Salman Hameed

Influence of Ce Doping on the Electrical and Optical Properties of TiO2 and Its Photocatalytic Activity for the Degradation of Remazol Brilliant Blue R

Nanocrystalline TiO2 particles doped with different concentrations of Cerium (Ce, 1–10%) have been synthesized using sol-gel method. The prepared particles were characterized by standard analytical techniques such as X-ray diffraction (XRD), FTIR and Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The XRD analysis shows no change in crystal structure of TiO2 after doping with different concentrations of Ce, which indicates the single-phase polycrystalline material. The SEM analysis shows the partial crystalline nature of undoped, and doped TiO2 and TEM analysis shows the particle sizes were in the range of 9–14 nm in size. The a.c. analysis shows that the dielectric constant and dielectric loss tan decrease with the increase in frequency. The dielectric property decreases with the increase in dopant concentration. It is also observed that the impedance increases with an increase in dopant concentration. The photocatalytic activity of the synthesized particles (Ce-doped TiO2) with dopant concentration of 9% (Ce) showed the highest photocatalytic activity for the degradation of the dye derivative Remazol Brilliant Blue R in an immersion well photochemical reactor with 500 W halogen linear lamp in the presence of atmospheric oxygen.

Power system stability enhancement using reduced rule base self-tuning fuzzy PI controller for TCSC

In this paper, a self-tuning fuzzy PI controller (STFPIC) for Thyristor Controlled Series Capacitor (TCSC) is proposed. Essentially, a STFPIC consists of two fuzzy logic controllers (FLC). In this work, for each FLC, 49 rules have been used and as a result, the overall complexity of the STFPIC increases substantially. To reduce this complexity, application of singular value decomposition (SVD) based rule reduction technique is also proposed in this paper. By applying this methodology, the number of rules in each FLC has been reduced from 49 to 9. Therefore, the proposed rule base reduction technique reduces the total number of rules in the STFPIC by almost 80% ( from 49×2 = 98 to 9×2 = 18 ), thereby reducing the complexity of the STFPIC significantly. The feasibility of the proposed algorithm has been tested on 10-machine 39-bus system through detailed digital simulation using MATLAB/SIMULINK.

Power system stability enhancement with genetically optimized SVC controller

Multi-machine power system stability improvement by tuning of Static Var Compensator (SVC)-based controller parameters is investigated in the proposed method. The design problem is formulated as an optimization problem with a timedomain simulation-based objective function and Real-Coded Genetic Algorithm (RCGA) is used for searching optimal controller parameters. A multi-machine power system model is developed using MATLABs SIMULINK which incorporates SVC Controller. A fault is created on the transmission line. The simulation results of the multi-machine power system without SVC Controller and with SVC Controller are presented. The simulation results are analyzed which shows that the power system becomes unstable on the occurrence of the fault if SVC controller is not used. This paper shows the effectiveness of the proposed design. The proposed method enhances the multi-machine power system stability.

Efficiency enhancement in dye-sensitized solar cells using silver nanoparticles and TiCl4

ABSTRACT This paper reports the efficiency enhancement in dye-sensitized solar cells (DSSCs) by incorporation of silver nanoparticles (AgNPs) in Titanium dioxide (TiO2) and using it as anode. Further enhancement in DSSC parameters was observed after TiCl4 treatment on TiO2Ag anode. It was observed that the short circuit current density Jsc was increased from 6.95 to 12.58 mA/cm2 by TiCl4 treatment with no change in Voc and fill factor increasing the efficiency from 3.29 to 5.61%. The fabricated DSSCs using TiO2AgNPs anode with both pre and post TiCl4 treatment appear to have the maximum efficiency as compared to other cells. Due to effective electron transport and enhanced absorption of dye on TiO2AgNPs anode surface, the maximum conversion efficiency of 7.3% was achieved.

Effect of different dyes on TiO2 based dye sensitized solar cell

In this paper, the dye sensitized solar cells are fabricated by use of natural pigments as well as synthetic dyes to act as sensitizer. Pomegranate juice, extract of butea mono sperma flower, methyl orange and methylene blue dyes was tested. TiO2 NPs was used as high band gap semiconductor as electron transporting layer in dye sensitized solar cells. The conversion efficiency of visible light into electricity of pomegranate juice, extract of butea mono sperma flower, methyl orange and methylene blue dyes are 4.47%, 3.74%, 1.42% and 1.01% respectively. It is found that the natural dye pomegranate juice has best photosensitized effect than the other dyes. So, due to the simple preparation technique, low cost and large availability, natural dyes are promising as environmentally friendly sensitizers.

Investigation of electrical and optical properties of TiO2-graphene for dye-sensitised solar cells

In the present work Graphene (G) was synthesized and incorporated into Titanium di oxide (TiO2). Electrical characterization was performed by using LCR meter. XRD Analysis, UV Visible spectroscopy was done for optical characterization. It was observed that crystallinity of samples were almost same but the conductivity of TiO2-G nanocomposite was increased whereas dielectric constant decreases after incorporation of graphene. This difference in conductivities was due to the enhancement of both the carrier concentration and mobility which shows that the electrical properties of TiO2 can be improved by the incorporation of graphene, while maintaining the structural and optical properties. The TiO2-G nanocomposite was used as photo anode of Dye sensitized solar cell (DSSC) and shows enhancement in power conversion efficiency in comparison to pure TiO2 under same test conditions.

Improvement of power system stability using genetically optimized SVC controller

Single machine infinite bus (SMIB) power system and multi-machine power system (MMPS) stability improvement by tuning of static var compensator (SVC) based controller parameters are investigated in the proposed method. The design problem is formulated as an optimization problem with a time-domain simulation-based objective function and real-coded genetic algorithm is used for searching optimal controller parameters. SMIB power system and MMPS models are developed using MATLAB’s SIMULINK which incorporates SVC controller. A fault is created on the transmission line. The simulation results of SMIB power system and MMPS without SVC controller and with SVC controller are presented. The simulation results are analyzed which show that the power system becomes unstable on the occurrence of the fault if SVC controller is not used. This paper proves the effectiveness of the proposed design. Thus the proposed method enhances the power system stability.

Study of photoconductivity of nanocrystalline titanium dioxide used in dye sensitized solar cell

In this work the nanocrystalline TiO2 - dye sensitized photovoltaic cells are constructed and studied. This type of photovoltaic cell consists of a thin film of nanocrystalline titanium dioxide (TiO2) particles with natural black berries juice as dye molecules on their surface. When the dye molecules are excited by a light source, electrons are transferred from the dye to the TiO2 and produce a photovoltaic effect. The circuit of the photovoltaic cell is completed by applying an electrolyte solution. The efficiency of such a photovoltaic cell depends on the state of the TiO2, the type of dye, and the electrolyte solution used. The purpose of this study is to develop solar cells with increasingly higher voltage and current outputs and to have our results as predictable and reproducible as possible. Research is still in the stages of testing various dyes, and electrolyte solution in order to obtain better results and more efficient solar cells.