A pre-coking process for acceleration of hydrotreating catalyst deactivation is proposed in this work. An artificial pre-coked catalyst is synthesized by using methylnaphthalene as a coke precursor. ...During the pre-coking process, coke precursor got cracked into smaller aromatic hydrocarbons which penetrates into the pore cavity and covers the active sites. The carbon-coated catalyst has been characterized using N2-sorption isotherms, thermogravimetric analyser (TGA), X-ray electron microscopy (XPS), scanning electron microscopy (SEM), and high resolution-transmission electron microscopy (HR-TEM). The activity of the carbon-coated catalyst has been evaluated using vacuum residue as feed and results were compared with fresh catalyst. The findings indicate that proposed methodology is able to deactivate the catalyst effectively. It also indicates that proposed pre-coking process can predict the causes of catalyst deactivation in advance. Kinetic parameters of hydrodesulfurization (HDS) reactions are also estimated. The quality of the hydrotreated products at different reaction temperature is also studied. The amount of aromatic and resin are higher in the products obtained with carbon coated catalyst.
In nature, hierarchically ordered supramolecular assemblies built from protein building blocks become key elements in the composition of both functional nanostructures such as collagens in ...extracellular matrix, biofilm matrix, and pathological nanostructures including amyloid deposits. Hence, the construction of multiprotein nanoarchitecture is an important research target for innovations in the designing of bioactive nanomaterials. Although β-strand-template-mediated coassembly/cross-seeding of diverse proteins have been reported, the structural and catalytic characteristics of the resultant heterogeneous nanofibers remain largely unknown. Here, we demonstrate the genesis of stable and chemoreactive multiprotein nanofibers via kinetically favored coassembly of diverse proteins with low sequence similarity (insulin, serum albumin, cytochrome c, lysozyme, β-lactoglobulin). The multiprotein-nanofibers contained β-sheet-rich amyloid-like conformers, and we find that gain of charge-complementarity and H-bond-promoting sticky-groups are crucial for fabricating heterogeneous nanofibers. Unlike self-assembly, a lower activation energy barrier was observed for coassembly process, and coaggregation rates increased with increasing degree of heterogeneity in protein mixture. The heterogeneous nanofibers exhibit surface-catalyzing property by hastening dopamine oxidation and triggering amyloid-cross-seeding of diverse proteins, and we also observed their cellular internalization and cytotoxic effect. Our results provide experimental and conceptual foundations for the construction of protein-based hybrid nanomaterials relevant to both biological and material science research.
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We evaluated seismic background noise at national network in India using PSD, Fourier spectra, Spectrogram, and HVSR approach, before and during the nationwide lockdown declared due to COVID-19 ...pandemic. The analyses were performed to understand characteristics of noise wave-field in such unprecedented situation and its effect on site response at the station. SBN in long period (> 20 s), primary microseism band (10-20 s) and secondary microseisms (1-10 s) performed well and the noise levels found within the new LNM and HNM. However, in short period (< 1 s) the variation in SBN performance found significant before and during the lockdown. We observed that the SBN at each site in short period (< 1 s) is found to be about 10-12 dB noisier in the time segment prior to the lockdown. The HVSR analysis of SBN at recording sites clearly indicates that the predominant frequency for the entire region remains stable and independent of seismic noise generated before or during lockdown. A substantial variation in amplification factor, however, observed in either situation. Most of the stations across the country experienced diminished cultural noise subsequent to declaration of lockdown on 25 March 2020. Such drastic decrease in cultural noise significantly enhanced the performance of noisy stations, and the best recording stations picked the seismic phases originated from micro to small earthquakes. We suggest installation of seismometers at some depth below the surface, particularly at disturbed sites, may substantially reduce short period noise in earthquake recording.
This is the first Indian book on the economics of organic farming, which offers a commercially viable and environment-friendly alternative to the conventional methods of agriculture.
Drought is a natural hazard that affects almost all regions. In recent years, it has become more intense and frequentcausing adverse impacts on the socio-economic conditions of the country. The ...primary cause of drought developmentis the deficiency in precipitation impacting crop production during kharif with a follow-up effect also in crops grownduring rabi. The present study was carried out over one of the most drought-prone regions of India, i.e. Marathwadaregion, Maharashtra to characterize meteorological drought through the Standardized Precipitation Index (SPI) duringboth kharif and rabi crop growing seasons. SPI was computed at different time scales (1, 3, 6, 9 and 12-month) usingin-situ precipitation data for 35 years (1980-2014). Drought area observed by multi-time-scale SPI was correlated withdrought declared by the Government and foodgrain production for 15 years (2000–14). It was observed that none ofthe time scales of SPI had a significant correlation with declared drought. However, correlation analysis of multiscaleSPI with foodgrain production showed that 3-month SPI had a significant correlation (r= -0.72) during kharif, while alow correlation was observed between multiscale SPI and foodgrain production for rabi season. Therefore, informationobserved by SPI would be useful if it could be combined with other biophysical conditions and drought indices toincrease its accuracy and reliability for effective drought characterization and monitoring.
This paper depicts the design of 0.55 Tb/s heterogeneous Flexi-rate Nyquist-wavelength division multiplexed (Nyquist-WDM) Superchannel. Here, for the first time, four subcarriers of different ...modulation formats are accommodated, namely polarization multiplexed-binary phase-shift keying, polarization multiplexed-quadrature phase-shift keying (PM-QPSK), polarization multiplexed-8-quadrature amplitude modulation and PM-16QAM, each with 27.75 Gbaud symbol rate. The system transmission performance with acceptable bit error rate (BER) 4 × 10
−3
is analyzed over pure silica core fiber (PSCF) in the presence of hybrid optical amplification, i.e., Raman amplifier along with a counter-propagating pump and Erbium-doped fiber amplifier. The presence of this hybrid optical amplification unit results in a limited optical signal-to-noise ratio requirement and makes the whole system cost
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effective. The proposed work delivers excellent spectral efficiency of 4.5 b/s/Hz and highest transmission reach of 5500 km for PM-QPSK subcarrier and 2300 km for PM-16QAM subcarrier in the presence of PSCF. The system performance against intersymbol interference and noise is also analyzed with the aid of eye pattern plot at a minimum and maximum transmission length.
Several liquid crystalline compounds derived from 2-aminonaphthalene have been synthesized. The molecules are designed to accommodate two napthalene moieties. The molecular structures of these new ...compounds have been characterized by element analysis, FTIR, and NMR spectral studies. The mesomorphic behavior has been studied using mainly polarized microscope and in some cases differential scanning calorimeter as well. Our investigation reveals that all the compounds exhibit enantiotropic nematic phase. The mesomorphic behaviors of these new compounds have been compared with those of structurally related materials.
The origins of free surface vortex and gas entrainment are investigated within a liquid pool using a rotating cylindrical disc having longitudinal axis normal to the gas–liquid interface with varying ...submergence from 1.40 to 2.85 times the disc radius (20 mm). A generalized vortex profile is obtained by suitable scaling for a range of rotational Froude numbers (2.38–11.18). The transient evolution rate of the vortex tip followed logarithmic law and is correlated with experimental data of air and glycerin. The axial pull that holds the vortex against gravity is found to be linearly increasing with the rise of disc rotation. Asymmetric vortex profiles with increased extent of asymmetry are obtained upon increase of disc inclination (0–17.45°). Axial and radial circulations are revealed by following the trajectory of a solid particle in the flow field. Entrainment of discrete air volumes is observed from the vortex core at the corresponding Froude number and submergence ratio.
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