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Nano-crystalline growth of electrochemically deposited apatite coating on pure titanium
, Article Journal of Electroanalytical Chemistry ; Volume 589, Issue 1 , 2006 , Pages 96-105 ; 15726657 (ISSN) ; Afshar, A ; Yang, X ; Li, X ; Yang, B ; Wu, Y ; Chen, J ; Zhang, X ; Sharif University of Technology
Elsevier
2006
Abstract
Hydroxyapatite (HA) coatings were deposited on commercially pure titanium plates using a hydrothermal-electrochemical deposition method in an electrolyte containing calcium and phosphate ions. The deposition conditions used in this study were the followings: electrolyte temperature (33-80 °C), current density (1-8 mA/cm2), and deposition time (10-120 min). Needle-like and granular crystals of apatite coating were created with different concentrations of calcium (0.0021-0.042 M) and phosphate (0.00125-0.025 M) salts. The size of HA crystals of the coating was considerably changed with different concentration of calcium and phosphate salts, temperature of the electrolyte, and deposition time....
Comparative study on the microstructures and properties of wire+arc additively manufactured 5356 aluminium alloy with argon and nitrogen as the shielding gas
, Article Additive Manufacturing ; Volume 34 , August , 2020 ; Zhang, L. J ; Ning, J ; Wang, X ; Zhang, G. F ; Zhang, J. X ; Na, S. J ; Fatemeh, B ; Sharif University of Technology
Elsevier B. V
2020
Abstract
This research explored the influences of shielding gases on the appearance of weld beads and the microstructures and mechanical properties of thin-wall samples using conventional gas metal arc welding as the heat source by using 5356 aluminium alloy welding wire as the raw materials and nitrogen (N2) and argon (Ar) as the shielding gases. The results showed that under the same parameters and after mono-layer single-bead welding was performed using N2 as the shielding gas, the bead height was higher, the bead width was narrower, and the penetration depth was shallower. The grain size of the thin-wall sample protected by N2 was 43.5–47.8 % smaller than that obtained under Ar protection....
Electrophoretic deposition of porous hydroxyapatite coatings using polytetrafluoroethylene particles as templates
, Article Materials Science and Engineering C ; Volume 27, Issue 5-8 SPEC. ISS , 2007 , Pages 1482-1486 ; 09284931 (ISSN) ; Afshar, A ; Chen, J ; Zhang, X ; Sharif University of Technology
2007
Abstract
The formation of macroporous bioactive hydroxyapatite(HA) coatings using polytetrafluoroethylene(PTFE) particles were studied. The porous HA coatings were prepared onto a pure titanium substrate by electrophoretic deposition(EPD) at 120 V for 1.5 min using ethanol suspensions mixture of HA (500 nm in size) and PTFE (1-3 μm in size) particles. Subsequently, the composite coatings obtained by EPD were heated at 900 °C for 60 min to disintegrate the organic PTFE particles and sinter the inorganic HA particles. The calcinations of the PTFE led to the formation of porosity in the HA coating. These results demonstrate a new method for creating porous HA coatings on titanium. © 2006 Elsevier B.V....
Bioactive layer formation on alkaline-acid treated titanium in simulated body fluid
, Article Materials and Design ; Volume 28, Issue 7 , 2007 , Pages 2154-2159 ; 02613069 (ISSN) ; Afshar, A ; Chen, J ; Zhang, X ; Sharif University of Technology
Elsevier Ltd
2007
Abstract
Porous surface on titanium induces apatite formation in simulated body fluid (SBF). This work shows alkaline, acid and polishing treatment, which lead to create apatite coating. Specimens were soaked in 5 M solution of NaOH, 85% HCl-6% HF-9% H3PO4 and 2% HF-4% HNO3-94% H2O. Also many samples were polished with sandpaper. Specimens treated under the above conditions were soaked in simulated body fluid (SBF) for 5 days. Apatite formed within 5 days. The evaluation of Ca/P ratio of samples were made by EDAX analysis to get information of the Ca/P ratio. The values obtained for the apatite were in the range of 1.55, which is near to the stoichiometric value of apatite, for the sample, which was...
N-Type conductive small molecule assisted 23.5% efficient inverted perovskite solar cells
, Article Advanced Energy Materials ; Volume 12, Issue 34 , 2022 ; 16146832 (ISSN) ; Li, Y ; Zhang, Y ; Zhao, J ; Wang, T ; Yang, B ; Pu, X ; Yang, J ; Chen, H ; Chen, X ; Li, X ; Ghasemi, S ; Salari, H ; Hagfeldt, A ; Li, X ; Sharif University of Technology
John Wiley and Sons Inc
2022
Abstract
Because of the compatibility with tandem devices and the ability to be manufactured at low temperatures, inverted perovskite solar cells have generated far-ranging interest for potential commercial applications. However, their efficiency remains inadequate owing to various traps in the perovskite film and the restricted hole blocking ability of the electron transport layer. Thus, in this work, a wide-bandgap n-type semiconductor, 4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-phenylpyrimidine (B4PyPPM), to modify a perovskite film via an anti-solvent method is introduced. The nitrogen sites of pyrimidine and pyridine rings in B4PyPPM exhibit strong interactions with the undercoordinated lead ions in...
Ultrafine Co nanoislands grafted on tailored interpenetrating N-doped carbon nanoleaves: An efficient bifunctional electrocatalyst for rechargeable Zn-air batteries
, Article Chemical Engineering Journal ; Volume 431 , 2022 ; 13858947 (ISSN) ; Chen, L ; Yang, H ; Zhang, Y ; Peng, Y ; Luo, X ; Ahmad, A ; Ramzan, N ; Xu, Y ; Shi, Y ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Zeolitic imidazole frameworks (ZIFs) provide an exciting platform to design and fabricate non-precious-metal carbon-based catalysts for oxygen reduction/evolution reaction (ORR/OER). Herein, we elaborately design a facile enzyme-assisted synthetic strategy that enables to tailor the ZIFs precursors into structural stable decussation shape, which derived Co nanoislands grafted on decussate N-doped carbon nanoleaves (D-Co@NC) can well retain the interpenetrating nanostructure. Benefiting from the combined advantages of compositions and interpenetrating nanostructures, D-Co@NC possesses 5.2 times higher exposed electrochemical active area than the conventional dodecahedral one, thus endowing...
An intelligent ACO-SA approach for short term electricity load prediction
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 18 August 2010 through 21 August 2010 ; Volume 6216 LNAI , 2010 , Pages 623-633 ; 03029743 (ISSN) ; 9783642149313 (ISBN) ; Hadavandi, E ; Abbasian Naghneh, S ; Huang D. S ; Zhang X ; Sharif University of Technology
2010
Abstract
Intelligent solutions, based on artificial intelligence (AI) technologies, to solve complicated practical problems in various sectors are becoming more and more widespread nowadays. On the other hand, electrical load prediction is one of the important concerns of power systems so development of intelligent prediction tools for performing accurate predictions is essential. This study presents an intelligent hybrid approach called ACO-SA by hybridization of Ant Colony Optimization (ACO) and Simulated Annealing (SA). The hybrid approach consists of two general stages. At the first stage time series inputs will be fed into ACO and it performs a global search to find a globally optimum solution....
Overcome low intrinsic conductivity of Niox through triazinyl modification for highly efficient and stable inverted perovskite solar cells
, Article Solar RRL ; Volume 6, Issue 9 , 2022 ; 2367198X (ISSN) ; Wang, T ; Li, Y ; Pu, X ; Chen, H ; Li, Y ; Yang, B ; Zhang, Y ; Zhao, J ; Cao, Q ; Chen, X ; Ghasemi, S ; Hagfeldt, A ; Li, X ; Sharif University of Technology
John Wiley and Sons Inc
2022
Abstract
Nickel oxide (NiOx) is a promising hole transport material in inverted organic-inorganic metal halide perovskite solar cells. However, its low intrinsic conductivity hinders its further improvement in device performance. Here, we employ a trimercapto-s-triazine trisodium salt (TTTS) as a chelating agent of Ni2+ in the NiOx layer to improve its conductivity. Due to the electron-deficient triazine ring, the TTTS complexes with Ni2+ in NiOx via a strong Ni2+-N coordination bond and increases the ratio of Ni3+:Ni2+. The increased Ni3+ concentration adjusts the band structure of NiOx, thus enhancing hole density and mobility, eventually improving the intrinsic conductivity of NiOx. As a result,...
Homozygous mutations in C14orf39/SIX6OS1 cause non-obstructive azoospermia and premature ovarian insufficiency in humans
, Article American Journal of Human Genetics ; Volume 108, Issue 2 , 2021 , Pages 324-336 ; 00029297 (ISSN) ; Jiao, Y ; Khan, R ; Jiang, X ; Javed, A. R ; Ali, A ; Zhang, H ; Zhou, J ; Naeem, M ; Murtaza, G ; Li, Y ; Yang, G ; Zaman, Q ; Zubair, M ; Guan, H ; Zhang, X ; Ma, H ; Jiang, H ; Ali, H ; Dil, S ; Shah, W ; Ahmad, N ; Zhang, Y ; Shi, Q ; Sharif University of Technology
Cell Press
2021
Abstract
Human infertility is a multifactorial disease that affects 8%–12% of reproductive-aged couples worldwide. However, the genetic causes of human infertility are still poorly understood. Synaptonemal complex (SC) is a conserved tripartite structure that holds homologous chromosomes together and plays an indispensable role in the meiotic progression. Here, we identified three homozygous mutations in the SC coding gene C14orf39/SIX6OS1 in infertile individuals from different ethnic populations by whole-exome sequencing (WES). These mutations include a frameshift mutation (c.204_205del [p.His68Glnfs∗2]) from a consanguineous Pakistani family with two males suffering from non-obstructive...
Combined effects of electric stimulation and microgrooves in cardiac tissue-on-a-chip for drug screening
, Article Small Methods ; Volume 4, Issue 10 , 2020 ; Zhou, X ; Nasiri, R ; Fang, J ; Jiang, X ; Wang, C ; Qu, M ; Ling, H ; Chen, Y ; Xue, Y ; Hartel, M.C ; Tebon, P ; Zhang, S ; Kim, H.-J ; Yuan, X ; Shamloo, A ; Dokmeci, M. R ; Li, S ; Khademhosseini, A ; Ahadian, S ; Sun, W ; Sharif University of Technology
John Wiley and Sons Inc
2020
Abstract
Animal models and traditional cell cultures are essential tools for drug development. However, these platforms can show striking discrepancies in efficacy and side effects when compared to human trials. These differences can lengthen the drug development process and even lead to drug withdrawal from the market. The establishment of preclinical drug screening platforms that have higher relevancy to physiological conditions is desirable to facilitate drug development. Here, a heart-on-a-chip platform, incorporating microgrooves and electrical pulse stimulations to recapitulate the well-aligned structure and synchronous beating of cardiomyocytes (CMs) for drug screening, is reported. Each chip...
Unexpected optical limiting properties from MoS2 nanosheets modified by a semiconductive polymer
,
Article
Chemical Communications
;
Volume 51, Issue 61
,
Jun
,
2015
,
Pages 12262-12265
;
13597345 (ISSN)
; Chang, M. J
; Wang, Q
; Zhu, Z. T
; Zhai, X. P
; Zirak, M
; Moshfegh, A. Z
; Song, Y. L
; Zhang, H. L
;
Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
Direct solvent exfoliation of bulk MoS2 with the assistance of poly(3-hexylthiophene) (P3HT) produces a novel two-dimensional organic/inorganic semiconductor hetero-junction. The obtained P3HT-MoS2 nanohybrid exhibits unexpected optical limiting properties in contrast to the saturated absorption behavior of both P3HT and MoS2 , showing potential in future photoelectric applications
Application of soft computing models in streamflow forecasting
, Article Proceedings of the Institution of Civil Engineers: Water Management ; Volume 172, Issue 3 , 2019 , Pages 123-134 ; 17417589 (ISSN) ; Yuan, X ; Kisi, O ; Yuan, Y ; Tayyab, M ; Lei, X ; Sharif University of Technology
ICE Publishing
2019
Abstract
The accuracy of five soft computing techniques was assessed for the prediction of monthly streamflow of the Gilgit river basin by a cross-validation method. The five techniques assessed were the feed-forward neural network (FFNN), the radial basis neural network (RBNN), the generalised regression neural network (GRNN), the adaptive neuro fuzzy inference system with grid partition (Anfis-GP) and the adaptive neuro fuzzy inference system with subtractive clustering (Anfis-SC). The interaction between temperature and streamflow was considered in the study. Two statistical indexes, mean square error (MSE) and coefficient of determination (R2), were used to evaluate the performances of the...
Machining precedence of 21/2D interacting features in a feature-based data model
, Article Journal of Intelligent Manufacturing ; Volume 22, Issue 2 , 2011 , Pages 145-161 ; 09565515 (ISSN) ; Xu, X ; Sharif University of Technology
2011
Abstract
In process planning, determining feature's machining precedence is an essential step. The task becomes more difficult if features interact with each other, in which case the feature precedence information may suggest multiple machining sequences of the features. This paper considers interacting features in a feature-based model for process planning tasks. For each feature, precedence information is generated considering both roughing and finishing operations. A rule-based system is developed and implemented based on the information about machining precedence of the interacting features. The STEP-NC data model is used as the underlying data model. This model is object-oriented and compliant...
Robust D-stability test of LTI general fractional order control systems
, Article IEEE/CAA Journal of Automatica Sinica ; Volume 7, Issue 3 , May , 2020 , Pages 853-864 ; Liu, X ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
This work deals with the robust D-stability test of linear time-invariant ( LTI ) general fractional order control systems in a closed loop where the system and - or the controller may be of fractional order. The concept of general implies that the characteristic equation of the LTI closed loop control system may be of both commensurate and non-commensurate orders, both the coefficients and the orders of the characteristic equation may be nonlinear functions of uncertain parameters, and the coefficients may be complex numbers. Some new specific areas for the roots of the characteristic equation are found so that they reduce the computational burden of testing the robust D-stability. Based on...
Fast algorithm for k-truss discovery on public-private graphs
, Article 28th International Joint Conference on Artificial Intelligence, IJCAI 2019, 10 August 2019 through 16 August 2019 ; Volume 2019-August , 2019 , Pages 2258-2264 ; 10450823 (ISSN); 9780999241141 (ISBN) ; Huang, X ; Sharif University of Technology
International Joint Conferences on Artificial Intelligence
2019
Abstract
In public-private graphs, users share one public graph and have their own private graphs. A private graph consists of personal private contacts that only can be visible to its owner, e.g., hidden friend lists on Facebook and secret following on Sina Weibo. However, existing public-private analytic algorithms have not yet investigated the dense subgraph discovery of k-truss, where each edge is contained in at least k − 2 triangles. This paper aims at finding k-truss efficiently in public-private graphs. The core of our solution is a novel algorithm to update k-truss with node insertions. We develop a classification-based hybrid strategy of node insertions and edge insertions to incrementally...
Group 6 transition metal dichalcogenide nanomaterials: synthesis, applications and future perspectives
, Article Nanoscale Horizons ; Volume 3, Issue 2 , 2018 , Pages 90-204 ; 20556756 (ISSN) ; Sarikhani, N ; Zirak, M ; Zhang, H ; Zhang, H. L ; Zaker Moshfegh, A. R ; Sharif University of Technology
Royal Society of Chemistry
2018
Abstract
Group 6 transition metal dichalcogenides (G6-TMDs), most notably MoS2, MoSe2, MoTe2, WS2 and WSe2, constitute an important class of materials with a layered crystal structure. Various types of G6-TMD nanomaterials, such as nanosheets, nanotubes and quantum dot nano-objects and flower-like nanostructures, have been synthesized. High thermodynamic stability under ambient conditions, even in atomically thin form, made nanosheets of these inorganic semiconductors a valuable asset in the existing library of two-dimensional (2D) materials, along with the well-known semimetallic graphene and insulating hexagonal boron nitride. G6-TMDs generally possess an appropriate bandgap (1-2 eV) which is...
Comparison between single, dual and triple rapid serial visual presentation paradigms for P300 speller
, Article Proceedings - 2018 IEEE International Conference on Bioinformatics and Biomedicine, BIBM 2018, 3 December 2018 through 6 December 2018 ; 2019 , Pages 2635-2638 ; 9781538654880 (ISBN) ; Shamsollahi, M. B ; Sheikh Hassani, M ; Jalilpour, S ; Schmidt H ; Griol D ; Wang H ; Baumbach J ; Zheng H ; Callejas Z ; Hu X ; Dickerson J ; Zhang L ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
P300 based Speller systems are a typical application of BCIs that can be used as a communication device for users with spinal cord injury. In this paper, three different RSVP paradigms; single, dual and triple RSVP are compared in terms of character detection accuracy and ITR to find the optimal communication method for these users. Three subjects were tested to compare these methods in offline mode. The results of this comparison shows that character detection accuracy for the single, dual and triple RSVP paradigms are 0.78, 0.63 and 0.64, respectively. The mean of ITR for the single, dual and triple RSVP paradigms was also recorded to be 3.6534, 7.72 and 11.5 bit/min, respectively....
NSSSD: A new semantic hierarchical storage for sensor data
, Article 20th IEEE International Conference on Computer Supported Cooperative Work in Design, 4 May 2016 through 6 May 2016 ; 2016 , Pages 174-179 ; 9781509019151 (ISBN) ; Movassagh, A. A ; Qin, Y ; Yong, J ; Tao, X ; Zhang, J ; Shen, H ; Liu, X. P ; Yong, J ; Barthes, J. P ; Shen, W ; Yang, C ; Luo, J ; Chen, L ; IEEE Systems, Man, and Cybernetics Society; International Working Group on Computer Supported Cooperative Work in Design (CSCWD) ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
Sensor networks usually generate mass of data, which if not structured for future applications, will require much effort on analytical processing and interpretations. Thus, storing sensor data in an effective and structured format is a key issue in the area of sensor networks. In the meantime, even a little improvement on data storing structure may lead to a significant effect on the lifetime and performance of the sensor network. This paper describes a new method for sensor storage that combines semantic web concepts, a data aggregation method along with aligning sensors in hierarchical form. This solution is able to reduce the amount of data stored at the sink nodes significantly. At the...
Two-level distributed demand-side management using the smart energy hub concept
, Article 10th International Conference on Applied Energy, ICAE 2018, 22 August 2018 through 25 August 2018 ; Volume 158 , 2019 , Pages 3052-3063 ; 18766102 (ISSN) ; Sheykhha, S ; Azimi, M. R ; Madlener, R ; Yang H. X ; Li H ; Chen X ; Yan J ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Demand-side management (DSM) and the integration of the energy hub concept as a main part of future energy networks play an essential role in the process of improving the efficiency and reliability of the power grids. In this paper, we consider a smart multi-carrier energy system in which users are equipped with energy storage and conversion devices (i.e., an energy hub). Users intend to reduce their energy payment by shifting energy consumption to off-peak hours and switching between different energy carriers. This system enables both users with shiftable loads and must-run loads to be active in a DSM program. We apply game theory to formulate the energy consumption and conversion for a...
Optimizing dynamical network structure for pinning control
, Article Scientific Reports ; Volume 6 , 2016 ; 20452322 (ISSN) ; Jalili, M ; Yu, X ; Sharif University of Technology
Nature Publishing Group
2016
Abstract
Controlling dynamics of a network from any initial state to a final desired state has many applications in different disciplines from engineering to biology and social sciences. In this work, we optimize the network structure for pinning control. The problem is formulated as four optimization tasks: i) optimizing the locations of driver nodes, ii) optimizing the feedback gains, iii) optimizing simultaneously the locations of driver nodes and feedback gains, and iv) optimizing the connection weights. A newly developed population-based optimization technique (cat swarm optimization) is used as the optimization method. In order to verify the methods, we use both real-world networks, and model...