International Journal of Nano Dimension
Volume:6 Issue: 4, Autumn 2015

Scanning Hall Probe Microscopy (SHPM) is a scanning probe microscopy technique developed to observe and image magnetic fields locally. This method is based on application of the Hall Effect, supplied by a micro hall probe attached to the end of cantilever as a sensor. SHPM provides direct quantitative information on the magnetic state of a material and can also image magnetic induction under applied fields up to ~1 tesla. This method is non-invasive with high spatial resolution and sensitivity. Furthermore, this microscopy technique can be operated in a wide range of temperatures while the magnetic field caused by hall probe is so minimal, which has negligible effect on the measuring process. Meanwhile, the sample does not need to be an electrical conductor, unless using Scanning Tunneling Microscope (STM) for height control. SHPM measurements can be performed in ultra-high vacuum (UHV) and are non-destructive for crystal lattice and complicated structures.

A facile and green approach has been developed to synthesize silver nanoparticle (Ag-NPs). This was carried out by a biosynthetic route using Justicia Adhatoda root extract as reducing and stabilizing agent. The structure, composition, average particle size (~25 nm) and surface morphology of Ag-NPs were characterized by the X-ray diffraction, transmission electron microscope and atomic force microscope analyses. The possible functional groups in the plant extracts were identified by FT-IR analysis. Electrochemical property of the Ag-NPs was analysed by cyclic voltammetry that displayed an oxidation peak potential at Epa = 0.438 V. Mechanism of the formation of Ag-NPs was proposed which showed that the phenolic compounds of the root extract respond for the reduction of silver ions to silver nanoparticles. Ag-NPs exhibit good antioxidant and antibacterial activities. This biosynthetic approach could open a path for environmentally friendly, simple, cost effective, alternate for conventional synthesis. This prevented hazardous chemicals and was useful for applications in medicine and large scale production of metallic nanoparticles.

The resonant frequency and sensitivity of an atomic force microscope (AFM) cantilever with assembled cantilever probe (ACP) have been analyzed and a closed-form expression for the sensitivity of vibration modes has been obtained. The proposed ACP comprises an inclined cantilever and extension, and a tip located at the free end of the extension, which makes the AFM capable of topography at sidewalls of microstructures. Because the extension is not exactly located at one end of the cantilever, the cantilever is modeled as two beams. In this study, the effects of the interaction stiffness and damping, and also some geometrical parameters of the cantilever on the resonant frequencies and sensitivities are investigated. Afterwards, the influence of the interaction stiffness and damping, and the geometrical parameters such as the angles of the cantilever and extension, the connection position of the extension and the ratio of the extension length to the cantilever length on the sensitivity and resonant frequency are investigated. The results show that the greatest flexural modal sensitivity occurs at a small contact stiffness of the system, when the connection position and damping are also small. The results also indicate that at low values of contact stiffness, an increase in the cantilever slope or a decrease in the angle between the cantilever and extension can rise the resonant frequency while reduces the sensitivity.

This work reports a facile sonochemical route in the synthesis of nano particle of deferasirox for the first time. One application of nanotechnology is in improvement of available treatments for various diseases. Deferasirox (ICL670 or Exjade) is a tridentate chelating agent for removing transfusion overload iron in thalassemia patients. In the present work, deferasirox was prepared in nano size by using of ultrasound waves. The effects of amount and reaction time on the size of deferasirox were investigated. These parameters were optimized at various amounts and different reaction times. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) studies show that the deferasirox in nature structure does not change during the reaction. The results show that the finest particle is related to the following conditions: 45min, time reaction and 0.1g, amount of deferasirox. Therefore, the ultrasonic bath method has a fundamental role in the preparation of deferasirox in nano scale. This method is simple, relatively fast and low cost.

Graphene-based nanocomposites are newly emerged materials with a wide range of applications such as in supercapacitors electrode. The high conductivity and ability for passing electric current, makes Graphene an appropriate new item to be used in cells. Electroactive transition metal oxides, owing fast reversible redox pairs, are used to store electrical charge. Furthermore, the Graphene/NiO nanocomposites can be used to improve the electrochemical properties of NiO. Here we report a new and facile route for synthesizing Graphene/NiO nanorods composite (GNC). High-quality few-layer Graphene/NiO nanorod composite (GNC) is synthesized via solvothermal method. Solution phase exfoliation of graphite is investigated in N-Methyl-Pyrrolidone (NMP). The existence of few-layer graphene is confirmed by Raman spectroscopy while presence of NiO is demonstrated by UV-Vis spectroscopy (UV) and X-ray diffraction (XRD) pattern. The Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffraction (XRD) pattern also provide proof of GNC on graphene. Images indicate NiO nanorods with average diameter of 35 nm and 100 nm lengths, deposited on graphene.

In this paper, the temperature dependence of some characteristics of cylindrical gate-all-around Si nanowire field effect transistor (GAA-Si-NWFET) is investigated to representing the temperature nano-sensor structures and improving their performance. Firstly, we calculate the temperature sensitivity of drain-source current versus the gate-source voltage of GAA-Si-NWFET to propose the temperature nano-sensor circuit. Then the solutions of increasing current temperature sensitivity are discussed by investigating the effects of the oxide thickness and the channel diameter on this parameter. Secondly, in this study, we demonstrate the temperature dependence of the transconductance (gm) and output resistance (ro) of the GAA-Si-NWFET. We have proposed the amplifier circuit as a temperature sensor based on the temperature dependence of these parameters. In addition, we have changed the channel diameter and the oxide thickness to increase the temperature sensitivity of gm and subsequently, temperature sensitivity of proposed sensor. Ultimately, the effects of channel diameter and oxide thickness on the temperature sensitivity of gm will be analytically investigated.

In this paper, we have tried to find a solution for quick transfer of nuclear wastes from pools of cool water to dry stores to reduce the environmental concerns and financial cost of burying atomic waste. Therefore, the rate of heat transfer from atomic waste materials to the outer surface of the container should be increased. This can be achieved by covering the bottom of the pool space with conical fins (vertically) embedded in porous medium and allowing natural convection flow of Newtonian nanofluid upon it. In this research, we studied the rate of heat transfer by using such special space. In this study, Heat transfer boundary layer flow in Nano-fluidics shifting from a vertical cone in porous medium, two-dimensional, steady, incompressible and low speed flow have been considered and attempts have been made to obtain analytical solutions for it. The obtained nonlinear ordinary differential equation has been solved through homotopy analysis method (HAM), considering boundary conditions and Nusselt number. Also, Nusselt number, which is an important parameter in heat transfer, is calculated using the obtained analytical solution by HAM. A comparison of the obtained analytical solution with the numerical results represented a remarkable accuracy. The results also indicate that HAM can provide us with a convenient way to control and adjust the convergence region.

In this research nanoparticles of Nickel (II) Chloride were synthesized and characterized using fourier transform infrared (FT-IR) spectra. Nanoparticles of Nickel (II) Chloride were prepared by using of ball mill device. A ball mill is one kind of grinding machine, and it is a device in which media balls and solid materials (the materials to be ground) are placed in a container. In the research Nickel (II) Chloride compound was milled for 10 h at 250 rpm in a hardened stainless steel medium. The resulting nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The SEM imaging technique was applied for the observation of grain sizes and the morphology of the nanoparticles. The Debye-Scherrer formula was used to confirm the grain sizes determined by the SEM slides. XRD results of nanoparticles showed that the crystallite size of reaching 59 mm after 10 h at 250 RPM. Thermal behavior of nanoparticles was considered by using of DTA /TGA thermal analysis device. TGA analysis reveals that the synthesized Nickel (II) Chloride nanoparticle was thermally stable up to 900°C.

In this paper, finite element model of woven fabric target has been investigated which is impacted by a cylindrical projectile. Fabrics are impregnated with Shear Thickening Fluid (STF). The effects of the (STF) have been considered as frictional effect. The STF has been made (Nano Silica and Polyethylene Glycol (PEG)) and then diluted by ethanol proportion of 3:1. Yarn pulling out test from inside of fabric is performed to estimate the pulling out force and the friction coefficient. The speed of pulling out was 500 mm/min and the samples were placed vertically in tensile device. The results of yarn pulled out indicated that the fabric impregnated in STF needs more force in order to gets out of fabric. Friction coefficient of a regular fabric is 0.26 and in a fabric impregnated by STF is 1.5. Friction coefficients of tow fabric types of raw fabric and fabric with STF are entered in ANSYS software along with mechanical characteristic of a yarn. Ballistic range velocity was extracted for samples in software and was compared with experience results.

The aim of the present study was to develop Exemestane loaded polymeric nanoparticles for improved oral bioavailability of Exemestane. Exemestane loaded nanoparticles were prepared by solvent displacement method with Eudragit RL 100 and Eudragit L 100 as polymers and Pluronic® F-68 as surfactant. The influence of various formulation factors (drug: polymer ratio and concentration of surfactant) on particle size, size distribution, zeta potential, encapsulation efficiency, in vitro drug release were investigated. The mean particle size of optimized formulations F5 and F13 were found to be 98.19nm and 48.16nm respectively. Zeta potential of optimized formulations F5 and F13 were found to be +22mV and -25mV respectively. Fourier Transform Infrared Spectroscopy (FT-IR) study indicated that, there was no interaction between drug and polymers. Scanning electron microscopy (SEM) study revealed spherical morphology of the developed NPs. The results of the present investigation indicate that the formulations F5 and F13 can be considered as best among various formulations with respect to particle size, entrapment efficiency and in-vitro drug release. In conclusion, this study indicates the capability of Eudragit nanoparticles in enhancing the oral bioavailability of exemestane.

Sol-gel derived sulfur modified and pure ZnO nanorod were prepared using zinc chloride and thiocarbamide as raw materials. Prepared nanorods were characterized by means of X-ray diffraction (XRD), thermogravimetry- differential scanning calorimetry (TG–DSC), UV- Vis absorption spectroscopy, Brunauer Emmett Teller (BET) specific surface area and Barrett Joyner Halenda (BJH) pore size distribution analyses, scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) analyses. The band gaps of sulfur modified and pure ZnO were estimated from UV-Vis spectroscopy data to be 2.75 and 3.18 ev, respectively. The specific surface area of sulfur modified ZnO nanorod calculated to be 2.63 m2/g using BET method. Pore size distribution curve of the mater obtained via BJH method revealed that the diameter of the pores is from several to more than 20nm. Photocatalytic activity of synthesized sulfur modified and pure ZnO nanorod were tested for degradation of Congoredazo dye under ultraviolet and visible light. The results revealed that the sulfur modified ZnO nanorod has excellent photocatalytic activity towards Congored under visible light illumination.

Nowadays, II – IV group semiconductor thin films have attracted considerable attention from the research community because of their wide range of application in the fabrication of solar cells and other opto-electronic devices. Cadmium zinc sulfide (Zn-CdS) thin films were grown by chemical bath deposition (CBD) technique. X-ray diffraction (XRD) is used to analyze the structure and crystallite size and scanning electron microscopy is used to study the morphology of Zn-CdS thin film. Optical studies have been carried out using UV-Visible-NIR transmission spectrum. The dielectric properties of Zn-CdS thin films have been studied in the different frequency at different temperatures. The AC conductivity study shows a normal dielectric behavior with frequency which reveals that the dispersion is due to the interfacial polarization.

Oxide nanoparticles can exhibit unique physical and chemical properties due to their limited size and a high density of corner or edge surface sites. In this study, MgO nanoparticle was synthesized using Mg(CH3COO)2 and hexamethylenetetramine as starting materials. The structure and optical properties of these particles are investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Visible absorption. The XRD analysis discloses that MgO nanoparticle is successfully synthesized. Dispersive analysis of X-RAY (EDAX) was used to characterize the size and morphology of the MgO nanoparticle on the template. The morphology of MgO was nanospheres.