Contemplations on the impressions of MeV swift heavy ion irradiation on nonlinear optical dimethyl-amino-pyridinium-4-nitrophenolate-4-nitro-phenol (DMAPNP) single crystals

Organic nonlinear optical crystal dimethyl-amino-pyridinium-4-nitrophenolate-4-nitro-phenol was subjected to 100 MeV Ag⁸⁺ ions and 50 MeV Si⁸⁺ ions. The radiation effects are studied in terms of processes observed with the pristine samples and in comparison with them. The dielectric properties of the crystals were studied before and after irradiation from 100 Hz to 5 MHz at various temperatures (308–383 K). A drastic increase in the dielectric constant is seen due to irradiation. The dielectric constant and conductivity increases with the increase of irradiation fluence for the samples. The observed results are discussed in detail.     

Role of aurone ligands in microwave enhanced Mn (II) and Co (II) catalyzed dehydrogenative coupling reaction: An efficient ligand for the synthesis of quinoline,pyridine, and pyrrole

The role of new series of phosphine-free aurone ligands have been investigated in microwave-enhanced Mn (II) and Co (II) dehydrogenative coupling reactions. Various heterocyclic compounds such as Quinoline, pyridine, and pyrrole have been synthesized and characterized by NMR spectroscopy. The synthesized ligands ( L1 – L4 ) with Mn(II) and Co (II) salt showed excellent catalytic activity and proved to be very effective for the dehydrogenative coupling reaction. This synthetic method involves the in-situ formation of a metal ligand complex that was analyzed by mass spectrometry. A broad range of substrates including aliphatic ketone, heterocycles, and sterically hindered Ketone coupling partners are well tolerated in the developed protocol.     

A novel full duplex 16 Gbps SCM/ASK radio over fiber WDM-PON sharing wavelength for up- and down-link using bidirectional reflective filter

In this paper, a new bidirectional wavelength division multiplexing radio-over-fiber (WDM-RoF) using Subcarrier Multiplexing/Amplitude Shift Keying (SCM/ASK) is proposed which shares the same wavelengths for both up-link and down-link. A bidirectional reflective filter (BRF) is utilized in the upstream link to provide a reliable bidirectional optical channel. WDM is used to further increase the capacity of system. Simulation of the proposed scheme demonstrates 1 Gbps down- and up-link data stream for 16 channels over the length of 25 km with acceptable Q-factor (>6 dB).     

Changes in dynamical behavior of ionic liquid in silica nano-pores

Dielectric relaxation measurement has been carried out on an ionic liquid (1-butyl-3-methyl imidazolium hexafluorophosphate, [BMIM][PF₆]) confined in nano-porous silica matrix. Two dielectric relaxation peaks have been observed in the confined ionic liquid (IL) while there is only one relaxation peak for bulk IL. Confinement results in layering of some IL molecules near the pore wall while other molecules, less affected by pore wall interaction, remain in the central core. The two relaxation peaks are assigned to the different dynamical behaviors of the central core and layered IL molecules.     

Synthesis of modified uracil and cytosine nucleobases using a microwave-assisted method

Modified nucleobases and nucleic acids have found many biological and pharmaceutical applications. Here we report a microwave-directed synthesis of a variety of modified uracil and cytosine nucleobases with high yields under solvent-free conditions. The reaction yields were further improved by addition of Lewis acid. The crystal structures of 5-isopropyl-6-methyluracil and 6-phenyluracil were also determined.     

A numerical study of a hollow water droplet falling in air

Theoretical and Computational Fluid Dynamics - We numerically study the dynamics of a hollow water droplet falling in the air under the action of gravity. The focus of our study is to investigate...     

A preliminary survey of natural radionuclides in soil and indoor radon in the town of Niš, Serbia

Journal of Radioanalytical and Nuclear Chemistry - The activity concentration of natural radionuclides in the samples of soil from the town of Ni? were measured using the gamma spectroscopy...     

Equilibrium points and equilibrium sets of some $$\textit{GI}/M/1$$ GI / M / 1 queues

Queueing Systems - Queues can be seen as a service facility where quality of service (QoS) is an important measure for the performance of the system. In many cases, the queue implements the optimal...     

An organocatalyzed highly regioselective one-pot approach to the synthesis of tetrahydrobenzofuranones

An organocatalyzed highly regioselective synthesis of substituted tetrahydrobenzofuran-4-ones based on the ring opening followed by cyclization of epoxides with enamines of 1,3-cyclohexanediones in a domino fashion is described. It is a high yielding (74–93%) synthetic protocol tolerant to a wide range of substrates. Ambient temperature, organocatalytic approach, atom-economy, and formation of water as the only by-product are some of the attractive features of the present methodology.