Publication
The details of my publications can be seen at Google Scholar and Research Gate.
Details of Publication
In International Journal
- Ultrasonic properties at the nanoscale in some metals”, R. R. Yadav and D. K. Pandey, Materials Letters, 59 (5) (2005) 564-569 (Netherlands).
- Size dependent acoustical properties of bcc metal, R. R. Yadav and D. K. Pandey, Acta Physica Polonica A, 107 (2005) 933-946 (Poland).
- Ultrasonic characterization of gallium nitride, R. R. Yadav and D. K. Pandey, Material Research Innovations, 10(4) (2006)1-6 (UK).
- Ultrasonic wave propagation in IIIrd group nitrides, D. K. Pandey, Devraj Singh and R. R. Yadav, Applied Acoustics, 68 (2007) 766–777 (USA).
- Acoustic wave propagation in Laves-phase compounds, D. K. Pandey, P. K. Yadawa and R. R. Yadav, Materials Letters, 61 (2007) 4747–4751 (Netherlands).
- Ultrasonic properties of hexagonal ZnS at nanoscale, D. K. Pandey, P. K. Yadawa and R. R. Yadav, Materials Letters, 61 (2007) 5194–5198 (Netherlands).
- Ultrasonic study of fission products precipitated in the nuclear fuel, A.K.Yadav, R.R.Yadav, D.K.Pandey, Devraj Singh, Materials Letters, 62 (2008) 3258-3261.
- Attenuation of ultrasonic waves in V, Nb and Ta at low temperatures, Devraj Singh, D.K.Pandey, P.K.Yadawa and Anil Kumar Yadav, Cryogenics, 49 (2009) 12-16.
- Temperature dependent ultrasonic properties of aluminium nitride, D. K. Pandey and R. R. Yadav, Applied Acoustics, 70 (3) (2009) 412-415.
- Ultrasonic wave propagation in rare-earth monochalcogenides, Devraj Singh, D.K.Pandey and P.K.Yadawa, Central European Journal of Physics (Versita-Springer), 7 (2009) 198-205.
- Ultrasonic investigations in intermetallics, Devraj Singh, D.K.Pandey, Pramana, 72 (2) (2009) 389-398.
- Synthesis and Nondestructive Characterization of Cr2O3 Nanoparticles-PVA Suspensions, D.K.Singh, R.R. Yadav and D.K.Pandey , Advanced Materials research, 67 (2009) 259-264.
- Ultrasonic study of osmium and ruthenium,D.K.Pandey, Devraj Singh and P.K.Yadawa, Platinum Metals Review, 53(2) (2009) 91-97.
- An ultrasonic characterization of ferrofluid, D.K.Singh, D.K.Pandey and R.R. Yadav, Ultrasonics, 49 (2009) 634-637 .
- Elastic and acoustic properties of heavy rare-earth metals, P.K.Yadawa, Devraj singh, D.K.Pandey and R.R.Yadav, TOACOJ (Bentham Science Publishers),2 (2009) 80-86.
- Computations of ultrasonic parameters of lanthanide metals Ti, Zr and Hf, P. K. Yadawa, D. K. Pandey, D. Singh, R. R. Yadav and G. Mishra, Turk. J. Phys., 34 (2010) 23-31.
- Propagation of ultrasonic waves in neptunium monochalcogenides, Devraj Singh, D.K.Pandey, D.K.Singh and R.R.Yadav, Applied Acoustics, 72 (2011)737-741.
- Acoustic Wave Propagation in Nanocrystalline RuCo Alloys, Pramod Kumar Yadawa, Devraj Singh, Dharmendra Kumar Pandey, Giridhar Mishra and Raja Ram Yadav, Advances in Materials Physics and Chemistry, 1(2011) 14-19.
- Temperature and orientation dependence of ultrasonic parameters in americium monopnictides, Devraj Singh, Rajkumar, Dharmendra Kumar Pandey, Advances in Materials Physics and Chemistry, 1(2011) 31-38.
- Ultrasonic Wave Propagation in Semi-Metallic Single Crystals, D. Singh, S. Tripathi, D. K. Pandey, A. Gupta, D.K.Singh and J. Kumar, Modern Physics Letters B, 25(31) (2011) 2377–2390.
- Non-linear elastic properties of single-walled carbon nanotubes, S.K.Verma, G. Mishra, D.K.Pandey and R.R.Yadav, Advanced Materials Letters, 3(1) (2012) 34-37.
- Characterization of CrO 2-poly-vinyl pyrrolidone magnetic nanofluid, D.K.Singh, D.K.Pandey R.R. Yadav and D. Singh,Journal of Magnetism and Magnetic Materials, 324 (2012) 3662–3667.
- A study of nanosized zinc oxide and its nanofluid, D.K.Singh, D. K. Pandey, R.R.Yadav and Devraj Singh, Pramana – Journal of Physics (Springer) 78(5) (2012) 759–766.
- Size dependent ultrasonic properties of InN nanowires, S.K. Verma , D.K.Pandey , R.R.Yadav, Physica B 407 (2012) 3731–3735.
- A study of ZnO nanoparticles and ZnO-EG nanofluid, Devraj Singh, D.K.Pandey, D.K.Singh and R.R.Yadav, Journal of Experimental Nanoscience, 8(5), (2013) 567-577.
- Study of Nanostructured Silver Sulfide and Its Nanofluid, S. K. Verma, D. K. Singh, D. K. Pandey, R. R. Yadav, National Academy Science Letters, 36(5) (2013) 535-540.
- Temperature dependent elastic and ultrasonic properties of ytterbium monopnictides, DK Pandey, D Singh, V Bhalla, S Tripathi, RR Yadav, Indian Journal of Pure & Applied Physics 52,(2014) 330-336.
- Effect of diameter and surface roughness on ultrasonic properties of GaAs nanowires, PK Dhawan, M Wan, SK Verma, DK Pandey, RR Yadav, Journal of Applied Physics 117 (7) (2015) 074307.
- Temperature Dependent Ultrasonic Characterization of Wurtzite Boron Nitride, CP Yadav, DK Pandey, Journal of Pure and Applied Ultrasonics 39 (4), (2017) 103-109.
- Ultrasonic attenuation in yttrium monochalcogenides, B Jyoti, D Singh, S Kaushik, V Bhalla, S Wadhwa, DK Pandey, Journal of Pure and Applied Ultrasonics 40 (4) (2018) 93-99.
- Pressure-and orientation-dependent elastic and ultrasonic characterisation of wurtzite boron nitride, CP Yadav, DK Pandey, Pramana 92 (1) (2019) 5.
- Elastic and thermo-acoustic study of YM intermetallics, A Khan, CP Yadav, DK Pandey, D Singh, D Singh, Journal of Pure and Applied Ultrasonics 41 (1) (2019) 1-8.
- Ultrasonic NDE of GdCu, SmCu, GdZn and SmZn intermetallics, DK Pandey, Journal of Pure and Applied Ultrasonics 41 (3) (2019) 57-62.
- Pressure dependent ultrasonic characterization of nano-structured w-BN, CP Yadav, DK Pandey, Ultrasonics 96 (2019) 181-184.
- Synthesis and Non-Destructive Characterization of Zinc Selenide Thin Films, BK Yadav, P Singh, DK Pandey, Zeitschrift fur Naturforschung a (A Journal of Physical Sciences) 74 (11) (2019) 1-7.
- Elastic and Ultrasonic Studies on RM (R = Tb, Dy, Ho, Er, Tm; M = Zn, Cu) Compounds, CP Yadav, DK Pandey, D Singh, Zeitschrift fur Naturforschung a (A Journal of Physical Sciences) 74 (12) (2019) 1-8.
- Ultrasonic study of Laves phase compounds ScOs2 and YOs2, CP Yadav, DK Pandey, D Singh, Indian Journal of Physics 93 (9) (2019) 1147-1153.
- Mechanical and Thermophysical Properties of ScM (M: Ru, Rh, Pd, Ag) Intermetallics, J Bala, D Singh, DK Pandey, CP Yadav, International Journal of Thermophysics 41 (2020) 46.
- Thermophysical and ultrasonic properties of GdCu under the effect of temperature and pressure, DK Pandey, CP Yadav, Phase Transitions 93 (3) (2020) 338-349.
- Ultrasonic Study of Si-oil based Magneto-Rheological Fluid, Chandreshvar Prasad Yadav, Dharmendra Kumar Pandey, Dhananjay Singh,Zeitschrift fur Naturforschung a (A Journal of Physical Sciences) accepted 7 (2020).
- Structural and Wavelength dependent optical study of thermally evaporated Cu2Se thin films, B K Yadav, Pratima Singh, C P Yadav, D K Pandey, Dhananjay Singh, Zeitschrift fur Naturforschung a (A Journal of Physical Sciences) accepted 8 (2020).
In National Journal
- “Phonon-Phonon Interaction in Low Carrier Heavy Fermion Systems” R. R. Yadav and D. K. Pandey, J. Acous. Soc. India, 31 (2003) 325-327
- “Acoustical investigation in HCP Metals”, R. R. Yadav and D. K. Pandey, J. Acoust. Soc. India, 32 (2004) 243-248.
- “Electron-Phonon interaction in nano crystalline Fe”, R. R. Yadav, A.K. Gupta and D. K. Pandey, J. Acoust. Soc. India, 32 (2004) 249-251.
- “Ultrasonic properties in some metals at nanoscale” R. R. Yadav, P. Awasthi and D. K. Pandey, J. Acoust. Soc. India, 32 (2004) 287-292.
- “Characterization of CdS and CdSe by ultrasonic technique”, P. K. Yadawa, D. K. Pandey and R. R. Yadav, J. Acoust. Soc. India, 33 (2005) 186-192.
- “High temperature anharmonic properties of InN”, A. K. Yadav, P. K. Yadawa, R. R. Yadav and D. K. Pandey, J. Acoust. Soc. India, 33 (2005) 193-199.
- “Ultrasonic investigation in particle reinforced nanofluids”, R. R. Yadav, P. K. Yadawa, A. K. Gupta and D. K. Pandey, J. Acoust. Soc. India, 33 (2005) 219-222.
- “Ultrasonic properties of beta-phase NiAl” R. R. Yadav and D. K. Pandey, J. Pure & applied Ultrasonics, 28(1) (2006) 4-11.
- Ultrasonic Velocity And Absorption Measurements In Lyotropic Liquid Crystal Systems, D.K.Pandey, Devraj Singh, P.K.Yadawa, R.R.Yadav, Macromolecule-An Indian Jornal, 3(3) (2007) 75-78..
- Ultrasonic studies of CTAB/decanol/water systems, D.K.Pandey, Devraj Singh, P.K.Yadawa, R.R.Yadav, Macromolecule-An Indian Jornal, 3(3) (2007) 79-83.
- Acoustic investigations on intermetallics, Devraj Singh and D.K.Pandey, Materials Science - An Indian Jornal, 4(2) (2008) 69-72.
Papers published in International Conferences Proceedings
- “Ultrasonic Attenuation in Low Carrier Heavy Fermion Systems.”R. R. Yadav and D. K. Pandey, Presented and published in Proceedings of 18th International Congress on Acoustics held at Kyoto (Japan), Vol. II (2004) 1149-1152.
- “Ultrasonic Properties at nanoscale in some metals”, R. R. Yadav and D. K. Pandey, Presented and published in the proceeding of the “International Symposium on Advanced Materials and Processing (ISAMAP2K4)” held at IIT Kharagpur, India, vol. II (2004) 1559-1566.
- “Particle size distribution and investigation of thermal properties of ZnO nanoparticles-ethylene glycol nanofluid” D.K.Singh, R.R.Yadav aand D.K.Pandey, presentated in International conference on “ Nanomaterlas and Nanotechnology (NANO-2010) held at KSR college of Technology, Tiruchengode, Namakkal, Tamilnadu, India and published in Process and characterization of Advanced Nanostructured Materials (Eds.: V.Rajendran, B. Hillbrands, N. Meenakshusundaram and K.E. Geckeler), (2010) 239-244 (Macmillan Publishers India Limited.
- Synthesis and frequency dependent ultrasonic characterization of NiO-EG nanofluids, M Wan, SK Verma, DK Pandey, RR Yadav, Proceedings of Meetings on Acoustics (Acoustical Society of America) 19 (2013) 045024.
- Attenuation of ultrasound in B1 and B2 structures of CdO, Jyoti Bala, V Bhalla, Devraj Singh, C P Yadav, D K pandey, Proceddings of International conference on Ultrasonics and Material Science For Advanced Technology (ICUMSAT-2019) Tile of Proceeding: Ultrasonics and Material Science for Advanced Technology (ISBN: 978 81 8487 703 8), Narosa Publishers, pp289.
Book Chapter/ Book Published
- Dharmendra Kumar Pandey and Shri Pandey, “Ultrasonics: A technique of material characterization” In Acoustic Waves” Book edited by: Don W. Dissanayake, ISBN 978-953-307-111-4, Sciyo Publishers, Sciyo, Croatia (2010) 397-430.
- R R YADAV, D SINGH, S P SINGH, D K PANDEY “MODERN PHYSICS FOR SCIENTISTS AND ENGINEERS”, PHI Publisher New Delhi, ISBN: 978-81-203-4858-5 (2013) Pages: 544
Invited Talk
- “Characteristics of Materials based on Ultrasonic Parameters” National seminar on Material characterization by Ultrasonics (NSMCU) held at AMITY School of Engineering and Technology, New Delhi. (affiliated with GGSIPU, New Delhi) during 3-4 April 2012.
- "Ultrasonic non-destructive testing of Magneto-rheological fluids", International conference on Ultrasonics and Material Science For Advanced Technology (ICUMSAT-2019) held at Jaunpur University on 16-18 November, 2019.
Papers presented in conferences and abstract published
- “Low Temperature Study of Metallic Alloys”, R. R. Yadav, D. K. Pandey and D.Singh, National Symposium on Ultrasonics (XII-NSU) (2003) held at G. N. D. University, Amritsar, India.
- “Acoustical Characterization of Hexagonal Compound GaN”, R. R. Yadav and D. K. Pandey, National Symposium on Ultrasonics (XIII-NSU) (2004) held at Bundelkhand University, Jhansi, India.
- “Ultrasonic Properties of Hexagonal ZnS at Nanoscale”, D. K. Pandey, P. K. Yadawa and R. R. Yadav, International workshop on Advanced materials and Technologies for Nano and oxide Electronics (AMTNOE 2007), held at IIT New Delhi.
- "NDT of Sodium Taurocholate / water systems”, D.K.Pandey, Devraj Singh, P.K.Yadawa, R.R.Yadav, National conference on Scientific Applications of Mathematics (NACSAM-2007), held at V.S.Mehta College of Science, Kausambi, U.P., India
- “Ultrasonic study of Osmium and Ruthenium”, D. K. Pandey, Devraj Singh, P. K. Yadawa etal., National Symposium on Ultrasonics (XVII-NSU) (2008) held at Banaras Hindu University, Varanasi, India.
- "Synthesis and Characterization of Cr+4 Oxide Nanofluid", D.K.Pandey, D.K.Singh, and R.R.Yadav, National Conference on Nanotechnology for sustainable Development 2010 held at Kulbhashker Ashram PG College, Allahabad during 9-10 Dec 2010 .
- “Ultrasonic Characterization of Some Lanthanide metals” D.K.Pandey, National Seminar on “Contribution of material science to the world today” held at DBS college, Kanpur during 18-19 Jan 2011.
- “Ultrasonic characterization of nanocrystalline silver and gold”, D. K. Pandey, National Symposium on Ultrasonics (XIX-NSU) (2012) held at NPL New Delhi India, during 30-31 Oct 2012.
- “Ultrasonic studies on nanosized zinc oxide and its nanofluid”, D.K.Singh, D.K.Pandey and R.R.Yadav, National seminar on Material characterization by Ultrasonics (NSMCU) held at AMITY School of Engineering and Technology, New Delhi. (affiliated with GGSIPU, New Delhi) during 3-4 April 2012.
- Temperature and Pressure dependent ultrasonic study of GdCu intermetallics, D K Pandey and C P Yadav, International conference on Ultrasonics and Material Science For Advanced Technology (ICUMSAT-2019) held at VBS Purvanchal University Jaunpur during 16-18 November 2019.
- “Ultrasonic properties in some metals at nanoscale”, R. R. Yadav, P. Awasthi and D. K. Pandey, National Symposium on Acoustics (NSA-2004) held at Mysore, Karnataka, India.
- “Ultrasonic Properties of Nanosized Tantalum”, R. R. Yadav and D. K. Pandey , International Conference on Nano Materials (NANO-2005), held at MEPCO Schlenk Engineering College, Sivakasi, Virudhunagar, Tamilnadu, India.
- “Ultrasonic Study of Lyotropic Liquid Crystal Systems based on N-Cetyl –N, N, N-Trimethyl Ammonium Bromide”, R. R. Yadav, P. K. Yadawa and D. K. Pandey , 17th AGM-MRSI Secretariat (2005) held at Lucknow, India.
- “Ultrasonic Characterization of Nanoparticles Suspended on Polymer Solution”, P.K. Yadawa, D. K. Pandey, R. R. Yadav and A. K. Gupta, National Conference on Advanced Characterization Techniques on Nanomaterials (ACTON-2005) held at IIT Roorakee, India.
- “Temperature and Orientation dependent Ultrasonic Properties of AlN”, R. R. Yadav, D. K. Pandey and P. K. Yadawa, Second Madhya Pradesh Science Congress 2005, held at Bhopal (Madhya Pradesh) during 17-18 Dec. 2005.
- “Ultrasonic Study of Quaternary Alloys”, A. K. Yadav , D. K. Pandey and R. R. Yadav, 15TH National Symposium on Ultrasonics (NSU-XV) held at University of Allahabad, Allahabad.
- “Ultrasonic Study of GaN, AlN and InN”, D. K. Pandey, P. K. Yadawa and R. R. Yadav, 15TH National Symposium on Ultrasonics (NSU-XV) held at University of Allahabad, Allahabad.
- ” Attenuation of ultrasonic waves in V, Nb and Ta at low temperatures”, Devraj Singh, D.K.Pandey, P.K.Yadawa, A.K.Yadav, National conference on Scientific Applications of Mathematics (NACSAM-2007), held at V.S.Mehta College of Science, Kausambi, U.P., India
- “Ultrasonic study of Hexagonal Lanthanides Metals Ti, Zr and Hf”, P. K. Yadawa, D. K. Pandey, Devraj Singh etal National Symposium on Ultrasonics (XVII-NSU) (2008) held at Banaras Hindu University, Varanasi, India.
- “Ultrasonic Attenuation in NPX (X: S, Se and Te)”, Devraj Singh, D. K. Pandey, P. K. Yadawa, etal. National Symposium on Ultrasonics (XVII-NSU) (2008) held at Banaras Hindu University, Varanasi, India.
- “Ultrasonic study of Hexagonal Lanthanides Metals”, P. K. Yadawa, D. K. Pandey, Devraj Singh, National Symposium on Acoustics (NSA-2008) held at Naval Science and Technological Laboratory (DRDO), Visakhapatnam , India.
- “Synthesis and ultrasonic characterization of GMR nanofluids”, D.K.Singh, Giridhar Mishra, D.K.Pandey, R.R.Yadav, International conference on Electroceramics (ICE 2009), held at Delhi University, Delhi, India.
- “Synthesis and ultrasonic characterization of ZnO-PVA nanofluids”, D.K.Singh, Giridhar Mishra, D.K.Pandey, R.R.Yadav, National Symposium on Ultrasonics 2009 (XVIII-NSU) held at VIT, Vellore, India.
- “Ultrasonic investigation of ZnO”, D.K.Singh, D.K.Pandey, R.R.Yadav, National Symposium on Ultrasonics 2009 (XVIII-NSU) held at VIT, Vellore, India.
- "Synthesis and ultrasonic Characterization of ZnO-EG Nanofluid", R. R. Yadav, Devraj singh, D.K.Pandey, D.K.Singh, and Giridhar Mishra, National Conference on Nanotechnology for sustainable Development 2010 held at Kulbhashker Ashram PG College, Allahabad during 9-10 Dec 2010 .
- "Temperature Dependent ultrasonic study of w-BN", C P Yadav and Dk Pandey, National seminar on Nano-science and nano-biotechnology, held at DAV College, Kanpur, 25-26 Feb 2017.
- "Ultrasonic Characterization of nanostructured w-BN" C P Yadav and D K Pandey, 22nd International conference of International academy of Physical Sciences (CONIAPSXXII), held at Dr. RML Awadh University, Faizabad during 13-15 April 2018.
- "Ultrasonic study of Lave phase compounds ScOs2 and YOs2" C P Yadav and DK Pandey, National symposium on Advanced Material Science, held at DDU Gorakhour, during 7-8 December 2018.
- "Ultrasonic study of RM intermetallic compounds" C P Yadav and DK Pandey, National seminar on Development and opportunities in Material Science, held at DBS College,Kanpur during 02 Feb 2019.
- Attenuation of ultrasound in B1 and B2 structures of CdO, Jyoti Bala, V Bhalla, Devraj Singh, C P Yadav, D K pandey, International conference on Ultrasonics and Material Science For Advanced Technology (ICUMSAT-2019) held at VBS Purvanchal University Jaunpur during 16-18 November 2019.
- Ultrasonic Study of Magneto-Rheological Fluids, C P Yadav, D K Pandey and Dhananjay Singh, International conference on Ultrasonics and Material Science For Advanced Technology (ICUMSAT-2019) held at VBS Purvanchal University Jaunpur during 16-18 November 2019.
- Ultrasonic Study of YM Intermetallics, Aftab Khan, C P Yadav, D K Pandey, Devraj Singh and Dhananjay Singh, International conference on Ultrasonics and Material Science For Advanced Technology (ICUMSAT-2019) held at VBS Purvanchal University Jaunpur during 16-18 November 2019.
- “Orientation workshop on radiation science and applications” organized by UGC DAE consortium scientific research Kolkata at Christ Church College, Kanpur, India, during 10-11 Feb, 2012
- “Workshop on Positive mental Health” sponsored by UGC under career and counseling at P.P.N. college kanpur, India on 4 March 2012
- Orientation Programme conducted by UGC ASC Lucknow University during 02-30 January 2012.
- Refresher Course in Physics conducted by UGC ASC Jabalpur University during 11.02.2013 to 28.02.2013.
- Faculty Development Programme on "Advancements in Material Characterization Techniques" organized by Department of Plastic technology, HBTU, Kanpur, during 16-21 December 2019.
- E-Faculty Development Programme on "E-Resources and Innovative Training Methods", organized by Dr. Gaur Hari Singhania Institute of Managment and research Kanpur, Uttar Pradesh during 27 April -03 May 2020 under UGC mandate DO No. 1-3/2020(CM) Dated 28 March 2020.
- E-Faculty Development Programme on "ICT Based Teaching and Learning", organized by Sharanabasaveshwar College of Arts, Kalburagi, Karnataka during 03 -07 June 2020 under UGC mandate DO No. 1-3/2020(CM) Dated 28 March 2020.
- E-Faculty Development Programme on "E-Learing Development in Higher Education", organized by Arya Mahila PG College, Varanasi, Uttar Pradesh, during 09 -15 June 2020 under UGC mandate DO No. 1-3/2020(CM) Dated 28 March 2020.
- E-Workshop on "E-Content Development for online Teaching and Learning: Need of the Hour", organized by Harish Chandra PG College, Varanasi, Uttar Pradesh, during 25June -01 July 2020 under UGC mandate DO No. 1-3/2020(CM) Dated 28 March 2020.
- E-Workshop on "Learning by Performing Through Virtual Labs", organized by Institute of engineering and Technology, Dr. RML Awadh University, Ayodhya, Uttar Pradesh, during 01-05 July 2020 under UGC mandate DO No. 1-3/2020(CM) Dated 28 March 2020.
- Webinar on topic - "Challenges and opportunities of Digital Higher Education in Post Corona scenario" organized by Swami Shukdevanand College, Shahjahanpur, UP held on 04 May 2020.
- Webinar on topic - "Challenges and Prospects in Higher Education in Global Pandemic" organized by Bareilly College, Bareilly, UP held on 10 May 2020.
- Webinar on topic - "The scenario of responsibility and dilema in building the individual and society between traditional and social media -A Dialogue " organized by Swami Shukdevanand College, Shahjahanpur, UP held on 11 May 2020.
- Webinar on topic - "Seven Criterion of NAAC" organized by Pt. DDU Givt. Girls Degree College, Sewapuri, Varanasi, UP held on 14 May 2020.
- Webinar on topic - "IDL LITE Talks", IEEE Photonics Society and IIT Bombay, Mumbai held on 16 May 2020.
- International Webinar on topic - "Cyber Security in Online Education" organized by Swami Vivekanand Subharti University, Meerut, UP held on 24 May 2020.
- Webinar on topic - "Understanding of Physics in 2020", IEEE and PSIT UP held on 27 May 2020.