Antimicrobial and Micro Raman Spectroscopy of Selected Zingiberaceae Species from Northeast India

Archana Das,Latha Rangan,Vigya Kesari,Arpita Nath,Alika Khare 한국작물학회 2013 Journal of crop science and biotechnology Vol.16 No.1

Antimicrobial activity of crude rhizome oils from some important members of Zingiberaceae from Northeast India was carried out in the present study. The plants used were Curcuma amada, C. longa, Zingiber moran, and Z. zerumbet. Rhizomes of the four species were collected and rhizome oil was extracted using six different polar and non-polar solvents. The antimicrobial property of the crude oil was studied against human pathogens using disc-diffusion and viability assay. The rhizome oil of all the 24 extracts exhibited potent antimicrobial activity against all pathogenic bacterial and fungal strains tested. Hydrodistilled fractions of the four species studied showed better effect among all solvents. Water extract of Z. moran was found to be the highest effective antimicrobial agent of all. Antibacterial effect of the water fractions was also characterized against Gram-positive and Gram-negative bacteria using micro Raman spectroscopy. This investigation shows that the essential oils from the wild and domestic species of the family Zingiberaceae from Northeast India are a potential source of bioactive compounds with tremendous medicinal, economic, and therapeutic value. The wild and endemic species Z. moran represents an interesting and promising source of plant-derived antimicrobial agent in the development of new drugs against pathogens.

Treatment of monazite processed effluent to recover rare earth metals (REMs)

Archana Kumari,Sunidhi Singh,Kavita Parmar,Devendra Deo Pathak,Manis Kumar Jha 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.83 No.-

Improper disposal of effluent generated in rare earth mining areas and ore processing industries resultsin loss of REMs and miserably affects the ecosystem. Thus, their appropriate treatment is required, whichcan be achieved via environmentally feasible processes. In this connection, systematic scientificadsorption studies were carried out to separate REMs using cationic resin, Amberlite IR120 Na from theeffluent generated during monazite processing for REMs recovery. To optimize feasible conditions forREMs recovery, bench scale studies were carried out varying different process parameters viz. pH, contacttime, resin dose, etc. It was observed that adsorption of 92.63% La, 92.79% Ce, 91.45% Nd, 90.95% Pr and95.09% Sm was achieved at aqueous/ resin (A/R) ratio 25 mL/g, pH 1.3 and contact time 10 min. Loadingcapacity of resin was found to hold 48.57 mg REMs/g resin. The adsorption data followed the second orderreaction ((t/q) = (1/h) + (1/qe)(t)) and Langmuir adsorption isotherm (1/q = [(1/k1 qm)(1/Ce)] + (1/qm)). The loaded REMs was effectively eluted using 15% H2SO4 in 10 min. The REMs enriched solution wastreated to get pure REM oxides as precipitate. This technical application will be useful for REMs recoveryas well as to mitigate environmental pollution.

Thermal treatment for the separation of phosphate and recovery of rare earth metals (REMs) from Korean monazite

Archana Kumari,Rekha Panda,Manis Kumar Jha,이진영,J. Rajesh Kumar,Vinay Kumar 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

Systematic study for thermal decomposition of monazite to remove phosphate as a valuable productusing Na2CO3 and NaOH roasting processes to validate the TG/DTA studies is reported here. Monazite in1:1 wt. ratio with Na2CO3 and NaOH requires a temperature of 900 8C and 400 8C, respectively, for120 min in order to achieve complete conversion of rare earth phosphate into its oxides. The roastedmass was washed, dried and leached in 6 M HCl for 2 h, pulp density 30 g/L at 80 8C which results in>90% REMs recovery. Leach liquor generated will be further processed by solvent extraction andprecipitation processes.

Performance evaluation of different environmental conditions on output characteristics during turning of EN-24 steel

Archana Thakur,Alakesh Manna,Sushant Samir 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.10

The present study investigated the effect of different machining environments such as dry, wet, cryogenic cooling, minimum quantity lubrication (MQL), Al2O3 nanofluids with MQL, CuO nanofluids with MQL and Al–CuO hybrid nanofluids with MQL on machining performance characteristics during turning of EN-24 steel. The nanofluids and hybrid nanofluids were prepared by adding different weight percentages (0.2 wt%, 0.4 wt%, 0.6 wt%) of Al2O3, CuO and Al–CuO to the soluble oil. The thermal and tribological properties of soluble oil, nanofluids and hybrid nanofluids were analysed. The thermal conductivity of Al–CuO hybrid nanofluids was more compared with Al2O3, CuO nanofluids. The specific heat of Al–CuO hybrid nanofluids was less compared with Al2O3, CuO nanofluids. The comparative analysis of machining performance was done during turning under different environments. Experimental results reveal that the turning performance under Al–CuO hybrid nanofluids with MQL was better as compared to other machining environments.

Effect of Repetitive Transcranial Magnetic Stimulation on Seizure Frequency and Epileptiform Discharges in Drug-Resistant Epilepsy: A Meta-Analysis

Archana Mishra,Rituparna Maiti,Biswa Ranjan Mishra,Monalisa Jena,Anand Srinivasan 대한신경과학회 2020 Journal of Clinical Neurology Vol.16 No.1

Background and Purpose The role of low-frequency repetitive transcranial stimulation (rTMS) in drug-resistant epilepsy (DRE) has been conflicting and inconclusive in previous clinical trials. This meta-analysis evaluated the efficacy of rTMS on seizure frequency and epileptiform discharges in DRE. Methods A standard meta-analysis protocol was registered in the International Prospective Register of Ongoing Systematic Reviews (PROSPERO: CRD42018088544). After performing a comprehensive literature search using specific keywords in MEDLINE, the Cochrane database, and the International Clinical Trial Registry Platform (ICTRP), reviewers assessed the eligibility and extracted data from seven relevant clinical trials. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed in the selection, analysis, and reporting of findings. A random-effects model was used to estimate the effect size as the mean difference in seizure frequency and interictal epileptiform discharges between the groups. Quality assessment was performed using a risk-of-bias assessment tool, and a meta- regression was used to identify the variables that probably influenced the effect size. Results The random-effects model analysis revealed a pooled effect size of -5.96 (95% CI= -8.98 to -2.94), significantly favoring rTMS stimulation (p=0.0001) over the control group with regard to seizure frequency. The overall effect size for interictal epileptiform discharges also significantly favored rTMS stimulation (p<0.0001), with an overall effect size of -9.36 (95% CI=-13.24 to -5.47). In the meta-regression, the seizure frequency worsened by 2.00±0.98 (mean±SD, p=0.042) for each week-long lengthening of the posttreatment follow-up period, suggesting that rTMS exerts only a short-term effect. Conclusions This meta-analysis shows that rTMS exerts a significant beneficial effect on DRE by reducing both the seizure frequency and interictal epileptiform discharges. However, the meta-regression revealed only an ephemeral effect of rTMS.

Super paramagnetic ZIF-67 metal organic framework nanocomposite

Archana, K.,Pillai, Nisha G.,Rhee, Kyong Yop,Asif, A. Elsevier Science Ltd 2019 Composites Part B, Engineering Vol.158 No.-

<P><B>Abstract</B></P> <P>Nanoparticle encapsulated metal-organic framework composites have attracted attention in many fields owing to the achievement of combined properties. We report a simple method for the encapsulation of magnetite nanoparticles into zeolitic imidazolate framework-67 (ZIF-67). ZIF-67 framework is prepared by using Cobalt nitrate as metal salt by hydrothermal method. The material shows functional properties of both magnetite and ZIF-67. The bonding interactions are analysed by Fourier transform infrared spectroscopy. The microstructure and morphology are characterized by powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Magnetic measurements are inquired by vibrating sample magnetometry and surface area studies done by Bruner-Emmett and Teller surface area analysis technique.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Super paramagnetic magnetite nanoparticle is encapsulated into the ZIF-67 framework. </LI> <LI> Resulting nanocomposite retains the super paramagnetic behaviour. </LI> <LI> Encapsulated nanocomposite retains the morphology of ZIF 67. </LI> <LI> Thermal stability of the nanocomposite has been improved significantly compared to magnetite nanoparticle alone. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>TEM image of magnetite encapsulated ZIF-67 framework shows the incorporation of magnetite nanoparticles into the surface cavities.</P> <P>[DISPLAY OMISSION]</P>

Synthesis and Characterization of a Novel Laser Ablation Sensitive Triazene Incorporated Epoxy Resin

Archana S. Patole,Jeong-min Hyeon,Jung-Mn Hyun,김태호,Shashikant P. Patole,Dae-Jo Hong,Chang-Bo Lee,Cheol-Ho Choi 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.1

New triazene monomer was synthesized and further employed as a crosslinking agent partner with epoxy matrix using ethyl methyl imidazole as a curing agent in order to investigate the effect of triazene moieties on polymeric properties for laser ablation application. The synthesized triazene monomer was characterized by analytical and spectroscopic methods, while the surface morphology of resist after laser ablation was visualized by optical laser scanning images and scanning electron microscopy. Thermogravimetrical investigations indicate the loss of nitrogen being the initial thermal decomposition step and exhibit sufficient stabilities for the requirements for laser ablation application. Fourier transform infra-red, nuclear magnetic resonance, and gas chromatography analyses showed the successful synthesis of triazene. The ablation results from the optical laser scanning images revealed that the etching depth could be controlled by varying the concentration of triazene monomer in the formulation of epoxy. The shear strength analysis revealed that that the shear strength increased with increasing the amount of triazene in the formulation of direct ablation sensitive resist.

Biotechnological Approach to Enhance the Growth and Biomass of Tectona grandis Linn. F. (Teak) Seedlings

Archana Sharma,O.P. Chaubey 보안공학연구지원센터 2015 International Journal of Bio-Science and Bio-Techn Vol.7 No.1

Bio-fertilizers play a significant and complex role in plant growth of forestry species, which have been proved in the present study. In the present investigation various bio–fertilizers were applied alone and in combination. The growth and biomass response of T. grandis were enhanced due to inoculation of bio- fertilizers. This was primarily due to amelioration of soil pH, organic matter per cent, phosphorus, nitrogen and other nutrients which were assimilated by plants with higher capacity in the presence of microbial inoculants. In neutral pH range (6.5 to 7.5), the bio-fertilizers were found to be more effective. In the case of organic matter effects of bio-fertilizers were found to be more effective with the increase of organic matter in soil. The results revealed that soil organic matter and pH plays an important role in determining plant growth and survival. The bio-fertilizers, which are now in use world wide in integrated plant nutrition system to ameliorate soil condition showed better response for teak in this study.

Impedance and modulus spectroscopy characterization of La^+3/Mn^+4 modified PbTiO_3 nanoceramics

Archana Shukla,R.N.P. Choudhary 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Nanocrystalline samples of Pb_0.92La_0.08Mn_xTi_(1-x)O_3 (PLMT) (x = 0, 0.04, 0.07, 0.10) were prepared by a high-energy ball-milling followed by a solid-state reaction method. Preliminary high resolution X-ray diffraction technique of PLMT ceramics showed that a single-phase was formed exhibiting a tetragonal crystal structure. The electrical behavior of PLMT ceramics was investigated by the impedance spectroscopy in the temperature range of 35 ℃―500 ℃. This study was carried out by means of the simultaneous analysis of the complex impedance (Z^*) and electrical modulus (M^*) functions from the measurement range of 1 kHz―1 MHz. A separation of the grain and grain boundary properties has been achieved using an equivalent circuit model in impedance analysis. Loss spectra reveal about the presence of temperature-dependent electrical relaxation phenomena in the materials. Modulus analysis provides wider information related to charge transport processes.

Geochemical investigations in bulk and clay size fractions from lower Krishna river sediments, southern India: implications of elemental fractionation during weathering, transportation and deposition

Archana Bhagwat Kaotekwar,Syed Masood Ahmad,Manavalan Satyanarayanan,Aradhi Keshav Krishna 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.6

Major and trace elements, including rare earth elements (REEs) geochemistry of bed sediments from the lower reaches of Krishna river suggest their origin mainly from weathering of Deccan basalts and Precambrian rocks of the southern India. The elemental compositions indicate evidence of sedimentary sorting during weathering, transportation and deposition. Highly depleted Na2O and high values of Chemical Index of Alteration (CIA) are suggestive of moderate to strong chemical weathering environment in lower reaches of Krishna river. Major, trace and REE concentrations of bulk sediments suggest marginal variations in relative contribution from mafic and felsic minerals. The bed sediments contain significantly low concentrations of trace elements like Ba, Sr, La, Ce and Nd and moderately low concentrations of V, Zr, Rb, Zn, Ni and Cr relative to upper continental crust (UCC) composition. Most of the other trace elements and REEs are almost similar to UCC indicating their origin from weathering of mixed rock types in catchment areas of Krishna river. Strong relationships of ΣREEs with Ti and Zr in bed sediments suggest that REEs are mainly controlled by heavy minerals such as titanite and zircon. A marked increase in REEs in clay fractions of sediments indicates their adsorption and/or substitution on clay lattice.