Concentration Dependent Optical Properties of Rhodamine B Doped Poly(vinyl alcohol) Solutions

Jitendra Tripathi,Anupam Sharma,Shilpa Tripathi,Kallol Kumar Das 한국고분자학회 2016 Macromolecular Research Vol.24 No.7

The optical properties, namely refractive index (RI) studies, are reported on a series of pure and doped poly(vinyl alcohol) (PVA) in solution form. The PVA solutions were synthesized with 1, 2, 3, 4, and 5 wt% of PVA in distilled water followed by doping with Rhodamine B in concentrations ranging from 0.05 wt% to 2 wt%. The absorption spectra show an observable shift in the band edge position towards higher wavelength with increase in PVA wt%. When the dopant molecules are added, the curves are drastically modified with the occurrence of new peaks arising at higher doping concentrations along with change in the bandgap. These effects are prominent for all the concentration of PVA solution. The RI does not change much for low doping wt%. but when dopant is added in higher concentrations, it increases slightly reaching a maximum of ~1.35 at 2 wt%. It is observed that host polymer properties dominate at low doping while a combination of host polymer and dopant dye properties dominate at higher doping concentrations.

Tales from Fragments: A Review of Indian Human Skeletal Studies

Veena Mushrif-Tripathy 대한체질인류학회 2019 해부·생물인류학 (Anat Biol Anthropol) Vol.32 No.2

India provides large number of skeletal data from the pre- and protohistoric levels covering a time span of almost 10,000 years. Major skeletal collection comes from the cultural phases ranging from the Mesolithic, Harappan, Neolithic, Chalcolithic and Iron Age levels. After the Early Historic phase cremation became the most common method for disposing the dead. Though the relevant documentation is far less than complete, recovery of human burials has been reported from more than 300 sites (Mushrif-Tripathy et al. 2016) and a conservative estimate would lead to imagine approximately 2000 human skeletons. The human skeletal analysis started around 1950s and initial focus of the study was to understand the racial classification of the skulls and to prove the Indo-Aryan invasion theory. Later from 1980s multidisplinary approach including socio-cultural anthropology, growth and nutrition and medical anthropology were considered. The recent development includes the use of new scientific methods like isotope, aDNA, DXA scans, and Scanning Electron Microscope studies etc. are consider to understand ancient inhabitants of Indian Sub-continent.

Morphological and Molecular Characterization of Endangered Medicinal Plant Species Coleus forskohlii Collected from Central India

Tripathi, Niraj,Saini, Navinder,Tiwari, Sharad 한국작물학회 2013 Journal of crop science and biotechnology Vol.16 No.4

In recent years, Coleus forskohlii has been considered plant as an important medicinal. Because of the continuous collection of roots from the wild sources, this plant has been included in the list of endangered species. This has necessitated the use of biotechnology in conservation and sustainable management of this endangered plant species. Morphological and molecular characterization of this herb will enhance our understanding in improving the optimal yields of Forskolin through breeding. To assess the morphological and molecular genetic diversity in 18 C. forskohlii genotypes collected from different places of central India, RAPD, ISSR, and AFLP marker systems were employed. Eleven RAPD, ten ISSRs and eight AFLP primers produced 101, 80, and 483 fragments, respectively. Among the three marker system used in this study, RAPD and ISSR showed 61.39 and 68.75% polymorphism, respectively, while eight AFLP primer combinations produced 70.81% polymorphism. UPGMA cluster analysis method group genotypes in two clusters with all marker systems separately and after combined analysis. Results show that both morphological and molecular factors are effective in observing variations. Our results also indicate that the RAPD, ISSR, and AFLP approaches, along with pharmaceutically important morphological trait analysis, seemed to be best-suited for assessing the genetic relationships among distinct C. Forskohlii genotypes with high accuracy.

Molecular Screening and Characterization of Antiviral Potatoes

Tripathi, Giriraj,Li, Hongxain,Park, Jae-Kyun,Park, Yoon-Kyung,Cheong, Hyeon-Sook The Korean Society for Biotechnology and Bioengine 2006 Biotechnology and Bioprocess Engineering Vol.11 No.2

Potato plants carrying the Ry gene are extremely resistance to a number of potyviruses, but it is not known which variety expressed the resistance. In this investigation, combined classical and molecular techniques were used to identify virus resistance potatoes. Mechanical inoculation of 32 varieties of Korean potato cultivars, with potato virus Y (PVY), induced various symptoms, such as mosaic, yellowing, necrosis, mottle, vein clearing and vein bending. Different virus spreading patterns were observed, such as highly sensitive, moderate and resistant to $PVY^o$ inoculated leaves in different cultivars. From the results of double antibody sandwich-enzyme links immunosorbant assays (DAS-ELISA), coupled with reverse transcription polymerase chain reaction (RT-PCR), Winter valley and Golden valley were found to be highly susceptible and resistant cultivars to $PVY^o$ respectively. TEM was used as a complementary method to conform the localization of the virus in leaf tissues. TEM detect virus particles in Golden valley, where, ELISA and RT-PCR were unable to detect the CP gene. However, the interior part of the tissues was severely deformed in $PVY^o$ infected Winter valley, than Golden valley The Ry gene is involved in an induced response in $PVY^o$ infected Golden valley plants. The methods described in this study could be applied for the screening and development of antiviral potatoes.

Time-Dependent Controlof Hole-Opening Degree of Porous ZnO Hollow Microspheres

Tripathy, Nirmalya,Ahmad, Rafiq,Jeong, Han-Sol,Hahn, Yoon-Bong American ChemicalSociety 2012 Inorganic Chemistry Vol.51 No.2

<P>Well-designed, monodispersed porous ZnO hollow microsphereswithcontrolled hole-opening were successfully synthesized by a faciletwo-step solution route at low temperature. The hollow microsphereshaving average diameter of 3–4 μm showed time-dependenthole-opening, i.e. 4–100% for 15–75 min. The hole-openingpercentage increases linearly with time until complete opening. TheZnO hollow microspheres also exhibited a high surface area (34 m<SUP>2</SUP> g<SUP>–1</SUP>), a large pore volume (0.19 cm<SUP>3</SUP> g<SUP>–1</SUP>) and an average pore diameter of 3.8nm. A plausible growth mechanism for the formation of ZnO hollow microsphereswas also proposed.</P><P>Well-designed, monodispersed porous ZnOhollow microsphereswith controlled hole-opening were synthesized by a facile low temperature,two-step solution route. The hollow microspheres having average diameterof 3−4 μm showed time-dependent hole-opening. The hole-openingpercentage increases linearly with time until complete opening. TheZnO hollow microspheres also exhibited high surface area, large porevolume and average pore diameter of 3.8 nm. A plausible growth mechanismfor the formation of ZnO hollow microspheres was also proposed.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/inocaj/2012/inocaj.2012.51.issue-2/ic2022598/production/images/medium/ic-2011-022598_0005.gif'></P>

Lacunary I-Convergent Sequences

Tripathy, Binod Chandra,Hazarika, Bipan,Choudhary, Bisweshwar Department of Mathematics 2012 Kyungpook mathematical journal Vol.52 No.4

In this article we introduce the concepts of lacunary I-convergent sequences. We investigate its different properties like solid, symmetric, convergence free etc.

Lacunary Statically Convergent and Lacunary Strongly Convergent Generalized Difference Sequences of Fuzzy Real Numbers

Tripathy, Binod Chandra,Baruah, Achyutanada Department of Mathematics 2010 Kyungpook mathematical journal Vol.50 No.4

In this paper we introduce the concept of lacunary statistical and lacunary strongly convergence of generalized difference sequence of fuzzy real numbers. We prove some inclusion relations and also study some of their properties.

Optical studies of Au@SnO2/poly-(vinyl) alcohol core-shell nanoparticle thin films

Tripathy, Suraj Kumar,Jo, Jin-Nyoung,O, Kwang-Joong,Han, Sang-Do,Lee, In-Hwan,Yu, Yeon-Tae Springer-Verlag 2010 Journal of materials science. Materials in electro Vol.21 No.8

Metal-induced redshift of optical spectra of gold nanoparticles: An instant, sensitive, and selective visual detection of lead ions

Tripathi, R.M.,Park, Sun Hee,Kim, Gahyeon,Kim, Do-Hwi,Ahn, Dohee,Kim, Yeong Mok,Kwon, Se Jeong,Yoon, Sun-Young,Kang, Hyo Jin,Chung, Sang J. Elsevier 2019 INTERNATIONAL BIODETERIORATION AND BIODEGRADATION Vol.144 No.-

<P><B>Abstract</B></P> <P>Environmental exposure to non-essential lead has become a serious problem in various developing and industrializing countries. There is an urgent need to develop a method offering instrument-free, rapid, highly sensitive, and selective detection of lead. Colorimetric detection of lead using gold nanoparticles (AuNPs) has been reported but these NPs require specific surface modifications and incubation times. In this study, we have developed an approach for instant, highly selective and sensitive detection of Pb<SUP>2+</SUP>. The as-synthesized AuNPs did not require any surface modification for the detection of Pb<SUP>2+</SUP>. The selectivity was evaluated by taking 300 μM of various metal ions and the assay color was found to change rapidly from red to blue in the presence of Pb<SUP>2+</SUP>, whereas the color remained the same for the other metal ions. The present method did not require a long incubation time as the assay color changed as soon as the AuNPs were added into the Pb<SUP>2+</SUP> solution. Therefore, the developed method realized rapid detection of Pb<SUP>2+</SUP>. The limit of detection and limit of quantification were calculated to be 18 μM and 53.5 μM, respectively. The detection mechanism was investigated using ultraviolet–visible spectroscopy, dynamic light scattering, Fourier transform infrared spectroscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The as-synthesized nanoparticles were used for the detection of Pb<SUP>2+</SUP>. </LI> <LI> Incubation with sample was not required as the method showed an ultra-rapid response. </LI> <LI> The LOD and LOQ were calculated to be 18 μM and 53.5 μM, respectively. </LI> <LI> The carboxylic group ligands governed the interaction between the AuNPs and Pb<SUP>2+</SUP>. </LI> <LI> A700/528 ratio shows Pb<SUP>2+</SUP> in highest aggregation but other metals similar to blank. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Graphene Coating via Chemical Vapor Deposition for Improving Friction and Wear of Gray Cast Iron at Interfaces

Tripathi, Khagendra,Gyawali, Gobinda,Lee, Soo Wohn American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.37

<P>This study reports the influence of CVD-graphene on the tribological performance of gray cast iron (GCI) from the internal combustion engine (ICE) cylinder liners by performing a ball-on-disk friction tests. The graphene-coated specimen exhibited a significant reduction (similar to 53%) of friction as compared to that of the uncoated specimen, whereas wear resistance increased by 2- and 5-fold regarding the wear of specimen and ball, respectively. Extremely low shear strength and highly lubricating nature of graphene contribute to the formation of a lubricative film between the sliding surfaces and decreases the interaction between surfaces in the dry environment. Under the applied load, a uniform film of iron oxides such as Fe2O3, Fe3O4, and FeOOH is found to be formed between the surfaces. It is proposed that the graphene encapsulation with the metal debris and oxides formed between the specimens increases the lubricity and decreases the shear force. The transformation of graphene/graphite into nanocrystalline graphites across the contact interfaces following the amorphization trajectory further increases the lubricity of the film that ultimately reduces friction and wear of the material.</P>