Search

Your search keyword '"MOHANTA, D"' showing total 207 results
Start Over Author "MOHANTA, D" Language english
207 results on '"MOHANTA, D"'

26. Atypical thermal transport in Cu nanorods in the diffusive-ballistic crossover

Author

Karmakar, P.K. and Mohanta, D.

Subjects
Copper -- Thermal properties, Nanorods -- Thermal properties, Physics
Abstract

We propose a simple theoretical calculation scheme based on the phenomenological Fourier heat-flow formalism to study thermal transport behaviors in nanoscale copper rods. The axial heat transport is characterized by a new super-oscillatory feature along with small-amplitude heat spikes. It is anticipated that these atypical spikes are generated by accumulation of localized 'hotspots' that have low heat dissipation characteristics. In the case of radial transport, we witness the existence of three distinct heat regimes owing to buildup of hot electrons after experiencing ballistic scattering events. It is important to note that, even though the nanorod diameter is comparable to or smaller than the electron mean free path length, [λ.sub.mfp] ~ 30 nm; multiple ballistic electronic scattering from the outer surface of the nanorods and subsequent accrual into several layers through secondary collisional events has led to concentric heat zones. The hotspots disappear when the nanorod diameter exceeds [λ.sub.mfp]. Key words: nanorod, metallic system, thermal transport, hotspot. Nous proposons un schema de calcul theorique base sur le formalisme de transfert de chaleur de Fourier, afin d'etudier le comportement du transport dans des nano-tiges de cuivre. Le transport axial est caracterise par une nouvelle super- oscillation avec de petits pics de chaleur de faible amplitude. Nous pensons que ces pics atypiques sont generes par l'accumulation locale de points chauds caracterises par une faible dissipation thermique. Dans le cas du transport radial, nous observons l'existence de trois regimes de chaleur distincts dus a l'accumulation d'electrons chauds suivant leur diffusion balistique. Il est un fait important, meme si le diametre de la nano-tige est comparable ou plus petit que le libre parcours moyen de l'electron, [λ.sub.mfp] ~ 30 nm: une diffusion electronique balistique multiple de la surface exterieure de la nano-tige et l'accumulation subsequente dans plusieurs couches via des collisions secondaires, menent a des zones de chaleur concentriques. Les points chauds disparaissent lorsque le diametre depasse [λ.sub.mfp]. [Traduit par la Redaction] Mots-cles: nano-tige, systeme metallique, transport thermique, point chaud., 1. Introduction In recent years, thermal properties of low-dimensional systems have gathered immense interest because of fundamental concern and relevance in diverse areas of nanotechnology research [1, 2]. An abrupt [...]

Published
2016
Full Text
View/download PDF

28. Prominent exciton emission dynamics and charged exciton (trion)-phonon coupling aspects in γ- irradiated WSe2 nanosheets.

Author

Sarmah, Hemanga J., Mohanta, D., and Saha, Abhijit

Subjects
*X-ray photoelectron spectroscopy, *BINDING energy, *HEAT sinks, *NANOSTRUCTURED materials, *POINT defects
Abstract

We report on the nature of charge-neutral exciton emission decay, exciton-trion conversion as well as their phonon coupling in exfoliated WSe2 nanosheets subjected to ~ 1.3 MeV energetic γ-photons. Steady-state photoluminescence (PL) spectra, upon deconvolution, showed prominent emission peaks at ~ 680 nm, ~ 712 nm, and ~ 730 nm and ascribed to 2s, and 1s excitons and trions respectively, while the chalcogen vacancy (VSe) mediated defect emission peak found at ~ 790 nm. From the X-ray photoelectron spectroscopy (XPS) analysis, we noticed a clear shifting of the fundamental peaks due to W and Se toward higher binding energy values and were attributed to the radiation-induced alteration in the oxidation states locally, taking advantage of the manifestation of point defects/vacancies. Moreover, the time-resolved PL spectra signify an anomalous variation in the fast parameter (0.4–0.86 ns), and with slow parameter (2.46–3.82 ns) getting slower with increasing γ-dose. A slight variation in the exciton-phonon coupling factor is noted with Se-ph < 1 indicating a weaker interaction and featuring maximal envelope over all the phonon replica near the zero-phonon line. In contrast, trion-phonon coupling factor, St-ph > 1, or < 1 depending on its spin degeneracy (ζ = 2 s + 1; with 2, for s = 1/2 and 4 for s = 3/2). The highest St-ph value determined was ~ 1.82 ± 0.2 which declines monotonically with increasing dose but remained greater than unity up to a γ-dose as high as 96 kGy. The implication of trion-phonon coupling has immense scope in nano-photovoltaics, and nano-electronics as well as heat sinks in nanogenerators. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

29. Experimental access to Transition Distribution Amplitudes with the P̄ANDA experiment at FAIR

Author

Singh, B. P., Erni, W., Keshelashvili, I., Krusche, B., Steinacher, M., Liu, B., Liu, H., Liu, Z., Shen, X., Wang, C., Zhao, J., Albrecht, M., Fink, M., Heinsius, F. H., Held, T., Holtmann, T., Koch, H., Kopf, B., Kümmel, M., Kuhl, G., Kuhlmann, M., Leyhe, M., Mikirtychyants, M., Musiol, P., Mustafa, A., Pelizäus, M., Pychy, J., Richter, M., Schnier, C., Schröder, T., Sowa, C., Steinke, M., Triffterer, T., Wiedner, U., Beck, R., Hammann, C., Kaiser, D., Ketzer, B., Kube, M., Mahlberg, P., Rossbach, M., Schmidt, C., Schmitz, R., Thoma, U., Walther, D., Wendel, C., Wilson, A., Bianconi, A., Bragadireanu, M., Caprini, M., Pantea, D., Pietreanu, D., Vasile, M. E., Patel, B., Kaplan, D., Brandys, P., Czyzewski, T., Czyzycki, W., Domagala, M., Hawryluk, M., Filo, G., Krawczyk, M., Kwiatkowski, D., Lisowski, E., Lisowski, F., Fiutowski, T., Idzik, M., Mindur, B., Przyborowski, D., Swientek, K., Czech, B., Kliczewski, S., Korcyl, K., Kozela, A., Kulessa, P., Lebiedowicz, P., Malgorzata, K., Pysz, K., Schäfer, W., Siudak, R., Szczurek, A., Biernat, J., Jowzaee, S., Kamys, B., Kistryn, S., Korcyl, G., Krzemien, W., Magiera, A., Moskal, P., Palka, M., Psyzniak, A., Rudy, Z., Salabura, P., Smyrski, J., Strzempek, P., Wrońska, A., Augustin, I., Lehmann, I., Nicmorus, D., Schepers, G., Schmitt, L., Al-Turany, M., Cahit, U., Capozza, L., Dbeyssi, A., Deppe, H., Dzhygadlo, R., Ehret, A., Flemming, H., Gerhardt, A., Götzen, K., Karabowicz, R., Kliemt, R., Kunkel, J., Kurilla, U., Lehmann, D., Lühning, J., Maas, F., Morales Morales, C., Mora Espí, M. C., Nerling, F., Orth, H., Peters, K., Rodríguez Piñeiro, D., Saito, N., Saito, T., Sánchez Lorente, A., Schmidt, C. J., Schwarz, C., Schwiening, J., Traxler, M., Valente, R., Voss, B., Wieczorek, P., Wilms, A., Zühlsdorf, M., Abazov, V. M., Alexeev, G., Arefiev, A., Astakhov, V. I., Barabanov, M. Yu., Batyunya, B. V., Davydov, Yu. I., Dodokhov, V. Kh., Efremov, A. A., Fedunov, A. G., Festchenko, A. A., Galoyan, A. S., Grigoryan, S., Karmokov, A., Koshurnikov, E. K., Lobanov, V. I., Lobanov, Yu. Yu., Makarov, A. F., Malinina, L. V., Malyshev, V. L., Mustafaev, G. A., Olshevskiy, A., Pasyuk, M. A., Perevalova, E. A., Piskun, A. A., Pocheptsov, T. A., Pontecorvo, G., Rodionov, V. K., Rogov, Yu. N., Salmin, R. A., Samartsev, A. G., Sapozhnikov, M. G., Shabratova, G. S., Skachkov, N. B., Skachkova, A. N., Strokovsky, E. A., Suleimanov, M. K., Teshev, R. Sh., Tokmenin, V. V., Uzhinsky, V. V., Vodopyanov, A. S., Zaporozhets, S. A., Zhuravlev, N. I., Zorin, A. G., Branford, D., Glazier, D., Watts, D., Woods, P., Britting, A., Eyrich, W., Lehmann, A., Uhlig, F., Dobbs, S., Seth, K., Tomaradze, A., Xiao, T., Bettoni, D., Carassiti, V., Cotta Ramusino, A., Dalpiaz, P., Drago, A., Fioravanti, E., Garzia, I., Savriè, M., Stancari, G., Akishina, V., Kisel, I., Kulakov, I., Zyzak, M., Arora, R., Bel, T., Gromliuk, A., Kalicy, G., Krebs, M., Patsyuk, M., Zuehlsdorf, M., Bianchi, N., Gianotti, P., Guaraldo, C., Lucherini, V., Pace, E., Bersani, A., Bracco, G., Macri, M., Parodi, R. F., Bianco, S., Bremer, D., Brinkmann, K. T., Diehl, S., Dormenev, V., Drexler, P., Düren, M., Eissner, T., Etzelmüller, E., Föhl, K., Galuska, M., Gessler, T., Gutz, E., Hayrapetyan, A., Hu, J., Kröck, B., Kühn, W., Kuske, T., Lange, S., Liang, Y., Merle, O., Metag, V., Mülhheim, D., Münchow, D., Nanova, M., Novotny, R., Pitka, A., Quagli, T., Rieke, J., Rosenbaum, C., Schnell, R., Spruck, B., Stenzel, H., Thöring, U., Ullrich, M., Wasem, T., Werner, M., Zaunick, H. G., Ireland, D., Rosner, G., Seitz, B., Deepak, P. N., Kulkarni, A. V., Apostolou, A., Babai, M., Kavatsyuk, M., Lemmens, P., Lindemulder, M., Löhner, H., Messchendorp, J., Schakel, P., Smit, H., van der Weele, J. C., Tiemens, M., Veenstra, R., Vejdani, S., Kalita, K., Mohanta, D. P., Kumar, A., Roy, A., Sahoo, R., Sohlbach, H., Büscher, M., Cao, L., Cebulla, A., Deermann, D., Dosdall, R., Esch, S., Georgadze, I., Gillitzer, A., Goerres, A., Goldenbaum, F., Grunwald, D., Herten, A., Hu, Q., Kemmerling, G., Kleines, H., Kozlov, V., Lehrach, A., Leiber, S., Maier, R., Nellen, R., Ohm, H., Orfanitski, S., Prasuhn, D., Prencipe, E., Ritman, J., Schadmand, S., Schumann, J., Sefzick, T., Serdyuk, V., Sterzenbach, G., Stockmanns, T., Wintz, P., Wüstner, P., Xu, H., Li, S., Li, Z., Sun, Z., Xu, H., Rigato, V., Fissum, S., Hansen, K., Isaksson, L., Lundin, M., Schröder, B., Achenbach, P., Bleser, S., Cardinali, M., Corell, O., Deiseroth, M., Denig, A., Distler, M., Feldbauer, F., Fritsch, M., Jasinski, P., Hoek, M., Kangh, D., Karavdina, A., Lauth, W., Leithoff, H., Merkel, H., Michel, M., Motzko, C., Müller, U., Noll, O., Plueger, S., Pochodzalla, J., Sanchez, S., Schlimme, S., Sfienti, C., Steinen, M., Thiel, M., Weber, T., Zambrana, M., Dormenev, V. I., Fedorov, A. A., Korzihik, M. V., Missevitch, O. V., Balanutsa, P., Balanutsa, V., Chernetsky, V., Demekhin, A., Dolgolenko, A., Fedorets, P., Gerasimov, A., Goryachev, V., Varentsov, V., Boukharov, A., Malyshev, O., Marishev, I., Semenov, A., Konorov, I., Paul, S., Grieser, S., Hergemöller, A. K., Khoukaz, A., Köhler, E., Täschner, A., Wessels, J., Dash, S., Jadhav, M., Kumar, S., Sarin, P., Varma, R., Chandratre, V. B., Datar, V., Dutta, D., Jha, V., Kumawat, H., Mohanty, A. K., Roy, B., Yan, Y., Chinorat, K., Khanchai, K., Ayut, L., Pornrad, S., Barnyakov, A. Y., Blinov, A. E., Blinov, V. E., Bobrovnikov, V. S., Kononov, S. A., Kravchenko, E. A., Kuyanov, I. A., Onuchin, A. P., Sokolov, A. A., Tikhonov, Y. A., Atomssa, E., Hennino, T., Imre, M., Kunne, R., Le Galliard, C., Ma, B., Marchand, D., Ong, S., Ramstein, B., Rosier, P., Tomasi-Gustafsson, E., Van de Wiele, J., Boca, G., Costanza, S., Genova, P., Lavezzi, L., Montagna, P., Rotondi, A., Abramov, V., Belikov, N., Bukreeva, S., Davidenko, A., Derevschikov, A., Goncharenko, Y., Grishin, V., Kachanov, V., Kormilitsin, V., Melnik, Y., Levin, A., Minaev, N., Mochalov, V., Morozov, D., Nogach, L., Poslavskiy, S., Ryazantsev, A., Ryzhikov, S., Semenov, P., Shein, I., Uzunian, A., Vasiliev, A., Yakutin, A., Yabsley, B., Bäck, T., Cederwall, B., Makónyi, K., Tegnér, P. E., von Würtemberg, K. M., Belostotski, S., Gavrilov, G., Izotov, A., Kashchuk, A., Levitskaya, O., Manaenkov, S., Miklukho, O., Naryshkin, Y., Suvorov, K., Veretennikov, D., Zhadanov, A., Rai, A. K., Godre, S. S., Duchat, R., Amoroso, A., Bussa, M. P., Busso, L., De Mori, F., Destefanis, M., Fava, L., Ferrero, L., Greco, M., Maggiora, M., Maniscalco, G., Marcello, S., Sosio, S., Spataro, S., Zotti, L., Calvo, D., Coli, S., De Remigis, P., Filippi, A., Giraudo, G., Lusso, S., Mazza, G., Mingnore, M., Rivetti, A., Wheadon, R., Balestra, F., Iazzi, F., Introzzi, R., Lavagno, A., Younis, H., Birsa, R., Bradamante, F., Bressan, A., Martin, A., Clement, H., Gålnander, B., Caldeira Balkeståhl, L., Calén, H., Fransson, K., Johansson, T., Kupsc, A., Marciniewski, P., Pettersson, J., Schönning, K., Wolke, M., Zlomanczuk, J., Díaz, J., Ortiz, A., Vinodkumar, P. C., Parmar, A., Chlopik, A., Melnychuk, D., Slowinski, B., Trzcinski, A., Wojciechowski, M., Wronka, S., Zwieglinski, B., Bühler, P., Marton, J., Suzuki, K., Widmann, E., Zmeskal, J., Fröhlich, B., Khaneft, D., Lin, D., Zimmermann, I., Semenov-Tian-Shansky, K., and The P̄ANDA Collaboration

Published
2015
Full Text
View/download PDF

41. Interfacial charge transfer mechanism in nanostructured Ti[O.sub.2]-ZnS coupled network for single electron device applications

Author

Mohanta, D., Deka, M., and Choudhury, A.

Subjects
Nanotechnology -- Research, Charge transfer -- Analysis, Titanium dioxide -- Chemical properties, Titanium dioxide -- Atomic properties, Physics
Abstract

The nanoporous Ti[O.sub.2] network sensitized by ZnS nanospheres is produced and described as an idealized scheme to facilitate interfacial charge transfer effects. The findings suggest that when a large band gap material is restricted in a confined geometry of lower energy band gap then the surface states are mainly responsible in the charge transport phenomena.

Published
2007

44. Application of Box-Behnken design in optimization of biodiesel yield using WO3/graphene quantum dot (GQD) system and its kinetics analysis.

Author

Borah, Manash J., Sarmah, Hemanga J., Bhuyan, Nilutpal, Mohanta, D., and Deka, D.

Abstract

In the current research, we report on the synthesis of WO3/GQD system as a heterogeneous catalyst for the transesterification of waste cooking oil into biodiesel using methanol. The characterization of the prepared catalyst was done by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscope (TEM), energy-dispersive X-ray (EDX), Fourier transform-infrared spectroscopy (FT-IR) techniques, and Brunauer-Emmett-Teller surface area measurement. To study the effect of process variables such as methanol to oil ratio, reaction temperature, and time, we have employed response surface methodology (RSM) based on Box-Behnken design (BBD). The suitability of the predicted model was verified, and the average biodiesel yield of (96.8 ± 0.16%) was reported at optimal reaction condition of 1:6 oil to methanol ratio, 70 °C reaction temperature, 2 wt% catalyst loading, and 3.5 h reaction time. Biodiesel was characterized using proton nuclear magnetic resonance (1H NMR) and carbon nuclear magnetic resonance (13C NMR) techniques, and fatty acid methyl ester composition was determined using gas chromatography-mass spectrometry (GC-MS). Fuel properties of the biodiesel obtained comply with ASTMD6751 biodiesel standards. The kinetics of transesterification was studied and found to follow pseudo-first order. The results showed the rate constant ranging from 0.0028 to 0.007 min−1, activation energy (Ea) of 55.92 kJ mol−1, and frequency factor (A) of 1.72 × 106 min−1. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

49. Synthesis and pore filling mechanism in anatase TiO2 nanostructured network mediated by PbS molecular adsorption.

Author

Dutta, N., Mohanta, D., and Choudhury, A.

Subjects
*TITANIUM dioxide, *ADSORPTION (Chemistry), *X-ray diffraction, *ELECTRON microscopy, *ATOMIC force microscopy
Abstract

In this work, we show that anatase nanoporous titanium dioxide (TiO2) structures can be sensitized by adequate PbS molecular adsorption. This was substantiated through x-ray diffraction, electron microscopy, atomic force microscopy, and nitrogen adsorption/desorption studies. The atomic force micrograph of the PbS/TiO2 system is characterized by a smooth surface topography as compared to the untreated TiO2 network. Further, N2 adsorption/desorption studies have revealed that the pores having a size greater than the Bohr exciton size (∼3.1 nm) of TiO2 can be efficiently filled by PbS molecules, whereas the smaller pores remain unfilled. The pore filling aspects, along with the kinetics of molecular adsorption in the coupled heterogeneous nanostructured system, would help to reveal the underlying mechanism of interfacial charge leakage phenomena in miniaturized nanoelectronic and nanophotonic junctions/components. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

50. Directed growth characteristics and optoelectronic properties of Eu-doped ZnO nanorods and urchins.

Author

Bayan, S. and Mohanta, D.

Subjects
*ZINC oxide, *EUROPIUM, *SEMICONDUCTOR doping, *NANOPARTICLES, *OPTOELECTRONICS
Abstract

Inexpensive fabrication of europium (Eu3+)-doped zinc oxide (ZnO) nanoparticles, nanorods, and urchin systems obtained by rapid thermal annealing is being reported. The polyvinyl alcohol films containing a reactant mixture [Zn(CH3COO)2, Eu(CH3COO)3, and NaOH] were casted on Al-foils followed by thermal annealing at 80, 300, and 650 °C. Gradual change-over from spherically symmetric nanoparticles to nanorods along with urchin like structures are obtained under different annealing environment. The nanorods and urchins are expected to have grown as a result of spontaneous decomposition of Zn(OH)2 followed by unidirectional growth. The nanorods are dislodged from the regular urchin structures at a high annealing temperature of 650 °C because of the loss of the crystalline substrate support. The as-received ZnO products possessed hexagonal wurtzite structure for all the annealing cases-as evident from the x-ray diffraction patterns. The photoluminescence study on the samples has revealed dominant defect related emissions compared to the near band edge emission. The band edge emission (∼382 nm) is recovered in the urchin systems whereas Eu3+ related transitions observed at ∼591 nm (5D0→7F1) and ∼613 nm (5D0→7F2) remained intact with structural modification. [ABSTRACT FROM AUTHOR]

Published
2010
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results