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.

Sequence Spaces of Fuzzy Real Numbers Using Fuzzy Metric

Tripathy, Binod Chandra,Borgohain, Stuti Department of Mathematics 2014 Kyungpook mathematical journal Vol.54 No.1

The sequence spaces $c^F$(M), $c^F_0$(M) and ${\ell}^F$(M) of fuzzy real numbers with fuzzy metric are introduced. Some properties of these sequence spaces like solidness, symmetricity, convergence-free etc. are studied. We obtain some inclusion relations involving these sequence spaces.

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>

On Some New Paranormed Difference Sequence Spaces Defined by Orlicz Functions

Tripathy, Binod Chandra,Dutta, Hemen Department of Mathematics 2010 Kyungpook mathematical journal Vol.50 No.1

The main aim of this article is to introduce a new class of sequence spaces using the concept of n-norm and to investigate these spaces for some linear topological structures as well as examine these spaces with respect to derived (n-1)-norm. We use an Orlicz function, a bounded sequence of positive real numbers and some difference operators to construct these spaces so that they become more generalized and some other spaces can be derived under special cases. These investigations will enhance the acceptability of the notion of n-norm by giving a way to construct different sequence spaces with elements in n-normed spaces.

Enhanced anticancer potency using an acid-responsive ZnO-incorporated liposomal drug-delivery system

Tripathy, Nirmalya,Ahmad, Rafiq,Ko, Hyun Ah,Khang, Gilson,Hahn, Yoon-Bong The Royal Society of Chemistry 2015 Nanoscale Vol.7 No.9

<P>The development of stimuli-responsive nanocarriers is becoming important in chemotherapy. Liposomes, with an appropriate triggering mechanism, can efficiently deliver their encapsulated cargo in a controlled manner. We explored the use of acid-sensitive zinc oxide nanoparticles (ZNPs) as modulators of the responsive properties of liposomes. Nanocomplexes formed by the incorporation of ZNPs in liposomes (ZNP-liposomes) were designed to demonstrate the pH-responsive release of a drug (daunorubicin) without premature drug leakage and with the maintenance of the relevant therapeutic concentrations. The nanocomplexes were spherical in shape with a narrow size distribution and showed a high drug-encapsulating efficiency. Under acidic conditions, the ZNP-liposome nanocomplexes released the loaded drug more rapidly than bare liposomes. Using flow cytometry, confocal microscopy and an MTT assay, we demonstrated that these nanocomplexes were readily taken up by cancer cells, resulting in significantly enhanced cytotoxicity. On exposure to the acidic conditions inside cancer cells, the ZNPs rapidly decomposed, releasing the entrapped drug molecules from the ZNP-liposome nanocomplexes, producing widespread cytotoxic effects. The incorporated ZNPs were multimodal in that they not only resulted in a pH-responsive drug-delivery system, but they also had a synergistic chemo-photodynamic anticancer action. This design provides a significant step towards the development of multimodal liposome structures.</P>

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>

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.

Paranormed I-convergent Double Sequence Spaces Associated with Multiplier Sequences

Tripathy, Binod Chandra,Sen, Mausumi Department of Mathematics 2014 Kyungpook mathematical journal Vol.54 No.2

In this article we introduce different types of multiplier I-convergent double sequence spaces. We study their different algebraic and topological properties like solidity, symmetricity, completeness etc. The decomposition theorem is established and some inclusion results are proved.

Mesoporous ZnO nanoclusters as an ultra-active photocatalyst

Tripathy, N.,Ahmad, R.,Kuk, H.,Hahn, Y.B.,Khang, G. Ceramurgica ; Elsevier Science Ltd 2016 CERAMICS INTERNATIONAL Vol.42 No.8

Morphology modulation of nanostructured materials are highly crucial for various applications including photocatalysis, drug delivery, etc. In this study, mesoporous zinc oxide (ZnO) nanoclusters (MZN) were synthesized via a simple, cost-effective, low-temperature wet chemical route and further sucessfully utilized for photodegradation of Rhodamine B (RhB). Firstly, polystyrene (PS) nanospheres (~300nm) were prepared by polymerization of styrene in aqueous solvent. Then the MZN were achieved by formation of ZnO nanoparticles-shell over the surface of PS nanospheres via esterification of zinc acetate dihydrate in isopropyl alcohol followed by toluene dissolution of PS core. The as-synthesized MZN were spherically-shaped, porous in nature with a diameter of ~ 400nm and composed of well-arranged highly-crystalline ZnO nanoparticles (~ 5nm). The MZN also exhibited a high surface area of 78.3+/-5.4m<SUP>2</SUP>g<SUP>-1</SUP> and an average pore diameter of ~26nm. Furthermore, this unique structure demonstrates an expeditious photodegradation of RhB under UV illumination, monitored by UV-visible spectroscopy at different time intervals until the dye was completely degraded to colorless end products. Fast RhB decomposition was observed with a degradation rate of ~98% within initial 40min which can be attributed to the porous nature, large specific surface area and excellent electron accepting features of the engineered nanoclusters.