International Journal of Nanoparticles (7 papers in press)
Thermomagnetic convection in a layer of magnetic nanofluid saturating porous medium with magnetic field dependent viscosity
by Amit Mahajan, Mahesh Sharma
Abstract: In this paper, the effect of magnetic field dependent (MFD) viscosity on the onset of thermomagnetic convection is examined for a horizontal layer of magnetic nanofluid (or ferrofluid) saturated porous layer. A model that comprises the effect of Brownian diffusion, thermophoresis, magnetophoresis, and Darcy's law is considered. We employed the Chebyshev pseudospectral QZ-method to solve the developed mathematical model and the results are derived for water-based and ester-based magnetic nanofluids. The effects of significant parameters are analyzed at the onset of convection in the gravity as well as in the microgravity environment. The influence of MFD viscosity, permeability parameter, the width of the fluid layer, Lewis number, Langevin parameter, particle concentration, and the concentration Rayleigh number at the onset of thermomagnetic convection are graphically illustrated.
Keywords: magnetic nanofluids; thermomagnetic convection; magnetic field dependent viscosity; microgravity; Darcy medium.
Synthesis of cadmium sulphide nanoparticles through liquid membrane pathway
by Sushma Chakraborty, Prabirkumar Saha
Abstract: This paper introduces a proof of concept that liquid membrane technology
that has always been used as a separation technique, can also be extended for
the generation of value added products in its downstream side. It is possible
to generate cadmium sulphide nanoparticles in the stripping phase of liquid
membrane separation unit which have wide industrial application such as
solar and photovoltaic cells. The process parameters such as concentration of
cadmium salt and pH in feed phase, concentration of strippant, concentration
of extractant/carrier agent etc. were optimized leading to maximum production
of CdS nanoparicles in the stripping phase. The characterization of CdS
nanoparticles were carried out using TEM, FESEM-EDX, FT-IR, XRD and
SAED. The nanosize and nanocrystalline nature of the CdS particles were
Keywords: Bulk Liquid Membrane; CdS nanoparticles; 1,10 Phenanthroline; TEM; FESEM-EDX; FT-IR; XRD; SAED.
Optimization of Carbon Nanotubes for Advanced Diagnosis and Biomedical Application
by Khalid Parwez
Abstract: Nanomaterials have a broad spectrum of applications in bioengineering and pharmaceutical fields, and carbon nanotubes (CNT) are among the most versatile and well-characterized members of this group of materials. The aim of this review is to discuss how CNTs can be exploited as diagnostic tools in various diseases. Various ways to functionalize the CNTs have been broadly discussed among which functionalization with antibodies has gained significance in recent years. Antibodies make their surface sensitive to surroundings which can be utilized in immuno-sensing. Surface passivation with other proteins is required to inhibit the non-specific binding of biomolecules on the hydrophobic carbon nanotube surface for ultrasensitive detection of biological species. The various intrinsic optical properties of SWCNT can be applicable in NIR-imaging of both in-vitro and in-vivo biological systems. They also have unique resonance-enhanced Raman signatures for Raman detection/imaging. CNT-based immuno-sensors provide very good results with a promising sensitivity and reproducibility and, in combination with novel devices (such as microfluidic electrochemical biosensor, Nanoelectromechanical systems (NEMS), Paper-based analytical devices (PADs), Field effect transistors (FET)), offer an attractive analytical approach for the fast, low-cost, and accessible detection of trace prognostic biomarkers, microbial pathogens, environmental pollutants and toxins.
Keywords: Nanomaterials; Carbon nanotubes; Functionalization; Biosensor; Immuno-sensor; FETs; MEMS; PADs; Tissue Engineering.
A Novel Approach for Computation of Cosine Function
by Abul Hasnat, Santanu Halder, Azizul Hoque, Debotosh Bhattacharjee
Abstract: Trigonometric function evaluation is required in almost all science and engineering applications. Objective of trigonometric function approximation in any digital systems are- faster computation in less number of clock cycles, optimizing hardware resource requirement for the circuit, accura-cy in more number of bits in the evaluated output etc. This study proposes a novel method for cosine function computation and its respective FPGA based architecture. In this method, a triangle is presumably located in the first quadrant of a circle with unit radius whose one vertex is the centre, other two vertices touches the perimeter of the circle. Using the area of the triangle, it is observed that the y coordinate of the third vertex of the triangle is the sine value. The error is difference between arch length and side length. Newtons interpolation method is used to formulate the error approximation function. Once the error is approximated, the value of the y co-ordinate is calculated. This method is implemented using VHDL, synthesized on Xilinx Spartan 3 xc3s200-5ft256 FPGA kit simulated on ModelSim 6.2c. The proposed architecture gives accuracy of the computed cosine value up to 14 bits or more in 96% cases in eleven clock cycles only. The proposed architecture operates as fast as 89.977 MHz.
Keywords: Triangle; Unit Circle; FPGA; CORDIC; Sine; Cosine; Newoton’s Interpolation.
Microwave assisted green synthesis of ZnO and Ag doped ZnO nanoparticles as antifungal and antibacterial agents using Colocasia esculenta leaf extract
by Kiran Kumar Prem Kumar, Satish Kumar Murari, Nandipura D. Dinesh
Abstract: Considering the growing popularity of biosynthesis methods, the use of plant extracts for environment friendly synthesis of nanoparticles and the novel biomedical applications of zinc oxide (ZnO), the present study aims to synthesise ZnO and Ag doped ZnO nanoparticles through microwave assisted green synthesis method using the leaf extract of Colocasia esculenta. The nanoparticles synthesised were characterised for the assessment of their crystal structure, chemical phases, optical properties, distribution of particle size, stability, morphology, elemental composition, etc., by using a range of techniques, taking into account that the benefits of ZnO nanoparticles as piezoelectric conductors, transducers, antimicrobial agents, etc., predominantly depend on such morphological aspects. The efficiency of the synthesised nanoparticles as antimicrobial agents and comparison of the biocidal effects of doped and undoped nanoparticles were examined against the bacterial species, Bacillus subtilis and Escherichia coli, as well as the fungal species, Aspergillus oryzae and Saccharomyces cerevisiae, by using the cell culture technique.
Keywords: ZnO nanoparticles; ZnO/Ag nanocomposites; nanotechnology; Colocasia esculenta; green synthesis; leaf extract; microwave method; characterisation; antifungal; antibacterial.
Silicon Based Core-shell Nanoparticles Nanobiomedical Characterization
by Ahmad Salmanogli, Farzin Asghari Sana
Abstract: Using functionalized nanoparticles in nanobiomedical applications cause to raise questions about unintentional effect of such powerful agents on the human body. In other words, the study of nanoparticle toxicity can be considered as a curtail key for the biological applications. In this study, the core/shell nanoparticles such as Si/Au and SiO2/Au were synthesized and functionalized with some biological elements. For satisfying some medical standards and biomedical critical test conditions, a few in-vitro assays as cytotoxicity and hemolysis should be done. For this reason, cytotoxicity and hemolytic effects of the functionalized nanoparticles such as Si/Au/Biotin and SiO2/Au/Biotin and their derivatives were evaluated on Hep-G2 cells and humane red blood samples. It is shown that cytotoxicity and hemolysis effects of the all synthesized nanoparticles are concentration-dependent. Also, the results are shown that most cytotoxicity and hemolytic effects are observed for Si/Au and SiO2/Au without Biotin groups after 48h and 30 minutes, respectively.
Keywords: Silicon Core/shell nanoparticle; Nanocytotoxicity; MTT cytotoxicity assay; hemolysis.
Bactericidal effect of silver nanoparticles from aqueous root extracts of Catharanthus Roseus
by Subha V, ERNEST RAVINDRAN R S, ATHUL BALAJI HEMANT KUMAR, Renganathan S
Abstract: In this study, green synthesis of silver nanoparticle (AgNPs) is synthesized using aqueous root extract of Catharanthus roseus as a reducing as well as capping agent. The bioactive molecules present in the root extract such as alkaloids, flavonoids, carbohydrates, amino acids and phenolic compounds were found to be responsible for the reducing and capping of nanoparticles. Stable nanoparticles were observed after the addition of aqueous root extract into the silver nitrate solution. Biotransformation of the silver nitrate to silver nanoparticles were investigated by UV-visible Spectroscopy (UV) and found that the Surface Plasmon Resonance of the nanoparticles a shallow peak at 490 nm. XRD pattern shows the crystalline nature of silver nanoparticle. Highly mono dispersed silver nanoparticles within 100 nm rage was revealed from TEM. The activity of the silver nanoparticles against microbes were found to be higher the zone of inhibition in all the species used for the studies.
Keywords: Silver Nanoparticles; Catharanthus roseus; Antimicrobial Activity.