The hydrothermal technique provides an excellent possibility for processing of advanced materials whether it is bulk single crystals, or fine particles, or nanoparticles. The advantages of ...hydrothermal technology have been discussed in comparison with the conventional methods of materials processing. The current trends in hydrothermal materials processing has been described in relation to the concept of soft solution processing, as a single-step low energy consuming fabrication technique. Also some recent developments in multi-energy processing of materials such as microwave-hydrothermal, mechanochemical-hydrothermal, electrochemical-hydrothermal, sonar-hydrothermal, etc. have been discussed. An overview of the past, present and future perspective of hydrothermal technology as a tool to fabricate advanced materials has been given with appropriate examples.
We study the process of radiative neutrino pair emission e> arrow right g>+ gamma +nunu from coherently excited heavy ions (quantum mixture of two ionic states-ground and excited states) in circular ...motion. Determination of the neutrino mass is found to be possible with simultaneous detection of the photon and one of the neutrinos in the pair down to the level of the smallest neutrino mass of order 5 meV in the three-flavor scheme.
Graphene has exceptional physical, chemical, mechanical, thermal and optical properties which offer huge potential for applications in various sectors. Chemical oxidation of graphite to graphene ...oxide followed by the reduction process is the commonly used method for mass scale production of graphene or reduced graphene oxide (RGO). Among the large number of chemical reducing agents used to prepare RGO or graphene, the most efficient reductant is hydrazine. It is toxic in nature and harmful to the environment, thus it is in high demand to use green reductants for RGO synthesis. We understand that due to high demand of graphene/graphene oxide/reduced graphene oxide recently and which is expected to be more in future, green synthesis methods are extremely important. In this article, we have studied the synthesis methods, characterization and the possible mechanism for green reduction, especially by ascorbic acid. This article could possibly motivate the researcher worldwide to innovate new green methods for mass scale production of graphene based materials.
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The emission with a bandwidth of 1.5 terahertz based on the spin current in the ferromagnetic heterostructure Co/Pt is demonstrated. The spin transient launched by the NIR femtosecond laser pulse in ...the Co/Pt is converted into the in-plane charge current due to the inverse spin Hall effect, which gives rise to the terahertz emission towards free space. The dependence of the terahertz emission on the Pt-layer thickness is investigated. To optimize the geometry structure of the new type of emitter, we developed the theoretical model by carefully analyzing the spin transport. Our model reveals the importance to take into account the interfacial spin loss. It can be used to analyze more complex heterostructures.
The laminated structure of graphene oxide (GO) confers unique interactions with water molecules which may be utilised in a range of applications that require materials with tuneable hygroscopic ...properties. The precise role of the expandable interlayer spacing and functional groups in GO laminates has not completely been understood to date. Herein, we report the experimental and theoretical investigations on the adsorption and desorption behaviour of water in GO laminates as a function of relative pressure. We observed that GO imparts high water uptake capacity of up to 0.58 gram of water per gram of GO (g g
), which is significantly higher than silica gel as a conventional desiccant material. More interestingly, the adsorption and desorption kinetics of GO is five times higher than silica gel. The observed extraordinary adsorption/desorption rate can be attributed to the high capillary pressure in GO laminates as well as micro meter sized tunnel-like wrinkles located at the surface
We propose how to implement precision neutrino mass spectroscopy using radiative neutrino pair emission (RNPE) from a macro-coherent decay of a new form of target state, a large number of activated ...atoms interacting with static condensate field. This method makes it possible to measure still undetermined parameters of the neutrino mass matrix, two CP violating Majorana phases, the unknown mixing angle and the smallest neutrino mass which could be of order a few meV, determining at the same time the Majorana or Dirac nature of masses. The twin process of paired superradiance (PSR) is also discussed.
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