Understanding carbon sequestration trends using model and satellite data under different ecosystems in India.

This study discusses carbon sequestration variability in different ecosystems of India. Four different biosphere regions, each over 0.5° × 0.5° area, have been selected considering the geospatial and climatic variability of these regions expanding from Central India (CI), the Northeast region (NER), the Western Ghats (WG), and the Western Himalayan region (WHNI). The climatic conditions of these four regions are different so are the biosphere constituents of these regions. We expect the Gross Primary Productivity (GPP) to enhance during the all India summer monsoon rainfall season but in varied magnitudes suggesting a role of climatic parameters and flora in these regions. The GPP from FLUXCOM for the duration of 2001 to 2019 (19 years) and satellite-derived vegetation indices like the Normalized Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Leaf Area Index (LAI) are used in this study to understand the response of regional vegetation to this variability. EVI seems to be better related to GPP in comparison to NDVI in the preliminary analysis. Further analysis suggests LAI correlates better to GPP than EVI and NDVI in different seasons in these four regions. Also, meteorological parameters like surface temperature, rainfall, soil water, and other derived parameters like Vapor Pressure Deficit (VPD) are studied. It is also observed that the year-to-year variability in the climatic conditions could also have a role to play in the observed features. It is proven that the climate around the world is experiencing changes. Vegetation is one of the potent markers to monitor the impact of climate change. These long-term data and trends were studied to understand if there is any significant impact of the changing climatic conditions on the vegetation in these regions. Our study shows that there is an increasing (positive) trend in GPP at these locations though at different rates. WG and WHNI have shown a significant high rate of increase (6.44 and 5.36 gCm-2 y-1, respectively) in GPP over the last two decades.

Template-assisted fabrication of magnetically responsive hollow titania capsules.

This study reports on the fabrication of magnetically responsive hollow titania capsules by confining the superparamagnetic Fe(3)O(4) nanoparticles within a hollow and porous titania (TiO(2)) shell. The employed protocol involves precipitation of titania shell on the magnetite (Fe(3)O(4)) encapsulated polystyrene beads followed by the calcination of resulting composite particles at elevated temperature. Scanning electron microscopy and transmission electron microscopy reveal the presence of a thick, complete but irregular titania shell on the magnetic polystyrene beads after the templating process. Electron energy loss mapping image analysis has been employed to investigate the spatial distribution of titania and magnetite phases of magnetic hollow titania capsules (MHTCs). Magnetic characterization indicates that both titania-coated magnetic polystyrene beads (TMPBs) and MHTCs are superparamagnetic in nature with the saturated magnetizations of 5.6 and 8.1 emu/g, respectively. X-ray diffraction (XRD) analysis reveals that titania shell of these capsules is composed of photoactive anatase phase. Nitrogen adsorption-desorption analysis has been employed to estimate the specific surface area and the average pore diameter of the fabricated hollow structures. Photocatalytic activity of the fabricated MHTCs for the photodegradation of rhodamine 6G dye has been demonstrated and compared with that of bulk titania nanoparticles.

Tailored growth of In(OH)(3) shell on functionalized polystyrene beads.

Fabrication of organic-inorganic composite particles with tailored size, shape, and morphology has been attracting great attention from researchers because of their fascinating properties and applications in a variety of potential fields. In this study, we report on the fabrication of PS-In(OH)(3) (polystyrene-indium hydroxide) composite particles by hydrolyzing the In(OC(3)H(7))(3) (indium isopropoxide) salt in the presence of beta-diketone functionalized PS colloidal particles. A systematic investigation of the employed reaction conditions allowed us to tune the morphology, size, and In(OH)(3) content of the PS-In(OH)(3) composite particles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results illustrate that variation in the employed concentration of the In(OC(3)H(7))(3) salt in reaction media can effectively tune the morphology of resulting composite particles between "core-shell" and "raspberry-like". X-ray diffraction (XRD) analysis confirms the phase purity of In(OH)(3) nanoparticles precipitated on the surface of PS beads. Colloidal stability of the composite particles has been found to be reduced with increasing the deposited amount of In(OH)(3) nanoparticles. Thermogravimetric analysis (TGA) suggests a continuous increase in the deposited amount of In(OH)(3) nanoparticles with increasing concentration of In(OC(3)H(7))(3) salt in reaction media. The resulting PS-In(OH)(3) composite particles are envisioned to be used in a myriad of potential applications including fabrication of optoelectronic devices, absorption/separation supporting material, catalysts, and hydrophobic surfaces.

A Novel Approach for Mixing ZnO Nanoparticles into Poly(ethyl methacrylate).

A novel and versatile approach for the mixing of ZnO nanofillers into a host polymer matrix, poly(ethyl methacrylate) (PEMA), is reported. Firstly, ZnO nanoparticles are deposited onto the surface of polystyrene (PS) colloidal particles in a "raspberry-like" fashion and subsequently obtained PS/ZnO composite particles are mixed into the PEMA matrix in the range of 0.5 to 5 wt.-%. Microscopic analyses reveal a homogenous distribution of PS/ZnO domains into the PEMA matrix even at 5 wt.-% loading level. Thermogravimetric analysis and differential scanning calorimetry results indicate an improvement in thermal stability of PEMA matrix after mixing with PS/ZnO filler particles. A significant enhancement in mechanical properties of PEMA matrix in the presence of PS/ZnO particles has been evidenced by dynamic mechanical analysis and three point bending measurements.

Synthesis of novel tantalum oxide sub-micrometer hollow spheres with tailored shell thickness.

Sub-micrometer-sized hollow tantalum oxide (Ta2O5) spheres with tunable shell thickness and void size have been fabricated exploiting beta-diketone-functionalized polystyrene (PS) beads as sacrificial templates in a sol-gel process. First, a controlled precipitation of Ta2O5 nanoparticles was carried out on the template surface by hydrolyzing tantalum ethoxide (Ta(OEt)5) at room temperature, and subsequently, the polymer core was removed either via chemical treatment with toluene or calcination at 650 degrees C. The thickness of the tantala shell precipitated on the PS core during the coating process was tuned between 100 and 142 nm by varying the concentration of tantala precursor in the reaction media. The obtained Ta2O5-coated PS particles and hollow microspheres were characterized by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. Due to the unique optical and dielectric properties, these nanostructured materials are envisaged to be used in applications such as novel building blocks for the fabrication of advanced materials, surface coatings, catalysts, and drug delivery systems.