Universality in Intensity Modulated Photocurrent in Bulk-Heterojunction Polymer Solar Cells

We observe a universal feature in the frequency dependence of intensity modulated photocurrent Iph based on studies of a variety of efficient bulk-heterojunction polymer solar cells (BHJ-PSCs). This feature of Iph appears in the form of a local maximum in the 5 kHz < frequency < 10 kHz range and is observed to be largely independent of the external parameters such as modulated light intensity (Lac), wavelength, temperature (T), and external field (EF) over a wide range. Simplistic kinetic models involving carrier generation, recombination and extraction processes are used to interpret the overall essential features of Iph and correlate it to the device parameters

Ultrahigh Charge Carrier Mobility in Nanotube Encapsulated Coronene Stack

Achieving high charge carrier mobility is the holy grail of organic electronics. In this letter we report a record charge carrier mobility of 14.93 cm$^2$ V$^{-1}$s$^{-1}$ through a coronene stack encapsulated in a single walled carbon nanotube (CNT) by using a multiscale modeling technique which combines MD simulations, first principle calculations and Kinetic Monte Carlo simulations. For the CNT having a diameter of 1.56 nm we find a highly ordered defect free organization of coronene molecules inside the CNT which is responsible for the high charge carrier mobility. The encapsulated coronene molecules are correlated with a large correlation length of $\sim$18 {\AA} which is independent of the length of the coronene column. Our simulation further suggests that coronene molecules can spontaneously enter the CNT, suggesting that the encapsulation is experimentally realizable

Overstretching of B-DNA with various pulling protocols: Appearance of structural polymorphism and S-DNA

We report a structural polymorphism of the S-DNA when a canonical B-DNA is stretched under different pulling protocols and provide a fundamental molecular understanding of the DNA stretching mechanism. Extensive all atom molecular dynamics simulations reveal a clear formation of S-DNA when the B-DNA is stretched along the 3' directions of the opposite strands (OS3) and is characterized by the changes in the number of H-bonds, entropy and free energy. Stretching along 5' directions of the opposite strands (OS5) leads to force induced melting form of the DNA. Interestingly, stretching along the opposite ends of the same strand (SS) leads to a coexistence of both the S- and melted M-DNA structures. We also do the structural characterization of the S-DNA by calculating various helical parameters. We find that S-DNA has a twist of ~10 degrees which corresponds to helical repeat length of ~ 36 base pairs in close agreement with the previous experimental results. Moreover, we find that the free energy barrier between the canonical and overstretched states of DNA is higher for the same termini (SE) pulling protocol in comparison to all other protocols considered in this work. Overall, our observations not only reconcile with the available experimental results qualitatively but also enhance the understanding of different overstretched DNA structures.Comment: To be published in the The Journal of Chemical Physics (AIP

The noise properties of stochastic processes and entropy production

Based on a Fokker-Planck description of external Ornstein-Uhlenbeck noise and cross-correlated noise processes driving a dynamical system we examine the interplay of the properties of noise processes and the dissipative characteristic of the dynamical system in the steady state entropy production and flux. Our analysis is illustrated with appropriate examples.Comment: RevTex, 1 figure, To appear in Phys. Rev.

Quantum escape kinetics over a fluctuating barrier

The escape rate of a particle over a fluctuating barrier in a double well potential exhibits resonance at an optimum value of correlation time of fluctuation. This has been shown to be important in several variants of kinetic model of chemical reactions . We extend the analysis of this phenomenon of resonant activation to quantum domain to show how quantization significantly enhances resonant activation at low temperature due to tunneling

Ti(IV) Complexes with Cinnamohydroxamic Acid & Its Extractive Spectrophotometric Determination in Trace Amounts

233-23

Spectrophotometric Determination of Pt(IV) Using N-(2'-Mercaptophenyl)salicylaldimine & Stepwise Formation Constants of Pt(IV) Complexes

545-54

The Concept of Theoretical Molar Absorptivity for Photometric Determination of Trace Amount of Metal & Thermodynamic Formation Constants of Mo(VI) Complexes with Disodium cis-1,2-Dicyanoethylene-1,2-dithiolate

724-72

Image Mining for Flower Classification by Genetic Association Rule Mining Using GLCM features

Image mining is concerned with knowledge discovery in image databases. It is the extension of data mining algorithms to image processing domain. Image mining plays a vital role in extracting useful information from images. In computer aided plant identification and classification system the image mining will take a crucial role for the flower classification. The content image based on the low-level features such as color and textures are used to flower image classification. A flower image is segmented using a histogram threshold based method. The data set has different flower species with similar appearance (small inter class variations) across different classes and varying appearance (large intra class variations) within a class. Also the images of flowers are of different pose with cluttered background under varying lighting conditions and climatic conditions. The flower images were collected from World Wide Web in addition to the photographs taken up in a natural scene. The proposed method is based on textural features such as Gray level co-occurrence matrix (GLCM). This paper introduces multi dimensional genetic association rule mining for classification of flowers effectively. The image Data mining approach has four major steps: Preprocessing, Feature Extraction, Preparation of Transactional database and multi dimensional genetic association rule mining and classification. The purpose of our experiments is to explore the feasibility of data mining approach. Results will show that there is promise in image mining based on multi dimensional genetic association rule mining. It is well known that data mining techniques are more suitable to larger databases than the one used for these preliminary tests. Computer-aided method using association rule could assist people and improve the accuracy of flower identification. In particular, a Computer aided method based on association rules becomes more accurate with a larger dataset .Experimental results show that this new method can quickly and effectively mine potential association rules