Kinetics, mechanism, isotherm and thermodynamic analysis of adsorption of cadmium ions by surface-modified Strychnos potatorum seeds

Ponnusamy Senthil Kumar,Rangasamy Gayathri,Chandrasekaran Senthamarai,Muthukumar Priyadharshini,Panimayam Sebastina Anne Fernando,Ramakrishnan Srinath,Vaidyanathan Vinoth Kumar 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.12

The surface-modified Strychnos potatorum seeds (SMSP) were used as an effective low-cost adsorbent for the removal of cadmium ions from aqueous solution. SMSP was characterized by Fourier transform infrared spectroscopy and scanning electron microscopic analyses. The effect of operating variables such as solution pH, adsorbent dose, contact time, initial cadmium ions concentration and temperature on the removal of cadmium ions were studied in a batch mode adsorption operation. The optimum conditions for the adsorption of cadmium ions onto the SMSP were found to be: pH of 5.0, SMSP dose of 2 g/L, contact time of 30min, temperature of 30 oC for an initial cadmium ions concentration of 100 mg/L. Kinetic data were analyzed using the pseudo-first order and pseudo-second order kinetic equations, intraparticle diffusion model, Boyd kinetic model and shrinking core model. The characteristic parameters for each model have been estimated. Adsorption of cadmium ions onto the SMSP follows the pseudo-second order kinetic model. The rate-limiting steps in the adsorption process were found to be external and internal diffusion. Equilibrium data were well described by the Langmuir isotherm model than the Freundlich isotherm model, which yields a maximum monolayer adsorption capacity of 200 mg/g. Thermodynamic parameters such as standard free energy change, enthalpy change and entropy change were also estimated. The results show that the removal of cadmium ions by the SMSP was found to be spontaneous and exothermic.

Time-Dependent Correlation of the Microbial Community and the Metabolomics of Traditional Barley <i>Nuruk</i> Starter Fermentation

PONNUSAMY, Kannan,LEE, Sarah,LEE, Choong Hwan Informa UK (TaylorFrancis) 2013 Bioscience, biotechnology, and biochemistry Vol.77 No.4

<P>The microbial community and the metabolites of barley nuruk were studied to determine the time-dependent correlation between the fermentation of microbes and metabolites. Samples were analyzed by a polyphasic approach based on culture-dependent, culture-independent (PCR-DGGE and qPCR analysis), and metabolite analysis using GC-MS. Barley nuruk consists of varying amounts of bacteria, yeasts, and molds. The PCR-DGGE results showed that only one phylotype, Aspergillus oryzae, was predominant throughout fermentation, reaching a maximum on day 9. The bacterial load was higher on day 6 of fermentation, and then gradually decreased because of increased fungal activity. The shift in fungal and bacterial diversity observed by DGGE was further confirmed by qPCR analysis. In addition, microbes closely related to Pantoea agglomerans and Saccharomycopsis fibuligera appeared to play key roles in the fermentation of barley nuruk. GC-MS analysis combined with multivariate analysis, including PCA, PLS-DA, and OPLS-DA, showed fermentation time-dependent metabolite patterns. A total of 21 metabolites, including organic acids, amino acids, sugars, and sugar alcohols, were identified. In particular, glycerol, malic acid, fructose, glucose, sucrose, and maltose were produced at the early fermentation stages (0-6 d), whereas glutamine, aspartic acid, glutamic acid, mannitol, and xylitol were produced during the latter stages of fermentation (9-18 d). Mixed culture fermentation was found throughout the natural fermentation of barley nuruk starter. Most likely, A. oryzae had a major role in saccharification, along with other mixed cultures.</P>

Removal of cadmium(II) from aqueous solution by agricultural waste cashew nut shell

Ponnusamy Senthil Kumar,Subramanian Sivanesan,Subramaniam Ramalingam,Vasanthakumar Sathyaselvabala,Selvaraj Dinesh Kirupha,Arukkani Murugesan 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.6

Cashew nut shell (CNS) is a low cost adsorbent that has been used for the removal of cadmium(II) from an aqueous solution. The effects of various parameters such as solution pH, CNS concentration, contact time, initial cadmium(II) concentration and temperature were examined. The CNS was effective for the quantitative removal of cadmium(II) ions in acidic conditions and equilibrium was achieved in 30 min. The experimental data were analyzed by two-parameter (Langmuir, Freundlich, Temkin and Dubinin-Radushkevich) and three-parameter models (Redlich-Peterson, Koble-Corrigan, Toth and Sips) by nonlinear regression analysis. The characteristic parameters for each isotherms and related correlation coefficients have been determined by using MATLAB 7.1. Thermodynamic parameters such as ΔGo, ΔHo and ΔSo have also been evaluated, and it was found that the sorption process was feasible, spontaneous and exothermic. Pseudo-first-order, pseudo-second-order, Elovich kinetic and intraparticle diffusion models were selected to follow the adsorption process. The results of the kinetic study show that the adsorption of cadmium(II)could be described by the pseudo-second order equation, suggesting that the adsorption process is presumably chemisorption. A single-stage batch adsorber was designed for different adsorbent dose-to-effluent volume ratios using the Freundlich equation. The results indicate that the cashew nut shell could be used to effectively adsorb cadmium(II)from an aqueous solution.

Performance Study on Stabilization of Fine Grained Clay Soils Using Calcium Source Producing Microbes

Ponnusamy Kulanthaivel,Balu Soundara,Arunava Das 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.9

In recent years, the method to produce bio-cementation in sand using bacterial calcium carbonate precipitation (BCCP) process has become more popular. The major objective of this research paper is to study the capability of BCCP to enhance the unconfined compressive strength of clayey soils. Two types of bacteria were used to generate calcium carbonate precipitation. The experimental design variables adopted in this study are bacteria types (L. fusiformis and S. pasteurii), soil types (low compressible clay and intermediate compressible clay), types of externally supplied calcium solution (calcium chloride and eggshell solution), molarities of cementing solution (0.25, 0.50, 0.75 and 1.00 M) and curing period (1, 3 and 7 days). The experimental test results showed that the BCCP process significantly improves the unconfined compressive strength (UCS) of both soils. The improvement however varied with bacterial types, soil types, types of externally supplied calcium solution, molarities of cementing solution and curing period. In BCCP treatment, S. pasteurii treated soils give more strength than L. fusiformis because of high urease activity of S. pasteurii in the order 450 U/ml. The maximum improvement ratio was achieved in CL soil (2.51) compared to CI soil (2.26) due to particle sizes. The optimum externally supplied calcium solution and molarity of cementing medium were established as an eggshell solution and 0.50 M, respectively. The images from scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis confirmed the experimental findings.

An Improved Switching Topology for Single Phase Multilevel Inverter with Capacitor Voltage Balancing Technique

Ponnusamy, Rajan Soundar,Subramaniam, Manoharan,Irudayaraj, Gerald Christopher Raj,Mylsamy, Kaliamoorthy The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

This paper presents a new cascaded asymmetrical single phase multilevel converter with a reduced number of isolated DC sources and power semiconductor switches. The proposed inverter has only two H-bridges connected in cascade, one switching at a high frequency and the other switching at a low frequency. The Low Switching Frequency Inverter (LSFI) generates seven levels whereas the High Switching Frequency Inverter (HSFI) generates only two levels. This paper also presents a solution to the capacitor balancing issues of the LSFI. The proposed inverter has lot of advantages such as reductions in the number of DC sources, switching losses, power electronic devices, size and cost. The proposed inverter with a capacitor voltage balancing algorithm is simulated using MATLAB/SIMULINK. The switching logic of the proposed inverter with a capacitor voltage balancing algorithm is developed using a FPGA SPATRAN 3A DSP board. A laboratory prototype is built to validate the simulation results.

NORM ESTIMATES AND UNIVALENCE CRITERIA FOR MEROMORPHIC FUNCTIONS

Ponnusamy, Saminathan,Sugawa, Toshiyuki Korean Mathematical Society 2008 대한수학회지 Vol.45 No.6

Norm estimates of the pre-Schwarzian derivatives are given for meromorphic functions in the outside of the unit circle. We deduce several univalence criteria for meromorphic functions from those estimates.

Microbial community and metabolomic comparison of irritable bowel syndrome faeces

Ponnusamy, Kannan,Choi, Jung Nam,Kim, Jiyoung,Lee, Sun-Young,Lee, Choong Hwan Society for General Microbiology 2011 Journal of medical microbiology Vol.60 No.6

<P>Human health relies on the composition of microbiota in an individual’s gut and the synthesized metabolites that may alter the gut environment. Gut microbiota and faecal metabolites are involved in several gastrointestinal diseases. In this study, 16S rRNA-specific denaturing gradient gel electrophoresis and quantitative PCR analysis showed that the mean similarity of total bacteria was significantly different (<I>P</I><0.001) in faecal samples from patients with irritable bowel syndrome (IBS; <I>n</I> = 11) and from non-IBS (nIBS) patients (<I>n</I> = 8). IBS subjects had a significantly higher diversity of total bacteria, as measured by the Shannon index (<I>H′</I>) (3.36<<I>H′</I><4.37, <I>P</I> = 0.004), <I>Bacteroidetes</I> and lactobacilli; however, less diversity was observed for <I>Bifidobacter</I> (1.7<<I> H′</I><3.08, <I>P</I><0.05) and <I>Clostridium coccoides</I> (0.9<<I> H′</I><2.98, <I>P</I> = 0.007). In this study, no significant difference was found in total bacterial quantity (<I>P</I>>0.05). GC/MS-based multivariate analysis delineated the faecal metabolites of IBS from nIBS samples. Elevated levels of amino acids (alanine and pyroglutamic acid) and phenolic compounds (hydroxyphenyl acetate and hydroxyphenyl propionate) were found in IBS. These results were highly correlated with the abundance of lactobacilli and <I>Clostridium</I>, which indicates an altered metabolism rate associated with these gut micro-organisms. A higher diversity of <I>Bacteroidetes</I> and <I>Lactobacillus</I> groups in IBS faecal samples also correlated with the respective total quantity. In addition, these changes altered protein and carbohydrate energy metabolism in the gut.</P>

유역하류지역의 토지이용변화 분석

Ponnusamy Malini,유연(Yeu Yeon) 대한공간정보학회 2010 대한공간정보학회지 Vol.18 No.2

인구의 증가는 하천 유역지역의 토지이용변화를 가속시켜왔으며, 토지이용변화에 대한 공간분포정보는 이들 지역에 대한 효과적인 관리와 계획에 중요한 자료가 되고 있다. 본 연구의 목적은 1989년, 1999년, 2002년도 IRS LISS III 영상자료를 이용하여 인도 서부에 위치한 Moyar유역지역의 1:50,000축척 토지이용변화도를 생성하는데 있다. 약 9가지의 토지이용분류자료는 3개년간의 영상자료를 시각적 판독방법에 의해 추출하였으며, 토지이용변화 검색은 관측시기 I(1989-1999)과 관측시기 II (1999-2002)에 대한 행렬분석방법에 의해 수행되었다. 본 연구를 통하여 기간 II가 기간 I보다 지속가능한 개발과 난개발을 방지하기 위한 실질적인 정보를 보여 주었다. Large pressure on the growing population has increased rapid change in the LULC (land use/land cover) patterns in the watershed area. Spatial distribution of LULC information and its changes are desirable for any effective planning, managing and monitoring activities. The aim of the study is to produce the 1,50,000 scaled LULC change map for the sub-watershed, Western Moyar, India using the multi-temporal satellite image dataset of IRS LISS III images for the year 1989, 1999, and 2002. About 9 classes are extracted using onscreen visual interpretation techniques for all the three years. The change detection analysis was performed using matrix method for period I (1989-1999) and period II (1999-2002). The study reveals that the changes noticed in period II (1999-2002) is comparatively more than period I (1989-1999), which is dynamic information to protect the sub-watershed area from the deterioration and paves the way to for the sustainable development.

Removal of methylene blue dye from aqueous solution by activated carbon prepared from cashew nut shell as a new low-cost adsorbent

Ponnusamy Senthil Kumar,Subramaniam Ramalingam,Kannaiyan Sathishkumar 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.1

Methylene blue dye was adsorbed on an adsorbent prepared from cashew nut shell. A batch adsorption study was carried out with variable adsorbent amount, initial dye concentration, contact time and pH. Studies showed that the pH of aqueous solutions affected dye removal as a result of removal efficiency increased with increasing solution pH. The experimental data were analyzed by the Langmuir, Freundlich, Redlich-Peterson, Koble-Corrigan, Toth, Temkin,Sips and Dubinin-Radushkevich models of adsorption using MATLAB 7.1. The experimental data yielded excellent fits within the following isotherm order: Redlich-Peterson>Toth>Sips>Koble-Corrigan>Langmuir>Temkin>Dubinin-Radushkevich>Freundlich, based on its correlation coefficient values. Three simplified kinetic models including a pseudofirst-order, pseudo-second-order and intraparticle diffusion equations were selected to follow the adsorption process. It was shown that the adsorption of methylene blue could be described by the pseudo-second-order equation. The results indicate that cashew nut shell activated carbon could be employed as a low cost alternative to commercial activated carbon in the removal of dyes from wastewater.

An Optimized Bagging Learning with Ensemble Feature Selection Method for URL Phishing Detection

Ponnusamy Ponni,Dhandayudam Prabha 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

This study proposes and implements an ensemble feature selection with a bagging classifer for URL phishing detection. Feature Selection is essential for reducing data's dimensionality and improving any proposed framework's performance. The feature selection stability is improved by using the ensemble feature selection method. In this work, Aggregation decides the fnal ranking of the ensemble feature selection by using four standard flter methods. Bagging classifer used for URL phishing dataset and accuracy of the model is determined with aggregation ranked features. In proposed work details the ensemble feature selection methods that embed with optimized ensemble bagging learning. The hyperparameter of the bagging classifer, such as multiple estimators with random patches, random subspaces, bagging, or bootstrap aggregation and pasting, are tuned, which produces the better performance model. The evaluation and comparison of experimental results showed the efectiveness of our method.