فهرست مطالب

Nanoscience and Nanotechnology - Volume:15 Issue:4, 2019
  • Volume:15 Issue:4, 2019
  • تاریخ انتشار: 1398/08/10
  • تعداد عناوین: 6
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  • M. J. Aghagoli, F. Shemirani * Pages 219-228
    Surfaces of synthesis cobalt disulfide has high electron density that could interact with polycyclic aromatic compounds by π-π stacking. Cobalt disulfide was synthesized with the hydrothermal method and characterized by field emission scanning electron microscopy, X-ray diffraction and energy-dispersive X-ray. Using tetracycline as a model analyte, the batch adsorption experiments were carried out in order to investigate the adsorption capacity of the adsorbent. It was revealed that pseudo-second-order kinetic model can better describe the adsorption kinetic. Furthermore, the equilibrium adsorption data were congruous with the model Langmuir with maximum adsorption capacity of 163.93 mg g-1.
    Keywords: Hydrothermal Synthesis of Cobalt ‎Disulfide Nanostructures, Adsorption ‎Kinetics, Isotherms, and Thermodynamics ‎of Tetracycline‎
  • M. Habibnejad Korayem *, M. Taheri, H. Khaksar, R. Nouhi Hefzabad Pages 229-237
    This paper deals with the development and modeling of cylindrical contact theories and also the simulation of contact forces to be applied in the manipulation of various biological micro/nanoparticles by means of the AFM. First, the simulation of contact forces in four environments has been carried out, which are the most commonly used fluid in biomanipulation. Then, the spherical and cylindrical contact models of Hertz and JKR have been compared for the nanoparticles of gold and DNA, and the developed cylindrical models have been validated by comparing the cylindrical contact results with the existing spherical contact results. The biomanipulation of rod-shaped micro/nanoparticles in different biological environments have been modeled and the results have been compared. The modeling results indicated that the JKR cylindrical model, developed in this article, had less deformation for gold nanoparticles compared with biological nanoparticles, which was justifiable in view of the considered particles’ mechanical properties.
    Keywords: Nanomanipulation, Contact forces, Cylindrical contact theories, Indentation depth.‎
  • N. Hajizadeh Bastani *, K. Navi Pages 239-248
    Nowadays, the portable multimedia electronic devices, which employ signal-processing modules, require power aware structures more than ever. For the applications associating with human senses, approximate arithmetic circuits can be considered to improve performance and power efficiency. On the other hand, scaling has led to some limitations in performance of nanoscale circuits. Accordingly, Carbon Nanotube Field Effect Transistors have gotten a widespread attention as the most appropriate replacement for MOSFETs. In this paper, an imprecise full adder cell based on CNFET minority gates is introduced. Evaluation and comparison of the minority-based and the-state-of-the-art imprecise full adders in terms of average power dissipation, delay and power delay product (PDP) are done. The error distance (ED), normalized error distance (NED) and PDP-NED product metrics are also considered for assessing the accuracy of the reviewed circuits. The HSPICE simulations, conducted using Stanford 32nm CNFET model, indicate that the minority-based design outperforms the other designs in terms of performance and error tolerance.
    Keywords: Approximate computing, Full adder, CNFET, Nanoelectronics.‎
  • S. Zeinali *, S. Tatian Pages 249-263
    A method for treating fuel oil and waste water of power plant is suggested which is including vanadium elimination through contacting with humic acid coated magnetic nano-adsorbent. The nano-adsorbent was modified with humic acid (HA) as a compound having carboxyl, hydroxyl and amin functional groups. HA/Fe3O4 nanoparticles were prepared by a co-precipitation procedure and were characterized using different techniques such as dynamic light scattering (DLS), Transmission electron microscopy (TEM), FTIR spectroscopy, X-ray diffraction spectroscopy. The surface charge of the nano-adsorbents was determined by Zeta potential technique and their magnetic properties were investigated by vibrational sample magnetometer (VSM). It was observed that the synthesized nanoparticles have a mean diameter about 14 nm. The effects of several experimental factors such as pH, adsorbent dosage, contact time and initial vanadium concentration, on the nano-adsorbent ability for vanadium removal were investigated. The best results were obtained using 10 mg/ml of nanoparticles at pH 5 and contact time 30 min. At this condition about 99.5 % of V(IV) could be removed from synthetic samples. Maximum adsorption capacity for vanadium (IV) was 8.97 mg/g which was fitted to Langmuir isotherm model. The ability of HA/Fe3O4 for the vanadium removal from fuel oil and wastewater of power plant was also investigated. It was observed that more than 93% of vanadium content could be removed from waste water and 67% form fuel oil using proposed nano-adsorbent.
    Keywords: Vanadium Removal, Magnetic Nanoparticle, Humic acid, Adsorption, Waste water, Fuel Oil.‎
  • M. Sepehrinia, M. M. Zerafat * Pages 265-275
    In this study, linearized transport pore model (LTPM) is applied for modeling nanofiltration (NF) membrane separation process. This modeling approach is based on the modified extended Nernst-Planck equation enhanced by Debye-Huckel theory to take into account the variations of activity coefficient especially at high salt concentrations. Rejection of single-salt (NaCl) electrolyte is investigated to take into account the effect of feed concentration, membrane charge density and pore size on rejection. The results show that the reduction of feed concentration and membrane pore size lead to increase the rejection of electrolyte in NF separation process. Furthermore, increasing the membrane charge density causes the rejection of co-ions to be increased leading to an enhanced total rejection. LTPM is compared to unmodified linearized model which approves the higher precision of the modified model especially at higher concentrations.
    Keywords: LTPM, Modified extended Nernst-Planck equation, Debye-Huckel. ‎
  • A. Vanaja *, M. Suresh, J. Jeevanandam Pages 277-286
    Zinc oxide (ZnO) is the most common and widely utilized nanomaterial for biological applications due to their unique characteristics, such as biocompatibility, biosafety and antimicrobial along with thermal stability and mechanical strength. Magnesium (Cu) is considered as a significant dopant for ZnO due to their almost similar ionic radii and their role in biological activities which enhances the biological properties of ZnO. Thus, pure and magnesium doped nanocrystalline ZnO particles were synthesized through sol-gel approach in the current study. The concentration of the dopant is varied from (0.1% - 0.3%) and the composition, structural and optical characterizations were performed by using X-Ray Diffraction (XRD), Transmission Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, UV-Vis optical absorption and photoluminescence (PL) spectrometer. The structural analysis confirmed that magnesium ions substitute Zn ions without altering their wurtzite structure with a high degree of crystallization. Morphological analysis confirmed that the magnesium doping process strongly influences the morphology of ZnO nanoparticles. PL measurement had been carried out at room temperature in which high intensity broad emission peaks were observed in the visible region around 450 - 700 nm that indicates the superposition of green emission bands. Thus, green photo luminescent magnesium doped ZnO nanoparticles from the current study are proposed to be highly beneficial as biosensors, photocatalysts and light-driven antibacterial agents.
    Keywords: ZnO nanoparticles, Magnesium dopants, Sol-gel approach, Photoluminescence, Wurtzite crystal.‎