02455nas a2200157   4500008004100000022001400041245012000055210006900175260000900244300001100253490000800264520186100272100001702133700001602150856013102166       2020                        eng d  a0167-732200aParticle size effect in different base fluids on the thermal conductivity of fatty acid coated magnetite nanofluids0 aParticle size effect in different base fluids on the thermal con  cAPR   a1126500 v3033 a<p>The effect of particle size on the thermal conductivity of nanofluids is studied by dispersing myristic acid coated magnetite (Fe3O4) nanoparticles in two different base fluids; toluene and kerosene. Magnetite nanoparticles of three different sizes 4, 7 and 10 nm dispersed in toluene and kerosene showed a linear increase in the thermal conductivity with increasing concentration of the nanopartides, above a critical concentration. The critical concentration below which the thermal conductivity remained unchanged with the concentration of the nanopartides is found to be lower for the kerosene-based fluids. The variation of thermal conductivity with particle size is without any clear trend. However, within the measurement errors (+/- 1%), the toluene-based fluids showed a decrease in the thermal conductivity with increasing particle size, whereas the opposite trend is observed for the kerosene-based fluids. Also, the kerosene-based fluids at similar concentrations of the nanopartides showed relatively larger enhancement in the thermal conductivity than the toluene-based fluids. The observed role of the base fluid in enhancing the thermal conductivity is correlated with the difference in the solvent-surfactant interactions which in turn affect the interfacial thermal resistance at the particle-fluid interface. The thermal conductivity of the nanofluids in toluene and kerosene is also found to show different trends with the size of the particles in the presence of an external magnetic field. The difference in the enhancement of thermal conductivity of the fluids in a magnetic field is explained in terms of the differences in the magnetic dipolar interactions, clustering/ agglomeration, and magnetic characteristics of the samples as well as the characteristics of the base fluid. (C) 2020 Elsevier B.V. All rights reserved.</p>
1 aDadwal, Arun1 aJoy, P., A.  uhttps://library.ncl.res.in/content/particle-size-effect-different-base-fluids-thermal-conductivity-fatty-acid-coated-magnetite01803nas a2200241   4500008004100000022001400041245011400055210006900169260000900238300001200247490000800259520100700267100001701274700001901291700001501310700001701325700001301342700001801355700001801373700002201391700002101413856012701434       2021                        eng d  a2469-995000aPossible electron doping of geometrically perfect spin-1/2 kagome-lattice barlowite by reduced graphene oxide0 aPossible electron doping of geometrically perfect spin12 kagomel  cSEP   aL1004180 v1043 aDoping of quantum spin liquid (QSL) insulators by electron or hole leads to intriguing phase transitions to metallic and superconducting states. The barlowite family with geometrically perfect S = 1/2 kagome planes and tunable interkagome coupling is an emerging platform to realize spin-ordered, valence bond crystal, QSL states. Theoretical investigations on electron doping revealed localized states in the band gap of barlowite unlike metallicity in cuprate (Nd2CuO4). We present successful anchoring of phase-pure barlowite crystallites onto reduced graphene oxide (rGO). The resulting barlowite-rGO system was found to be an electrical semiconductor with Arrhenius activation energy of 0.07 eV. Semiconducting properties of the barlowite-rGO system were further modulated with retention of structural integrity. We have attributed such a transformation of electrical transport response to plausible electron doping thereby making charge-doping experiments on barlowite and its analogs propitious.1 aGupta, Kriti1 aNinawe, Pranay1 aJain, Anil1 aDadwal, Arun1 aAnas, M.1 aMalik, V., K.1 aYusuf, S., M.1 aJoy, Pattayil, A.1 aBallav, Nirmalya  uhttps://library.ncl.res.in/content/possible-electron-doping-geometrically-perfect-spin-12-kagome-lattice-barlowite-reduced