Studies of Protonation of Some Aminopolycarboxylates by Carbon-13 NMR Spectroscopy

¹³C nmr chemical shifts are used to evaluate successive protonations of the aminopolycarboxylate systems diethylenetriaminepentaacetic acid (DTPA) and triethylenetetraminehexaacetic acid (TTHA).     

Synthesis of α-alkenyl-α-amino esters via addition of potassium Alkenyltrifluoroborate salts to imine in the presence of Yb(OTf)3

A simple protocol which led to an effective construction of α-alkenyl-α-amino esters was achieved under mild conditions. This transformation proceeded by Yb-catalyzed addition of alkenyltrifluoroborates across the imine double bond. A variety of functional groups could be applicable to both partners.     

Fingerprint image enhancement using data driven Directional Filter Bank

A new method based upon data driven tool, principal component analysis (PCA), for fingerprint enhancement is proposed in this paper. PCA is a very useful statistical technique that has found application in many different fields like image compression, face recognition and is commonly used for finding patterns in data of high dimension. In the proposed method, the input image is first decomposed into directional images using decimation free Directional Filter Bank (DDFB). Then these directional images are normalized. A data driven technique PCA is applied to these normalized directional fingerprint images, which gives the PCA filtered images. These are basically directional images. Then these directional images are reconstructed into one image which is the enhanced one. Simulation results are included illustrating the capability of the proposed method.     

Nitrogen dissociation and its excitation/vibrational temperature with hydrogen admixture in 50 Hz DC discharge

Trace rare gas optical emission spectroscopy (TRG-OES) is carried out to determine the excitation temperature, vibrational temperature, dissociation fraction and nitrogen (N) atom density in 50?Hz active screen cage nitrogen plasma, as a function of discharge parameters (current density and fill pressure) and hydrogen concentrations. The excitation temperature is determined from Ar–I emission lines and is found to increase with hydrogen mixing. In a similar fashion, the vibrational temperature of second positive system is determined and found to have increasing trend with hydrogen addition. The dissociation fraction increases with hydrogen concentration up to 40% H₂ in the nitrogen plasma, so as the nitrogen atom density.     

Recurrence Tracking Microscope Based on Two Magnetic Mirrors

We introduce a recurrence tracing microscope based on the reflection of cold atoms from two magnetic mirrors placed in parallel. A cantilever is attached perpendicularly to one of the two mirrors at the lower end that probes surface structures. The quantum dynamics in the system provides the matter waves to store information on the height and spacing between the nanostructures. We use the recurrence tracking microscope in static and dynamic modes to study arbitrary and periodic nanostructures.     

Synthetic approaches toward stilbenes and their related structures

Compounds belonging to the stilbene family have gained remarkable significance in pharmaceutical as well as material chemistry. The current review covers the various synthetic approaches for the syntheses of stilbene scaffold and related structures over last 30 years. In addition, this review also highlights the role of stilbene intermediates used in the synthesis of important molecules with diverse applications in the field of pharmaceutics and material science.