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Optimization of process variables for a biosorption of nickel(Ⅱ) using response surface method
Shreela Murugesan,Sheeja Rajiv,Murugesan Thanapalan 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.2
The biosorption of nickel(Ⅱ) was studied by using crab shell particles of diameter (dp=0.012 mm) under different initial concentrations of nickel(Ⅱ) in solution (0.01-5.0 g/l), temperature (20-40℃), pH (2-6.5), and biosorbent dosages (0.5-10 g/l). The maximum removal of nickel(Ⅱ) occurred at pH 6.5 and temperature 40℃ for a biosorbent dosage of 6 g/l. The results were modeled by response surface methodology (RSM), which determines the maximum biosorption of nickel(Ⅱ) as a function of the above four independent variables, and the optimum values for the efficient biosorption of nickel(Ⅱ) were obtained. The RSM studies were carried out using Box-Behnken design and the analysis of variance confirms the adequacy of the quadratic model with coefficient of correlation R2 to be 0.9999. The quadratic model fitted the data well with Prob>F to be <0.0001, indicating the applicability of the present proposed model.
Murugesan Manikkampatty Palanisamy,Kannan Kandasamy 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.1
The quantity of electronic waste subjected to disposal annually is increasing alarmingly and is of major environmental concerndue to the existence of heavy metals and other toxic substances. In this present study, by combining leaching and adsorptionthe recovery of heavy metals from Printed circuit boards (PCBs) has been performed. The two stage aqua-regia leachingextracts Copper (Cu), Tin (Sn), Lead (Pb), and Zinc (Zn) from PCB. Bentonite Clay (Bent) and Peanut Shell Carbon (PSC)in their pristine, thermally and chemically activated forms were employed as adsorbents to remove the heavy metals fromleached solution. Effect of parameters (contact time, temperature, adsorbent dosage and size) on % adsorption was studied. Chemically activated bent (C-A Bent) has proven to be an effective among all adsorbents studies with % adsorption for Cu97%, Sn 98%, Zn 96%, and Pb 96%. Leaching and adsorption combination can become a promising methodology for handingelectronic waste.
Optimization of Laccase Production from Bacillus sp. PK4 through Statistical Design of Experiments
( Murugesan Rajeswari ),( Vembu Bhuvaneswari ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 한국미생물·생명공학회지 Vol.45 No.4
Statistical design of experiments was employed to optimize the media composition for the production of laccase from Bacillus sp. PK4. In order to find the key ingredients for the best yield of enzyme production from the selected eleven variables viz yeast extract, glucose, zinc sulphate, copper sulphate, potassium chloride, magnesium sulphate, calcium chloride, ferrous sulphate, sodium chloride, potassium dihydrogen phosphate (KH<sub>2</sub>PO<sub>4</sub>) and dipotassium hydrogen phosphate (K<sub>2</sub>HPO<sub>4</sub>), Plackett-Burman design was applied. The MgSO<sub>4</sub>, FeSO<sub>4</sub>, and CuSO<sub>4</sub> showed positive estimate, and their concentration optimized further. The steepest ascent method and Box-Behnken method revealed that 1.5 mM MgSO<sub>4</sub>, 0.33 g/l FeSO<sub>4</sub> and 1.41 mM CuSO<sub>4</sub> were optimal for the laccase production by Bacillus sp. PK4. This optimization strategy leads to enhancement of laccase production from 2.13 U/ml to 40.79 U/ml. Agro-wastes residues replace the carbon source glucose in the optimized media namely sugarcane bagasse, wheat bran, rice husk, and groundnut shell, among these groundnut shells (117 U/ml) was found to enhance the laccase production significantly. The laccase produced by Bacillus sp. PK4 was found to have the potential to degrade persistent organic pollutant benzo[a]pyrene.
Murugesan Chandrasekaran,Dharaneedharan Subramanian,Ee Yoon,Taehoon Kwon,천세철 한국식물병리학회 2016 Plant Pathology Journal Vol.32 No.3
Biological control agents (BCAs) from different micro-bial taxa are increasingly used to control bacterial wilt caused by Ralstonia solanacearum. However, a quan-titative research synthesis has not been conducted on the role of BCAs in disease suppression. Therefore, the present study aimed to meta-analyze the impacts of BCAs on both Ralstonia wilt disease suppression and plant (host) growth promotion. The analysis showed that the extent of disease suppression by BCAs varied widely among studies, with effect size (log response ra-tio) ranging from –2.84 to 2.13. The disease incidence and severity were significantly decreased on average by 53.7% and 49.3%, respectively. BCAs inocula-tion also signifiantly increased fresh and dry weight by 34.4% and 36.1%, respectively on average. Also, BCAs inoculation significantly increased plant yield by 66%. Mean effect sizes for genus Pseudomonas sp. as BCAs were higher than for genus Bacillus spp. Among antagonists tested, P. fluorescens, P. putida, B. cereus, B. subtilis and B. amyloliquefaciens were found to be more effective in general for disease re-duction. Across studies, highest disease control was found for P. fluoescens, annual plants, co-inoculation with more than one BCA, soil drench and greenhouse condition were found to be essential in understanding plant responses to R. solanacearum. Our results sug-gest that more efforts should be devoted to harnessing the potential beneficial effects of these antagonists, not just for plant growth promoting traits but also in mode of applications, BCAs formulations and their fieldstudies should be considered in the future for R. solanacearum wilt disease suppression.
Murugesan, C.,Rudramoorthy, R. Korean Society for Fluid machinery 2016 International journal of fluid machinery and syste Vol.9 No.2
This paper focuses on the single stage and multistage performance characteristics of centrifugal mixed flow submersible borewell pump. This study reveals that the performance of single stage pump is higher than that of multistage pumps. The head, input power and efficiency of single stage pump are higher than the per stage head, per stage input power and efficiency of multistage pumps. This study is divided into three parts. In the first part, five prototype pumps were made in single stage and multistage construction and the performance tests were conducted. In the second part, numerical validation has been done for different turbulence models and grid sizes. k-Omega SST model has been selected for the performance simulation and was validated with the performance of the test pump with static pressure tappings. In the third part, single and three stage pump performance were simulated numerically and compared with experimental results. The detailed analysis of pressure and velocity distributions reveals the difference in performance of single and three stage pump, due to non-uniform flow and difference in averaged flow velocities at the subsequent impeller inlets except the 1st stage impeller inlet.
Murugesan Sathishkumar,Yen-Chen Liu 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.6
This work addresses the memory event-triggered consensus control design problems of multi-agent systems (MASs) under actuator failures and aperiodic denial-of-service (DoS) attacks. In order to overcome an unpredictable traffic in the network communication channel, an appropriate memory event-triggered scheme (METS) is proposed. The purpose of this scheme is to utilize certain release packets to create new event compared with the existing event-triggered scheme (ETS). In this fashion, the event generator can achieve accurate decision as well as better performance of the control can be expected. Further, a new switched approach is established to describe the consensus performance of system model with aperiodic DoS attacks. By incorporating the Lyapunov-Krasovskii functional (LKF), adequate constraints of the consensus for MASs are derived. Based on the obtained conditions, the consensus control gain matrices are presented by utilizing the technique of linear matrix inequalities (LMIs). Eventually, simulation results are given to validate the applicability of the proposed theoretical results which is based on the F-18 aircraft model systems.
Murugesan, Kumarasamy,Yang, In-Hee,Kim, Young-Mo,Jeon, Jong-Rok,Chang, Yoon-Seok Springer-Verlag 2009 Applied microbiology and biotechnology Vol.82 No.2
<P>In this study, we investigated the efficacy of phenolic extract of wheat bran and lignin-related phenolic compounds as natural redox mediators on laccase-mediated transformation of malachite green (MG) using purified laccase from the white-rot fungus Ganoderma lucidum. G. lucidum laccase was able to decolorize 40.7% MG dye (at 25 mg l(-1)) after 24 h of incubation. Whereas, the addition of phenolic extract of wheat bran enhanced the decolorization significantly (p < 0.001) by two- to threefold than that of purified laccase alone. Among various natural phenolic compounds, acetovanillone, p-coumaric acid, ferulic acid, syringaldehyde, and vanillin were the most efficient mediators, as effective as the synthetic mediator 1-hydroxybenzotriazole. Characterization of MG transformation products by HPLC, UV-Vis, and liquid chromatography-mass spectrometry-electrospray ionization analysis revealed that N-demethylation was the key mechanism of decolorization of MG by laccase. Growth inhibition test based on mycelial growth inhibition of white rot fungus Phanerochaete chrysosporium revealed that treatment with laccase plus natural mediators effectively reduced the growth inhibitory levels of MG than that of untreated one. Among all the tested compounds, syringaldehyde showed the highest enhanced decolorization, as a consequence reduced growth inhibition was observed in syringaldehyde-treated samples. The results of the present study revealed that the natural phenolic compounds could alternatively be used as potential redox mediators for effective laccase-mediated decolorization of MG.</P>