Metal Ions in Biological Systems

In recent years solar energy has received worldwide attention in the field of renewable energy systems Among the various research thrusts in solar PV, the most proverbial area is extracting maximum power from solar PV system Application dof Maximum Power Point Tracking (MPPT) for extracting maximum power is very much appreciated and holds the key in developing efficient solar PV system In this paper, a state of the art review on various maximum power point techniques for solar PV systems covering timeworn conventional methods and latest soft computing algorithms is presented To date critical analysis on each of the method in terms of (1) tracking speed, (2) algorithm complexity, (3) Dynamic tracking under partial shading and (4) hardware implementation is not been carried out In this regard the authors have attempted to compile a comprehensive review on various solar PV MPPT techniques based on the above criteria Further, it is envisaged that the information presented in this review paper will be a valuable gathering of information for practicing engineers as well as for new researchers

A comprehensive review on solar PV maximum power point tracking techniques

Studying non-covalent drug-DNA interactions.

Understanding the interaction of small molecules with DNA has become an active research area at the interface between chemistry, molecular biology and medicine. Plant derived polyphenols possess diverse biological and pharmacological properties. Esculetin is a coumarin derivative polyphenolic compound having diverse pharmacological and therapeutic properties. However, its mode of interaction with DNA is still not well understood. In the present study, we have attempted to determine the mode of binding of esculetin with calf thymus DNA (Ct-DNA) through various biophysical techniques. Analysis of UV-visible absorbance spectra and fluorescence spectra indicates the formation of a complex between esculetin and Ct-DNA. The binding constant was found to be 1.87 × 104 M−1. Thermodynamic parameters ΔG, ΔH, and ΔS at different temperatures indicated that hydrophobic interactions and hydrogen bonding played major roles in the binding process. Several other experiments such as iodide induced quenching and competitive displacement studies with ethidium bromide, acridine orange and Hoechst 33258 suggested that esculetin possibly binds to the minor groove of the Ct-DNA. The strong dependence on ionic strength in controlling the binding of esculetin with Ct-DNA confirms the possibility of electrostatic interaction. These observations were further supported by DNA melting studies, viscosity measurements, CD spectral analysis and in silico molecular docking.

Multi-spectroscopic and molecular modelling studies on the interaction of esculetin with calf thymus DNA.

Relationship between structure and inhibition behaviour of quinolinium salts for mild steel corrosion: Experimental and theoretical approach

Studies on DNA binding behaviour of biologically active transition metal complexes of new tetradentate N2O2 donor Schiff bases: inhibitory activity against bacteria.

The structures of phosphated titania and sulphated titania are studied with a combined approach using DFTB3LYP/Lan12DZ and experimental studies such as XRD, XPS, and DRIFT spectra. The infrared absorptions, Mulliken charges, bond lengths, and dipole moments are investigated for the phosphated and sulphated titania structures optimized by DFT calculations. The XRD patterns obtained for both the modified titania show that the as-synthesized materials are amorphous in nature. The DRIFT spectra show the presence of bidentate complex in both sulphated and phosphated titania. The XPS data show the presence of Ti-O-S and Ti-O-P linkages in sulphated and phosphated titania respectively. The evaluation of IR absorptions obtained by DFT and DRIFT spectra reveal the most favorable structure of bridged bidentate for sulphated titania and a combination of monodentate and chelating bidentate for phosphated titania.

/pdf/xps-and-ir-spectral-studies-on-the-structure-of-phosphate-ykid0gctf4.pdf

XPS and IR spectral studies on the structure of phosphate and sulphate modified titania: A combined DFT and experimental study

This paper proposes Maximum Power Point Tracking (MPPT) of a photovoltaic system under variable temperature and solar radiation conditions using Fuzzy Logic Algorithm. The cost of electricity from the PV array is more expensive than the electricity from the other non- renewable sources. So, it is necessary to operate the PV system at maximum efficiency by tracking its maximum power point at any weather conditions [1]. Boost converter increases output voltage of the solar panel and converter output voltage depends upon the duty cycle of the MOSFET present in the boost converter. The change in the duty cycle is done by Fuzzy logic controller by sensing the power output of the solar panel. The proposed controller is aimed at adjusting the duty cycle of the DC-DC converter switch to track the maximum power of a solar cell array. MATLAB/Simulink is used to develop and design the PV array system equipped with the proposed MPPT controller using fuzzy logic [2][3]. The results show that the proposed controller is able to track the MPP in a shorter time with less fluctuation. The complete hardware setup with fuzzy logic controller is implemented and the results are observed and compared with the system without MPPT (Fuzzy logic controller).

Design of Fuzzy Logic based Maximum Power Point Tracking controller for solar array for cloudy weather conditions

The present contribution reports a thorough characterization of newly obtained metallointercalators incorporating Schiff bases, formed by the condensation of N-acetoacetyl-o-toluidine with 1-amino-4-nitrobenzene (L(1))/1-amino-4-chlorobenzene (L(2)) as main ligand and 1,10-phenanthroline as co-ligand respectively. The characterization of newly formed metallointercalators has been done by (1)H NMR, UV-Vis, IR, EPR spectroscopy and molar conductivity studies. X-ray powder diffraction illustrates that they are crystalline nature. Binding interaction of these complexes with calf thymus (CT-DNA) has been investigated by emission, absorption, viscosity, cyclic voltammetry and differential pulse voltammetry. DNA binding experiments results reveal that the synthesized complexes interact with DNA through intercalative mode. The in vitro antibacterial and antifungal assay indicate that these complexes are good antimicrobial agents against various pathogens. The DNA cleavage exhibits that they act as efficient cleaving agents.

Metal based pharmacologically active complexes of Cu(II), Ni(II) and Zn(II): synthesis, spectral, XRD, antimicrobial screening, DNA interaction and cleavage investigation.

Bio-sensitive activities of coordination compounds containing 1,10-phenanthroline as co-ligand: synthesis, structural elucidation and dna binding properties of metal(II) complexes.

Rajkumar Mahalakshmi

Papers

Studies on DNA binding behaviour of biologically active transition metal complexes of new tetradentate N2O2 donor Schiff bases: inhibitory activity against bacteria.

XPS and IR spectral studies on the structure of phosphate and sulphate modified titania: A combined DFT and experimental study

Design of Fuzzy Logic based Maximum Power Point Tracking controller for solar array for cloudy weather conditions

Metal based pharmacologically active complexes of Cu(II), Ni(II) and Zn(II): synthesis, spectral, XRD, antimicrobial screening, DNA interaction and cleavage investigation.

Bio-sensitive activities of coordination compounds containing 1,10-phenanthroline as co-ligand: synthesis, structural elucidation and dna binding properties of metal(II) complexes.