Indian Institute of Technology Guwahati

About: Indian Institute of Technology Guwahati is a education organization based out in Guwahati, Assam, India. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 6933 authors who have published 17102 publications receiving 257351 citations.

Characterization of non-edible lignocellulosic biomass in terms of their candidacy towards alternative renewable fuels

Abstract: Lignocellulosic biomass off late are considered as potential feedstock for biofuel production to meet the world energy demand. For designing the process to convert biomass into an alternative source of energy, it is essential to determine the characteristics of these lignocellulosic biomass. The aim of the present study is to determine the physicochemical characterization of selected non-edible and waste lignocellulosic biomass and utilization of these biomass in the best possible way for the production of fuels and chemicals. Physical and chemical characterization of lignocellulosic and waste biomass were carried out by thermogravimetric analysis (TGA), heating value, crystallinity index, CHNS/O analysis, FTIR, compositional analysis, EDX analysis, and extractives analysis. Further, XRF analysis was used to confirm the presence of inorganic elements in ash. TGA confirmed that maximum degradation (active pyrolytic zone) of these biomass occurred in the temperature range of 200–500 °C. These biomass were further characterized by finding out the structural constituents along with oil percentage and amount of mineral matters. The physical analysis confirmed that these biomass are suitable feedstock for pyrolysis due to the presence of lower amount of sulfur, nitrogen, moisture, and ash and higher amount of volatile matters. A higher percentage of extractives (30–57%) further reaffirmed that all these seeds could be utilized for producing fuels and valuable chemicals.

Synthesis of superparamagnetic Fe3O4 nanoparticles coated with green tea polyphenols and their use for removal of dye pollutant from aqueous solution

Abstract: Superparamagnetic Fe 3 O 4 nanoparticles coated with Green Tea Polyophenols (GTP), i.e. Fe 3 O 4 @GTPs NPs were synthesized by wet-chemical method with eco-friendly and environmentally benign approach. The coated NPs were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectroscopy (EDS). These analyses revealed that the particles were of uniform shapes and sizes of 10 ± 3 nm with a coating of GTPs. The vibrating-sample magnetometer (VSM) measurement of the coated sample demonstrated a saturation magnetization of 61emu/g with negligible coercivity (∼0.001 T) and retentivity (∼0.9 emu/g) indicating superparamagnetic behavior the NPs at room temperature. The synthesized NPs were highly stable and well-dispersed in aqueous medium through their hydrophilic coating of GTPs. These particles showed high adsorption capacity (7.25 mg/g) for removal of methylene blue (MB) dye in wastewater treatment. The sorption dynamic and equilibrium data were in good agreement with the pseudo-second-order kinetic and Langmuir isotherm models respectively. In addition, the particles could be easily separated from the liquid medium through magnetic separation and potentially reused in multiple cycles.

Removal of EOG Artifacts From Single Channel EEG Signals Using Combined Singular Spectrum Analysis and Adaptive Noise Canceler

Abstract: The electroencephalogram (EEG) signals represent the electrical activity of the brain. In applications, such as brain–computer interface (BCI), features of the EEG signals are used to control the devices. However, while recording, EEG signals often contaminated by electrooculogram (EOG) artifacts; such artifacts degrade the performance of the BCI. In this paper, we proposed a new technique using singular spectrum analysis (SSA) and adaptive noise canceler (ANC) to remove the EOG artifact from the contaminated EEG signal. In this technique, first, we proposed a novel grouping technique for SSA to construct the reference signal (EOG) for ANC. Later, using the extracted reference signal, the adaptive filter was employed to remove EOG artifact from the contaminated EEG signal. To quantify the performance of the proposed technique, we carried out simulations on synthetic and real-life EEG signals. In terms of relative root mean square error and mean absolute error, the proposed SSA-ANC method outperforms the existing techniques.

Epigenetic induction of tissue inhibitor of matrix metalloproteinase-3 by green tea polyphenols in breast cancer cells.

Abstract: Aberrant epigenetic silencing of the tissue inhibitor of matrix metalloproteinase-3 (TIMP-3) gene that negatively regulates matrix metalloproteinases (MMPs) activity has been implicated in the pathogenesis and metastasis of breast cancer. In the present study, we demonstrate that green tea polyphenols (GTP) and its major constituent, epigallocatechin-3-gallate (EGCG) mediate epigenetic induction of TIMP-3 levels and play a key role in suppressing invasiveness and gelatinolytic activity of MMP-2 and MMP-9 in breast cancer cells. Treatment of MCF-7 and MDA-MB-231 breast cancer cells with 20 µM EGCG and 10 µg/mL GTP for 72 h significantly induces TIMP-3 mRNA and protein levels. Interestingly, investigations into the molecular mechanism revealed that TIMP-3 repression in breast cancer cells is mediated by epigenetic silencing mechanism(s) involving increased activity of the enhancer of zeste homolog 2 (EZH2) and class I histone deacetylases (HDACs), independent of promoter DNA hypermethylation. Treatment of breast cancer cells with GTP and EGCG significantly reduced EZH2 and class I HDAC protein levels. Furthermore, transcriptional activation of TIMP-3 was found to be associated with decreased EZH2 localization and H3K27 trimethylation enrichment at the TIMP-3 promoter with a concomitant increase in histone H3K9/18 acetylation. Our findings highlight TIMP-3 induction as a key epigenetic event modulated by GTPs in restoring the MMP:TIMP balance to delay breast cancer progression and invasion.