Novel route to synthesis of N-doped graphene/Cu-Ni oxide composite for high electrochemical performance

Balamurugan, J.,Thanh, T.D.,Heo, S.B.,Kim, N.H.,Lee, J.H. Pergamon Press ; Elsevier Science Ltd 2015 Carbon Vol.94 No.-

A facile and cost-effective one-pot solvothermal method has been successfully developed to synthesize an N-doped graphene (NG) and copper-nickel oxide (CuNiO) composite. The novel NG/CuNiO composite is proposed to be used as an electrode material for supercapacitors and non-enzymatic glucose sensors. Transmission electron microscopy images indicate the formation of CuNiO nanoparticles with an average diameter of approximately 5.6nm, with good dispersion on the NG sheets. The composite exhibited an excellent specific capacity of ~892Fg<SUP>-1</SUP> (current density of 1Ag<SUP>-1</SUP>) and high long-cycle stability with a 98.5% retention in specific capacitance after 5000 cycles at a current density of 5Ag<SUP>-1</SUP>. This superior electrochemical performance is attributed to high charge mobility, the flexibility of the N-doped graphene structure, and the synergetic effect between CuNiO nanoparticles and NG sheets. Further, the proposed sensor exhibited rapid response (<10s), high sensitivity (7.49μAmM<SUP>-1</SUP>cm<SUP>-2</SUP>), a wide detection range (0.2μM-0.3mM), good reproducibility, long-term stability, and a low detection limit 50nM (S/N=3). The NG/CuNiO composite electrode can be used for high performance supercapacitor and non-enzymatic glucose sensor applications.

Simple replication methods for producing nanoslits in thermoplastics and the transport dynamics of double-stranded DNA through these slits

Chantiwas, Rattikan,Hupert, Mateusz L.,Pullagurla, Swathi R.,Balamurugan, Subramanian,Tamarit-Ló,pez, Jesú,s,Park, Sunggook,Datta, Proyag,Goettert, Jost,Cho, Yoon-Kyoung,Soper, Steven A. Royal Society of Chemistry 2010 Lab on a chip Vol.10 No.23

<P>Mixed-scale nano- and microfluidic networks were fabricated in thermoplastics using simple and robust methods that did not require the use of sophisticated equipment to produce the nanostructures. High-precision micromilling (HPMM) and photolithography were used to generate mixed-scale molding tools that were subsequently used for producing fluidic networks into thermoplastics such as poly(methyl methacrylate), PMMA, cyclic olefin copolymer, COC, and polycarbonate, PC. Nanoslit arrays were imprinted into the polymer using a nanoimprinting tool, which was composed of an optical mask with patterns that were 2–7 µm in width and a depth defined by the Cr layer (100 nm), which was deposited onto glass. The device also contained a microchannel network that was hot embossed into the polymer substrate using a metal molding tool prepared <I>via</I> HPMM. The mixed-scale device could also be used as a master to produce a polymer stamp, which was made from polydimethylsiloxane, PDMS, and used to generate the mixed-scale fluidic network in a single step. Thermal fusion bonding of the cover plate to the substrate at a temperature below their respective <I>T</I><SUB>g</SUB> was accomplished by oxygen plasma treatment of both the substrate and cover plate, which significantly reduced thermally induced structural deformation during assembly: ∼6% for PMMA and ∼9% for COC nanoslits. The electrokinetic transport properties of double-stranded DNA (dsDNA) through the polymeric nanoslits (PMMA and COC) were carried out. In these polymer devices, the dsDNA demonstrated a field-dependent electrophoretic mobility with intermittent transport dynamics. DNA mobilities were found to be 8.2 ± 0.7 × 10<SUP>−4</SUP> cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> and 7.6 ± 0.6 × 10<SUP>−4</SUP> cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> for PMMA and COC, respectively, at a field strength of 25 V cm<SUP>−1</SUP>. The extension factors for λ-DNA were 0.46 in PMMA and 0.53 in COC for the nanoslits (2–6% standard deviation).</P> <P>Graphic Abstract</P><P>Thermoplastic nanoslits were replicated from a simple molding tool and consisted of mixed-scale structures with successful DNA translocation through the slits demonstrated. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0lc00096e'> </P>

Experimental Investigation of Modular Multilevel Converter Using Space Vector Pulse Width Modulation

Balamurugan S.,Palanisamy R.,Karthikeyan B. 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.5

The modular multilevel converter (MMC) is a promising topology for high-voltage and high-power applications due to its modularity, scalability, and low harmonic distortion. In this paper, the design and implementation of an MMC using space vector pulse width modulation (SVPWM) technique is presented. The SVPWM technique is used to generate the switching signals for the MMC to achieve a high-quality output voltage waveform with low harmonic distortion. The MMC is designed using half-bridge sub-modules with a DC capacitor voltage balancing control method. The performance of the proposed MMC topology is validated through simulation studies in MATLAB/Simulink and hardware implementation using fi eld programmable gate array platforms. The results show that the proposed MMC using SVPWM technique achieves a better output voltage waveform with low harmonic distortion compared to the conventional pulse width modulation (PWM) technique. The proposed MMC topology is suitable for high-voltage and high-power applications such as renewable energy systems and electric vehicles.

Porous nanostructured GdFeO₃ perovskite oxides and their gas response performance to NO_x

Balamurugan, C.,Song, S.-J.,Lee, D.-W. Elsevier 2018 Sensors and actuators. B Chemical Vol.272 No.-

<P><B>Abstract</B></P> <P>Gas sensing characteristics of rare-earth-based orthoferrite (GdFeO<SUB>3</SUB>) mesoporous nanostructures were prepared by a facile one-step hydrothermal process. The structural analyses of the obtained materials showed sphere, leaf and flower-like nanostructured architectures. Further, the chemiresistive gas-response properties of the GdFeO<SUB>3</SUB> nanostructure were investigated with various combustible gases, such as nitric oxide (NO), nitrogen dioxide (NO<SUB>2</SUB>), carbon monoxide (CO), ammonia (NH<SUB>3</SUB>), hydrogen sulfide (H<SUB>2</SUB>S), formaldehyde (HCHO), ethanol (C<SUB>2</SUB>H<SUB>5</SUB>OH) and gasoline, at different operating temperatures. The sphere-like GdFeO<SUB>3</SUB> nanostructure shows a significantly high resistance variation to NO compared with the other architectures, exhibits a high response (91%) when exposed to 100 ppm NO, and detects a level as low as 2 ppm (7%) at an optimum operating temperature of 140 °C. The GdFeO<SUB>3</SUB> nanostructure shows an excellent stability and repeatability after successive repeated cycles with a fast response and recovery time when exposed to 100 ppm NO gas. The superior response and excellent selectivity of the perovskite GdFeO<SUB>3</SUB> nanostructure are due to its higher catalytic activity, large surface area, oxygen deficiency, mesoporosity, and peculiar morphology. The response mechanism of NO on the GdFeO<SUB>3</SUB> nanostructured surface is also discussed in detail.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mesoporous rare-earth orthoferrite (GdFeO<SUB>3</SUB>) nanostructures were prepared by a facile one-step hydrothermal process. </LI> <LI> Structural effects of GdFeO<SUB>3</SUB> nanostructure on NO<SUB>x</SUB> gas-response properties were systematically investigated. </LI> <LI> Mesosphere-like GdFeO<SUB>3</SUB> nanostructure exhibited the best gas-response characteristics to nitric oxide (NO) at 140 °C. </LI> <LI> NO gas-response mechanism of GdFeO<SUB>3</SUB> nanostructure was discussed. </LI> </UL> </P>

High-energy asymmetric supercapacitors based on free-standing hierarchical Co-Mo-S nanosheets with enhanced cycling stability

Balamurugan, J.,Li, C.,Peera, S.,Kim, N.,Lee, J. Royal Society of Chemistry 2017 Nanoscale Vol.9 No.36

Analytical Modeling and Simulation of Dual Material Gate Tunnel Field Effect Transistors

T.S.Arun Samuel,N.B.Balamurugan,S.Sibitha,R.Saranya,D.Vanisri 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.6

In this paper, a new two dimensional (2D) analytical model of a Dual Material Gate tunnel field effect transistor (DMG TFET) is presented. The parabolic approximation technique is used to solve the 2-D Poisson equation with suitable boundary conditions. The simple and accurate analytical expressions for surface potential and electric field are derived. The electric field distribution can be used to calculate the tunneling generation rate and numerically extract tunneling current. The results show a significant improvement of on-current and reduction in short channel effects. Effectiveness of the proposed method has been confirmed by comparing the analytical results with the TCAD simulation results.

Ellagic acid normalizes mitochondrial outer membrane permeabilization and attenuates inflammation-mediated cell proliferation in experimental liver cancer.

Srigopalram, S,Jayraaj, I A,Kaleeswaran, B,Balamurugan, K,Ranjithkumar, M,Kumar, T Senthil,Park, J I,Nou, I S Humana Press 2014 Applied biochemistry and biotechnology Vol.173 No.8

<P>Despite great advances in our understanding of the molecular causes of liver cancer, significant gaps still remain in our knowledge of the disease pathogenesis and development of effective strategies for early diagnosis and treatment. The present study was conducted to evaluate the chemopreventive activity of ellagic acid (EA) against experimental liver cancer in rats. This is the first report that implies a possible role of EA in controlling liver cancer through activation of mitochondrial outer membrane permeability via activating proteins such as Bax, bcl-2, cyt-C, and caspase-9, which play important roles in apoptosis. Downregulation of NF-κB, cyclin D1, cyclin E1, matrix metalloproteinases (MMP)-2, MMP-9, and proliferating cell nuclear antigen (PCNA) were noted in EA-treated experimental rats and controlled inflammation mediated liver cancer when compared to the diethylnitrosamine (DEN)-induced group. Transmission electron microscopy (TEM) analysis of the livers of experimental rats demonstrated that EA treatment renovated its internal architecture. Overall, these results demonstrate the value of molecular approaches in identifying the potential role of EA as an effective chemopreventive agent.</P>

Evaluation of Composite Cements using Cyclic Polarization Techniques

V. Saraswathy,S. Muralidharan,L. Balamurugan,P. Kathirvel,A. S. S. Sekar 대한토목학회 2011 KSCE JOURNAL OF CIVIL ENGINEERING Vol.15 No.8

Slag Cement (PSC) extracts in the presence and absence of nitrite inhibitor were studied by cyclic polarization technique. Studies also carried out in composite (binary and ternary) cement extracts. The re-passivation potential (Erep) is an important parameter to characterize the corrosion resistant property of cements and the efficiency of inhibitor. Blended cements (PPC and PSC) have higher tolerable limit of chloride than OPC. Binary cements increase the tolerable limit of chloride than individual cements. The passivity of steel maintained by ternary cement was found to be less than 45000 ppm of chloride along with 5000 ppm of nitrite (pitting occurred at 45000 ppm). This chloride level is more than that of chlorides in natural sea water (35000 ppm). Hence the use of composite cement especially in marine atmosphere increases the corrosion resistance of steel in concrete.

Analytical Modeling and Simulation of Dual Material Gate Tunnel Field Effect Transistors

Samuel, T.S.Arun,Balamurugan, N.B.,Sibitha, S.,Saranya, R.,Vanisri, D. The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.6

In this paper, a new two dimensional (2D) analytical model of a Dual Material Gate tunnel field effect transistor (DMG TFET) is presented. The parabolic approximation technique is used to solve the 2-D Poisson equation with suitable boundary conditions. The simple and accurate analytical expressions for surface potential and electric field are derived. The electric field distribution can be used to calculate the tunneling generation rate and numerically extract tunneling current. The results show a significant improvement of on-current and reduction in short channel effects. Effectiveness of the proposed method has been confirmed by comparing the analytical results with the TCAD simulation results.

Genomic Analyses of Toll-like Receptor 4 and 7 Exons of Bos indicus from Temperate Sub-himalayan Region of India

Malik, Y.P.S.,Chakravarti, S.,Sharma, K.,Vaid, N.,Rajak, K.K.,Balamurugan, V.,Biswas, S.K.,Mondal, B.,Kataria, R.S.,Singh, R.K. Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.7

Toll-like receptors (TLRs) play an important role in the recognition of invading pathogens and the modulation of innate immune responses in mammals. The TLR4 and TLR7 are well known to recognize the bacterial lipopolysaccharide (LPS) and single stranded (ssRNA) ligands, respectively and play important role in host defense against Gram-negative bacteria and ssRNA viruses. In the present study, coding exon fragments of these two TLRs were identified, cloned, sequenced and analyzed in terms of insertion-deletion polymorphism, within bovine TLRs 4 and 7, thereby facilitating future TLR signaling and association studies relevant to bovine innate immunity. Comparative sequence analysis of TLR 4 exons revealed that this gene is more variable, particularly the coding frame (E3P1), while other parts showed percent identity of 95.7% to 100% at nucleotide and amino acid level, respectivley with other Bos indicus and Bos taurus breeds from different parts of the world. In comparison to TLR4, sequence analysis of TLR7 showed more conservation among different B. indicus and B. taurus breeds, except single point mutation at 324 nucleotide position (AAA to AAM) altering a single amino acid at 108 position (K to X). Percent identity of TLR7 sequences (all 3 exons) was between 99.2% to 100% at nucleotide and amino acid level, when compared with available sequence database of B. indicus and B. taurus. Simple Modular Architecture Research Tool (SMART) analysis showed variations in the exon fragments located in the Leucine Rich Repeat (LRR) region, which is responsible for binding with the microbial associated molecular patterns and further, downstream signaling to initiate anti-microbial response. Considering importance of TLR polymorphism in terms of innate immunity, further research is warranted.