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Bioprocess Optimization - a Challenge
( Tapobrata Panda ),( P S R Babu ),( J A Kumari ),( D S Rao ),( K Theodore ),( K Jagannandha Rao ),( S Siva Kesava ),( A Kapat ),( S R Nair ),( J Sinha ),( R Sreenivas ),( G Lakshmi Prasanna ),( V Ven 한국미생물생명공학회 1997 Journal of microbiology and biotechnology Vol.7 No.6
Power Conversion System for Low Power High Altitude Wind Power Generating System
Jeevan Adhikari,Prasanna IV,Godwin Ponraj,S. K. Panda 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6
In high altitude wind power (HAWP) generating system, medium voltage AC (MV-AC) permanent magnet synchronous generator (PMSG) is used. The generated electrical power is transmitted to ground without any power conditioning in the air-borne unit. The ground based power conversion system (PCS) interfaces variable voltage and variable frequency medium voltage power into distribution level grid voltage. The proposed PCS consists of a three-level vienna rectifier for generation side control, a half bridge DC-DC converter for isolation and stepdown purpose and a grid/load connected inverter for load side active power control. Three-level operation in the generation side converter reduces the switch/diode voltage stress to half and therefore allows to use low voltage rating power semiconductor devices. The vienna rectifier is controlled for sensorless maximum power-point tracking (MPPT) of the air-borne wind turbine. The phase lock loop (PLL) is used for speed and rotor position detection of the PMSG for optimal torque control of the airborne wind turbine (AWT). Simulation studies have been carried out using computer programs like PSIM and MATLAB. For the validation of the proposed methodology, scaled down laboratory based prototype is built and tested. The obtained experimental results confirm the performance of the PCS for interfacing HAWP generation system to the grid.
( Manoranjan Nayak ),( Swagat S Rath ),( Manikkannan Thirunavoukkarasu ),( Prasanna K Panda ),( Barada K Mishra ),( Rama C Mohanty ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.9
A series of experiments were carried out with three native strains of microalgae to measure growth rates, biomass, and lipid productivities. Scenedesmus sp. IMMTCC-6 had better biomass growth rate and higher lipid production. The growth, lipid accumulation, and carbon dioxide (CO2) consumption rate of Scenedesmus sp. IMMTCC-6 were tested under different NaOH concentrations in modified BBM. The algal strain showed the maximum specific growth rate (0.474/day), biomass productivity (110.9 mg l-1d-1), and CO2 consumption rate (208.4 mg l-1d-1) with an NaOH concentration of 0.005 M on the 8th day of cultivation. These values were 2.03-, 6.89-, and 6.88-fold more than the algal cultures grown in control conditions (having no NaOH and CO2). The CO2 fixing efficiency of the microalga with other alternative carbon sources like Na2CO3 and NaHCO3 was also investigated and compared. The optimized experimental parameters at shake-flask scale were implemented for scaling up the process in a self-engineered photobioreactor. A significant increase in lipid accumulation (14.23% to 31.74%) by the algal strain from the logarithmic to stationary phases was obtained. The algal lipids were mainly composed of C16/C18 fatty acids, and are desirable for biodiesel production. The study suggests that microalga Scenedesmus sp. IMMTCC-6 is an efficient strain for biodiesel production and CO2 biofixation using stripping solution of NaOH in a cyclic process.
( Jaya Shree Jena ),( Nilotpala Pradhan ),( Rati Ranjan Nayak ),( Bishnu P Dash ),( Lala Behari Sukla ),( Prasanna K Panda ),( Barada K Mishra ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.4
Bionanotechnology has revolutionized nanomaterial synthesis by providing a green synthetic platform using biological systems. Among such biological systems, microalgae have tremendous potential to take up metal ions and produce nanoparticles by a detoxification process. The present study explores the intracellular and extracellular biogenic syntheses of silver nanoparticles (SNPs) using the unicellular green microalga Scenedesmus sp. Biosynthesized SNPs were characterized by AAS, UV-Vis spectroscopy, TEM, XRD, FTIR, DLS, and TGA studies and finally checked for antibacterial activity. Intracellular nanoparticle biosynthesis was initiated by a high rate of Ag+ ion accumulation in the microalgal biomass and subsequent formation of spherical crystalline SNPs (average size, 15-20 nm) due to the biochemical reduction of Ag+ ions. The synthesized nanoparticles were intracellular, as confirmed by the UV-Vis spectra of the outside medium. Furthermore, extracellular synthesis using boiled extract showed the formation of well scattered, highly stable, spherical SNPs with an average size of 5-10 nm. The size and morphology of the nanoparticles were confirmed by TEM. The crystalline nature of the SNPs was evident from the diffraction peaks of XRD and bright circular ring pattern of SAED. FTIR and UV-Vis spectra showed that biomolecules, proteins and peptides, are mainly responsible for the formation and stabilization of SNPs. Furthermore, the synthesized nanoparticles exhibited high antimicrobial activity against pathogenic gram-negative and gram-positive bacteria. Use of such a microalgal system provides a simple, cost-effective alternative template for the biosynthesis of nanomaterials in a large-scale system that could be of great use in biomedical applications.