Nanoindentation on a rough surface is simulated using a three-dimensional finite-element model. The results are compared with the results of...
Hierarchical rutile/anatase TiO 2 nanorod/nanoflower thin film: Synthesis and characterizations
, Article Materials Science in Semiconductor Processing ; Volume 93 , 2019 , Pages 252-259 ; 13698001 (ISSN) ; Eslami Saed, A ; Sadrnezhaad, S. K ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Hierarchical TiO 2 nanorod/nanoflower thin film was synthesized on fluorine doped tin oxide glass via hydrothermal and aqueous chemistry methods. According to field emission scanning electron microscopy results, the thin film was crack-free and uniform. Primary nanorods had an average diameter of 95 nm and a length of 2 µm. They were perpendicular to the substrate owing to the TiO 2 prenucleation. Growth of the nanoflowers on the nanorods could increase both the specific surface area and roughness. X-ray diffraction and Raman spectroscopy showed that the nanorods were rutile; while the nanoflowers were anatase. Efficient electron transfer from anatase to rutile could therefore occur....
Tunable Stopband HTS Josephson Junction Left-Handed Transmission Line with Independently Biasable Unit Cells
, Article IEEE Transactions on Applied Superconductivity ; Volume 30, Issue 1 , 2020 ; Rejaei, B ; Fardmanesh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
A practical coplanar Josephson junction left-handed transmission line based on a step-edge junction technique is proposed in high-temperature superconductor technology and analyzed by electromagnetic simulations. The layout is designed for monolayer Yttrium Barium Copper Oxide thin film fabrication process. The propagation stopbands are tunable by controlling bias currents of Josephson junction arrays acting as parallel inductors for unit cells of the transmission line. Unlike the reported designs, each unit cell of our left-handed transmission line is independently biasable due to dc isolation of the unit cells along the transmission line. Being individually biasable is practically...
Facile deposition of porous fluorine doped tin oxide by Dr. Blade method for capacitive applications
, Article Ceramics International ; 2020 ; Tajabadi, F ; Dastan, D ; Sangpour, P ; Shi, Z ; Taghavinia, N ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Three-dimensional macroporous fluorine-doped tin oxide (p-FTO) films were successfully deposited using commercial ink of FTO powder and SnCl2 salt via Dr. Blade method. Various features of p-FTO thin films were studied as a function of the ink composition and sintering temperature. The morphological studies corroborated formation of porous, uniform, and crack-free FTO films after annealing at 300 °C for 10 min in air. X-ray diffraction pattern demonstrated development of highly crystalline FTO films. The lowest sheet resistance of 47 Ω/□ was obtained for the p-FTO film with a thickness of 21 μm. The capacitance of thin p-FTO films was investigated using a three-electrode system and the...
Biphasic TiO2 nanoleafed nanorod electrode for dye-sensitized solar cell
, Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 123 , 2020 ; Sadrnezhaad, S. K ; Sharif University of Technology
Elsevier B.V
2020
Abstract
The thin-film of hierarchical rutile/anatase TiO2 nanorod/nanoleafs on fluorine-doped tin oxide glass was prepared via a facile method. For this purpose, the hydrothermal method was used for the synthesis of rutile-phase nanorods on the TiO2 seeded FTO, and aqueous chemistry was applied for growing anatase-phase nanoleafs on the nanorods. The structural, morphological, and optical properties of coating characterized, and the thin-film utilized as the photoelectrode for dye-sensitized solar cell. The energy conversion efficiency of the newly developed nanostructure was higher than that of TiO2 nanorod thin-film by 40%. This increase could be ascribed to: (1) superior specific surface area...
Study on spray-pyrolyzed In2S3 thin films, targeted as electron transport layer in solar energy
, Article Journal of Photonics for Energy ; Volume 10, Issue 2 , 2020 ; Heidariramsheh, M ; Ghorashi, S. M. B ; Taghavinia, N ; Mahdavi, S. M ; Sharif University of Technology
SPIE
2020
Abstract
Efficient electron transport layers (ETLs) play a pivotal role in the performance of solar cells. In recent years, Indium sulfide (In2S3) has been studied as a promising ETL in CuInGaS(e)2, Cu2ZnSnS(e)4, and perovskite solar cells. Despite several studies on spray-deposited In2S3, there is no complete experimental investigation on In2S3 thin films. The effect of the molar ratio of S/In and the type of indium precursor on the structural, morphological, optical, and electrical properties of sprayed-In2S3 layers has been studied. Films were characterized using x-ray diffraction, scanning electron microscopy (SEM), optical transmission (UV-Vis), Mott-Schottky analysis, four-point probe, and...
Pure sulfide Cu2ZnSnS4 layers through a one-step low-temperature PLD technique: Insight into simulation on modified back contact to overcome the barrier of MoS2
, Article Materials Science and Engineering B: Solid-State Materials for Advanced Technology ; Volume 262 , 2020 ; Haghighi, M ; Dabbagh, M. M ; Mahdavi, S. M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Targeting on the selenium free, pure sulfide kesterite compound (CZTS) allows retention of the higher band gap nontoxic absorber for a single-junction solar cell. In this work, CZTS thin films were deposited by the PLD method and the Structural/optical properties, as well as Mott–Schottky analysis, were studied at different substrate temperatures. Without undergoing the sulfurization process, the single-phase CZTS thin film is prepared at 300 ℃. In the second step, a numerical simulation is performed using the solar cell capacitance simulator to study the effect of the grading layer of MoS(Se)2 on the rear side of pure sulfide kesterite based solar cells. The device with a MoSe2 coated...
One-pot microwave synthesis of hierarchical C-doped CuO dandelions/g-C3N4 nanocomposite with enhanced photostability for photoelectrochemical water splitting
, Article Applied Surface Science ; Volume 530 , 2020 ; Siavash Moakhar, R ; Soleimani, F ; Sadrnezhaad, S. K ; Masudy Panah, S ; Katal, R ; Seza, A ; Ghane, N ; Ramakrishna, S ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Cupric oxide (CuO) is a semiconductor of choice for photocathode in photoelectrochemical (PEC) applications due to its great sunlight absorption capability. However, photocorrosion is the main drawback of CuO. Herein, CuO/graphitic carbon nitride (g-C3N4) with a unique microstructure, enhanced PEC performance, and considerable photostability is synthesized under microwave irradiation. A facile, one-pot method is utilized to directly deposit the nanocomposite onto fluorine-doped tin oxide from a solution containing copper precursor and urea. Possible mechanism of CuO/g-C3N4 formation through this novel method is investigated. It is elucidated that controlled amounts of urea critically...
Anti-reflection and self-cleaning meso-porous TiO2 coatings as solar systems protective layer: Investigation of effect of porosity and roughness
, Article Optical Materials ; Volume 107 , 2020 ; Afshar, A ; Azadeh, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Anti-reflection and self-cleaning coatings on the glass substrate are used to improve the performance of solar systems. TiO2 are one of the most used semiconductors for this application. In this research meso-porous TiO2 coatings (that synthesized by the sol-gel process) with the various extent of porosity (using different concentrations of Pluronic F127, as pore-forming agent) have been investigated. The coating's thickness and porosity and anti-reflective properties were studied by FE-SEM and UV/VIS spectrometer (transmission spectra test), respectively. It was found that the use of F127 leads to the formation of pores smaller than 30 nm and increases the surface roughness from 1.5 (for...
Effect of photoelectrochemical activity of ZnO-graphene thin film on the corrosion of carbon steel and 304 stainless steel
, Article Journal of Materials Engineering and Performance ; Volume 29, Issue 1 , 2020 , Pages 497-505 ; Bahadormanesh, B ; Ghorbani, M ; Simchi, A ; Sharif University of Technology
Springer
2020
Abstract
In this research, the ZnOG hybrid thin film was produced via solgel method. The surface morphology, band gap and photoactive properties of the films were studied by means of SEM, UV–Vis and photoluminescence analysis. In addition, the ability of the thin film in photocathodic protection of carbon steel (CS) and 304 stainless steel in 3.5 wt.% NaCl and Na2S solutions under dark and UV illumination was investigated by polarization test as well as OCP and current measurements during coupling of steels with ZnOG photoanode. The mix band gap is reduced to the orders of 1.17 eV through hybridization of ZnO with graphene oxide. In both NaCl and Na2S solutions, the ZnOG thin film could effectively...
Modeling of magnetic shape memory alloy plates for pressure sensor application
, Article Journal of Intelligent Material Systems and Structures ; 2020 ; Naderi, H ; Sharif University of Technology
SAGE Publications Ltd
2020
Abstract
This article investigates the basis for pressure sensor application based on the magnetic shape memory effect in membranes. Von Karmans nonlinear terms are considered in strain–displacement relationships of thin films, and a new method is presented for solution of large deflections of thin films with arbitrary boundary condition. In this study, the equations of motion of magnetic shape memory alloys are extended. In pressurized membranes, the complex distribution of mechanical stress can cause the martensitic reorientation, which is the underlying mechanism for sensing applications in magnetic shape memory alloys. To examine the obtained model, the governing equations of magnetic shape...
Optical properties, microstructure, and multifractal analyses of ZnS thin films obtained by RF magnetron sputtering
, Article Journal of Materials Science: Materials in Electronics ; Volume 31, Issue 7 , 2020 , Pages 5262-5273 ; Arman, A ; Ţălu, Ş ; Ghosh, K ; Rezaee, S ; Luna, C ; Mwema, F ; Sherafat, K ; Salehi, M ; Mardani, M ; Sharif University of Technology
Springer
2020
Abstract
The morphology, structure and optical properties of zinc sulfide (ZnS) thin films prepared through radio-frequency (RF) magnetron sputtering have been analyzed using atomic force microscopy (AFM), UV–Vis–NIR spectrophotometry, X-ray diffraction, and multifractal analyses. The X-ray diffraction patterns revealed that all ZnS thin films show a single peak at around 29.6°, which has been ascribed to the (111) planes of sphalerite phase, indicating that the growth direction of the films is the [111] direction. UV–Vis–NIR transmittance spectra were used to determine the refractive index of the samples, their thickness, and their band gap energy, showing the optical and semiconductor properties a...
Optical properties and morphology analysis of hexagonal WO3 thin films obtained by electron beam evaporation
, Article Journal of Materials Science: Materials in Electronics ; 2020 ; Arman, A ; Rezaee, S ; Korpi, A. G ; Kulesza, S ; Luna, C ; Bramowicz, M ; Mardani, M ; Sharif University of Technology
Springer
2020
Abstract
WO3 films with thicknesses between 550 and 853 nm were deposited on glass substrates using the electron beam evaporation method at room temperature. The microstructures and surface roughness of the films were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). It was observed that the crystalline structure of the WO3 thin films significantly changes from the amorphous to crystalline states with a crystalline texture, and the mosaicity and grain size dependent on the film thickness. The transmittance spectra of the obtained WO3 films were measured in the range from 340 to 850 nm, and the Swanepoel method was used to determine the refractive indices and the thicknesses of the...
XPS study of the Cu@Cu 2 O core-shell nanoparticles
, Article Applied Surface Science ; Volume 255, Issue 5 PART 2 , 2008 , Pages 2730-2734 ; 01694332 (ISSN) ; Vesaghi, M. A ; Shafiekhani, A ; Baghizadeh, A ; Lameii, M ; Sharif University of Technology
Elsevier
2008
Abstract
Cu@Cu 2 O core-shell nanoparticles on the a-C:H thin films are prepared by co-deposition of RF-Sputtering and RF-PECVD. The samples with different Cu concentration and Cu nanoparticle with different size are grown. X-ray photoelectron spectroscopy (XPS) characterization indicates that the surface of the Cu nanoparticles oxidizes when they are exposed to air. The results are indicative that the shell of nanoparticle is mainly Cu 2 O phase with CuO cover thin layer. Surface plasmon resonance (SPR) peak that is signature of the existence of the Cu core nanoparticles appears in visible spectra of these films. Several interesting information are obtained from XPS study of these core-shells...
Influence of secondary oxide phases on microstructural and gas sensitive properties of nanostructured titanium dioxide thin films
, Article Multi-functional Materials and Structures - International Conference on Multifunctional Materials and Structures, Hong Kong, P.R., 28 July 2008 through 31 July 2008 ; Volume 47-50 PART 1 , 2008 , Pages 41-44 ; 10226680 (ISSN); 0878493786 (ISBN); 9780878493784 (ISBN) ; Ghorbani, M ; Fray, D. J ; Sharif University of Technology
Trans Tech Publications
2008
Abstract
A systematic comparison of single and binary metal oxide T1O2, TiO2-Ga2O3, TiO2-Er 2O3 and TiO2-Ta2O5 gas sensors with nanocrystalline and mesoporous microstructure, prepared by sol-gel route, was conducted. The gas sensitivity was increased by secondary phase introduction into TiO2 film via two mechanisms, firstly through the inhibition of anatase-to-rutile transformation, since the anatase phase accommodates larger amounts of adsorbed oxygen, and secondly through the retardation of grain growth, since the higher surface area provides more active sites for gas molecule adsorption. The binary metal oxides exhibited a remarkable response towards low concentrations of CO and NO2 gases at low...
Fabrication of high conductivity TiO2/Ag fibrous electrode by the electrophoretic deposition method
, Article Journal of Physical Chemistry C ; Volume 112, Issue 47 , 2008 , Pages 18686-18689 ; 19327447 (ISSN) ; Taghavinia, N ; Sharifi, N ; Chavoshi, M ; Rahman, M ; Sharif University of Technology
2008
Abstract
TiO2 deposited on a membrane of Ag fibers was prepared as a photoelectrochemical cell electrode. Ag fibers were made by reduction of Ag complexes on cellulose fibers, followed by burning out the template. TiO 2 photocatalyst layers were grown on the fibers by electrophoretic deposition of TiO2 nanoparticles. Ag fibers could be uniformly deposited. Photocatalytic tests by dye decomposition and electrochemical impedance spectroscopy (EIS) under UV illumination demonstrate that Ag fibers act as a good substrate that provides both high surface area and good separation of photogenerated electron-hole pairs and causes the enhancement of photocatalytic activity in comparison with a thin film of...