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ACENAPHTHO[1,2-B]QUINOXALINE AND ACENAPHTHO[1,2-B]PYRAZINE AS CORROSION INHIBITORS FOR MILD STEEL IN ACID MEDIUM
(Elsevier, 2016-01) Saranya, J; Sounthari, P; Parameswari, K; Chitra, S
The corrosion inhibition of mild steel in 1 M H2SO4 using acenaphtho[1,2-b]quinoxaline and acenaphtho[1,2-b]pyrazine at 303–333 K have been investigated. The study was performed using weight loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Polarization measurements proved that the inhibitors behave as mixed-type. EIS data showed that the charge transfer resistance of mild steel increases in acid solution containing inhibitors. The surface morphology was evaluated using scanning electron microscope (SEM), atomic force microscopy (AFM) techniques. Density functional theory (DFT) at the B3LYP/6-311G(d,p) basis set level was performed. Excellent correlation was found between experimental and theoretical results.
ASSESSMENT OF COMPETENCE OF THE PSEUDOMONAS AERUGINOSA TO SOLUBILIZE INSOLUBLE FORM OF ZINC UNDER VARIOUS CULTURAL PARAMETERS
(Springer Link, 2016) Padma Devi, S N; Sunitha kumari, K; Vasandha, S
Efficiency of Pseudomonas aeruginosa to solubilize insoluble form of zinc to soluble form was studied under various cultural parameters such as carbon (glucose, fructose, sucrose, maltose and lactose), nitrogen (ammonium sulphate, sodium nitrate, potassium nitrate and urea), pH (5.0, 7.0 and 9.0) and temperature (20, 30 and 40°C). The experimental study was carried out by both qualitative (plate assay) and quantitative (broth assay) methods. The Zn-solubilizing efficiency of the isolate was found more when glucose was added as C-source in both plate (150 %) and broth (16.62 mg/l) assays, and the efficiency was less in the medium amended with sucrose as carbon source in both qualitative (105.8 %) and quantitative (2.56 mg/l) estimation. Among the four nitrogen sources, P. aeruginosa showed best solubilizing efficiency (262.5 %) and solubilization of Zn (29.91 mg/l) in the presence of ammonium sulphate and recorded least solubilization efficiency in the presence of sodium nitrate as nitrogen source in both plate (181.82 %) and broth (21.92 mg/l) assays. It showed highest solubilization of zinc from ZnO at the incubation temperature of 30°C, and the activity was less at the temperature of 40°C. pH 7 was the most favourable pH for solubilization, and the efficacy was least when the pH reached its alkalinity. Thus the study confirmed the efficiency of P. aeruginosa to solubilize insoluble form of zinc and can be used as a source of bioinoculants to eradicate zinc deficiency in plants.
ASSESSMENT OF PHYSICOCHEMICAL CHARACTERISTICS AND THE LEVEL OF NUTRIENT CONTENTS AS WELL AS HEAVY METAL IONS IN WATERS OF THREE LAKES AT COIMBATORE, TAMIL NADU, INDIA
(Journal of Materials and Environmental Science, 2016-02-26) Manikandan, R; Ezhili, N; Muthulakshmiandal, N; Paulo J. C, Favas; Venkatachalam, P
Lake water quality degradation and heavy metals pollution have been serious environmental threats for last decades, especially in those fresh water lakes situated in the vicinity of the cities and human habitations. The present study aimed to investigate the physicochemical parameters, level of nutrient contents and heavy metals to determine the water quality of Ukkadam, Kuruchi and Singanallur Lakes. All the physicochemical parameters except dissolved oxygen, sulphate, silicate and nitrate values were found above the prescribed limit as recommended by WHO (2011) and BIS (2003) drinking water quality. The concentrations of Ca, Cr, Cu, Fe, Niand Pb in waters of the selected three lakes ranged from 0.014 – 0.038, 0.145 – 0.063, 0.025 – 0.552, 0.100 – 3.460, 0.028 – 0.117 and 0.463 – 2.172 mg/L respectively. The concentrations of heavy metals except Cu were found to be higher than the permeable dose. This investigation revealed that the water in these lakes is partially contaminated with high level of heavy metals. It is recommended that proper implementation of new wetland waste management system and constant monitoring is urgently required to maintain good water quality in these lakes for future generation.
BIOSORPTION OF DIVALENT ION ONTO TREATED PROSOPIS JULIFLORA BARK FROM AQUEOUS SOLUTIONS - ISOTHERMAL AND STATISTICAL ANALYSIS
(Oriental Journal of Chemistry, 2016-04-13) Muthulakshmi Andal, N; Charulatha, S; Gayathri, N S
The present work emphasizes the utilization of Prosopis juliflora bark, an agro waste material for the adsorption of Cu(II). The raw Prosopis juliflora bark (PJB) is treated using 0.1N hydrochloric acid to enhance the sorption efficiency. The characterization studies of TPJB using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDAX), Brunauer-Emmet-Teller(BET) and Barrett-Joyner-Halenda (BJH) analyses carried out. The batch mode experimental set up is verified to assess the sorption capacity of the chosen material for the operating factors viz., particle sizes/ doses of the sorbent material upon a range of initial concentrations of Cu(II) at different temperatures, agitation time and pH of the Cu(II)- TPJB system. The amount of Cu(II) ion adsorbed on to TPJB surface is found to be 43.11 mg/g (97.4%) under optimized conditions, its efficiency 3 fold times more than the Ce values reported by other researchers. The sorption characteristic of TPJB is quantitatively estimated through column experiments based on the C value by batch mode. The removal is observed as 98%. Langmuir, Freundlich and Tempkin isothermal curves at various initial concentrations are plotted for Cu(II)-TPJB system wherein the straight line fit is best suited for the Freundlich isotherm model. The results show that the response of TPJB in trapping Cu(II) ions are influenced by various parameters being statistically verified using SPSS software, indicative of good correlation.
BIOSYNTHESIS OF PVA ENCAPSULATED SILVER NANOPARTICLES
(Una Publication, 2016-10-01) Sharmila, Chandran; Vinuppriya, Ravichandran; Selvi, Chandran; Jincy, Chemmanda; Bellan, Chandarshekar
Green synthesis of metal nanoparticles is an important technique in the methods of eco-friendly nanoparticle production. The synthesis of silver nanoparticles was accomplished using Ocimum sanctum leaf extract at room temperature. These particles were then encapsulated with polyvinyl alcohol (PVA) polymer matrix. The presence of silver was confirmed by different characterization techniques such as UV–vis spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD). Scanning electron microscopic (SEM) images of the synthesized powder shows spherical shaped silver nanoparticles embedded in sponge-like polymer matrix. The energy dispersive X-ray analysis confirms the presence of elemental silver along with iron signal. Energy dispersive signal corresponding to elemental iron has been attributed to O. sanctum plant. The silver nanoparticles in PVA matrix thus obtained shows high antibacterial activity against gram positive Staphylococcus aureus (S. aureus) and gram negative Escherichia coli (E. coli) water borne bacteria. The inhibition zone against S. aureus and E. coli were also calculated.
CO(II) COMPLEX OF 2-AMINO-6-METHYLBENZOTHIAZOLE: SYNTHESIS, STRUCTURE AND BIOLOGICAL EVALUATION
(Indian Journal of Chemistry, 2016-11) Jone Kirubavathy, S; Velmurugan, R; Karvembu, R; Bhuvanesh, N S P; Enoch, I V M V; Mosae Selvakumar, P; Chitra, S
Cobalt(II) complex of 2-amino-6-methylbenzothiazole has been synthesized and characterized by various physicochemical methods. The ligand 2-amino-6-methylbenzothiazole acts as monodentate, neutral ligand with N as the donor site. The molecular structure of the title complex has been determined by single crystal X-ray diffraction studies. The Co(II) complex shows significant antioxidant activity against DPPH radical. The complex shows cytotoxicity with a IC50 value of 14.12 µM against MCF-7 cell line. In addition, the complex shows good antimicrobial and anti-tuberculosis activities against various microbes and mycobacterium tuberculosis respectively. DNA binding of the title complex has been investigated by absorption spectroscopic technique, which reveals that the complex acts as minor groove binder. These results have been validated by molecular docking studies
CORROSION INHIBITION OF N80 STEEL IN 15% HCL BY PYRAZOLONE DERIVATIVES: ELECTROCHEMICAL, SURFACE AND QUANTUM CHEMICAL STUDIES
(Royal Society of Chemistry, 2016-02-23) Ansari, K R; Quraishi, M A; Ambrish, Singh; Sowmya, Ramkumar; Ime B, Obote
The corrosion protection of N80 steel in 15% HCl by two pyrazolone derivatives namely 2-(3-amino-5-oxo-4,5-dihydro-1H-pyrazol-1-yl)(p-tolyl)methyl)malononitrile (PZ-1) and 2-((3-amino-5-oxo-4,5-dihydro-1H-pyrazol-1-yl)(phenyl)methyl)malononitrile (PZ-2) has been investigated by using gravimetric, electrochemical and quantum chemical studies. The observed results reveal that PZ-1 is a better inhibitor than PZ-2. Tafel polarization showed that PZs are mixed type inhibitors but dominantly affect the cathodic reaction. Both inhibitors were found to obey the Langmuir adsorption isotherm. Scanning electron microscopy (SEM) and scanning electrochemical microscopy (SECM) images support the protection of the N80 steel in the presence of the PZs. Quantum chemical study reveals that both inhibitors have a tendency to get protonated and this result supports the experimental observations.
CORROSION INHIBITION PROPERTY OF POLYESTER–GROUNDNUT SHELL BIODEGRADABLE COMPOSITE
(Elsevier, 2016-12) Sounthari, P; Kiruthika, A; Saranya, J; Parameswari, K; Chitra, S
The use of natural fibers as reinforcing materials in thermoplastics and thermoset matrix composites provide optimistic environmental profits with regard to ultimate disposability and better use of raw materials. The present work is focused on the corrosion inhibition property of a polymer matrix composite produced by the use of groundnut shell (GNS) waste. Polyester (PE) was synthesized by condensation polymerization of symmetrical 1,3,4-oxadiazole and pimelic acid using sodium lauryl sulfate as surfactant. The polyester–groundnut shell composite (PEGNS) was prepared by ultrasonication method. The synthesized polyester–groundnut shell composite was characterized by FT-IR, TGA and XRD analysis. The corrosion inhibitory effect of PEGNS on mild steel in 1 M H2SO4 was investigated using gravimetric method, electrochemical impedance spectroscopy, potentiodynamic polarization, atomic absorption spectroscopy and scanning electron microscopy. The results showed that PEGNS inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration and decrease with increasing temperature. The composite inhibited the corrosion of mild steel through adsorption following the Langmuir adsorption isotherm. Changes in the impedance parameters Rt, Cdl, Icorr, Ecorr, ba and bc suggested the adsorption of PEGNS onto the mild steel surface, leading to the formation of protective film.
DRY AND WET LAB ANALYSIS ON BENZOFUSED HETEROCYCLIC COMPOUNDS AS EFFECTIVE CORROSION INHIBITORS FOR MILD STEEL IN ACIDIC MEDIUM
(Elsevier, 2016-08-25) Venkatesan, Hemapriya; Mayakrishnan, Prabakaran; Kandasamy, Parameswari; Subramaniyan, Chitra; Seung-Hyun, Kim; Ill-Min, Chung
The influence of two benzofused heterocyclic compounds, namely 2-phenylquinazolin-4(3H)-one(PQO) and 2-phenyl-4H-benzo[d]oxazin-4-one(POO) in controlling mild steel corrosion in 1 M H2SO4 solution was investigated using gravimetric and electrochemical methods. The experimental results revealed that both the inhibitors inhibit corrosion and their inhibition efficiency follows the order PQO > POO. A mixed mode of inhibition from polarization and a charge transfer mechanism from impedance study in the absence and presence of inhibitors were found. The passive film formed on the mild steel surface was characterized using SEM-EDX. Quantum chemical parameters derived using DFT performed at B3LYP/6-31G(d, p) level were used to correlate the molecular structure.
EFFECT OF PARTICLE SIZE ON OPTICAL AND ELECTRICAL PROPERTIES IN MIXED CDS AND NIS NANOPARTICLES SYNTHESIS BY ULTRASONIC WAVE IRRADIATION METHOD
(Elsevier, 2016-12) Mohanraj, V; Jayaprakash, R; Robert, R; Balavijayalakshmi, J; Gopi, S
The mixed phase CdS and NiS nanoparticles are prepared by adopting ultrasonic wave irradiation method under different doping concentration of Ni in CdS. The well defined nano spheres are obtained during this synthesis process. The predicted particle sizes from X-ray diffraction (XRD) analysis are found to lie in the range between 37 and 49 nm. The effective doping of Ni lead to form the mixture of two phases such as CdS and NiS. The respective change due to the formation of mixture of CdS and NiS is reflected well in the band gap energy which is measured in Diffused Reflectance Spectra (DRS). It is predicted in the range of 2.41–2.23 eV respectively. Consistency of particle size with XRD are confirmed from Transmission Electron Microscope (TEM) images and also identified the presence of Nickel Sulfide and Cadmium Sulfide in nanostate with average particle size as 54 nm. The Energy Dispersive X-ray (EDAX) analysis confirmed the existence of Ni, Cd and S the doping levels. The optical absorption analysis of samples are performed in UV–vis range 400–600 nm. The synthesized samples are further characterized Fourier Transform Infrared (FT-IR) spectroscopy, Thermogravimetric (TGA) analysis, I-V characteristic and conductivity measurements.
EFFICACY OF PLEUROTUS SAJOR CAJU AS AN EXCELLENT POTTING MEDIUM FORGARDEN PLANTS
(International Journal of Pharma and Bio Sciences, 2016) Harathi, P; Radha, R; Gayathri, M
Coir is a natural fibre found between the hard, internal shell and the outer coat of a coconut is used as a by-product of the coir manufacturing industry. Normally, they are dumped as agricultural wastes in the fields or disposed by burning which causes air pollution. Composting of coir pith is an alternate method to reduce pollution and it also serves as a source for the maintenance of organic matter of the soil. Coir pith is an ideal soil re-conditioner and soil substrate with excellent water holding capacity. Coir pith contains high quality of nutrients which keeps the soil healthy in a natural way. It acts as a top dressing that helps to maintain moisture content of the soil and re-conditions the soil. The proportion yielded effective growth of the plant and indicating its use as an excellent potting media for garden plants. Hence the objective of the present study focused on the efficacy of basidiomycetes fungus, Pleurotus sajor-caju for the cultivation of medicinal plant, Ocimum santum using the biodegraded coir pith
EFFICIENCY OF ASPERGILLUS TERREUS TO SOLUBILIZE INSOLUBLE FORM OF PHOSPHORUS INTO SOLUBLE FORM UNDER VARIOUS CULTURAL CONDITIONS
(International Journal of Pharma and Bio Sciences, 2016-03) Anitha, S; Padma Devi, S N
Phosphorous forms the second major nutrient required by the plants for its growth. It is supplied to the plants in the form of synthetic fertilizer which gets accumulated in the soil due its conversion into unavailable form. Transformation of unavailable form of phosphorus (P) to an available form becomes inevitable due to its physiological and biochemical role in plants. Since its deficiency results in the cessation of plant growth, supplementation of soluble form of phosphorus becomes essential. Fungus has the capability to convert insoluble form of phosphorus to soluble form through the secretion of organic acid as one of the solubilization mechanism. Thus in the present study, Aspergillus terreus was isolated from the rhizospheric soil sample of tomato field and was tested for its phosphorus solubilization efficacy by Broth assay method. The strain showed highest solubilization (7.5 mg/l) at the 10th day of incubation with the pH drop of 4.0. Solubilization efficacy of the isolate was high due to the secretion of organic acid (gluconic acid) which was confirmed by HPLC method. Effect of various parameters such as Carbon sources, Nitrogen sources, pH and Temperature on the solubilization of phosphorus by A. terreus was also tested. The strain showed maximum solubilization in the presence of fructose as carbon source, ammonium sulphate as a nitrogen source, at the temperature of 30ËšC and at the pH of 7.0 in both qualitative and quantitative assays. Thus A. terreus shall be used as a viable Bioinoculant to eradicate P- deficiency in plants.
EVALUATION OF POLYPHENOL COMPOSITION AND ANTI-CORROSION PROPERTIES OF CRYPTOSTEGIA GRANDIFLORA PLANT EXTRACT ON MILD STEEL IN ACIDIC MEDIUM
(Elsevier, 2016-05-25) Mayakrishnan, Prabakaran; Seung-Hyun, Kim; Venkatesan, Hemapriya; Ill-Min, Chung
The total phenolic and flavonoid compounds present in Cryptostegia grandiflora leaf extract were analyzed. The results confirmed that the extract contains the Myricetin 3582.22(μg/g) and Rutin 45.62(μg/g) as major components. C. grandiflora extract was evaluated for its anti-corrosion property on mild steel in 1 M H2SO4. A maximum inhibition efficiency of 87.54% was achieved by using 500 ppm of the inhibitor. Polarization studies indicate that the extract acts as a mixed inhibitor. The formation of productive layer on mild steel by inhibitor was confirmed by SEM-EDS and AFM. The extract is adsorbed on the mild steel according to Temkin adsorption isotherm.
EXISTENCE AND EXPONENTIAL STABILITY FOR NEUTRAL STOCHASTIC INTEGRODIFFERENTIAL EQUATIONS WITH IMPULSES DRIVEN BY A FRACTIONAL BROWNIAN MOTION
(Elsevier, 2016-03) Arthi, G; Ju H, Park; H Y, Jung
In this paper, we establish the results on existence and uniqueness of mild solution of impulsive neutral stochastic integrodifferential equations driven by a fractional Brownian motion. Further, by using an impulsive integral inequality, some novel sufficient conditions are derived to ensure the exponential stability of mild solution in the mean square moment. The results are obtained by utilizing the fractional power of operators and the semigroup theory. Finally, an example is presented to demonstrate the effectiveness of the proposed result.
HIGHLY EFFICIENT LIGULARIA FISCHERI GREEN EXTRACT FOR THE PROTECTION AGAINST CORROSION OF MILD STEEL IN ACIDIC MEDIUM: ELECTROCHEMICAL AND SPECTROSCOPIC INVESTIGATIONS
(Elsevier, 2016-02) Mayakrishnan, Prabakaran; Seung-Hyun, Kim; Kathirvel, Kalaiselvi; Venkatesan, Hemapriya; Ill-Min, Chung
A methanol extract of Ligularia fischeri was studied for its inhibitive effect on the corrosion of mild steel in a 1 M hydrochloric acid medium, using the metrics of weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The corrosion rate of mild steel and Ligularia fischeri's inhibition efficiencies were calculated. The inhibition efficiency [η (%)] was observed to increase with increasing concentrations of Ligularia fischeri. A maximum inhibition efficiency of 92% was achieved using 500 ppm of the inhibitor. The weight loss experiments were performed at different temperatures to understand the thermodynamic mechanism of inhibition. A mixed inhibition mechanism was proposed for the effects of Ligularia fischeri extract, as revealed by the potentiodynamic polarization technique. A solution analysis by atomic absorption spectroscopy (AAS) for mild steel showed decreased dissolution of iron in the presence of Ligularia fischeri. The adsorption mechanism and surface morphology of the mild steel, both with and without the inhibitor, were studied using UV–visible, Fourier transform infrared (FT-IR), Raman, wide-angle X-ray diffraction (WAXD), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS), and atomic force microscopy (AFM).
IDENTIFICATION OF RARE GENETIC DISORDER FROM SINGLE NUCLEOTIDE VARIANTS USING SUPERVISED LEARNING TECHNIQUE
(Institute of Advanced Engineering and Science (IAES), 2016) Sathyavikasini, K; Vijaya, M S
Muscular dystrophy is a rare genetic disorder that affects the muscular system which deteriorates the skeletal muscles and hinders locomotion. In the finding of genetic disorders such as Muscular dystrophy, the disease is identified based on mutations in the gene sequence. A new model is proposed for classifying the disease accurately using gene sequences, mutated by adopting positional cloning on the reference cDNA sequence. The features of mutated gene sequences for missense, nonsense and silent mutations aims in distinguishing the type of disease and the classifiers are trained with commonly used supervised pattern learning techniques.10-fold cross validation results show that the decision tree algorithm was found to attain the best accuracy of 100%. In summary, this study provides an automatic model to classify the muscular dystrophy disease and shed a new light on predicting the genetic disorder from gene based features through pattern recognition model.
INVESTIGATION OF STRUCTURAL, OPTICAL AND MORPHOLOGICAL PROPERTIES OF COPPER DOPED ZINC SULPHIDE NANOPARTICLES
(Elsevier, 2016-06-15) Balavijayalakshmi, J; Manju, S
Semiconductor nanoparticles doped with transition metal ions can influence the transition probabilities and electronic structure. The undoped and copper doped zinc sulphide nanoparticles with various concentrations are synthesized by wet chemical co-precipitation method. These nanoparticles are characterized by using X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), UV–visible (UV–vis) absorption spectroscopy, Fourier Transform Infrared (FT-IR) Spectroscopy, conductivity measurement and time-resolved photoluminescence studies. X-ray powder diffraction analysis reveals that the synthesized samples have cubic zinc blende structure. The Scanning Electron Microscope shows the synthesized nanoparticles are agglomerated. The UV–visible spectra reveal the absorption edge is red shifted. The FT-IR spectra show vibrational peaks around 617 cm−1 which indicate the presence of Cu–S stretching modes. The AC conductivity measurement confirms the semiconducting nature and shows a marked increase in conductivity as the doping concentration of copper increases. The photoluminescence shows that the emission at 426 nm may be due to transition from the conduction band to the zinc vacancies. These transition metal ions doped semiconductor nanoparticles have important applications in solid state lighting, imaging, and other photonic devices.
N-HETEROCYCLES AS CORROSION INHIBITORS FOR MILD STEEL IN ACID MEDIUM
(Elsevier, 2016-04) Jagadeesan, Saranya; Murugaiyan, Sowmiya; Palanisamy, Sounthari; Kandhasamy, Parameswari; Subramanian, Chitra; Kittusamy, Senthilkumar
The corrosion behavior of mild steel in 1 M H2SO4 was studied using 2,3-diphenylpyrazine (DP), 2,3-di(furan-2-yl)pyrazine (FP) and 2,3-di(furan-2-yl)quinoxaline (FQ) as inhibitors using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) methods were utilized for surface characterization. The results showed that the three inhibitors possess excellent inhibition effect toward mild steel corrosion. The inhibitor molecules are adsorbed on the mild steel surface, blocking the reactive sites available for acid attack. Adsorption of the inhibitor was found to obey Langmuir isotherm. Electronic structure calculations were used to study the inhibition efficiency of the inhibitor molecules on Fe (100) surface. The calculated results are in agreement with the experimental findings.
NEW POSSIBILITY ON INZNO NANO THIN FILM FOR GREEN EMISSIVE OPTOELECTRONIC DEVICES
(Elsevier, 2016-04) Sathish, Sugumaran; Mohd Noor, Bin Ahmad; Mohd, Faizal Jamlos; Chandar Shekar, Bellan; Sharmila, Chandran; Manoj, Sivaraj
Indium zinc oxide (InZnO) nano thin film was prepared from InZnO nanoparticles (NPs) by thermal evaporation technique. Fourier transform infrared spectroscopy showed the presence of metal-oxide bond. X-ray diffraction pattern revealed the mixed phase structure. The presence of elements In, Zn and O were identified from energy dispersive X-ray analysis. Size of the NPs was found to be 171 and 263 nm by transmission electron microscopy. Scanning electron microscopy image showed the spherical shape uniform morphology with uniform distribution grains. Photoluminescence spectrum exhibited a broad green emission for InZnO nano thin film. The acquired results of structure, smooth morphology and photoluminescence property suggested that the InZnO nano thin film to be a promising material for room temperature green emissive optoelectronic, laser diodes, solar cells and other optical devices.
NON-FRAGILE OBSERVER-BASED PASSIVE CONTROL FOR DISCRETE-TIME SYSTEMS WITH REPEATED SCALAR NON-LINEARITIES
(Oxford Academic, 2016-09) Arthi, G; Tae H, Lee; Ju H, Park; Jung, H Y
In this paper, the non-fragile observer-based passive control problem is discussed for a class of systems with repeated scalar non-linearities and time-varying delays. The non-linear system is defined by a discrete-time state equation containing a repeated scalar non-linearity. The system under consideration is modelled by assuming the random imperfect communication links existing between the controller and observer. The random fluctuations are defined by utilizing the Bernoulli distributed white sequences. The non-fragile observer-based feedback controller gains are designed to guarantee that the considered closed-loop control system with repeated scalar non-linearities and time-varying delays is passive. Sufficient conditions are derived for the existence of controller and observer gains by using the Lyapunov stability theory, passivity theory and linear matrix inequalities. As a final point, a numerical example by using a marketing-production system is presented to demonstrate the effectiveness of the proposed theoretical results.