Negative 4ƒ-induced hyperfine field on samarium in paramagnetic Eu(Sm)Al2

The hyperfine field at samarium nuclear site induced by the paramagnetism of 4? electrons has been measured in Eu(Sm)Al₂ using perturbed angular correlation technique and found to have a negative sign which is in striking contrast to the positive sign expected in free Sm³⁺ ion. It amounts to a large negative Knight shift at samarium nuclear site in this alloy.     

Angular forces and phonon dispersion of Mg2Pb

Phonon dispersion of Mg₂Pb, a II–IV compound having an anti-fluorite structure, has been studied by a non-central model using CGW type angular forces. Good agreement with experimentally measured frequencies is observed. The results are also compared with those obtained for Mg₂Sn.The author express their gratitude to Messrs. S. Guermah, O. El Kechai, Directors, INES en Electrotechnique and Génie-Civil of Tizi-Ouzou, respectively, for encouragement and facilities provided.     

Towards an ideal photon correlator with a SAW-device

The advantages and disadvantages of the clipped correlator for photoelectric correlation measurements are analysed. A scheme is suggested by which the problem of inversion (an inherent disadvantage of clipping) is obviated. With the availability of surface acustic wave (SAW) delay lines, we would like to point out that one can make an almost ideal photon correlator.     

Experimental studies of entropy and concentration fluctuation by photon correlation technique

Recently we reported the design and fabrication of an inexpensive, simple and versatile digital photon correlator. We have used it to investigate the entropy and concentration fluctuations in number of liquid systems i.e. pure, mixtures and solutions. Further we measure the parameters like thermal diffusivity and diffusion coefficient at different concentrations in a time much shorter than the conventional techniques.     

Syntheses of lespedezaflavanone-B and amorilin

Two naturally occurring benzopyranones, lespedezaflavanone-B and amorilin have been synthesised from the same chalcone. Prenylation of the chalcone using prenyl bromide affords mono- and di-prenylated chalcones which on cyclization followed by demethoxymethylation furnishes the respective benzopyranones.     

Slow rotation of a sphere with source at its centre in a viscous fluid

In this note, the problem of a sphere carrying a fluid source at its centre and rotating with slow uniform angular velocity about a diameter is studied. The analysis reveals that only the azimuthal component of velocity exists and is seen that the effect of the source is to decrease it. Also, the couple on the sphere is found to decrease on account of the source.     

Interplay of Anion-π+ and π+-π+ Interactions in Novel Pyrido[2,1-a]isoquinolinium-Based AIEgens - Substituent- and Counterion-Dependent Fluorescence Modulation and Applications in Live Cell Mitochondrial Imaging**

Recently, the concept of anion-π⁺ interactions has witnessed unique applications in the field of AIEgen development. In this contribution, we disclose a consolidated study of a library of N-doped ionic AIEgens accessed through silver-mediated cyclization of pyridino-alkynes. A thorough photophysical, computational and crystallographic study has been conducted to rationalize the observed substituent- and counterion-dependent fluorescence properties of these luminogens. We further elucidate the prominent role of anion-π⁺ interactions, π⁺-π⁺ interactions and other non-covalent interactions, in inhibiting the undesired ACQ effect. Finally, we have also demonstrated the application of selected AIEgens for imaging of mitochondria in live cells.     

An investigation of pine needles fluidization,combustion performance,and fly ash behavior in fluidized bed combustor

Journal of Thermal Analysis and Calorimetry - Coniferous forest residue, such as pine needles, has enormous potential in Himalayan territories and could play a significant role in energy supply....