Some seismic models derived from tomographic studies indicate elevated shear‐wave velocities (≥4.7 km/s) around 120–150 km depth in cratonic lithospheric mantle. These velocities are higher than those of cratonic peridotites, even assuming a cold cratonic geotherm (i.e., 35 mW/m2 surface heat flux) and accounting for compositional heterogeneity in cratonic peridotite xenoliths and the effects of anelasticity. We reviewed various geophysical and petrologic constraints on the nature of cratonic roots (seismic velocities, lithology/mineralogy, electrical conductivity, and gravity) and explored a range of permissible rock and mineral assemblages that can explain the high seismic velocities. These constraints suggest that diamond and eclogite are the most likely high‐Vs candidates to explain the observed velocities, but matching the high shear‐wave velocities requires either a large proportion of eclogite (>50 vol.%) or the presence of up to 3 vol.% diamond, with the exact values depending on peridotite and eclogite compositions and the geotherm. Both of these estimates are higher than predicted by observations made on natural samples from kimberlites. However, a combination of ≤20 vol.% eclogite and ~2 vol.% diamond may account for high shear‐wave velocities, in proportions consistent with multiple geophysical observables, data from natural samples, and within mass balance constraints for global carbon. Our results further show that cratonic thermal structure need not be significantly cooler than determined from xenolith thermobarometry.

We present a high‐resolution 3‐D lithospheric model of the Indian plate region down to 300 km depth, obtained by inverting a new massive database of surface wave observations, using classical tomographic methods. Data are collected from more than 550 seismic broadband stations spanning the Indian subcontinent and surrounding regions. The Rayleigh wave dispersion measurements along ~14,000 paths are made in a broad frequency range (16–250 s). Our regionalized surface wave (group and phase) dispersion data are inverted at depth in two steps: first an isotropic inversion and next an anisotropic inversion of the phase velocity including the SV wave velocity and azimuthal anisotropy, based on the perturbation theory. We are able to recover most of the known geological structures in the region, such as the slow velocities associated with the thick crust in the Himalaya and Tibetan plateau and the fast velocities associated with the Indian Precambrian shield. Our estimates of the depth to the Lithosphere‐Asthenosphere boundary (LAB) derived from seismic velocity Vsv reductions at depth reveal large variations (120–250 km) beneath the different cratonic blocks. The lithospheric thickness is ~120 km in the eastern Dharwar, ~160 km in the western Dharwar, ~140–200 km in Bastar, and ~160–200 km in the Singhbhum Craton. The thickest (200–250 km) cratonic roots are present beneath central India. A low velocity layer associated with the midlithospheric discontinuity is present when the root of the lithosphere is deep.

In the western Indian Ocean, the Réunion hot spot is one of the most active volcanoes on Earth. Temporal interactions between ridges and plumes have shaped the structure of the zone. This study investigates the mantle structure using data from the Réunion Hotspot and Upper Mantle‐Réunions Unterer Mantel (RHUM‐RUM) project, which significantly increased the seismic coverage of the western part of the Indian Ocean. For more than 1 year, 57 ocean bottom seismometer stations and 23 temporary land stations were deployed over this area. For each earthquake station path, the Rayleigh wave fundamental mode phase velocities were measured for the periods from 30 s to 300 s and group velocities for the period from 16 s to 250 s. A three‐dimensional model of the shear velocity in the upper mantle was built in two steps. First, the path mean phase and group velocities were inverted, to obtain regionalized velocity maps for each separate period. Then, all of the phase and group velocity maps were combined and inverted at each grid point, to obtain the local S wave velocity as a function of depth, using a transdimensional inversion scheme. The three‐dimensional anisotropic S wave velocity model has resolution down to 300 km in depth. The tomographic model and surface tectonics are correlated down to ∼100 km in depth. Starting at 50 km in depth, a slow velocity anomaly beneath Rodrigues Ridge and the east‐west orientation of the azimuthal anisotropy show a connection between Réunion upwelling and the Central Indian Ridge. The slow velocity signature beneath La Réunion is connected at greater depths (150–300 km) with a large slow velocity zone beneath the entire Mascarene Basin. This develops along a northeast direction, following the general motion direction of the African Plate. These observations indicate nonisotropic spreading of hot plume material and dominant horizontal flow in the upper mantle beneath this area.

In this work, we synthesized graphene oxide from silk cocoon embarking its new dimension as a magnetic fluorophore when compared with its present technical status, which at best is for extracting silk as a biomaterial for tissue engineering applications. We produced graphene oxide by pyrolysing the silk cocoon in an inert atmosphere. The collected raw carbon is oxidized by nitric acid that readily produces multilayer graphene oxide with nano carbon particulates. Structural properties of the graphene oxide were analyzed using scanning electron microscopy, transmission electron microscopy, Fourier transform infra-red spectroscopy, and Raman spectroscopy. The oxidized sample shows remarkable fluorescence, multi-photon imaging and magnetic properties. On increasing the excitation wavelength, the fluorescence emission intensity of the graphene oxide also increases and found maximum emission at 380 nm excitation wavelength. On studying the two photon absorption (TPA) property of aqueous graphene oxide using Z-scan technique, we found significant TPA activity at near infrared wavelength. In addition, the graphene oxide shows ferromagnetic behavior at room temperature. The observed fluorescence and magnetic property were attributed to the defects caused in the graphene oxide structure by introducing oxygen containing hydrophilic groups during the oxidation process. Previously silk cocoon has been used extensively in deriving silk-based tissue engineering materials and as gas filter. Here we show a novel application of silk cocoon by synthesizing graphene oxide based magnetic-fluorophore for bio-imaging applications.Electronic supplementary materialThe online version of this article (doi:10.1007/s13205-013-0128-2) contains supplementary material, which is available to authorized users.

The development of conductive fibers and yarns is growing exponentially due to their utilization in wearable electronic textiles for heating, sensing, and energy storage applications. Herein, we report the electrothermal and mechanical properties of stainless steel (SS) and silver-coated (SC) cabled yarn for application in knitted wearable heating pads. SC yarn offers superior heating performance over SS yarn due to its low resistance, but its long-term durability, washability, and thermal stability are lower than SS yarn. The SS yarn is thermally stable up to 70 °C with minimal resistance change. However, the resistance of SC yarn increased by 81.12%, and the average temperature was reduced by 23.23% due to the oxidation of silver in an open environment after exposure for 50 days. The localized heating pad was designed using SC and SS cabled yarn. The temperature of the SC-based pad was 37.5 °C, while the temperature of the SS-based pad was 34.3 °C at a 9 V DC power supply. However, the variation between the maximum and minimum surface temperatures is considerable in the case of an SC-based heating pad.

p-type transparent conducting Cu alloyed ZnS thin films from Cu x Zn 1−x S targets (x = 0.1, 0.2, 0.3, 0.4, and 0.5) were deposited on glass substrates via radio frequency (RF) sputtering. XRD and TEM-SAED analysis show that all the films have sphalerite ZnS as the majority crystalline phase. In addition, films with 30% and 40% Cu show the presence of increasing amounts of crystalline Cu 2 S phase. Conductivity values ≥ 400 S cm −1 were obtained for the films having 30% and 40% Cu, with the maximum conductivity of 752 S cm −1 obtained for the film with 40% Cu. Temperature dependent electrical transport measurements indicate metallic as well as degenerate hole conductivity in the deposited films. The reflection-corrected transmittance of this Cu alloyed ZnS (40% Cu

Large-grained Cu 2 O photocathodes in a superstrate configuration on a F-doped SnO 2 (FTO) coated glass substrate are synthesized via two-step electrodeposition. Only submicrometer sized grains were obtained during single-step electrodeposition in the potential window (−0.31 to −0.7 V vs Ag/AgCl) of stable Cu 2 O formation. We observe reductive decomposition of the Cu 2 O to Cu metal in the potential range of −0.7 to −0.98 V; bulk reduction of Cu 2+ in the solution to Cu metal occurs only beyond −0.98 V. In the potential window of stable Cu 2 O deposition, only the growth of the few nuclei occurs until a certain time. Minimal nucleation on the pristine FTO sites occurs during this period of deposition. The time to secondary nucleation is ∼6 min at −0.31 V and ∼15 s at −0.37 V. Interrupting the deposition at −0.31 V after 6 min and increasing the potential to −0.37 V leads to uniform, large grains (∼3 μm) of Cu 2 O. Photoinduced conducting atomic force microscopy reveals shunting and the presence of sub-bandgap states at the grain boundaries of Cu 2 O. Also, the lower carrier concentration (∼10 16 cm −3 ) in the large-grained Cu 2 O film obtained from Mott−Schottky analysis suggests a lower rate of Auger recombination. Thus, lowering the grain boundary crosssection in the two-step deposited film leads to a 30% increase in photocurrent at 0.0 V vs RHE.

We present continental‐scale seismic isotropic and anisotropic imaging of shear wave upper‐mantle structure of tectonically diversified terranes creating the European continent. Taking into account the 36–200 s period range of surface waves enables us to model the deep subcontinental structure at different vertical scale‐lengths down to 300 km. After very strict quality selection criteria, we have obtained phase wave speeds at different periods for fundamental Rayleigh and Love modes from about 9000 three‐component seismograms. Dispersion measurements are performed by using Fourier‐domain waveform inversion technique named “roller‐coaster‐type” algorithm. We used the reference model with a varying average crustal structure for each source‐station path. That procedure led to significant improvement of the quality and number of phase wave speed dispersion measurements compared to the common approach of using a reference model with one average crustal structure. Surface wave dispersion data are inverted at depth for retrieving isotropy and anisotropy parameters. The fast axis directions related to azimuthal anisotropy at different depths constitute a rich database for geodynamical interpretations. Shear wave anomalies of the horizontal dimension larger than 200 km are imaged in our models. They correlate with tectonic provinces of varying age‐provenance. Different anisotropy patterns are observed along the most distinctive feature on our maps–the bordering zone between the Palaeozoic and Precambrian Europe. We discuss the depth changes of the lithosphere‐asthenosphere boundary along the profiles crossing the chosen tectonic units of different origin and age: Fennoscandia, East European Craton, Anatolia, Mediterranean subduction zones. Within the flat and stable cratonic lithosphere, we find traces of the midlithospheric discontinuity.