Synthesis, characterization of Fe3O4@glycine doped polypyrrole magnetic nanocomposites and their potential performance to remove toxic Cr(VI)

N. Ballav,최형진,S.B. Mishra,A. Maity 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

Fe3O4 coated glycine doped polypyrrolemagnetic nanocomposite (Fe3O4@gly-PPy NC) was prepared viacoating of suspended Fe3O4 nanoparticles with gly-PPy. FE-SEM and HR-TEM images indicated thatFe3O4 nanoparticles were encapsulated by precipitating gly-PPy moieties. Chromium(VI) adsorptionfollowed a Langmuir isothermwith maximum capacity of 238–303 mg/g for a temperature range of 25–45 ℃ at pH 2. The adsorption process was governed by the ionic interaction and the reduction of Cr(VI) toCr(III) by the PPy moiety. Results showed that NCs are effective adsorbents for the removal of Cr(VI) fromwastewater and can be separated by external magnetic field from the reactor.

Screening for the Hormonal Properties of the Chloroform Extract of Carica papaya Linn. Seeds for Antifertility Investigation

Mishra, P.K.,Pathak, N.,Manivannan, B.,Lohiya, N.K. The Korean Society of Pharmacognosy 2000 Natural Product Sciences Vol.6 No.1

The chloroform extract of the seeds of Carica papaya has been screened for the hormonal properties using ovariectomized female rats for estrogenicity, estrogen primed immature rats for progestogenicity and castrated adult male rats for androgenicity. The results revealed that the extract lacks progestogenicity and androgenicity as evident from the failure of the extract treated animals to mimic progestogen and androgen related changes in the target tissues. The increased weight of vagina and uterus, open status of vagina, cornified and epithelial cells in the vaginal smears and hypertrophy in the uterine epithelium, endometrium and stroma with increased glycogen and sialic acid content in the uterus of the chloroform extract treated animals, which are comparable to those of the ovariectomized estrogen treated animals, suggest that the chloroform extract possesses mild estrogenic activity.

Synthesis, characterization of Fe₃O₄χlycine doped polypyrrole magnetic nanocomposites and their potential performance to remove toxic Cr(VI)

Ballav, N.,Choi, H.J.,Mishra, S.B.,Maity, A. Korean Society of Industrial and Engineering Chemi 2014 Journal of industrial and engineering chemistry Vol.20 No.6

Fe<SUB>3</SUB>O<SUB>4</SUB> coated glycine doped polypyrrole magnetic nanocomposite (Fe<SUB>3</SUB>O<SUB>4</SUB>χly-PPy NC) was prepared via coating of suspended Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles with gly-PPy. FE-SEM and HR-TEM images indicated that Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles were encapsulated by precipitating gly-PPy moieties. Chromium(VI) adsorption followed a Langmuir isotherm with maximum capacity of 238-303mg/g for a temperature range of 25-45<SUP>o</SUP>C at pH 2. The adsorption process was governed by the ionic interaction and the reduction of Cr(VI) to Cr(III) by the PPy moiety. Results showed that NCs are effective adsorbents for the removal of Cr(VI) from wastewater and can be separated by external magnetic field from the reactor.

Polypyrrole-coated halloysite nanotube clay nanocomposite: Synthesis, characterization and Cr(VI) adsorption behaviour

Ballav, N.,Choi, H.J.,Mishra, S.B.,Maity, A. Elsevier 2014 Applied clay science Vol.102 No.-

A polypyrrole-coated halloysite nanotube nanocomposite (PPy-HNTs NC) was prepared via in situ polymerization of pyrrole (Py) in the dispersion of HNTs and assessed for the removal of toxic Cr(VI) from aqueous solutions. ATR-FTIR and XRD results confirmed the formation of the nanocomposite. The FE-SEM and TEM images revealed the coating of PPy in the halloysite matrix and the surface morphology of the PPy-HNTs NC. Batch adsorption study showed that the adsorption process was very fast and kinetic data well fitted with pseudo-second-order kinetic model. Adsorption isotherms followed the Langmuir isotherm model and the maximum adsorption capacity was found to be 149.25mg/g at pH2.0 at 25<SUP>o</SUP>C. The adsorption process was spontaneous and endothermic in nature. XPS study confirmed the adsorption of Cr(VI) onto the NC where some part of Cr(VI) reduced to Cr(III) by electron-rich PPy moiety. The desorption study suggested that the nanocomposite (NC) can be reused three times without loss of its original removal efficiency. Tests on contaminated groundwater and chrome mine water indicated the potential applicability of the adsorbents for the removal of Cr(VI) for actual field application.

Gum ghatti and Fe3O4 magnetic nanoparticles based nanocomposites for the effective adsorption of methylene blue from aqueous solution

H. Mittal,N. Ballav,Shivani B. Mishra 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

This article reports the development and biosorption properties of iron oxide magnetic nanoparticles incorporated Gum ghatti based nanocomposites for the remediation of methylene blue contaminated water. The physico-chemical and structural characterization confirmed the incorporation of Fe3O4 MNPs with in the polymer matrix. Adsorption kinetics followed pseudo second order rate model. Adsorption isotherm fitted well with the Langmuir adsorption isotherm with the maximum adsorption capacity of 671.14 mg/g. Thermodynamic parameters like △S0, △H0 and △G0 were investigated and the desorption studies showed that the nanocomposite can be regenerated and reused for the removal of methylene blue.

Characteristics of SiO₂ etching by using pulse-time modulation in 60 MHz/2 MHz dual-frequency capacitive coupled plasma

Jeon, M.H.,Mishra, A.K.,Kang, S.K.,Kim, K.N.,Kim, I.J.,Lee, S.B.,Sin, T.H.,Yeom, G.Y. Elsevier 2013 Current Applied Physics Vol.13 No.8

60 MHz pulsed radio frequency (rf) source power and 2 MHz continuous wave rf bias power, were used for SiO<SUB>2</SUB> etching masked with an amorphous carbon layer (ACL) in an Ar/C<SUB>4</SUB>F<SUB>8</SUB>/O<SUB>2</SUB> gas mixture, and the effects of the frequency and duty ratio of the 60 MHz pulse rf power on the SiO<SUB>2</SUB> etch characteristics were investigated. With decreasing duty ratio of the 60 MHz pulse rf power, not only the etch rate of SiO<SUB>2</SUB> but also the etch rate of ACL was decreased, however, the etch selectivity of SiO<SUB>2</SUB> over ACL was improved with decreasing the duty ratio. On the other hand, when the pulse frequency was varied at a constant duty ratio, no significant change in the etch rate and etch selectivity of both materials could be observed. The variation of the etch characteristics was believed to be related to the change in the gas dissociation characteristics caused by the change in the average electron temperature for different pulsing conditions. The improvement in the etch selectivity with the decrease of duty ratio, therefore, was related to the decreased gas dissociation of C<SUB>4</SUB>F<SUB>8</SUB> by the decrease of average electron temperature and, which resulted in a change in composition of the fluorocarbon polymer on the etched materials surface from C-C rich to CF<SUB>2</SUB> rich. With decreasing the duty ratio, not only the etch selectivity but also the improvement in the SiO<SUB>2</SUB> etch profile could be observed.

Characteristics of SiO2 etching by using pulse-time modulation in 60 MHz/2 MHz dual-frequency capacitive coupled plasma

M. H. Jeon,A.K. Mishra,S-K. Kang,K.N. Kim,I.J. Kim,S.B. Lee,T.H. Sin,염근영 한국물리학회 2013 Current Applied Physics Vol.13 No.8

60 MHz pulsed radio frequency (rf) source power and 2 MHz continuous wave rf bias power, were used for SiO2 etching masked with an amorphous carbon layer (ACL) in an Ar/C4F8/O2 gas mixture, and the effects of the frequency and duty ratio of the 60 MHz pulse rf power on the SiO2 etch characteristics were investigated. With decreasing duty ratio of the 60 MHz pulse rf power, not only the etch rate of SiO2 but also the etch rate of ACL was decreased, however, the etch selectivity of SiO2 over ACL was improved with decreasing the duty ratio. On the other hand, when the pulse frequency was varied at a constant duty ratio, no significant change in the etch rate and etch selectivity of both materials could be observed. The variation of the etch characteristics was believed to be related to the change in the gas dissociation characteristics caused by the change in the average electron temperature for different pulsing conditions. The improvement in the etch selectivity with the decrease of duty ratio, therefore, was related to the decreased gas dissociation of C4F8 by the decrease of average electron temperature and, which resulted in a change in composition of the fluorocarbon polymer on the etched materials surface from CeC rich to CF2 rich. With decreasing the duty ratio, not only the etch selectivity but also the improvement in the SiO2 etch profile could be observed.

Design of an ON/OFF Mist Duty Cycle in Mist Bioreactors for the Growth of Hairy Roots

Ritu Ranjan,Naseem Ahmed,Rajesh Khanna,B. N. Mishra 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.1

In this study, we designed a strategy for selecting the operating conditions of a mist reactor for the growth of hairy roots. This was accomplished by developing a mathematical model to optimize the ON/OFF mist duty cycle for the specified growth of hairy roots. The availability and rate of transport of nutrients to the roots are important parameters in the design and operation of the reactor. The thin liquid film over the root surface, which continuously builds up during the ON cycle, is a major factor that limits mass transfer. The same film also acts as a finite reservoir of nutrients in the absence of any replenishment during the OFF cycle. This reservoir gets depleted as growing roots continue to consume the nutrients. As a result of this depletion the duration of the OFF cycle must be limited such that the nutrient concentration does not go below the critical value required for the specified growth rate. The depleted reservoir is then replenished during the next ON cycle to an extent that depends on feed concentration and duration of the next ON cycle. It was shown that the use of increasing feed concentrations in the fed-batch mode of operation could maintain a specified growth rate in the reactor. Interestingly, this also resulted in the efficient operation of the reactor whereby the reactor operated at slightly above the required concentration and close to the point of minimum mass transfer resistance.

Development of Diagnostic and Vaccine Markers Through Cloning, Expression, and Regulation of Putative Virulence-Protein-Encoding Genes of Aeromonas hydrophila

Vijai Singh,Dharmendra Kumar Chaudhary,Indra Mani,Rohan Jain,B.N. Mishra 한국미생물학회 2013 The journal of microbiology Vol.51 No.3

Aeromonas hydrophila is an opportunistic bacterial pathogen that is associated with a number of diseases in fish, amphibians, reptiles, and humans. In fish it causes several disease symptoms including tail and skin rot, and haemorrhagic septicemia; in human it causes soft-tissue wound infection and diarrhoea. The pathogenesis of A. hydrophila is multifactorial, but the mechanism is unknown so far. It is considered to be mediated by expression and secretion of extracellular proteins such as aerolysin, lipase, chitinase, amylase, gelatinase, hemolysins, and enterotoxins. A number of the putative virulence-protein-encoding genes that are present in the genome of A. hydrophila have been targeted by PCR for molecular diagnosis. These significant genes are also targeted for over-production of proteins by cloning and expression methods. In this review, we emphasize recent progress in the cloning, expression, and regulation of putative virulence-protein-encoding genes of A. hydrophila for a better understanding of the pathogenesis and also help to provide effective strategies for control of diseases.

Assessment of genetic diversity in androgenic-based doubled haploid-derived improved restorer lines of indica rice

Bhuyan Sudhansu Sekhar,Barik Durga Prasad,Dash Byomkesh,Rout Prachitara,Pattnaik Snigdha Samir,Verma Ramlakhan,Katara Jawahar Lal,Parameswaran C.,Devanna B. N.,Sahoo Raj Kishore,Mishra Anindita,Sabari 한국작물학회 2024 Journal of crop science and biotechnology Vol.27 No.2

Hybrid rice has a considerable yield advantage over inbred lines, but the adoption rate in India is quite slow. In a three-line hybrid rice breeding programme, the development of fertility restorer lines that have enhanced grain quality is crucial. Employment of doubled haploid (DH) technology will accelerate the development of improved R lines in a short period of time, thus hastening the pace of hybrid rice breeding. This investigation was carried out for the evaluation of genetic diversity and assessment of population differentiation in 113 DHs derived from BC1F1s of IMP. IR 42266-29-3R and Nagina 22. A total of 46 SSR (Simple Sequence Repeat) markers resulted in an average of 2.00 alleles per locus. Polymorphism information content (PIC) value ranged from 0.31 to 0.37 with an average of 0.36. RM496, RM25520, RM483 and RM553 were found to be the best markers for the identification of genetic diversity. Structure analysis classified 113 DHs into four groups, which matched the Neighbour-Joining method using UPGMA cluster analysis. The AMOVA results demonstrated substantial genetic variations within subpopulation than among sub-population. The SSR marker-based molecular fingerprinting could serve as a sound basis in the identification of genetically distant as well as in the duplicate sorting of the morphologically close population in future breeding programmes