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Parameter Estimation of Single Phase Core Type Transformer Using Bacterial Foraging Algorithm

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Engineering（科研） 2010年第11期2卷 917-925页

作者： seeni padma Srikrishna Subramanian 不详

The electrical circuit equivalents of magnetic device structures such as transformer require an exact knowledge of its parameters. Efficient parameter estimation technique is essential to obtain the equivalent circuit parameters of transformer because the parameters are used to manipulate parasitic elements and to obtain the enhanced circuit performance. In this paper, Bacterial Foraging Algorithm (BFA) has been applied to estimate the equivalent circuit parameters of single phase core type transformer. The information of open Circuit (OC) and Short Circuit (SC) tests has been utilized in BFA algorithm. The effectiveness of the proposed approach has been tested with a sample transformer and the simulation results are compared against the conventional method. The numerical results show that the proposed approach outperforms the conventional method in the aspects of solution quality.

关键词： Parameter Estimation Transformer Equivalent Circuit Bacterial Foraging Algorithm

Doping effect of rare-earth(lanthanum, neodymium and gadolinium) ions on structural,optical, dielectric and magnetic properties of copper nanoferrites

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Journal of Rare Earths 2018年第12期36卷 1299-1309页

作者： R. Rajesh Kanna K. Sakthipandi S.M.seeni Mohamed Aliar Maraikkayar N. Lenin M. Sivabharathy Department of Physics Sethu Institute of Technology Department of Computer Science and Engineering Sethu Institute of Technology

Copper and rare earth-doped(RE = La, Gd, Nd) CuFe1.85RE0.15O4nano ferrites were prepared using the so nochemical method. The effective doping of rare-earth(La3+, Nd3+, Gd3+) ions with copper nanoferrites was confirmed by X-ray diffraction. The tetrahedral and octahedral sites of the nano ferrites were identified through the Fourier transform infrared spectra. The doping of rare-earth elements enhances the optical bandgap energy of the nanoferrites that are observed through Ultraviolet-DRS spectra. The oxidation state of the elements Cu 2 p, La 3 d, Nd 3 d, Gd 3 d, Fe 2 p and O 1 s was analyzed. Scanning electron microscopy images indicate a spherical morphology with agglomeration to some elongate. The values of dielectric constant and conductivity decrease considerably due to doping rare-earth ions in copper nanoferrites. Low saturation magnetization and high coercivity values of rare earth-doped copper nanoferrites are observed from the typical hysteresis curves.

关键词： Nanoferrites Optical properties Dielectric response Magnetic measurements Rare earths

Review on Zinc Oxide Nanoparticles: Antibacterial Activity and Toxicity Mechanism

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Nano-Micro Letters 2015年第3期7卷 219-242页

作者： Amna Sirelkhatim Shahrom Mahmud Azman seeni Noor Haida Mohamad Kaus Ling Chuo Ann Siti Khadijah Mohd Bakhori Habsah Hasan Dasmawati Mohamad Nano-Optoelectronics Research and Technology Laboratory (N.O.R.Lab) School of Physics Universiti Sains Malaysia Advanced Medical and Dental Institute Cluster of Integrative Medicine Universiti Sains Malaysia School of Chemical Sciences Universiti Sains Malaysia Nano-Optoelectronics Research and Technology Laboratory(N.O.R.Lab) School of Physics Universiti Sains Malaysia Department of Medical Microbiology Parasitology and Immunology School of Medical Sciences Universiti Sains Malaysia School of Dental Sciences Universiti Sains Malaysia

Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. Zn O-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. Zn O is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered Zn O-NPs antibacterial activity including testing methods, impact of UV illumination, Zn O particle properties(size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species(ROS) including hydrogen peroxide(H2O2), OH-(hydroxyl radicals), and O2-2(peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to Zn O-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc *** have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on Zn O abrasive surface texture. One functional application of the Zn O antibacterial bioactivity was discussed in food packaging industry where Zn O-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of Zn O-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or in

关键词： Antibacterial activity Zn O-NPs Toxicity mechanism Reactive oxygen species Zinc ions release Food antimicrobial

Investigation of the Biochemical and Histological Changes Induced by Zearalenone Mycotoxin on Liver in Male Mice and the Protective Role of Crude Venom Extracted from Jellyfish <i>Cassiopea Andromeda</i>

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Food and Nutrition Sciences 2011年第4期2卷 314-322页

作者： Madeha Al-seeni Nagwa El-Sawi Soad Shaker Asma Al-Amoudi 不详

Zearalenone (ZEN) is a non steroidal estrogenic mycotoxin produced by Fusarium species of fungi which contaminate human foods and animal feeds worldwide. In this study hepatotoxicity of ZEN was evaluated in mice by oral adminis-tration of single and repeated doses of ZEN mycotoxin (2.7 mg/kg b.w.). The protective effect of crude venom extracted from jellyfish Cassiopea andromeda was also assessed. Mice were divided into four groups (N = 10). G1: receiving the toxin once and sacrificed 48 h later, G2: toxin administered twice for one week, G3: toxin administered twice a week for two weeks, G4: pretreated orally by a single dose of crude venom (1.78 mg/20g) 24 hours prior to administration of ZEN twice a week for two weeks. Each treated group had its corresponding control which received 1% DMSO *** treatment significantly increased alanine aminotransferase (ALT), aspartateaminotrnsferase (AST) and alka-line phosphatase (ALP) activities after 48 hours and two weeks, while ALT was also significantly increased after one week. Tumor necrosis factoralpha (TNF-α) level was undetected in treated and control groups except the group treated with ZEN for one week. Alphafetoprotein (AFP) level was increased significantly only after two weeks. The activity of antioxidants was significantly increased in all groups. ZEN was also found to modify the serum proteins especially gamma-globulin which showed a significant decrease after 48 h and two weeks. Improvement in liver func-tion occurred in the group pretreated with the crude venom, and AFP and antioxidants returned to normal level, while TNF-α level was also undetected. Gamma globulin was significantly increased. The recovery observed in the group which was pretreated with crude venom may related to bradykinin content of this venom which exhibits a hepatoprotective effect. Histological changes in mouse liver coincided with biochemical changes. In conclusion, this study revealed that ZEN induced liver function and structur

关键词： Mycotoxin Zearalenone Liver Mice Jellyfish Crude Venom

Analysis of Genetic Diversity in <i>Poeciloneuron pauciflorum</i>Bedd.―An Endemic Tree Species from the Western Ghats of India

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American Journal of Plant Sciences 2011年第3期2卷 416-424页

作者： Padmesh Pandaram Pillai Jayakumari Sanakan Sajan Kuttapetty Manikantan Menon Achuthan Sudarshanan Hemanthakumar Alagramam Govindasamy Pandurangan Peringatulli Narayanan Krishnan Soorimuthu seeni 不详

Poeciloneuron pauciflorum is a narrow endemic having highly restricted distribution in the southern-western Ghats region of India. 18 accessions of P. pauciflorum collected from four different locations were analyzed for genetic variation using 20 random primers. Out of 141 amplicons generated, 130 of them were polymorphic (92.20% polymorphism). Contrary to the general concept of low genetic variation associated with endemic plant species, P. pauciflorum exhibits high genetic diversity as the similarity index value based on Nei & Li’s similarity coefficient ranges from 0.36 to 0.95 with mean GS = 0.72 and Shannon’s information measure (0.43). Cluster analysis showed grouping of all accessions from the State of Tamil Nadu into two major clusters with few outliers while those from the State of Kerala also clustered with them. Accessions from Kalliankadu forest segment harbors maximum diversity as indicated by various genetic diversity indices like h, I, Ht, Hs, Gst, PL and hence this site is recommended for in situ conservation of this narrow endemic. The main factors responsible for the high level of genetic diversity among accessions are probably related to the reproductive isolation and ecological breadth. The strong genetic variability among accessions indicates that the management for the conservation of the genetic diversity in P. pauciflorum should aim to preserve every accession. The present study assumes significance as it negotiates endemism and genetic variation in tree species, a global phenomenon having wide implications in species diversity and conservation.

关键词： RAPD Neoendemism Xanthones