Bio-extract assisted in-situ green synthesis of Ag-RGO nanocomposite film for enhanced naproxen removal

Somen Mondal,Surabhi Patel,Subrata Kumar Majumder 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.2

The present study reports in-situ green synthesis of Ag-RGO nanocomposite film using turnip leavesextract as a reducing as well as a capping agent and its application as a highly efficient naproxen adsorbent from a contaminated aqueous solution. The nanocomposite was characterized employing XRD, Raman and FT-IR spectroscopy, FETEM and FESEM microscopy, EDS spectroscopy. The pseudo-second-order and Elovich kinetic model furnished the best correlation of the experimental data, specifying the adsorption as the rate-limiting step for naproxen (NPX) removal by Ag-RGO composite film. The Freundlich and Dubinin-Radushkevich (D-R) isotherms represented the experimental adsorption data satisfactorily, suggesting a multilayered chemical adsorption process on the heterogeneous adsorbent surfaces. The process parameters were optimized to get the maximum adsorption capacity, which was obtained as 229.25mg g1 (92.62%). The parametric effects of pHs and NPX concentrations were tested within a range of 2.50- 8.50 and 25-100mg dm3, respectively, for the contact time of 0.33-3 min at a constant temperature (298 K) and adsorbent dose (20.2mg). The feasibility of the regeneration of the materials after adsorption is based on the experimental results. The experimentally optimized process parameters were validated using response surface methodology (RSM).

Experimental and Microscopic Investigation on Mechanical Performance of Textile Spread-tow Thin Ply Composites

Somen Kumar Bhudolia,Sunil Chandrakant Joshi,Yi Di Boon 한국섬유공학회 2019 Fibers and polymers Vol.20 No.5

Textile non-crimp carbon fabrics (NCCFs) are made of several dry uni-directional (UD) tows which are alignedstraight and stitched together. The use of these reduces resin rich areas and stress concentrations that are likely found inwoven fabrics composites during manufacturing. The use of spread tows to manufacture the thin plies leads to the fibre arealweight (FAW) of lower than 150 g/m2. This current research aims at investigating the tensile, flexure and interlaminar shearresponse of thin ply carbon composites with a view to deduce the failure mechanisms. The baseline comparison is carried outwith conventional thick ply composites and differences in the failure mechanisms are studied. For tensile tests, reducednumber of acoustic emission counts in the case of thin ply composites indicated that the stresses were unaffected until thelaminate ultimate strength. In flexural tests, it was noticed that the resin rich sites near the stitches first initiated compressionfailure followed by translaminar cracking or longitudinal fibre fracture. This is due to the strong fibre-matrix adhesion in thecase of thin ply composites. No interlaminar shear fracture was seen to occur throughout the laminate thickness and acrossthe width, leading to a significant improvement in the flexural properties of the thin ply composites. These thin laminateshave better interlaminar shear properties. It was observed through microscopy that thin ply laminates first undergointerlaminar shear followed by inelastic deformation at the ultimate strength of the material.

Energy Characteristics and Failure Mechanisms for Textile Spread Tow Thin Ply Thermoplastic Composites under Low-velocity Impact

Somen K. Bhudolia,Sunil C. Joshi,Anthony Bert,Goram R. Gohel,Makam Raama 한국섬유공학회 2019 Fibers and polymers Vol.20 No.8

Carbon composites are deemed suitable for components with complex geometries which require high impactresistance. The broad range of industrial applications requires composite structures to be lighter and not to compromise withtheir mechanical performance. Non-crimp fabrics with lower fibre areal weight (FAW) are the class of reinforcement materialwhich will only bring the advantages of better mechanical properties but will also offer more longevity to the structures andreduced maintenance costs. This research aims at investigating the low-velocity impact performance of textile spread towthin ply (100 gsm) composites with an aim to study the load bearing capability, deflection characteristics and energycharacteristics. The results are compared with the baseline thick (200 gsm) fibre reinforced composites. There was 19.2 %,16.6 %, and 6.57 % higher peak load for spread tow thin ply composites when compared to thick ply composites at 25 J, 42 J,and 52 J impact energies respectively. Significantly lower residual deflection (40 % to 76 %) and higher major damageenergy (20 % to 33 %) were observed for spread tow thin ply laminates compared to the thick ply variant at different impactenergies. At 42 J and 52 J impact energies, the damage index (DI) was 2 times and 4 times higher for Thick ply laminateshighlighting extensive damage, which is also observed with detailed failure mechanisms study.

Synthesis of phosphate functionalized highly porous activated carbon and its utilization as an efficient copper (II) adsorbent

Somen Mondal,Subrata Kumar Majumder 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.5

The effects of activating agents on the characteristics of the activated carbons prepared from the tea waste were investigated. A three-step chemical activation process consisting of impregnation, carbonization and the secondary activation or phosphate functionalization was followed for the synthesis of the activated carbons. The surface area and the total pore volume of the best-activated carbon prepared in the present investigation at optimized conditions were found to be 1,329m2/g and 0.4167 cm3/g. The potentiality of the copper adsorption onto the best quality activated carbon with the highest surface area and pore volume was investigated. The maximum adsorption capacity of the activated carbon was 76.22mg/gat room temperature (28 oC). The copper (II) adsorption onto the activated carbon followed the pseudo-second-order kinetics which satisfied the Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. Best activated carbon obtained from the present investigation may be recommended to use in water purification processes as a revamped copper (II) bio-adsorbent.

Exploring the ambient environment for charland formation in Rajmahal downstream Ganga river of Eastern India in post Farakka barrage Period

Shahana Khatun,Somen Das,Swades Pal 대한공간정보학회 2018 Spatial Information Research Vol.26 No.3

Up to 2005, more than 700,000 people and 53 villages of Malda and Murshidabad districts have been displaced and wiped out due to bank erosion of river Ganga. Population displacement due to massive river bank erosion and rehabilitation for them with livelihood options are the emerging challenge in both up and downstream of Farakka barrage. This paper also wants to find out potential areas of charland formation along with exploring existing charland over the selected phases. Normalized differences water index (NDWI) from 55 Landsat images is used for flow and charland mapping. Water presence frequency (WPF) and NDWI map are taken as parameters for mapping new habitat for chaland. Total existing charland area in phase 3 is 463.58 km2 and potential habitat for charland is 117.59 km2. Out of this potential area, in post monsoon season, 35.26% comes under highly potential zone where both depth of flow is very low and frequency of flow is irregular. Highly suitable area has been increased over the recent phases. Potential charland maps in 1st and 2nd phases are validated in reference to the appeared charland area in the successive phases. New charlands expectedly would be the resource hunting ground of the displaced people.

Effect of nonsurgical periodontal therapy and smoking status on hematological variables related to anemia of chronic disease in chronic periodontitis patient: a case-control study

Sangita Show,Somen Bagchi,Arka Kanti Dey,Ramanarayana Boyapati,Pritish Chandra Pal,Kanikanti Siva Tejaswi 영남대학교 의과대학 2022 Yeungnam University Journal of Medicine Vol.39 No.3

Background: Chronic infectious, inflammatory, or neoplastic disorders are associated with anemia of chronic disease. Chronic inflammatory diseases such as periodontitis may contribute to masked anemia, especially in smokers. This study was aimed at verifying and comparing the efficacy of nonsurgical periodontal therapy (NSPT) for improving anemia among chronic periodontitis patients with and without the habit of smoking. Methods: Thirty systemically healthy individuals with chronic periodontitis were divided into two groups of 15 each, smokers (group A) and nonsmokers (group B). The groups were compared based on hematological parameters such as serum erythropoietin (SE) and serum ferritin (SF) levels at baseline and 3 months after NSPT for anemia evaluation. Results: The baseline SE levels in groups A and B were 11.84 and 15.19 mIU/mL (p=0.031), respectively; the corresponding levels at 3 months after NSPT were 13.00 and 17.74 mIU/mL (p=0.022). The baseline SF levels in groups A and B were 95.49 and 44.86 ng/mL (p=0.018), respectively; the corresponding levels at 3 months after NSPT were 77.06 and 39.05 ng/mL (p=0.009). Group B showed a significant increase and decrease in the SE and SF levels, respectively, at 3 months after NSPT (p=0.035 and p=0.039, respectively), whereas group A showed insignificant changes (p=0.253 and p=0.618, respectively). Conclusion: NSPT led to an improvement in anemia among chronic periodontitis patients. However, the improvement is less in smokers compared to that in nonsmokers. Furthermore, SF and SE levels might serve as effective biomarkers for assessing anemia in smokers and nonsmokers with chronic periodontitis.

Highly aligned polarization splay modulated (B7) smectic liquid crystal with linearly polarized light emission

김민준,Srikanth Turlapati,Somen Debnath,Nandiraju V. S. Rao,윤동기 한국고분자학회 2015 한국고분자학회 학술대회 연구논문 초록집 Vol.2015 No.4

Electric field-induced uniaxial orientation of polarization splay modulated (B7) liquid crystal phase

김민준,( Srikanth Turlapati ),( Somen Debnath ),( Nandiraju V. S. Rao ),윤동기 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

To generate large optical texture, we have utilized chemically modifying substrates using self-assembled monolayers (SAM) having molecule-phobic characteristic. A droplet on the substrate treated by SAM exhibited large focal conic domains. And an in-plane electric field spread out droplet that finally changed to uniform thin film. The liquid crystalline molecules in the film exhibited uniaxial orientation in the same direction of the electric field, resulting in linearly polarized light emission due to fluorescence of the molecules. The highly aligned B7 film with large area was characterized by depolarized transmitted light microscopy (DTLM) and fluorescence polarizing microscopy (FPM). And the B7 film will provide great opto-electronic applications such as a linearly polarized light emission film and a fast light modulator.

Genetic Diversity among Indian Oak Tasar Silkworm, Antheraea proylei J. Revealed by ISSR Markers

( Kanghujam Ibsorani Devi ),( Kangayam M. Ponnuvel ),( Laishram Somen Singh ),( Kangjam Chaoba Singh ),( Karabi Dutta ) 한국잠사학회 2012 International Journal of Industrial Entomology Vol.24 No.2

The Indian Oak Tasar silkworm, Antheraea proylei J. is a beneficial insect with great economic importance in India for its silk production. In this study, six populations of Antheraea proylei and A. frithi Moore (as an out group) were subjected to inter simple sequence repeat (ISSR) marker analysis in order to assess its genetic diversity. Fifteen ISSR primers produced 91 markers among different breeds of A. proylei and A.frithi of which 89 are polymorphic, generating 97.8% polymorphism. The dendrogram constructed using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) and cluster analysis made using Nei`s genetic distance resulted in the formation of one major group containing four sub-groups separating the breeds. This result suggests that ISSR amplification is potentially useful for molecular characterization of oak tasar silkworm genotypes.

Highly Polarized Fluorescent Illumination Using Liquid Crystal Phase

Gim, Min-Jun,Turlapati, Srikanth,Debnath, Somen,Rao, Nandiraju V. S.,Yoon, Dong Ki American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.5

<P>Liquid crystal (LC) materials are currently the dominant electronic materials in display technology because of the ease of control of molecular orientation using an electric field. However, this technology requires the fabrication of two-polarizers to create operational displays, reducing light transmission efficiency below 10%. It is therefore desirable to develop new technologies to enhance the light efficiency while maintaining or improving other properties such as the modulation speed of the molecular orientation, Here we report a uniaxial-oriented B7 smectic liquid crystalline film, using fluorescent bent-core LC molecules, a chemically modified substrate, and an in-plane electric field. A LC droplet under homeotropic boundary conditions of air/LC as well as LC/substrate exhibits large focal conic like optical textures. The in-plane electric field induced uniaxial orientation of the LC molecules) in which molecular polar directors are aligned in the direction of the electric field. This highly oriented LC film exhibits linearly polarized luminescence and microsecond time-scale modulation characteristics. The resultant device is both cheap and easy to.fabricate and thus has great potential for electro-optic applications, including LC displays, bioimaging systems, and optical communications.</P>