Current Nanoscience (v.10, #3)

Behavior of EDTMP (Ethylene-diaminetetramethylene-phosphonate)- Nanoparticles in Blood: Considerations on the Site of Injection by Beatriz Ferreira de Carvalho Patricio, Osmar Flavio da Silveira Leite Neto, Marta de Souza Albernaz, Ralph Santos-Oliveira (323-325).
The nanotechnology and the use of nanoparticles are increasing each day. The number of experiments withnanoparticles is enormous and is corroborating the use in humans. However some points must be more defined before afinal approval. In this study we analyzed nanoparticles of EDTMP under different conditions in rats and observed somecharacteristics that should be taken into account. Nanoparticles were injected either intraocular or in a jugular vein, andthe data were compared. The behaviors of the samples were very different, which may have led to erroneous interpretationof nanoparticle data in previous studies by many authors. In all cases, the results of the biodistribution were quite different,which may lead to different conclusions. Analyzing the data, we conclude that the biodistribution test should be standardized,and the way that it is conducted may change the final results drastically.

We review a compact, semi-empirical model of Carbon Nanotube Field Effect Transistors (CNTFETs), alreadyproposed by us, in which we have introduced several issues to allow an easy implementation in the most common circuitsimulators.;The CNTFET equivalent circuit is similar to a common MOSFET one, where the quantum capacitances have been computedfrom the charge in the channel.;A procedure, based on a best-fitting between the measured and simulated values of output device characteristics, is reviewedin order to extract the optimal values of the CNTFET equivalent circuit elements.;Finally we have implemented our model both in SPICE, using ABM library, and in Verilog-A in order to demonstrate themodel flexibility and in order to compare them.;Typical analogue circuits and logic blocks have been simulated and results have been presented to validate the implementationof our CNTFET model both in Verilog-A and in SPICE.

Design Trends in Fully Integrated 2.4 GHz CMOS SPDT Switches by Mohammad Arif Sobhan Bhuiyan, Mamun Bin Ibne Reaz, Jubayer Jalil, Labonnah Farzana Rahman, Tae Gyu Chang (334-343).
Fully integrated CMOS single pole double through (SPDT) Transmit/Receive (T/R) switch is an essential componentof every compact transceiver for enabling sharing of a single antenna between its transmitter and receiver. Theswitch is expected to encompass very low insertion loss, relatively higher isolation with high power handling capability.But there is inevitable trade-off among the parameters of the switch which makes the design even more challenging at 2.4GHz ISM band. This paper presents a bibliographical survey of the work published on improved performance of differentswitch topologies for 2.4 GHz ISM band transceiver applications. Different techniques reported in literatures for furtherimprovements in the characteristics of CMOS switches are also highlighted. This review will serve as a comparative studyand reference for the researchers in designing T/R switches for future 2.4 GHz ISM band applications.

Structure-controlled Nanomaterial Synthesis using Surfactant-assisted Ball Milling- A Review by Mahbub Ullah, Md. Eaqub Ali, Sharifah Bee Abd Hamid (344-354).
The applications of nanoparticles have been tremendously increased in the field of targeted drug release, genesilencing, therapeutics, industrial and environmental catalysis, water purification and optoelectronics. These are becauseof their versatile sizes and shapes, large specific surface area with convenient surface properties, high chemical reactivity,physical affinity and optical, electrical and magnetic properties. However, the synthesis of nanoparticles with controllednano/microstructures and desired surface properties has been remaining a challenging task. Various approaches have beenproposed for the commercial production of nanostructured particles from solid bulk materials. Chemical methods for thesynthesis of controlled structure nanoparticles from rare-earth solid compounds have showed limited success in terms ofyield, purity and cost. Recently, surfactant assisted high energy ball milling has been exploited for the synthesis of variousnanomaterials, nanograins and nanocomposites from solid state. Self-assembled structures of surfactants act as cationic,anionic or charge neutral lubricants to control the nano/microenviroment of the nanostructured materials, producingnanoparticles with improved dispersion. In high-energy ball milling, plastic deformation, cold-welding and fracture predominantlycontribute to bring a change in size, shape and nano/microenvironment of nanoparticles. In this review, wehave systematically presented the basic concept and applications of surfactant assisted mechanical milling for the synthesisof various nanomaterial, nanocomposite and nanoparticles.

The goal of this work was to evaluate the microstructure and dynamics of water nanodroplets in isopropylmyristate (IPM)/dioctyl sodium sulfosuccinate (DOSS)/water nanoemulsions (NE) utilized as reactors for nanoparticlesynthesis. The characterization of the microstructure and dynamics of selected NE's was performed using rheology, dynamiclight scattering (DLS), and sub-ambient differential scanning calorimetry (SA-DSC). The results obtained fromrheological evaluation demonstrated that all the selected IPM/DOSS/water systems exhibited Newtonian behavior. TheDLS measurements showed that depending on composition, the water nanodroplets had diameters in the range of 6 to16 nm. The nanoemulsions did not show droplet aggregation or coalescence over a one-month period of observation, asindicated by the multi-angle DLS study. SA-DSC experiments delineated the states of water within the ternary mixtures.A concentration-related variation in the internal microstructure was identified when water-freezing temperatures wereplotted as a function of water content. The ternary mixtures reported in this research were utilized to synthesize silver sulfadiazineand calcium alginate nanoparticles. Insights obtained from this study are being assimilated to design efficientand effective reactors capable of use in nanoparticle synthesis.

Evaluation of Three Synthetic Membranes as Limiting Barrier for in vitro Drug Release Studies from Hydrogels Containing Polymeric Nanocapsules by Diego Fontana de Andrade, Márcia Camponogara Fontana, Ruy Carlos Ruver Beck (367-373).
In this work we evaluated the suitability of three synthetic membranes for the in vitro assessment of drug releasefrom semisolid dosage forms containing polymeric nanocapsules. The use of cellulose acetate (0.45 µm pore size),polycarbonate (0.05 µm pore size) and dialysis cellulose (12 kDa cut off) membranes was investigated. For this purpose,drug release studies from hydrogels containing clobetasol propionate-loaded lipid-core nanocapsules were carried out. Ahigher amount of clobetasol propionate reached the release medium using cellulose acetate and polycarbonate membranes,compared to the use of dialysis cellulose membrane. Photon correlation spectroscopy analyses showed an overlap betweenthe particle size distributions of the receptor media from the release studies using cellulose acetate and polycarbonatemembranes and the original lipid-core nanocapsules suspension diluted in the receptor medium. The presence of nanoparticleswas further confirmed by transmission electron microscopy. On the other hand, particle size distribution observed inthe receptor medium of release studies using dialysis cellulose membrane did not show particles at nanoscale. The overallresults suggest that the dialysis cellulose membrane ensures that only released drug will reach the receptor compartment,and that it should be the first choice for in vitro drug release studies from semisolid dosage forms containing drug-loadednanocapsules.

Application of Biosynthesized Silver Nanoparticles in Agricultural and Marine Pest Control by M. Yokesh Babu, V. Janaki Devi, C.M. Ramakritinan, R. Umarani, Nayimabanu Taredahalli, A.K. Kumaraguru (374-381).
The present study is focused on the applications of biosynthesized silver nanoparticles in various fields. Silvernanoparticles are synthesized in vitro using marine bacteria Shewanella algae bangaramma in the laboratory. The silvernanoparticles are characterized by using UV-Vis spectrum, TEM, FTIR, EDAX, XRD and AFM analysis. The synthesizedsilver nanoparticles are spherical, crystalline and 5-30 nm in diameter. They were found to have both larvicidal andbactericidal activities. There is no mortality in the control. The maximum LC 50 and LC 90 values with 95% confidentiallimit (4.529 mg/ml (2.478 - 5.911), 9.580 mg/ml (7.528-14.541) were observed with III- instar larvae of Lepidiota mansueta(Burmeister). In exposed groups the mortality of the larvae was significantly increased in all concentrations (p <0.0001). The order of bactericidal activity against marine fouling bacteria is found to be Pseudomonas sp. < Vibriocholerae < Roseobacter sp. < Alteromonas sp. To date, this is the first report on the marine bacteria mediated synthesis ofsilver nanoparticles in culture medium which has effective larvicidal and antifouling activities.

Impacts of Iron Oxide Nanoparticles on the Invasion Power of Listeria monocytogenes by Alireza Ebrahiminezhad, Sara Rasoul-Amini, Soodabeh Davaran, Jaleh Barar, Younes Ghasemi (382-388).
Recently, magnetic nanoparticles have been introduced as a novel antimicrobial material. Listeria monocytogenesare the causative agent of listeriosis and stands among the major public health issues. This bacterium can attach tothe host cell membrane and trigger molecular responses leading to phagocytosis of the bacterial cell. In the present study,the effect of iron oxide nanoparticles (IONs) on the invasion power of L. monocytogenes was investigated. IONs weresynthesized by coprecipitation method and coated with 3-aminopropyltriethoxysilane (APTES). Listeria monocytogenescells were exposed to the prepared particles and interactions between IONs and bacterial cells were visualized by scanningelectron microscopy. Invasion power of listerial cells for penetration HepG-2 cells monolayer was also examined in variousconcentrations of IONs. IONs have reduced invasion power of L. monocytogenes in a concentration-dependent manner.Almost 4-fold reduction in the invasion power of L. monocytogenes was observed at 20 µg ml-1 IONs concentration.

Photocatalytic Performance of Ag Nanoparticles Modified ZnO Microplates Prepared by One-Step Method by Y.Q. Liang, Z.H. Gao, Z.D. Cui, S.L. Zhu, Z.Y. Li, X.J. Yang (389-393).
Flower-shaped Ag-ZnO microplates were directly synthesized from an aqueous solution of zinc nitrate and silvernitrate in the presence of CTAB at 120°C. The as-synthesized products were investigated in terms of their morphological,structural, photocatalytic properties. Methylene blue (MB) and gaseous iso-propanol (IPA) are employed to evaluatethe photocatalytic activity of the Ag-doped ZnO microplates. The photocurrent response experiments are also carried out.The as-formed composite shows higher efficiency of photocatalytic degradation on MB and IPA. Moreover, it also exhibitsobvious photocurrent under light irradiation.

FPGA Based Precise and High Speed Current dq PI Controller for FOC PMSM Drive by Mohammad Marufuzzaman, Mamun Bin Ibne Reaz, Labonnah Farzana Rahman, Tae Gyu Chang (394-401).
A faster and precise field programmable gate array (FPGA) based current dq proportional and integral (PI) controlleris developed to reach the optimal efficiency and steadiness of the motor drive. Current dq PI controller is generallyimplemented in digital signal processor (DSP) based computer. However, DSP based solution reaches its physical limits,which are usually few microseconds. Conversely, FPGA indeed enhances the performance of current controllers. FPGAimplementation of the overall controlling algorithm will certainly trim down the execution time significantly to guaranteethe steadiness of the motor. In this research, an FPGA based current dq PI controller is developed. The controller operatesat 30MHz clock speed and results show that the overall execution time is only 68 ns that is the lowest computational cyclefor the era.

Influence of Experimental Conditions on the Antireflection Properties of Silicon Nanowires Fabricated by Metal-Assisted Etching Method by Jianning Ding, Fuqing Zhang, Ningyi Yuan, Guanggui Cheng, Xiuqin Wang, Zhiyong Ling, Zhongqiang Zhang (402-408).
In this paper, silicon nanowire (SiNW) arrays with the different structural parameters were prepared by theelectroless metal assisted chemical etching method through changing the AgNO3 concentration in the etching solution andetching time. For the concentration of AgNO3 of 0.04M and the etching time of 8 min, the SiNW arrays with minimum reflectancewere obtained. The average reflectivity of the SiNW arrays could be as low as 2.0% for the wavelength in therange of 300-1100nm. The measurements of reflectivity and morphology of SiNW arrays indicated that the reflectivity ofSiNW arrays were not only sensitive to the length of the nanowires, but also dependent on the diameter, distribution periodand the filling ratio of diameter to distribution period of the nanowires. When the filling ratio is around 0.45, the distributionperiod of the SiNW arrays is 110 ± 10nm, diameter is smaller and length is longer, the reflectivity will be lower.

Stokes’ First Problem in Nanofluids by Haliza Rosali, Anuar Ishak, Ioan Pop (409-413).
This paper discusses numerically the unsteady flow and heat transfer of a viscous fluid driven by an impulsivelystarted infinite flat plate in a nanofluid. The governing partial differential equations are transformed into a system ofordinary differential equations, which is then solved numerically by a shooting method. Results are presented graphicallyand the effects of the Brownian motion parameter Nb and the thermophoresis parameter Nt on the dimensionless heattransfer rate are discussed. It is found that the heat transfer rate is a decreasing function of both Nb and Nt.

Strontium titanate (SrTiO3) nanocrystals have been synthesized, for the first time, through a facile method usingSrC2O4·H2O-TiO2 precursor. DTA-TG techniques were used to follow the titanate formation process. XRD and FT-IRmeasurements were used to characterize the intermediate decomposition products as well as the titanate formation. XRDshowed single-phase, crystalline, cubic perovskite with a lattice constant of 3.9017 Å. TEM image exhibited agglomeratedcubic particles with size of about 70 nm. BET measurements, used to characterize the surface properties, revealed a surfacearea of 9.5 m2 g-1. The study of the electrical properties as a function of temperature and frequency exhibited semiconductingbehavior with conduction activation energy of 0.45 eV. Kinetic analysis of non-isothermal TG curves, usingthree different computational integral methods revealed an activation energy value, for the titanate formation, of 240 kJmol-1 according to the phase boundary controlled mechanism (R2).

Effect of Nd Substitution on Magnetic and Microwave Absorption Properties of Nanocrystalline Sr(MnSn)0.5Fe11O19 by Ali-Sharbati, Javad-Mola Verdi Khani, G.R. Amiri, R. Mousarezaei (422-426).
The preparation of Sr1-xNdx(MnSn)0.5Fe11O19 M-type hexaferrites powders by a citrate sol-gel method was investigated.The samples were determined by X-ray diffraction (XRD) and transmission electron microscope (TEM). Microwaveabsorption properties of hexaferrite- acrylic resin composites were measured using SWR (standing-wave-ratio)method in the range of 12 to 20 GHz. It was shown that small amounts of Nd+3 substitution could significantly modify themicrowave electromagnetic parameters. Furthermore, the investigation indicated that substitution of Nd+3 ions for Sr+2ions in Sr(MnSn)0.5Fe11O19 resonant frequency would move toward higher frequency. The results showed that the powderpossesses excellent microwave absorption properties. A minimum reflection loss of –43 dB was observed for the composite,where x = 0.03. A broad bandwidth of microwave absorption (with a –10 dB reflection loss as a reference) is predictedin the composite samples containing the ferrite powders of x=0.02, and x=0.03 in Ku-band frequencies.

La-doped Barium-ferrite/Poly-m-toluidine Composites : Preparation, Characterization and Properties by Yu Xie, Jinmei Liu, Xiaowei Hong, Zhanggao Le, Yunhua Gao, Yuancheng Qin, Yun Ling, Yuanfu Yu, Juan Wang (427-431).
La-doped Barium-ferrite/Poly-m-toluidine composites with electromagnetic behavior were prepared by in situpolymerization of m-toluidine in the presence of La-doped Barium-ferrite particles. The structures, morphologies andproperties of composites were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmissionelectron microscopy (TEM), four-probe conductivity tester and vibrating sample magnetometer (VSM). FTIR and XRDspectra demonstrated that there were interactions between ferrite and poly-m-toluidine (PMT). TEM studies showed thatthe composites presented the core-shell structure. Under applied magnetic field, nanocomposite exhibited the hystereticloops of the ferromagnetic behavior. The magnetic parameter saturation magnetization of composites depends on the contentof La-doped barium-ferrite particles.

In this article free convective peristaltic motion of MHD Jeffrey nano fluid in an irregular channel is considered.Convective surface boundary conditions are incorporated for the thermal flow analysis. Energy equation exhibits theviscous dissipation. The problem prescribed under long wavelength and low Reynold's number approximation. HPM(homotopy perturbation method) is used to developed the solutions for nano particle fraction and heat transfer phenomena,while exact solutions are calculated for stream function and pressure gradient. The obtained results grip on “convectionBiot number Bi, Hartmann number M, , Jeffrey fluid parameter λ, thermophoresis parameter Nt and Brownian motion parameterNb”. The assets of different parameters on the flow quantities of observation are analyzed. As a concluding point,the streamlines are plotted and examined.

Refinement Behavior of Scrap Silicon by Mechanical Milling by Rumman Md. Raihanuzzaman, Joon-Woo Song, Ilseuk Lee, Soon-Jik Hong, Jar Myung Koo (441-444).
In this research, the refinement behavior of scrap silicon during mechanical milling with varying time was observed.Initial premilled Si powder with 106µm size was milled using high energy ball milling equipment in order to producecommercially applicable 10 µm target Si powders. Milling time was changed from 1 min to 60min while the characteristicsand morphological changes of the powders according to the milling time were observed by Scanning ElectronMicroscopy (SEM), Transmission Electron Microscopy (TEM) and X-ray diffractometer (XRD). The average particle sizewas found to have reached 10?m after a short milling time of 20~30 min, while 60min of milling yielded fine sphericalparticles of around 3.5 µm, surrounded by fine nanoparticles. In addition, it has also been found that there is presence ofnano Si particles after 60 minutes of milling. The refinement mechanism suggests that the longer the milling time, thefiner the powder size becomes with identifiable stages observed in between.

The problem of an axisymmetric flow of a nanofluid over a radially permeable shrinking sheet with convectivesurface boundary condition is studied numerically. The governing partial differential equations are transformed into ordinarydifferential equations by a similarity transformation, before being solved numerically using a shooting method. Theeffects of the Lewis number Le , Brownian motion parameter Nb , thermophoresis parameter Nt , and the Biot numberBi on the heat and mass transfer characteristics are studied. It is found that the solution exists only if adequate suctionthrough the permeable sheet is introduced. Moreover, unique, dual and triple solutions are found to exist for a certainrange of the suction parameter. Furthermore, increasing the Lewis number and the Brownian motion parameter are to decreasethe heat transfer rate at the surface but increase the mass transfer rate. Both the heat and mass transfer rates at thesurface decrease with increasing values of the thermophoresis parameter.

RNA-Loaded Chitosan Nanoparticles for Enhanced Growth, Immunostimulation and Disease Resistance in Fish by S. Ferosekhan, Subodh Gupta, Arvind R. Singh, Mohd. Ashraf Rather, Rakhi Kumari, Dushyant C. Kothari, Asim Kumar Pal, Sanjay Balkrishna Jadhao (453-464).
Exogenous nucleotide supplementation during times of rapid growth and stress is preferred because de novosynthesis is insufficient and energetically a costly process. To overcome inefficient utilization of dietary nucleotides dueto intestinal cell repulsion and dependency on pH, an efficient controlled delivery system based on chitosan nanoparticles(NPs) was developed. The effects of these (0.2% and 0.4%) RNA-loaded chitosan NPs (Chitosan: RNA ratio 2:1), 0.4%bare RNA, and 0.8% chitosan NPs on productive efficiency (growth rate, feed conversion and protein efficiency ratio),body composition, organo-somatic indices, haemato-biochemical and immune responses (WBC count, phagocytic activity,serum lysozyme, serum total protein and albumin : globulin ratio) and survival of Labeo rohita fish fingerlings, followingchallenge with pathogenic bacteria were evaluated. Dietary chitosan NPs were found not to affect productive efficiency,but improved (P < 0.01) immunity by increasing WBC and phagocytic activity. Dietary RNA significantly improved(P < 0.01) productive efficiency, immunity and survival, which was further potentiated (P < 0.01) by its nanosizeddelivery by loading onto chitosan NPs. Blood glucose, haemoglobin, RBC count, serum uric acid and whole bodycomposition were unaffected (P > 0.05) by dietary treatments. RNA-loaded chitosan NPs increased hepato- and viscerosomaticindices. The activity of metabolic enzymes (intestinal and liver alkaline phosphatase, alanine- and aspartateaminotransferases, lactate- and malate-dehydrogeneases) corresponded with the performance of the respective diets. Asgrowth, immunity and disease resistance in fish given dietary nano-sized RNA were significantly higher than in thosegiven bare RNA or chitosan alone, and as nanoformulation reduced the usage of individual components by half, the use ofRNA-loaded chitosan NPs can be favoured in the feed/food industry over chitosan and RNA alone.