Strain-controlled Flexible DNA-curcumin on PET Substrate

Siva Pratap Reddy Mallem(말렘 시바 프래탑 래디),Jung-Hee Lee(이정희) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

High-performance strain-modulated flexible sensors are significant modules of the systems for human motion detection, electronic skin, human-machine interaction, soft robotics, etc., which are intended as important technologies for applications in future human personal healthcare monitoring and artificial intelligence. Resistive switching, which use modification in resistance measurement, is considered as one of the prospective candidate for the future generation key technology. We introduce a simple technique to fabricate a flexible resistive-type strain sensor composted of DNA-curcumin composite and graphene on polyethylene terephthalate (PET) substrate. Double helical DNA has unique attributes including its high thermal stability, high negative charge density and strong resistance to both bending and twisting. Particularly, flexible DNA-curcumin/graphene on PET substrate displays piezo-resistive characteristics, is likely a good candidate for fabricating resistance-based strain sensors.

HEAT AND MASS TRANSFER EFFECTS ON MHD NATURAL CONVECTION FLOW PAST AN INFINITE INCLINED PLATE WITH RAMPED TEMPERATURE

SIVA REDDY SHERI,ANJAN KUMAR SURAM,PRASANTHI MODULGUA 한국산업응용수학회 2016 Journal of the Korean Society for Industrial and A Vol.20 No.4

This work is devoted to investigate heat and mass transfer effects on MHD natural convection flow past an inclined plate with ramped temperature numerically. The dimensionless governing equations for this investigation are solved by using finite element method. The effects of angle inclination, buoyancy ratio parameter, permeability parameter, magnetic parameter, Prandtl number, heat generation, thermal radiation, Eckert number, Schmidt number, chemical reaction parameter and time on velocity, temperature and concentration fields are studied and presented with the aid of figures. The effects of the pertinent parameters on skin friction, rate of heat transfer and mass transfer coefficients are presented in tabular form. The numerical results are compared graphically with previously published result as special case of the present investigation and results found to be in good agreement.

Influence of Series Resistance and Interface State Density on Electrical Characteristics of Ru/Ni/n-GaN Schottky structure

Reddy, M. Siva Pratap,Kwon, Mi-Kyung,Kang, Hee-Sung,Kim, Dong-Seok,Lee, Jung-Hee,Reddy, V. Rajagopal,Jang, Ja-Soon The Institute of Electronics and Information Engin 2013 Journal of semiconductor technology and science Vol.13 No.5

We have investigated the electrical properties of Ru/Ni/n-GaN Schottky structure using current-voltage (I-V) and capacitance-voltage (C-V) measurements at room temperature. The barrier height (${\Phi}_{bo}$) and ideality factor (n) of Ru/Ni/n-GaN Schottky structure are found to be 0.66 eV and 1.44, respectively. The ${\Phi}_{bo}$ and the series resistance ($R_S$) obtained from Cheung's method are compared with modified Norde's method, and it is seen that there is a good agreement with each other. The energy distribution of interface state density ($N_{SS}$) is determined from the I-V measurements by taking into account the bias dependence of the effective barrier height. Further, the interface state density $N_{SS}$ as determined by Terman's method is found to be $2.14{\times}10^{12}\;cm^{-2}\;eV^{-1}$ for the Ru/Ni/n-GaN diode. Results show that the interface state density and series resistance has a significant effect on the electrical characteristics of studied diode.

Dual detection of ultraviolet and visible lights using a DNA-CTMA/GaN photodiode with electrically different polarity

Reddy, M. Siva Pratap,Kim, Bong-Joong,Jang, Ja-Soon The Optical Society 2014 Optics express Vol.22 No.1

DNA-CTMA/a-Si:H bio-hybrid photodiode: A light-sensitive photosensor

Reddy, M. Siva Pratap,Puneetha, P.T.,Lee, Young-Woong,Jeong, Seong-Hoon,Park, Chinho Elsevier 2017 Organic electronics Vol.50 No.-

<P><B>Abstract</B></P> <P>Recently, considerable interest have occurred in the development of an organic-inorganic-based bio-hybrid photodiodes (Bio-HPDs) with metal-free, eco-friendly, and cost-competitive features for light-sensitive devices. This paper reports a bio-inspired optical absorber material for the fabrication of Bio-HPDs using n-type hydrogenated amorphous silicon (a-Si:H) and a natural deoxyribonucleic acid (DNA)-cetyltrimethylammonium chloride (CTMA) biomaterial. a-Si:H is inexpensive and abundant, and DNA-CTMA is metal-free and eco-friendly. A DNA-CTMA coating on n-type a-Si:H leads to a chemically stable material with increased absorption and effective ties of dangling bonds and interface state density. Analysis results showed that the rectification ratio (RR) of the Bio-HPD is found to be 4 times higher than reference PD. This indicates that the effective RR is improved by the DNA-CTMA layer since it creates molecular charge interactions between DNA-CTMA layer and a-Si:H substrate. Moreover, Bio-HPD shows a light photosensitivity (I<SUB>photo</SUB>/I<SUB>dark</SUB>) of 474 with more reliable and has longer life time. In addition, the formation and feasible charge transport mechanisms are discussed. This biomaterial can be used for the development of commercially viable and environmentally safe large-scale Bio-HPDs applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High-contrast DNA-CTMA/a-Si:H bio hybrid light-sensitive device fabricated. </LI> <LI> The photodiode parameters investigated by I–V measurements. </LI> <LI> XPS and XRD structural properties were examined. </LI> <LI> FTIR, Raman and UV–Vis measurements were used. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synthesis and Antimicrobial Activity of Dimethyl (2-cyanophenylamino) (Substituted Aryl) Methyl Phosphonates

Reddy, G. Chandra Sekhar,Kumar, B. Siva,Sankar, A. Uma Ravi,Reddy, C. Suresh Korean Chemical Society 2008 대한화학회지 Vol.52 No.6

Gate Architecture Effects on the Gate Leakage Characteristics of GaN Wrap‑gate Nanowire Transistors

Siva Pratap Reddy Mallem,Ki‑Sik Im,Terirama Thingujam,Jung‑Hee Lee,Raphael Caulmilone,Sorin Cristoloveanu 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.5

Gate leakage current in lateral GaN wrap-gate nanowire transistors (WG-NWT) was investigated using current density–voltage (Jg–Vg) characteristics at room temperature. We found that the gate leakage current is strongly dependent on thetop corner angle of the gate architecture. This leakage current was characterized by considering hopping (Poole–Frenkelemission) and trap-assisted thermionic emission mechanisms. Despite its smaller gate area, the gate leakage current of thelateral GaN WG-NWT without a 2DEG channel was higher than that of the device with a 2DEG channel for all applied gatebiases. The reason for this is that the lateral GaN WG-NWT without 2DEG channel has a triangular cross-section with asharp top corner angle resulting in a strong electric field due to geometrical field enhancement.

The Line n-sigraph of a Symmetric n-sigraph-V

Reddy, P. Siva Kota,Nagaraja, K.M.,Geetha, M.C. Department of Mathematics 2014 Kyungpook mathematical journal Vol.54 No.1

An n-tuple ($a_1,a_2,{\ldots},a_n$) is symmetric, if $a_k$ = $a_{n-k+1}$, $1{\leq}k{\leq}n$. Let $H_n$ = {$(a_1,a_2,{\ldots},a_n)$ ; $a_k$ ${\in}$ {+,-}, $a_k$ = $a_{n-k+1}$, $1{\leq}k{\leq}n$} be the set of all symmetric n-tuples. A symmetric n-sigraph (symmetric n-marked graph) is an ordered pair $S_n$ = (G,${\sigma}$) ($S_n$ = (G,${\mu}$)), where G = (V,E) is a graph called the underlying graph of $S_n$ and ${\sigma}$:E ${\rightarrow}H_n({\mu}:V{\rightarrow}H_n)$ is a function. The restricted super line graph of index r of a graph G, denoted by $\mathcal{R}\mathcal{L}_r$(G). The vertices of $\mathcal{R}\mathcal{L}_r$(G) are the r-subsets of E(G) and two vertices P = ${p_1,p_2,{\ldots},p_r}$ and Q = ${q_1,q_2,{\ldots},q_r}$ are adjacent if there exists exactly one pair of edges, say $p_i$ and $q_j$, where $1{\leq}i$, $j{\leq}r$, that are adjacent edges in G. Analogously, one can define the restricted super line symmetric n-sigraph of index r of a symmetric n-sigraph $S_n$ = (G,${\sigma}$) as a symmetric n-sigraph $\mathcal{R}\mathcal{L}_r$($S_n$) = ($\mathcal{R}\mathcal{L}_r(G)$, ${\sigma}$'), where $\mathcal{R}\mathcal{L}_r(G)$ is the underlying graph of $\mathcal{R}\mathcal{L}_r(S_n)$, where for any edge PQ in $\mathcal{R}\mathcal{L}_r(S_n)$, ${\sigma}^{\prime}(PQ)$=${\sigma}(P){\sigma}(Q)$. It is shown that for any symmetric n-sigraph $S_n$, its $\mathcal{R}\mathcal{L}_r(S_n)$ is i-balanced and we offer a structural characterization of super line symmetric n-sigraphs of index r. Further, we characterize symmetric n-sigraphs $S_n$ for which $\mathcal{R}\mathcal{L}_r(S_n)$~$\mathcal{L}_r(S_n)$ and $$\mathcal{R}\mathcal{L}_r(S_n){\sim_=}\mathcal{L}_r(S_n)$$, where ~ and $$\sim_=$$ denotes switching equivalence and isomorphism and $\mathcal{R}\mathcal{L}_r(S_n)$ and $\mathcal{L}_r(S_n)$ are denotes the restricted super line symmetric n-sigraph of index r and super line symmetric n-sigraph of index r of $S_n$ respectively.

Dopant-induced red emission, paramagnetism, and hydrogen evolution of diluted magnetic semiconductor ZnS : Eu nanoparticles

Siva Pratap Reddy Mallem,Peddathimmula Puneetha,Kalupudi Subramanyam,Varra Rajagopal Reddy,이동연,김영래,안성진,박귀일 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.4

Cubic-structured europium (Eu) doped zinc sulfide (ZnS) nanoparticles (NPs) were prepared via refluxing at 150 °C. Absolute structural studies showed that Eu+ ions were successfully substituted into the ZnS host lattice and changed the original structure of the host. As-fabricated ZnS:Eu NPs exhibited typical red emission due to the transition of the Eu dopant in the 5d0-7f1, 5d0-7f2, 5d0-7f3, and 5d0-7f4 energy levels of the 4f orbital of the dopant. The typical diamagnetic ZnS could be converted to tunable paramagnetic as a function of Eu-doping content. These NPs were quantified for hydrogen evolution through water splitting by artificial solar spectrum. Eu doping can drastically enhance the hydrogen (H2) evolution capability of ZnS, which is higher than that of bare ZnS NPs. The causes behind these engrossing results will be revealed. These interesting properties may find applications in optoelectronics, spintronics, and H2 evolution.

n-th power signed graphs

Siva Kota Reddy,Vijay,Lokesha 장전수학회 2009 Proceedings of the Jangjeon mathematical society Vol.12 No.3

A signed graph (marked graph) is an ordered pair S = (G, σ) (S = (G, μ)), where G = (V,E) is a graph called the underlying graph of S and σ : E → {+, −} (μ : V → {+, −}) is a function. The n-th power graph of a graph G = (V,E) is a graph Gn = (V,E'), with same vertex set as G, and has two vertices u and v are adjacent if their distance in G is n or less. Analogously, one can define the nth power signed graph of a signed graph S = (G, σ). Consider the marking μ on vertices of S defined as follows: each vertex v ∈ V , μ(v) is the product of the signs on the edges incident at v. The nth power signed graph of S is a signed graph Sn = (Gn, σ') where Gn is the underlying graph of Sn, where for any edge e = uv 2 Gn, 0(uv) = μ(u)μ(v). It is shown that for any signed graph S, its nth power signed graph Sn is balanced. We then give structural characterization of n-th power signed graphs. Two signed graphs S1 and S2 are switiching equivalent written S1 ~ S2, whenever there exists a marking μ of S1 such that the signed graph Sμ(S1) obtained by changing the sign of every edge of S1 to its opposite whenever its end vertices are of opposite signs, is isomorphic to S2. Further, we present solutions of some signed graph switching equations involving the line signed graph, complement and n-th power signed graph operations. One such equation (L(S))n ~ S generalizes a result of P. Siva Kota Reddy and M. S. Subramanya (L(S) ~ S) [11].