A Linear-Time Algorithm for the Geodesic Center of a Simple Polygon

Ahn, H. K.,Barba, L.,Bose, P.,Carufel, J. L.,Korman, M.,Oh, E. Springer Science + Business Media 2016 Discrete & Computational Geometry Vol.56 No.4

<P>Let P be a closed simple polygon with n vertices. For any two points in P, the geodesic distance between them is the length of the shortest path that connects them among all paths contained in P. The geodesic center of P is the unique point in P that minimizes the largest geodesic distance to all other points of P. In 1989, Pollack et al. (Discrete Comput Geom 4(1): 611-626, 1989) showed an -time algorithm that computes the geodesic center of P. Since then, a longstanding question has been whether this running time can be improved. In this paper we affirmatively answer this question and present a deterministic linear-time algorithm to solve this problem.</P>

Biopolymer phytagel-derived porous nanocarbon as efficient electrode material for high-performance symmetric solid-state supercapacitors

Karuppasamy, K.,Prasanna, K.,Ilango, P. Robert,Vikraman, Dhanasekaran,Bose, Ranjith,Alfantazi, Akram,Kim, Hyun-Seok Elsevier 2019 Journal of industrial and engineering chemistry Vol.80 No.-

<P><B>Abstract</B></P> <P>In the present work, a porous nano-carbon (PNC) based electrode materials were successfully derived from the natural biopolymer phytagel via a facile hydrothermal and combustion process. The carbon phase structure of the PNC electrode was confirmed using different spectroscopy, microscopy and N<SUB>2</SUB> adsorption-desorption analyses. The surface morphology investigation showed a distinct shape and size for the PNC that demonstrated its porous nature. The electrochemical performance of PNC was completely reliant on the calcination temperature (800°C) and it delivered the maximum capacitance of 122Fg<SUP>−1</SUP> at 0.25Ag<SUP>−1</SUP>. An AC impedance and cyclic voltammetry analyses proved the intrinsic electrochemical behavior by their cycling. Besides, the fabricated symmetric solid-state supercapacitor displayed an outstanding cycle durability with a stable capacitance retention of 85.8% over 8000 cycles, suggesting favorable prospects for its use as an active candidate for symmetric solid-state supercapacitor applications.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

EMPIRICAL APPROACH FOR PREDICTING THE CETANE NUMBER OF BIODIESEL

P. K. BOSE 한국자동차공학회 2009 International journal of automotive technology Vol.10 No.4

The cetane number is an indicator of ignition quality and thus of fuel quality in the realm of diesel engines. It is conceptually similar to the octane number used for gasoline. Generally, a compound that has a high octane number tends to have a low cetane number and vice versa. The cetane number of a diesel fuel is related to the ignition delay time. In our work the first approach is a statistical one the accuracy of which depends upon the data obtained from various papers and literature sources, as all equations used were based on this data. During prediction using more than one equation is a good approach, as it provides the accuracy as well as the relative error. The second approach is also a statistical one, but its value depends upon the saponification number and iodine value. Therefore the accuracy of this equation may be higher, since we can collect the data for saponification numbers and iodine values from literature, without needing to calculate them. Using the saponification number and iodine value we can select an optimal biodiesel as generally a good biodiesel is selected using these three values. Thus the second approach allows us the freedom to select a biodiesel.

IMPROVED THEORETICAL MODELING OF A CYCLONE SEPARATOR AS A DIESEL SOOT PARTICULATE EMISSION ARRESTER

P. K. BOSE,K. ROY,N. MUKHOPADHYA,R. K. CHAKRABORTY 한국자동차공학회 2010 International journal of automotive technology Vol.11 No.1

Particulate matter is considered to be the most harmful pollutant emitted into air from diesel engine exhaust, and its reduction is one of the most challenging problems in modern society. Several after-treatment retrofit programs have been proposed to control such emission, but to date, they suffer from high engineering complexity, high cost, thermal cracking,and increased back pressure, which in turn deteriorates diesel engine combustion performance. This paper proposes a solution for controlling diesel soot particulate emissions by an improved theoretical model for calculating the overall collection efficiency of a cyclone. The model considers the combined effect of collection efficiencies of both outer and inner vortices by introducing a particle distribution function to account for the non-uniform distribution of soot particles across the turbulent vortex section and by including the Cunningham correction factor for molecular slip of the particles. The cut size diameter model has also been modified and proposed by introducing the Cunningham correction factor for molecular slip of the separated soot particles under investigation. The results show good agreements with the existing theoretical and experimental studies of cyclones and diesel particulate filter flow characteristics of other applications.

Surface and interface studies of RF sputtered HfO2 thin films with working pressure and gas flow ratio

Das, K. C.,Ghosh, S. P.,Tripathy, N.,Bose, G.,Ashok, A.,Pal, P.,Kim, D. H.,Lee, T. I.,Myoung, J. M.,Kar, J. P. Springer Science + Business Media 2015 Journal of materials science Materials in electron Vol.26 No.8

Biopolymer phytagel-derived porous nanocarbon as efficient electrode material for high-performance symmetric solid-state supercapacitors

K. Karuppasamy,K. Prasanna,P. Robert Ilango,Dhanasekaran Vikraman,Ranjith Bose,Akram Alfantazi,김현석 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

In the present work, a porous nano-carbon (PNC) based electrode materials were successfully derivedfrom the natural biopolymer phytagel via a facile hydrothermal and combustion process. The carbonphase structure of the PNC electrode was confirmed using different spectroscopy, microscopy and N2adsorption-desorption analyses. The surface morphology investigation showed a distinct shape and sizefor the PNC that demonstrated its porous nature. The electrochemical performance of PNC wascompletely reliant on the calcination temperature (800 C) and it delivered the maximum capacitance of122 F g 1 at 0.25 Ag 1. An AC impedance and cyclic voltammetry analyses proved the intrinsicelectrochemical behavior by their cycling. Besides, the fabricated symmetric solid-state supercapacitordisplayed an outstanding cycle durability with a stable capacitance retention of 85.8% over 8000 cycles,suggesting favorable prospects for its use as an active candidate for symmetric solid-state supercapacitorapplications.

Additive Main Effects and Multiplicative Interaction Analysis of Host-Pathogen Relationship in Rice-Bacterial Blight Pathosystem

Nayak, D.,Bose, L.K.,Singh, S.,Nayak, P. The Korean Society of Plant Pathology 2008 Plant Pathology Journal Vol.24 No.3

Host-pathogen interaction in rice bacterial blight pathosystem was analyzed for a better understanding of their relationship and recognition of stable pathogenicity among the populations of Xanthomonas oryzae pv. oryzae. A total number of 52 bacterial strains isolated from diseased leaf samples collected from 12 rice growing states and one Union Territory of India, were inoculated on 16 rice varieties, each possessing known genes for resistance. Analysis of variance revealed that the host genotypes(G) accounted for largest(78.4%) proportion of the total sum of squares(SS), followed by 16.5% due to the pathogen isolates(I) and 5.1% due to the $I{\times}G$ interactions. Application of the Additive Main effects and Multiplicative Interaction(AMMI) model revealed that the first two interaction principal component axes(IPCA) accounted for 66.8% and 21.5% of the interaction SS, respectively. The biplot generated using the isolate and genotypic scores of the first two IPCAs revealed groups of host genotypes and pathogen isolates falling into four sectors. A group of five isolates with high virulence, high absolute IPCA-1 scores, moderate IPCA-2 scores, low AMMI stability index '$D_i$' values and minimal deviations from additive main effects displayed in AMMI biplot as well as response plot, were identified as possessing stable pathogenicity across 16 host genotypes. The largest group of 27 isolates with low virulence, small IPCA-1 as well as IPCA-2 scores, low $D_i$ values and minimal deviations from additive main effect predictions, possessed stable pathogenicity for low virulence. The AMMI analysis and biplot display facilitated in a better understanding of the host-pathogen interaction, adaptability of pathogen isolates to specific host genotypes, identification of isolates showing stable pathogenicity and most discriminating host genotypes, which could be useful in location specific breeding programs aiming at deployment of resistant host genotypes in bacterial blight disease control strategies.

Microstructural evolution of sputtered ZnO thin films with rapid thermal annealing

Ghosh, S. P.,Das, K. C.,Tripathy, N.,Bose, G.,Kim, D. H.,Lee, T. I.,Myoung, J. M.,Kar, J. P. Springer Science + Business Media 2015 Journal of materials science Materials in electron Vol.26 No.10

A green approach for the reduction of graphene oxide by wild carrot root

Kuila, T.,Bose, S.,Khanra, P.,Mishra, A.K.,Kim, N.H.,Lee, J.H. Pergamon Press ; Elsevier Science Ltd 2012 Carbon Vol.50 No.3

A green approach for the reduction of graphene oxide (GO) using wild carrot root is reported in this work. It avoids the use of toxic and environmentally harmful reducing agents commonly used in the chemical reduction of GO to obtain graphene. The endophytic microorganisms present in the carrot root, reduces exfoliated GO to graphene at room temperature in an aqueous medium. Transmission electron microscopy and atomic force microscopy images provide clear evidence for the formation of few layer graphene. Characterization of the resulting carrot reduced GO by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy shows partial reduction of GO to graphene. Raman spectroscopy data also indicates the partial removal of oxygen-containing functional groups from the surface of GO and formation of graphene with defects.

Additive Main Effects and Multiplicative Interaction Analysis of Host-Pathogen Relationship in Rice-Bacterial Blight Pathosystem

D. Nayak,L. K. Bose,S. Singh,P. Nayak 한국식물병리학회 2008 Plant Pathology Journal Vol.24 No.3

Host-pathogen interaction in rice bacterial blight pathosystem was analyzed for a better understanding of their relationship and recognition of stable pathogenicity among the populations of Xanthomonas oryzae pv. oryzae. A total number of 52 bacterial strains isolated from diseased leaf samples collected from 12 rice growing states and one Union Territory of India, were inoculated on 16 rice varieties, each possessing known genes for resistance. Analysis of variance revealed that the host genotypes (G) accounted for largest (78.4%) proportion of the total sum of squares (SS), followed by 16.5% due to the pathogen isolates (I) and 5.1% due to the I x G interactions. Application of the Additive Main effects and Multiplicative Interaction (AMMI) model revealed that the first two interaction principal component axes (IPCA) accounted for 66.8% and 21.5% of the interaction SS, respectively. The biplot generated using the isolate and genotypic scores of the first two IPCAs revealed groups of host genotypes and pathogen isolates falling into four sectors. A group of five isolates with high virulence, high absolute IPCA-1 scores, moderate IPCA-2 scores, low AMMI stability index ‘Di’ values and minimal deviations from additive main effects displayed in AMMI biplot as well as response plot, were identified as possessing stable pathogenicity across 16 host genotypes. The largest group of 27 isolates with low virulence, small IPCA-1 as well as IPCA- 2 scores, low Di values and minimal deviations from additive main effect predictions, possessed stable pathogenicity for low virulence. The AMMI analysis and biplot display facilitated in a better understanding of the host-pathogen interaction, adaptability of pathogen isolates to specific host genotypes, identification of isolates showing stable pathogenicity and most discriminating host genotypes, which could be useful in location specific breeding programs aiming at deployment of resistant host genotypes in bacterial blight disease control strategies.