Browsing by Author "D. Tripathi"

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Deep states in hydrogenated Pd/Si diodes
(1988) P.C. Srivastava; D. Tripathi; S. Chandra
C-V characteristics of Pd/c-Si(n) diodes have been studied before and after hydrogenation. It has been found that there is a substantial deviation from theoretical calculations in the C-V plots in forward bias. It has been explained in terms of hydrogen-related acceptor-like states at 0.57 eV, spatially located at 0.15 mu m from the interface.
Hydrogen passivation studies on Pdn-type-Si diodes
(1989) D. Tripathi; P.C. Srivastava; S. Chandra
The effect of hydrogenation on the capacitance and the infrared absorption has been studied for a Pdn-type-Si diode. The hydrogenation reduces the carrier density by approximately 30%. The infrared spectrum after hydrogenation shows the following changes: (i) A small peak near 234010 cm-1 (corresponding to phosphorus-hydrogen bond) existing in the original sample grows and (ii) a new band near 21502050 cm-1 appears (corresponding to silicon-hydrogen bond). The growth of the silicon-hydrogen band is faster than that of the phosphorus-hydrogen band. These results show that the hydrogen passivates the donor states through the formation of phosphorus-hydrogen and silicon-hydrogen (adjacent to the substitutional phosphorus) -like species. © 1989 The American Physical Society.
Room temperature hydrogenation studies on silicon
(SPIE, 1992) P.C. Srivastava; D. Tripathi; S. Chandra
Pd/Si devices both on n/n and p/p substrates have been placed in hydrogen atmosphere with the intention of introducing atomic hydrogen in silicon at room temperature. The palladium films on the top of the silicon substrates absorbs hydrogen to form PdH and the hydrogen is subsequently released into silicon, which causes the passivation effect. The shallow dopants, both in n and p silicon substrates, are passivated to the extent of 30% and 50% respact-ively on hydrogenation. Frequency dispersion of capacitance shows the hydrogen passivation of deep states. © 1992 SPIE. All rights reserved.
Scoping review on the role and interactions of hydroxytyrosol and alpha-cyclodextrin in lipid-raft-mediated endocytosis of SARS-CoV-2 and bioinformatic molecular docking studies
(Verduci Editore s.r.l, 2021) Stefano Paolacci; A.K. Kiani; P. Shree; D. Tripathi; Y.B. Tripathi; P. Tripathi; G.M. Tartaglia; M. Farronato; G. Farronato; S.T. Connelly; M.R. Ceccarini; M. Coatto; M.C. Ergoren; T. Sanlidag; A. Dautaj; M. Bertelli
OBJECTIVE: The aim of the study was to show the effect that two naturally occurring compounds, a cyclodextrin and hydroxytyrosol, can have on the entry of SARS-CoV-2 into human cells. MATERIALS AND METHODS: The PubMed database was searched to retrieve studies published from 2000 to 2020, satisfying the inclusion criteria. The search keywords were: SARS-CoV, SARS-CoV-2, coronavirus, lipid raft, endocytosis, hydroxytyrosol, cyclodextrin. Modeling of alpha-cyclodextrin and hydroxytyrosol were done using UCSF Chimera 1.14. RESULTS: The search results indicated that cyclodextrins can reduce the efficiency of viral endocytosis and that hydroxytyrosol has antiviral properties. Bioinformatic docking studies showed that alpha-cyclodextrin and hydroxytyrosol, alone or in combination, interact with the viral spike protein and its host cell receptor ACE2, thereby potentially influencing the endocytosis process. CONCLUSIONS: Hydroxytyrosol and alpha-cyclodextrin can be useful against the spread of SARS-CoV-2. © 2021 Verduci Editore s.r.l. All rights reserved.
Studies on hydrogenated Pd/p-type Si diodes
(1992) D. Tripathi; P.C. Srivastava; S. Chandra
The effect of hydrogen on the Pd/p-type Si diode has been studied through capacitance and i.r. absorption measurements. For hydrogenation, the device was kept in an H2-atomosphere at ∼1 atm with the possibility that hydrogen would reach interface and bulk through the hydrogen storage property of Pd. The capacitance studies show that the hydrogenation results in passivation with the reduction of the free carrier concentration, deep bulk and interface states. The i.r. spectrum after hydrogenation shows the growth of the peaks related to the silicon-hydrogen-boron (SiHB) bonds and different modes of silicon-hydrogen (SiHx) bonds in the Si lattice. © 1992.