Synthesis and Activation of Gold and Bimetallic Clusters for Catalysis

This thesis investigates the synthesis and activation of highly monodisperse Au25(SR)18 - clusters and bimetallic clusters (AuAg and AuPd) protected with various stabilizers for reduction and hydrogenation catalytic reactions. The first chapter is the introduction chapter, which summarizes the literature involving monolayer protected Au clusters, atomically precise Au clusters, bimetallic clusters, X-ray absorption spectroscopy, research objectives, and organization and scope. The second chapter describes the synthesis of Au25(SR)18 - clusters protected with various thiolate stabilizers for nitrophenol reduction catalysis using NaBH4 as a reducing agent. This chapter also describes the stability of these clusters under reaction conditions using UV-Vis spectroscopy and MALDI mass spectrometry. The third chapter details the synthesis of carboxylic acid-protected Au25 clusters using a NaBH4 purification strategy. Here, the knowledge obtained in the second chapter regarding the exceptional stability of Au25(SR)18 - clusters in the presence of NaBH4 was used to isolate carboxylic acid protected Au25 clusters from a polydisperse reaction mixture. The fourth chapter describes the synthesis and activation of mesoporous carbon supported Au25(SR)18 - clusters for nitrophenol reduction catalysis. Here, thermal removal of thiolate stabilizers led to the enhancement in the catalytic activity at low calcination temperatures; however, at higher calcination temperatures activity dropped as particle sintering was observed. Activation of these clusters on mesoporous carbon support was followed by TEM and X-ray absorption spectroscopy. The fifth chapter describes the thermal and chemical removal of thiolate stabilizers from supported Au25(SC8H9)18 - clusters. Here, the removal of thiolate stabilizers and subsequent growth of Au25 clusters was followed by TEM and EXAFS spectroscopy. The sixth and seventh chapters describe the synthesis of AuPd and AuAg bimetallic clusters using Au25(SR)18 - clusters as precursors and their characterization using UV-Vis spectroscopy, transmission electron microscopy, and X-ray absorption spectroscopy. Here, AuPd bimetallic clusters were thermally and chemically treated, which resulted in the formation of AuPd bimetallic nanoparticles with segregated Pd atoms on the surface. AuPd bimetallic nanoparticles were used for the selective hydrogenation catalysis of allyl alcohol. The last chapter of this thesis includes final conclusions and possible avenues for future work

Ayurveda Perspective of Rasamanikya and its Role in Skin Disorders: A Review

Rasamanikya is drug used commonly in Ayurveda practice for various therapeutic purposes. Rasamanikya made out of Shuddha Haratala and due to the Manikya (Ruby) colour of formulation it is termed as Rasamanikya. Rasamanikya can be prepared by classical Abhraka Patra method and Sharava Samputa method, etc. It is recommended for the management of Kustha Roga, Shwasa, Phirana Roga, Vicharchika, Bhaganadara and Vatarakta. The classical descriptions on Rasamanikya establish it as drug of choice for skin related health ailments due to its Ayurveda properties and health benefits. Therefore present article reviewed Ayurveda perspective of Rasamanikya and its role in skin disorders.       Keywords: Ayurveda, Rasamanikya, Skin, Disorders, Kustha Rog

Investigation of Low Optical-Gap Donor and Acceptor Materials for Organic Solar Cells

Development of efficient and clean energy sources to meet the ever-increasing de- mand of humankind is one of the greatest challenges of the 21st century. There is a dire need to decarbonise the power sector, and the focus needs to shift to re- newable resources such as wind and solar energy. In this regard, organic solar cells are a promising and novel technology owing to its low carbon footprint, innovative applications, and possible integration into the current infrastructure. Due to its unique advantages, a considerable research effort has been put into its development in the last decades. As a result, the power conversion efficiency (PCE) of the organic photovoltaics has steadily risen from as low as 0.5% to around 17 % at the current stage. This improvement primarily originates from the better understanding of the underlying physical processes and as a result of extensive material development. In the most general case, organic solar cells consist of a binary blend of an electron donating and an electron accepting organic semiconductor forming the so-called ‘bulk-heterojunction’ (BHJ) morphology. Thermodynamics places an upper limit on the power conversion efficiency (PCE) of binary blend BHJ devices and for further enhancement in efficiency novel device concepts like the use of ternary blends and tandem device architectures is being investigated. In relation to these approaches, the development of low optical-gap (Eopt ≤ 1.5 eV) organic semiconductors has gained importance as these materials provide for the complementary absorption with respect to the other components and better harvesting of the solar spectrum. This work mainly deals with the investigation of low optical gap donor and acceptor materials for organic solar cells. We investigate the effect of the molecular structure on the device performance and the photophysical processes in the binary and ternary blend configuration. In the first part of the thesis, we study a family of low optical- gap diketopyrrolopyrrole (DPP) based polymers while varying the conjugated core and the branching position and length of the solubilizing alkyl side chains. The branching position of the side chains is found to have a significant influence on the polymers ability to crystallize, which in turn influences the mobility of free charge carriers. The branching position also affects the solubility of the polymer, which in turn influences the morphology of the bulk-heterojunction (BHJ) and ultimately the yield of photogenerated charge carriers. To investigate the electron transfer and charge separation dynamics in the blends consisting of DPP polymers and fullerene, we employed ultrafast pump-probe spec- troscopic techniques. In the spectroscopy data, we observe signatures suggesting an ultrafast electron transfer process and an efficient charge separation process due to the high mobility of the free charge carriers shortly after separation (∼10-100 ps). Lastly, we investigated indacenodithiophene (IDT) based non-fullerene acceptor (NFA) molecules. In particular, we studied the effect of fluorination on the device performance when these acceptors are blended with PTB7-Th and P3HT donor polymers. The kinetics of the photophysical processes in the binary and ternary blends are characterized using ultrafast spectroscopy and related to the morphology of the blend and the molecular structure of the acceptors. Overall, we investigated the structural variations in the DPP polymers and flu- orinated non-fullerene acceptor (NFA) molecules and suggest design rules for the synthesis of optimal DPP polymers and non-fullerene acceptors to achieve supe- rior device performance. Additionally, we also shed light on the phenomenological processes happening on an ultrafast time scale (0.2-1000 ps) in the binary and the ternary blends with the aim of developing a better understanding of the photophys- ical processes in these promising material systems

Object Tracking in Video using Mean Shift Algorithm including Effect of AWGN channel

One of the analytic ventures in object tracking is the tracking of fast-moving objects in arbitrary movement, mainly in the area of video vision applications. Thus a technique of mean shift (MS) algorithm in visual video tracking is put forward. In this suggested method, arbitrary motion and partial occlusion of an object can be managed due to its capacity in estimating the object position with modifying motion model. Although the techniques like particle filter (PF) is able to manage numerous hypotheses to manipulate clutters in background and short-term breakdown. However, on the other hand, it needs a huge number of particles to estimate the actual posterior of the target dynamics. Therefore, MS algorithm is employed to the sampling process of the PF to carry these particles in gradient ascent direction. As a result of this, a little sample size will be adequate to constitute the system dynamics precisely. The proposed algorithm is directed to track the moving object in arbitrary directions under altering states with reasonable computational time. The dissimilarity between the target model and the target candidates is expressed by a metric derived from the Bhattacharya Coefficient

Assessment of Healing Potential of Formulated Herbal Cream on Burn Wound

The current protocol of the study was planned to assess the healing potential of formulated herbal cream containing different medicinal plant extracts. Formulated herbal cream was containing the methanolic extract of Chenopodium album, Coccinia indica, Momordica dioica, Precitrullus fistulosus and Trichosanthes dioica with cream base. Formulated herbal cream was assessed pharmacologically for healing potential in burn wound model. The formulation showed a significantly higher contraction rate, shortened epithelialization period, better tensile strength and increase in hydroxyproline content in the burn wound model. Thus, it is concluded that formulation has the potential wound healing activity which justifying its use as wound healer. Keywords:  Formulation, Burn, Wound, Contractio

Phytochemical Appraisal of Cucurbitaceae Plants Extracts

The present study deals with the phytochemical screening of selected medicinal plant drugs of Cucurbitaceae family. Leaves of test plants (Coccinia indica, Momordica dioica, Praecitrullus fistulosus and Trichosanthes dioica) were extracted successively with petroleum ether, methanol and water by hot extraction method and screened for the presence of alkaloids, carbohydrates, glycosides, flavonoids, proteins, resins, steroids and tannins. Obtained findings concluded that selected plants are good source of various phytochemicals. This experimental work revealed the presence of various biologically active secondary metabolites which could be helpful in the lead to drug discovery and development. Keywords: Phytochemical, Screening, Medicinal plants, Extrac

Content Based Image Retrieval by Using Interactive Relevance Feedback Technique - A Survey

Due to rapid increase in storing and capturing multimedia data with the digital device, Content Based Image Retrieval play a very important role in the field of image processing. Although wide ranging studies have been done in the field of CBIR but image finding from multimedia data basis is still very complicated and open problem. If paper provide an review of CBIR based on some of the famous techniques such as Interactive Genetic Algorithm, Relevance Feedback (RS), Neural Network and so on. Relevance Feedback can be used to enhance the ability of CBIR effectively by dropping the semantic gap between low level feature and high level feature. Interactiveness on CBIR can also be done with the help of Genetic Algorithms. GA is the branch of evolutionary computation which makes the retrieval process more interactive so that user can get advanced results from database by comparing to Query Image with its evaluation. The result of traditional implicit feedback can also be improved by Neuro Fuzzy Logic based implicit feedback. This paper covers all the aspect of Relevance Feedback (RF), Interactive Genetic Algorithms, Neural Network in Content Based Image Retrieval, various RF techniques and applications of CBIR. DOI: 10.17762/ijritcc2321-8169.15075

Parametric Seismic Analysis of Tall Buildings with Different Geometry and Constant Plan Area.

In this study, seismic analysis of high rise building frames have been carried out considering four buildings of different geometrical plan but same area , three diaphragms and four seismic zones. In this way total 48 frames were analysed for 27 load combinations. STADD-Pro software has been used for analysis purpose. Structural analyses results are collected in terms of maximum moments in columns and beams, storey displacement, peak storey displacement which are critically analysed to quantify the effects of various parameters