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    Metal organic framework nanoparticles loaded- PVDF/chitosan nanofibrous ultrafiltration membranes for the removal of BSA protein and Cr(VI) ions

    , Article Journal of Molecular Liquids ; Volume 317 , 2020 Pishnamazi, M ; Koushkbaghi, S ; Hosseini, S. S ; Darabi, M ; Yousefi, A ; Irani, M ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    The UiO-66 NH2 and ZIF-8 metal organic framework nanoparticles (NMOFs) were incorporated into the polyvinylidene fluoride (PVDF) nanofibrous membrane. Then, the chitosan nanofibers were coated on the PVDF nanofibers to produce the PVDF/chitosan nanofibers. The performance of synthesized PVDF/NMOFs single layer and PVDF/chitosan/NMOFs two layers nanofibrous membranes was investigated for BSA protein molecules and Cr(VI) ions separation via ultrafiltration membrane process. The potential of synthesized nanofibers was also examined for BSA and Cr(VI) adsorption in a batch system. The characteristics of synthesized nanofibrous membranes were determined using SEM, EDX, TGA, BET, porosity and... 

    Friction reduction in grafted carbon nanochannels by applying an electric field

    , Article Computational Materials Science ; Volume 213 , 2022 ; 09270256 (ISSN) Saleki, O ; Moosavi, A ; Hannani, S. K ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Water can be pumped in nanochannels by limiting it between the surfaces with different hydrophobicities and exerting a spinning electric field. The asymmetrical hydrophobicity combined with the spinning electric field and the fact that the water molecules have a dipole moment create a situation in which the angular momentum of water molecules is transformed into a linear momentum and the water is pumped into the nanochannel. The hydrophobicity of the surfaces can be manipulated by using nanostructures to reduce friction. In this study, two types of nanostructures have been used which are hierarchical nanostructures and polymer nanostructures made of Poly(N-isopropylacrylamide). The walls of... 

    Self-Powered humidity sensors based on sns2nanosheets

    , Article ACS Applied Nano Materials ; Volume 5, Issue 11 , 2022 , Pages 17123-17132 ; 25740970 (ISSN) Shooshtari, L ; Rafiefard, N ; Barzegar, M ; Fardindoost, S ; Irajizad, A ; Mohammadpour, R ; Sharif University of Technology
    American Chemical Society  2022
    Abstract
    With the advent of the Internet of Things (IoT), the development of self-powered sensors has received much attention. Introducing triboelectric nanogenerators (TENGs) as a power source that converts mechanical movement into electrical signals has been admired recently. Moreover, the monitoring of humidity has become enormously essential in several technological contexts from environment monitoring to biomedical applications, thus joining these two subjects provides a huge benefit in achieving self-powered humidity sensors. Here, in this research, facile, low-priced and self-powered humidity sensors are fabricated utilizing transition-metal dichalcogenides (TMD) nanosheets. Semi-vertical SnS2... 

    Thermodynamic modeling of hydrogen sulfide solubility in ionic liquids using modified SAFT-VR and PC-SAFT equations of state

    , Article Fluid Phase Equilibria ; Volume 309, Issue 2 , 2011 , Pages 179-189 ; 03783812 (ISSN) Rahmati Rostami, M ; Behzadi, B ; Ghotbi, C ; Sharif University of Technology
    2011
    Abstract
    Equations of state based on the statistical associating fluid theory for potentials of variable range (SAFT-VR) and the perturbed chain statistical associating fluid theory (PC-SAFT) have been used to model the PVT behavior of ionic liquids and the solubility of H2S in six imidazolium-based ionic liquids. The studied systems included [bmim][PF6], [hmim][PF6], [bmim][BF4], [hmim][BF4], [bmim][NTF2] and [hmim][NTF2] at various temperatures and pressures.For pure components, parameters of the models have been obtained by fitting the models to experimental data on liquid densities; the average relative deviation between the calculated and experimental densities for ionic liquids is less than... 

    Personalised deposition maps for micro- and nanoparticles targeting an atherosclerotic plaque: attributions to the receptor-mediated adsorption on the inflamed endothelial cells

    , Article Biomechanics and Modeling in Mechanobiology ; Volume 18, Issue 3 , 2019 , Pages 813-828 ; 16177959 (ISSN) Shamloo, A ; Forouzandehmehr, M ; Sharif University of Technology
    Springer Verlag  2019
    Abstract
    Endothelial inflammation as a prominent precursor to atherosclerosis elicits a distinct pathological surface expression of particular vascular proteins. To exhibit a site-specific behaviour, micro- and nanoparticles, as carriers of therapeutics or imaging agents, can distinguish and use these proteins as targeted docking sites. Here, a computational patient-specific model capturing the exclusive luminal qualities has been developed to study the transport and adsorption of particles decorated with proper antibodies over an atherosclerotic plaque located in the LAD artery of the patient. Particles, in nano- and micron sizes, have been decorated with Sialyl Lewisx (sLex), P-selectin aptamer... 

    Influence of Intramolecular Hydrogen Bonding on Ability of Leaving Group in SN2 Reactions

    , M.Sc. Thesis Sharif University of Technology Ahmadi, Aliakbar (Author) ; Fattahi, Alireza (Supervisor)
    Abstract
    Many of the significant reactions in chemistry and biology are related to bimolecular nucleophilic substitution (SN2) reactions which have been studied first by Hughes and Ingold in the 1930s. Afterward, many organic chemists have continued this work. Up to now, numerous experimental kinetic and theoretical researches have studied the mechanism of these reactions. Since most SN2 reactions occur in solution, a large number of these studies have been devoted to the solvent effects. One of these effects that has been examined extremely is H-bonding via protic solvents that lowers the energy of an anionic nucleophile relative to the transition state, in which the charge is more diffuse, and... 

    Design, Simulation and Fabrication of Integrated Centrifugal Microfluidic Platform for Separation and Lysis of Circulating Tumor Cells

    , M.Sc. Thesis Sharif University of Technology Momeni, Maede (Author) ; Shamloo, Amir (Supervisor) ; Firoozbakhsh, Keykhosrow (Supervisor)
    Abstract
    Cancer diagnosis area has recently been in the limelight of the medical research and there exist an unremitting focus on the devices & technologies which enable cancer detection in its victims. Lately a genius diagnostic method based on isolation and entrapment of circulating tumor cells has been developed which pave the path for cancer identification. These circulating cells which are detached from the primary tumor are carried out through body by means of circulation system. They play key role in phenomenon called metastasis. Separating these rare cells from multifarious background blood cells, assessing their quantity can supply valuable information on the stage of disease as well as its... 

    Generation and Optimization of High-order Harmonics in the Interaction of Laser with N2O Molecule

    , M.Sc. Thesis Sharif University of Technology Monfared, Mohammad (Author) ; Sadighi-Bonabi, Rasoul (Supervisor) ; Irani, Elnaz (Co-Supervisor)
    Abstract
    The X-ray attosecond pulses have many useful applications for studying atomic and sub-atomic scales phenomena in attosecond scale duration. Generation and optimization of high-order harmonics is an efficient way to produce such attosecond pulses which are studied in this thesis. There are several limitations in the attosecond pulse generation such as low efficiency of high-order harmonics, long duration of output pulses and the impossibility of producing an attosecond pulse with any desired wavelength in the x-ray region. Therefore, more investigations into high harmonic generation and fully control and optimization of this process is significant. In this thesis, high harmonic generation... 

    Investigation of I the Stability of B-DNA Molecule: A Molecular Dynamics Simulation

    , Ph.D. Dissertation Sharif University of Technology Izanloo, Cobra (Author) ; Parsafar, Gholam Abbas (Supervisor)
    Abstract
    In this thesis, the molecular dynamics simulation is used to investigate the melting transition of B-DNA molecule, via of configurational entropy, the fraction of broken hydrogen bonds (f-curve) and hydrogen bonding energy.We have performed molecular dynamics simulation on Drew-Dickerson oligomer with sequence of (CGCGAATTGCGC) at different temperatures, within the range of 280-400 K with the 20 K intervals. The simulation was done in two different mediums (pure water and 1 M NaCl), to see influences of water and salt in stabilizing the DNA molecule. At each temperature, configurational entropy is calculated by the Schlitter’s formula, using the Cartesian coordinate of all atoms. So, in each... 

    Theoretical Investigation of Hydrogen Bonding Effects on Interaction of Metal Nanoclusters with Biomolecules & Acidity Enhancement of Alcohols

    , Ph.D. Dissertation Sharif University of Technology Ali Akbar Tehrani, Zahra (Author) ; Fattahi, Alireza (Supervisor) ; Mahmoodi Hashemi, Mohammad (Supervisor) ; Jamshidi, Zahra (Co-Advisor)
    Abstract
    This thesis is divided into three parts: In part I, conformational properties of neutral, anionic, cationic and zwitterionic forms of glutathione tripeptide were investigated by means of DFT-B3LYP method with 6-31+G (d,p) basis set. Results show that glutathione is a very flexible molecule and its conformational energy landscape is strongly influenced by forming intramolecular hydrogen bond and its charge. Conformation of each amino acid in glutathione tripeptide depends on its orientation within the peptide sequence in addition to the conformation of other amino acids within the chain. Investigation of intramolecular hydrogen bonds in these conformers by means of AIM analysis demonstrates... 

    Theoretical Investigation of Hydrogen Bonding Effects on Acidity Enhancement of Alkyl sulfonic Acids and Hydroxy Alkyl Sulfonic Acids in Gas and Solution Phase

    , M.Sc. Thesis Sharif University of Technology Najdian, Atena (Author) ; Fattahi, Ali Reza (Supervisor) ; Hormozi-Nezhad, Mohammad Reza (Supervisor)
    Abstract
    Hydrogen bonding is an important weak interaction encountered in gas, liquid, as well as solid phases. The hydrogen bond plays a very vital role in many life processes and is one of the most frequently used terms in chemistry and biology.
    Polyols or polyhydric alcohols are, strictly speaking, simply organic chemicals containing more than two hydroxyl groups. Each hydroxyl is attached to separate carbon atoms of an aliphatic skeleton.They may also contain ester, ether, amide, acrylic, metal, metalloid and other functionalities; along with hydroxyl groups. Polyols are obtained from many plant and animal sources and are synthesized by a variety of methods. Among important properties of... 

    Molecular Dynamics Study in the Interaction of Intense Femtosecond Laser Pulse with Methane Molecule

    , Ph.D. Dissertation Sharif University of Technology Irani, Elnaz (Author) ; Sadighi-Bonabi, Rasul (Supervisor) ; Anvari, Abbas (Co-Advisor) ; Asgari, Reza (Co-Advisor)
    Abstract
    In this project, the ionization and dissociation of methane molecule by intense femto-second lasers has been studied. Dissociation probability is calculated for interacting CH4 molecule under Ti: Sapphire laser pulse with pulse durations of 10- 40fs in intensities at the range of 1014-1016 Wcm-2. Calculations are carried out with time-dependent density functional theory using Gaussian03 and Octopus packages as powerful computational chemical physics programs. Due to importance of the dependence of interaction dynamics to laser parameters, the effect of these parameters including different intensities, polarization, various pulse durations and pulse envelopes are investigated. The optimal... 

    Design, Simulation and Construction of a Rapid Gene Amplification Microfluidic Device Using Polymerase Chain Reaction (PCR) Method

    , M.Sc. Thesis Sharif University of Technology Amadeh, Ali (Author) ; Shamloo, Amir (Supervisor)
    Abstract
    Polymerase chain reaction method is a conventional method for obtaining multiple copies of a specified segment in the DNA molecule and to amplify the DNA molecule itself. Therefore, this method has been of paramount importance in different fields of research and has been applied for different applications. PCR requires thermal cycling, or repeated temperature changes between two or three discrete temperatures to amplify specific nucleic acid target sequences. To achieve such thermal cycling, conventional bench-top thermal cyclers generally use a metal heating block powered by Peltier elements or benefit from forced convection heat transfer. Although efforts have been made in order to reduce... 

    Molecularly Imprinted Polymers for the Treatment of Disease

    , Ph.D. Dissertation Sharif University of Technology Nematollahzadeh, Ali (Author) ; Abd Khodaei, Mohammad (Supervisor) ; Shojaei, Akbar (Supervisor)
    Abstract
    In the present investigation, experimental design, synthesis and evaluation of Verapamil, Albumin, Immonuglubline G and Trypsin imprinted polymers and finally Albumin imprinted poly(dopamine) nano-layer were presented. A bimodal polymerization approach as a combination of precipitation and dispersion polymerization was taken towards producing 500 nm particles for verapamil imprinting purpose. In this case the imprinting factor was 2.17. In a challenge for producing spherical particles with predefined size and pore properties the hierarchical polymerization in packed beds, using porous silica particles (particle size ca. 40 µm) was developed, as well. The method resolving the problems... 

    Study, Optimization and Construction of a Microfluidic Gene Amplification Device by Using Thin Film Layer Method

    , M.Sc. Thesis Sharif University of Technology Eslami, Sara Sadat (Author) ; Vosoughi, Manouchehr (Supervisor) ; Alemzadeh, Iran (Co-Supervisor) ; Shamloo, Amir (Co-Supervisor)
    Abstract
    Polymerase Chain Reaction (PCR) is a process in which a special piece of a gene is amplified millions of times over a short period. This method has been of paramount importance in different fields of research and has been applied for different applications. PCR requires thermal cycling, or repeated temperature changes between two or three discrete temperatures to amplify specific nucleic acid target sequences. To achieve such thermal cycling, conventional bench-top thermal cyclers generally use a metal heating block powered by Peltier elements or benefit from forced convection heat transfer. Due to the fact that these methods are time consuming, it seems that design and fabrication of a fast... 

    Design and Simulation of CMOS Based Magnetic Sensor for Biosensing Applications

    , M.Sc. Thesis Sharif University of Technology Mafi, Alireza (Author) ; Akbari, Mahmood (Supervisor) ; Fotowat-Ahmady, Ali (Supervisor)
    Abstract
    This paper presents a scalable and ultrasensitive magnetic biosensing scheme based on on-chip LC resonance frequency-shifting. The sensor transducer gain is demonstrated as being location-dependent on the sensing surface and proportional to the local polarization magnetic field strength |B|2 generated by the sensing inductor. To improve the gain uniformity, a periodic coil is proposed as a substitution for the standard process coil. As an implementation example, the circuit is designed in a 65nm CMOS process. The spatially uniform sensor gain of the array is verified by COMSOL simulations. Overall, the presented sensor demonstrates an improvement in the uniformity of the inductor’s magnetic... 

    Modeling Two-Dimensional Face from DNA Using the Face Embedding Approach in Deep Learning

    , M.Sc. Thesis Sharif University of Technology Mirzaei, Mohammad Amin (Author) ; Hossein Khalaj, Babak (Supervisor)
    Abstract
    the purpose of this research is to construct the facial image of a person from corresponding DNA. In this problem, we have a set of DNAs and facial images and we want to find the relation between the DNA and the features of facial images.using this relation we can find the facial Image of a person using the DNA. for this purpose we should first extract the features of faces that have the most variation among the population. by studying the feature extraction methods in this field, we borrow the deep neural network method that is used in face recognition fields.we found significant relations between DNA and extracted features from this network. finally using this relation we can predict the... 

    Free vibrations of single walled carbon peapods

    , Article Physica E: Low-Dimensional Systems and Nanostructures ; Vol. 56 , February , 2014 , pp. 410-413 Firouz-Abadi, R. D ; Hojjati, M ; Rahmanian, M ; Sharif University of Technology
    Abstract
    In this paper the free vibration of single walled carbon nanopeapods encapsulating C60 molecules is considered. The nanopeapod is embedded in an elastic medium and clamped at both ends. The Euler-Bernoulli beam model is used for the carbon nanotube and the C60 molecules are considered as lumped masses attached to the beam. Based on the nonlocal elasticity theory the governing equation of motion is derived and the resonance frequencies of the nanopeapod are obtained. The effects of small scale, foundation stiffness and ratio of the fullerenes' mass to the nanotube's mass on the frequencies are studied and some conclusions are drawn  

    Simulation of mixed electroosmotic/pressure-driven flows by utilizing dissipative particle dynamics

    , Article Microfluidics and Nanofluidics ; Vol. 17, issue. 1 , July , 2014 , pp. 199-215 ; ISSN: 16134982 Mehboudi, A ; Noruzitabar, M ; Mehboudi, M ; Sharif University of Technology
    Abstract
    In this paper, we present an extension of dissipative particle dynamics method in order to study the mixed electroosmotic/pressure-driven micro- or nano-flows. This method is based on the Poisson-Boltzmann equation and has a great potential to resolve the electric double layer (EDL). Hence, apart from studying the bulk flow, it also provides a strong capability in order to resolve the complex phenomena occur inside the EDL. We utilize the proposed method to study the pure electroosmotic and also the mixed electroosmotic/pressure-driven flow through the straight micro-/nano-channels. The obtained results are in good agreement with the available analytical solutions. Furthermore, we study the... 

    A comparative study on hydrogen interaction with defective graphene structures doped by transition metals

    , Article Physica E: Low-Dimensional Systems and Nanostructures ; Vol. 60 , June , 2014 , pp. 104-111 ; ISSN: 13869477 Lotfi, R ; Saboohi, Y ; Sharif University of Technology
    Abstract
    In the present work, the interaction of hydrogen molecules with defective graphene structures doped by transition metal (TM) atoms is investigated by using first principles density functional theory (DFT). Defective graphene structures include Stone-Wales (SW), 585 and 555-777 and transition metals include early TMs, i.e. scandium (Sc), titanium (Ti) and vanadium (V). It is found that in comparison with the pristine graphene, presence of defects significantly enhances the metal binding. Among three defects, 585 divacancy leads to the strongest binding between graphene and metal. Hydrogen adsorption is then evaluated by sequential addition of hydrogen molecules to the system. The results...