Restoration of the cantilever bowing distortion in Atomic Force Microscopy

Due to the mechanics of the Atomic Force Microscope (AFM), there is a curvature distortion (bowing effect) present in the acquired images. At present, flattening such images requires human intervention to manually segment object data from the background, which is time consuming and highly inaccurate. In this paper, an automated algorithm to flatten lines from AFM images is presented. The proposed method classifies the data into objects and background, and fits convex lines in an iterative fashion. Results on real images from DNA wrapped carbon nanotubes (DNACNTs) and synthetic experiments are presented, demonstrating the effectiveness of the proposed algorithm in increasing the resolution of the surface topography. In addition a link between the flattening problem and MRI inhomogeneity (shading) is given and the proposed method is compared to an entropy based MRI inhomogeniety correction method

Structure of poly(propyl ether imine) (PETIM) dendrimer from fully atomistic molecular Dynamics Simulation and by Small Angle X-ray scattering

We study the structure of carboxylic acid terminated neutral poly (propyl ether imine) (PETIM) dendrimer from generation 1 through 6 (G1-G6) in a good solvent (water) by fully atomistic molecular dynamics (MD) simulations. We determine as a function of generation such structural properties as: radius of gyration, shape tensor, asphericity, fractal dimension, monomer density distribution, and end-group distribution functions. The sizes obtained from the MD simulations have been validated by Small Angle X-Ray Scattering (SAXS) experiment on dendrimer of generation 2 to 4 (G2-G4). A good agreement between the experimental and theoretical value of radius of gyration has been observed. We find a linear increase in radius of gyration with the generation. In contrast, Rg scales as ~ N^x with the number of monomers. We find two distinct exponents depending on the generations: x = 0.47 for G1-G3 and x = 0.28 for G3-G6 which reveals their non-space filling nature. In comparison with the amine terminated PAMAM dendrimer, we find Rg of G-th generation PETIM dendrimer is nearly equal to that of (G+1)-th generation of PAMAM dendrimer as observed by Maiti et. al. [Macromolecules,38, 979 2005]. We find substantial back folding of the outer sub generations into the interior of the dendrimer. Due to their highly flexible nature of the repeating branch units, the shape of the PETIM dendrimer deviates significantly from the spherical shape and the molecules become more and more spherical as the generation increases. The interior of the dendrimer is quite open with internal cavities available for accommodating guest molecules suggesting using PETIM dendrimer for guest-host applications. We also give a quantitative measure of the number of water molecules present inside the dendrimer.Comment: 33 page

Preparation of Undoped and Phosphorus Doped μc-Si:H Films: Effect of Extended Period of Hydrogen Plasma Annealing in Interrupted Growth

Interrupted growth and H-plasma annealing of stacking layers of Si:H film resulted in a significant improvement in material properties towards microcrystallization. Increase of dark conductivity and reduction of optical absorption due to extended period of hydrogen plasma exposure was noted. An associated improvement in the network structure towards crystallinity was observed by Raman, TEM and XRD studies. Highly conducting ( σD ~ 6 × 10-3 s. cm-1) undoped mc-Si:H films have been prepared at significantly low thickness of 650 Å. P-doped mc-Si:H films having conductivity ~ 26.2 S.cm-1 were obtained from very low level of PH3 dilution. Large number of dopants introduce additional defects at the grain boundary and inhibits the crystallization process

BNKR-1 (Dhiren) – A newly released late duration high-yielding rice variety an alternative to Swarna (MTU 7029) for West Bengal, India

BNKR – I (Dhiren), a new late duration high yielding rice variety developed at Rice Research Station, Bankura, West Bengal, India was released by “State Variety Release Committee” (SVRC), West Bengal in 2011 for cultivation in irrigated late areas of West Bengal, India. Before release as BNKR – I (Dhiren), this rice culture completed three years of national testing (2008-2010) in the designation of CN 1340-76-1-BNKR 23-7-1 (IET 20760) and had been recommended for release in irrigated areas of Bihar and West Bengal under transplanted condition in 46th National Group Meeting on Rice organized by Directorate of Rice Research (ICAR), Hyderabad, India during April 2011. It gave 7.65 to 12.12% yield advantage over national check in national level. Not only that this culture of rice tested extensively in the farm of Rice research Station, Bankura, West Bengal and farmer’s field. It showed 11.64% and 19.30% yield advantage during 2006 and 2007 in observational trial, 10.44 to 14.38% yield advantage in on station yield trial during 2008-2010 and 12.51 to 17.93% yield advantage in farmer’s field during 2009 and 2010 over Swarna (MTU 7029), which is the most popular rice variety of West Bengal. BNKR – I (Dhiren) is non-lodging, non-shattering and late maturing variety (seed to seed : 142 days). It is moderately resistant to leaf blast, neck blast, brown spot, sheath rot and leaf folder. It’s average yield is 5000 – 5500 kg ha-1 . Grain type is short bold. It is expected that BNKR – I (Dhiren) can be able to replace Swarna (MTU 7029), the most popular rice variety of West Bengal, India