Characterisation and optimisation of hybrid polymer/metal oxide photovoltaic devices

Imperial Users onl

Determinants of Efficiency of Commercial Banks in India After Global Crises

This study contributes to the bank efficiency literature by estimating the technical efficiency, pure efficiency, and scale efficiency of banks in four different ownership groups in India from 008-09 to 019-20, utilizing the DEA method and three alternative approaches to choosing inputs and outputs of banks-intermediation approach, value-added approach, and operating approach. It also uses the Tobit estimation procedure to identify the factors determining the variations in the technical efficiency of banks. Results indicate a high degree of inefficiency of several banks during the study period, and there is greater scope for improving their performances. Sizable scale inefficiency exists, and banks are likely to lose sizable output. The results also indicate that banks with a larger capital adequacy ratio, young banks, larger banks, or more profitable banks are more efficient. Foreign banks and nationalized banks are more efficient than private domestic banks. We hope that the findings of this study will be useful to international agencies and other stakeholders in evaluating and improving the performance of Indian banks

Development and Application of a Stream Flashiness Index based on Imperviousness and Climate using GIS

This work examines the relationship between imperviousness, climate, and the Richards-Baker (R-B) index, a measure of ow variability. Regression equations to predict the R-B index are developed for annual, cool, and warm seasons. The re- gression equations developed, are calibrated using stream ow data from 1970-2000 for 29 USGS streamgages throughout Maryland. Regression equations for the R-B ashiness index are developed as a function of imperviousness, precipitation char- acteristics, and drainage area. The relationship is used to estimate stream quality conditions throughout Maryland for present and future land use and climate. The regression equations are used to calculate the future stream ow variability by pro- jecting the R-B index predictors to re ect the following conditions: (1) Increasing imperviousness only, (2) Climate change only, and (3) Jointly changing impervious- ness and climate. Finally, the relationship between R-B index and stream quality is studied

A Structural and Biochemical Study on the Stapholococcal Surface Proteins Interactions with Host Extracellular Proteins

Staphylococcus aureus (S. aureus), a gram positive bacterium, expresses multiple surface proteins (MSCRAMMs) that target host proteins for its colonization on the host tissue and later for the pathogenesis. ClfA is a virulence factor that interacts with fibrinogen (Fg) and the interaction of ClfA with the Fg is crucial for the pathogenesis. The virulence potential of ClfA/Fg interactions in the pathogenesis of S.aureus had been proven in sepsis and endocarditis infection animal models. ClfB is a chief colonizing factor that interacts with multiple host proteins like loricrin, cytokeratin-10, dermokine and Fg. The binding mechanism and structure of the ClfB:Ln complex is crucial for designing inhbitors against ClfB that aid in preventing the host colonization of S. aureus. My thesis work includes two chapters (1) crystal structure of ClfA with a proteolytic fragment of Fg (FgD). (2) Crystal structure of ClfB in complex with Ln. Chapter-1 results describe the structure of ClfA/FgD complex and identify the residues involved in the interactions of ClfAcc and Fg. The results of this chapter explains the structural basis for the fg mediated virulence of ClfA and the mechanism of Fg interactions of ClfA of S. aureus and its functional homologs fbl of S. lugdunensis and SpsD of S .pseudintermedius. The ClfAcc interacting region in Fg overlaps with the M1 protein of S. pyogenes and Fg interacting site in ClfA overlaps with the ‘tefibazumab’ interacting site. Chapter-2 results describe the structure of the ClfB/Ln complex and the mechanism of ClfB/Ln interactions. Comparison of ClfB/Ln structure with other ClfB ligand peptide complexes (Ck10, DK and Fg) shows that ClfB/Ln binding mechanism is unique and different from the previously known Dock, Lock and Latch mechanism of ClfB ligand binding. My study was the first structure to show that, the Ln peptide can induce the dimerization of ClfB which is not observed in the interaction of ClfB with other known ligands. Furthermore, the crystal structure led to the discovery of an additional ligand binding site on top of the N3 subdomain in ClfB which is also present in other MSCRAMMS that forms the basis for chapter-1

Lithium doped poly(3-hexylthiophene) for efficient hole transporter and sensitizer in metal free quaterthiophene dye treated hybrid solar cells

Abstract This work focuses on the role of Lithium doped Poly(3-hexylthiophene)(P3HT) in metal-free quaterthiophene (4T) dye treated Titanium dioxide (TiO2) based hybrid solar cells. The dye treated hybrid solar cells with Lithium doped P3HT showed efficiencies (3.95%) of nearly a factor of four times higher than the pristine P3HT based control TiO2/4T/P3HT devices (1.04%). The enhancement of the efficiency is mainly due to highly efficient charge collection attributed to enhanced charge transport and light harvesting properties of Lithium doped P3HT polymer. The optimized solar cells with Lithium doped P3HT showed a high short circuit current density over 13 mA/cm2, under simulated irradiation of intensity 100 mW/cm2 with AM 1.5 filter. This significant increase in current density in TiO2/4T/doped P3HT solar cell is also confirmed by both the broadened External Quantum Efficiency spectrum and significant photoluminescence quenching upon replacement of pristine P3HT with doped P3HT on 4T dye treated TiO2 electrode. With Lithium doped Spiro-OMeTAD instead of Lithium doped P3HT, similar devices showed efficiencies over 3.30% under simulated irradiation of 100 mW/cm2 with AM 1.5 filter

A Quarterthiophene-Based Dye as an Efficient Interface Modifier for Hybrid Titanium Dioxide/Poly(3-hexylthiophene)(P3HT) Solar Cells

This work focused on studying the influence of dyes, including a thiophene derivative dye with a cyanoacrylic acid group ((E)-2-cyano-3-(3′,3′′,3′′′-trihexyl-[2,2′:5′,2′′:5′′,2′′′- quaterthiophene]-5-yl) acrylicacid)(4T), on the photovoltaic performance of titanium dioxide (TiO2)/poly(3-hexyl thiophene)(P3HT) solar cells. The insertion of dye at the interface improved the efficiency regardless of the dye used. However, 4T dye significantly improved the efficiency by a factor of three when compared to the corresponding control. This improvement is mainly due to an increase in short circuit current density (JSC), which is consistent with higher hole-mobility reported in TiO2/P3HT nanocomposite with 4T dye. Optical absorption data further revealed that 4T extended the spectral response of the TiO2/P3HT nanocomposite, which could also enhance the JSC. The reduced dark current upon dye insertion ensured the carrier recombination was controlled at the interface. This, in turn, increased the open circuit voltage. An optimized hybrid TiO2/P3HT device with 4T dye as an interface modifier showed an average efficiency of over 2% under-simulated irradiation of 100 mWcm−2 (1 sun) with an Air Mass 1.5 filter

Eco-friendly Egyptian blue (CaCuSi4O10) dye for luminescent solar concentrator applications

This study focuses on synthesizing the heavy metal-free ancient Egyptian blue (EB; CaCuSi4O10) dye using a facile ceramic method for luminescent solar concentrator (LSC) application. XRD, SEM and EDX results confirmed that this well-crystallized material is successfully synthesized. Optical studies revealed that EB has a high Stokes shift and possesses an average lifetime of 110.50 μs with a quantum yield of 12.93%. Finally, an EB-integrated LSC was fabricated that exhibits a power conversion efficiency (η) of 0.15% and an optical conversion efficiency (ηopt) of 1.21%, which are the highest values reported so far using EB.publishedVersio

Resistance to the larvicide temephos and altered egg and larval surfaces characterize salinity-tolerant Aedes aegypti.

Aedes aegypti, the principal global vector of arboviral diseases and previously considered to oviposit and undergo preimaginal development only in fresh water, has recently been shown to be capable of developing in coastal brackish water containing up to 15 g/L salt. We investigated surface changes in eggs and larval cuticles by atomic force and scanning electron microscopy, and larval susceptibility to two widely-used larvicides, temephos and Bacillus thuringiensis, in brackish water-adapted Ae. aegypti. Compared to freshwater forms, salinity-tolerant Ae. aegypti had rougher and less elastic egg surfaces, eggs that hatched better in brackish water, rougher larval cuticle surfaces, and larvae more resistant to the organophosphate insecticide temephos. Larval cuticle and egg surface changes in salinity-tolerant Ae. aegypti are proposed to respectively contribute to the increased temephos resistance and egg hatchability in brackish water. The findings highlight the importance of extending Aedes vector larval source reduction efforts to brackish water habitats and monitoring the efficacy of larvicides in coastal areas worldwide