• 제목/요약/키워드: Chandra

검색결과 426건 처리시간 0.024초

Solvent Free Microwave Accelerated Synthesis of Heterocyclic Thiazolidin-4-ones as Antimicrobial and Antifungal Agents

  • Sekhar, Kondapalli Venkata Gowri Chandra;Rao, Vajja Sambasiva;Reddy, Aravalli Satish;Sunandini, Ravada;Satuluri, V S A Kumar
    • Bulletin of the Korean Chemical Society
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    • 제31권5호
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    • pp.1219-1222
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    • 2010
  • A simple and efficient method has been developed for conversion of arenecarbaldehyde-3-methylquinoxalin-2-ylhydrazones to 3-(2-methylquinoxalin-3-yl)-2-(substitutedphenyl)thiazolidin-4-ones in good yields using microwave irradiation technique on silica as solid support under solvent free conditions. The synthesized compounds were characterized by elemental microanalysis, infrared spectroscopy, $^1H$ NMR, and mass spectroscopy. All the synthesized thiazolidinones were investigated for their antimicrobial and antifungal activities. The results of the biological activities revealed that the compounds 3b, 3d, 3f and 3h exhibited excellent antibacterial activities while 3d and 3h exhibited good antifungal activity.

Molecular and Morphological Characterization of Endophytic Heterobasidion araucariae from Roots of Capsicum annuum L. in Korea

  • Paul, Narayan Chandra;Deng, Jian Xin;Shin, Kyu-Seop;Yu, Seung-Hun
    • Mycobiology
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    • 제40권2호
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    • pp.85-90
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    • 2012
  • A species of Heterobasidion was encountered during a diversity study of endophytic fungi from healthy root tissues of chili pepper (Capsicum annuum L.) in Korea. The fungal species (CNU081069) was identified as Heterobasidion araucariae based on phylogenetic analyses of the internal transcribed spacer and translation elongation factor gene sequences. Morphological descriptions of the endophytic isolate matched well with the previous references and supported the molecular identification. The fungus Heterobasidion araucariae CNU081069 is new to Korea.

Effect of generalized thermoelasticity materials with memory

  • Baksi, Arup;Roy, Bidyut Kumar;Bera, Rasajit Kumar
    • Structural Engineering and Mechanics
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    • 제25권5호
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    • pp.597-611
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    • 2007
  • Many works have been done in classical theory of thermoelasticity in materials with memory by researchers like Nunziato, Chen and Gurtine and many others. No work is located in generalized thermoelasticity regarding materials with memory till date. The present paper deals with the wave propagation in materials with memory in generalized thermoelasticity. Plane progressive waves and Rayleigh waves have been discussed in details. In the classical theory of heat conduction it was observed that heat propagates with infinite speed. This paradox has been removed in the present discussion. The set of governing equations has been developed in the present analysis. The results of wave velocity and attenuation coefficient corresponding to low and high frequency have been obtained. For thermal wave the results show appreciable differences with those in the usual thermoelasticity theory.

MAC Layer Based Certificate Authentication for Multiple Certification Authority in MANET

  • Sekhar, J. Chandra;Prasad, Ramineni Sivarama
    • IEIE Transactions on Smart Processing and Computing
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    • 제3권5호
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    • pp.298-305
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    • 2014
  • In this study, a novel Randomly Shifted Certification Authority Authentication protocol was used in ad hoc networks to provide authentication by considering the MAC layer characteristics. The nodes achieve authentication through the use of public key certificates issued by a CA, which assures the certificate's ownership. As a part of providing key management, the active CA node transfers the image of the stored public keys to other idle CA nodes. Finally the current active CA randomly selects the ID of the available idle CA and shifts the CA ownership by transferring it. Revoking is done if any counterfeit or duplicate non CA node ID is found. Authentication and integrity is provided by preventing MAC control packets, and Enhanced Hash Message Authentication Code (EHMAC) can be used. Here EHMAC with various outputs is introduced in all control packets. When a node transmits a packet to a node with EHMAC, verification is conducted and the node replies with the transmitter address and EHMAC in the acknowledgement.

A Novel Alternaria Species Isolated from Peucedanum japonicum in Korea

  • Deng, Jian Xin;Cho, Hye Sun;Paul, Narayan Chandra;Lee, Hyang Burm;Yu, Seung Hun
    • Mycobiology
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    • 제42권1호
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    • pp.12-16
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    • 2014
  • We isolated and examined a new Alternaria sp., which causes leaf spots on Peucedanum japonicum in Korea, by using molecular and morphological methods. Phylogenetic analysis based on a combined internal transcribed spacer region analysis and two protein-coding genes (gpd and Alt a1) demonstrated that the causal fungus was most closely related to A. cinerariae and A. sonchi, and relevant to A. brassicae. However, conidial morphology indicated that it is a novel species within the genus Alternaria, and therefore we have assigned the fungus a new name in this study.

On (H, μn) Summability of Fourier Series

  • CHANDRA, SATISH
    • Kyungpook Mathematical Journal
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    • 제43권4호
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    • pp.513-518
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    • 2003
  • In this paper, we have proved a theorem on Hausdorff summability of Fourier series which generalizes various known results. We prove that if $${\int}_{o}^{t}\;{\mid}{\phi}(u){\mid}\;du=o(t)\;as\;t{\rightarrow}0\; and\;\lim_{n{\rightarrow}{\infty}}{\int}^{\eta}_{{\pi}/n}{\frac{{\mid}{\phi}(t)-{\phi}(t+{\pi}/n){\mid}}{t}}dt=o(n)$$ where 0 < ${\eta}$ < 1, then the Fourier series is (H, ${\mu}_n$) summable to s at t = x where the sequence ${\mu}_n$ is given by ${\mu}_n={\int}^1_0x^n{\chi}(x)\;dx\;n=0,1,2\;and\;K_n(t)=\limits\sum_{{\nu}=0}^n(\array {n\\{\nu}})({\Delta}^{{n}-{\nu}}{\mu}_{\nu}){\frac{sin{\nu}t}{t}}$.

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Adsorption of Atomic Hydrogen on ZnO Single Crystal Surfaces: A Study on the Impact of Surface Structure

  • ;;김창민
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.216-216
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    • 2012
  • The interaction of hydrogen with ZnO single crystal surfaces, ZnO (0001), ZnO (000-1), and ZnO (10-10) has been investigated using temperature programmed desorption (TPD) and X-ray photoelectron Spectroscopy (XPS) techniques. When the ZnO single crystal surfaces are exposed to atomic hydrogen at 200 K, all three surfaces show hydrogen desorption at 450 K. ZnO (0001) surface shows hydrogen desorption feature at ~260 K as the hydrogen exposure is increased. The ZnO (10-10) surface shows low-temperature desorption feature first and the high-temperature desorption feature appears as the hydrogen exposure increases. The ZnO (000-1) surface does not show any lower temperature hydrogen desorption. We will report the adsorption configuration of hydrogen atoms on ZnO single crystal surfaces with different surfaces structures.

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COINCIDENCE THEOREMS VIA CONTRACTIVE MAPPINGS IN ORDERED NON-ARCHIMEDEAN FUZZY METRIC SPACES

  • Prasad, Gopi;Tomar, Anita;Dimri, Ramesh Chandra;Bartwal, Ayush
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제27권4호
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    • pp.187-205
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    • 2020
  • In this article, we prove coincidence point theorems for comparable 𝜓-contractive mappings in ordered non-Archimedean fuzzy metric spaces utilizing the recently established concept of 𝓣-comparability and relatively weaker order theoretic variants. With a view to show the usefulness and applicability of this work, we solve the system of ordered Fredholm integral equations as an application. In the process, this presentation generalize and improve some prominent recent results obtained in Mihet [Fuzzy Sets Syst., 159 (6), 739-744, (2008)], Altun and Mihet [ Fixed Point Theory Appl. 2010, 782680, (2010)], Alam and Imdad [Fixed Point Theory, 18(2), 415-432, (2017)] and several others in the settings of partially ordered non-Archimedean fuzzy metric spaces.

Pharmacophore Hypothesis for Atypical Antipsychotics

  • Sekhar, Kondapalli Venkata Gowri Chandra;Vyas, Devambhatla Ravi Kumar;Nagesh, Hunsur Nagendra;Rao, Vajja Sambasiva
    • Bulletin of the Korean Chemical Society
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    • 제33권9호
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    • pp.2930-2936
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    • 2012
  • A three-dimensional pharmacophore hypothesis was developed for atypical antipsychotics in order to map common structural features of highly active compounds by using HipHop in CATALYST program. The pharmacophore hypotheses were generated using 12 compounds as training set and validated using 11 compounds as test set. The most predictive hypothesis (Hypo1) comprises five features viz. two hydrophobic regions, two hydrogen bond acceptor lipid and one aromatic ring. In the absence of information like crystallized structure of 5-$HT_{2A}$ receptor and binding mode of antipsychotics with 5-$HT_{2A}$ receptor, this hypothesis will serve as a potentially valuable tool in the design of novel atypical antipsychotics acting primarily at 5-$HT_{2A}$ and $D_2$ receptors.