The Millimeter Continuum Size-Frequency Relationship in the UZ Tau E Disk

Tripathi, Anjali,Andrews, Sean M.,Birnstiel, Tilman,Chandler, Claire J.,Isella, Andrea,Pé,rez, Laura M.,Harris, R. J.,Ricci, Luca,Wilner, David J.,Carpenter, John M.,Calvet, N.,Corder, S. A.,Del American Astronomical Society 2018 The Astrophysical journal Vol.861 No.1

<P>We present high spatial resolution observations of the continuum emission from the young multiple star system UZ Tau at frequencies from 6 to 340 GHz. To quantify the spatial variation of dust emission in the UZ Tau E circumbinary disk, the observed interferometric visibilities are modeled with a simple parametric prescription for the radial surface brightnesses at each frequency. We find evidence that the spectrum steepens with radius in the disk, manifested as a positive correlation between the observing frequency and the radius that encircles a fixed fraction of the emission (R-eff proportional to nu(0.34 +/- 0.08)). The origins of this size-frequency relation are explored in the context of a theoretical framework for the growth and migration of disk solids. While that framework can reproduce a similar size-frequency relation, it predicts a steeper spectrum than that observed. Moreover, it comes closest to matching the data only on timescales much shorter (<= 1 Myr) than the putative UZ Tau age (similar to 2-3 Myr). These discrepancies are direct consequences of the rapid radial drift rates predicted by models of dust evolution in a smooth gas disk. One way to mitigate that efficiency problem is to invoke small-scale gas pressure modulations that locally concentrate drifting solids. If such particle traps reach high-continuum optical depths at 30-340 GHz with a similar to 30%-60%. filling fraction in the inner disk (r less than or similar to 20 au), they can also explain the observed spatial gradient in the UZ Tau E disk spectrum.</P>

Monocrotophos Induces the Expression of Xenobiotic Metabolizing Cytochrome P450s (CYP2C8 and CYP3A4) and Neurotoxicity in Human Brain Cells

Tripathi, V. K.,Kumar, V.,Pandey, A.,Vatsa, P.,Dhasmana, A.,Singh, R. P.,Appikonda, S. H.,Hwang, I.,Lohani, M. Humana Press 2017 Molecular Neurobiology Vol. No.

<P>Expression of various cytochrome P450s (CYPs) in mammalian brain cells is well documented. However, such studies are hampered in neural/glial cells of human origin due to nonavailability of human brain cells. To address this issue, we investigated the expression and inducibility of CYP2C8 and CYP3A4 and their responsiveness against cyclophosphamide (CPA) and organophosphorus pesticide monocrotophos (MCP), a known developmental neurotoxicant in human neural (SH-SY5Y) and glial (U373-MG) cell lines. CPA induced significant expression of CYP2C8 and CYP3A4 in both types of cells in a time-dependent manner. Neural cell line exhibited relatively higher constitutive and inducible expression of CYPs than the glial cell line. MCP exposure alone could not induce the significant expression of CYPs, whereas the cells preexposed to CPA showed a significant response to MCP. Similar to the case of CPA induced expressions, neural cells were found to be more vulnerable than glial cells. Our data indicate differential expressions of CYPs in cultured human neural and glial cell lines. The findings were synchronized with protein ligand docking studies, which showed a significant modulatory capacity of MCP by strong interaction with CYP regulators-CAR and PXR. Similarly, the known CYP inducer CPA has also shown significant high docking scores with the two studied CYP regulators. We also observed a significant induction in reactive oxygen species (ROS), lipid peroxides (LPO), micronucleus (MN), chromosomal aberration (CA), and reduction in reduced glutathione (GSH) and catalase following the exposure of MCP. Moreover, the expressions of apoptotic markers such as caspase-3, caspase-9, Bax, and p53 were significantly upregulated, whereas the levels of antiapoptotic marker, Bcl2, was downregulated after the exposure of MCP in both cell lines. These findings confirm the involvement of ROS-mediated oxidative stress, which subsequently triggers apoptosis pathways in both human neural (SH-SY5Y) and glial (U373-MG) cell lines following the exposure of MCP.</P>

Weak Ligaments and Sloping Joints: A New Hypothesis for Development of Congenital Atlantoaxial Dislocation and Basilar Invagination

Avnish K. Chauhan,P. Sarat Chandra,Nishant Goyal,Madhumita R. Chowdhury,Jyotirmoy Banerjee,Manjari Tripathi,Madhulika Kabra 대한척추신경외과학회 2020 Neurospine Vol.17 No.4

Objective: Developmental bony craniovertebral junction (CVJ) anomalies seem to have a genetic basis and also abnormal joint morphology causing atlantoaxial dislocation (AAD) and basilar invagination (BI). Methods: DNA extracted polymerase chain reaction single-stranded conformation polymorphism (SSCP) performed for mutation screening of FBN1 gene (n=50 cases+ 50 age/sex-matched normal; total: 100). Samples with a deviated pattern of bands in SSCP were sequenced to detect the type of variation. Computed tomography (CT) scans of 100 patients (15–45 years old) compared with an equal number of age/sex-matched controls (21.9±8.2 years). Joint parameters studied: sagittal joint inclination (SI), craniocervical tilt (CCT), coronal joint inclination (CI). Results: Thirty-nine samples (78%) showed sequence variants. Exon 25, 26, 27, and 28 showed variable patterns of DNA bands in SSCP, which on sequencing gives various types of DNA sequence variations in intronic region of the FBN1 gene in 14%, 14%, 6%, and 44% respectively. CT radiology:SI and CCT correlated with both BI and AAD (p<0.01). The mean SI value in controls: 83.35°±8.65°, and in patients with BI and AAD:129°±24.05°. Mean CCT in controls: 60.2°±9.2°, and in patients with BI and AAD: 86.0°±18.1°. Mean CI in controls:110.3°±4.23°, and in cases: 125.15°±16.4°. Conclusion: The study showed mutations in FBN1 gene (reported in Marfan syndrome). There is also an alteration of joint morphology, correlating with AAD and BI severity. Hence, we propose a double-hit hypothesis: the presence of weak ligaments (due to FB1 gene alterations) and abnormal joint morphology may contribute to AAD and BI.

The predictability of the extratropical stratosphere on monthly time‐scales and its impact on the skill of tropospheric forecasts

Tripathi, Om P.,Baldwin, Mark,Charlton‐,Perez, Andrew,Charron, Martin,Eckermann, Stephen D.,Gerber, Edwin,Harrison, R. Giles,Jackson, David R.,Kim, Baek‐,Min,Kuroda, Yuhji,Lang, Andrea,Mah John WileySons, Ltd 2015 Quarterly journal of the Royal Meteorological Soci Vol.141 No.689

<P>Extreme variability of the winter‐ and spring‐time stratospheric polar vortex has been shown to affect extratropical tropospheric weather. Therefore, reducing stratospheric forecast error may be one way to improve the skill of tropospheric weather forecasts. In this review, the basis for this idea is examined. A range of studies of different stratospheric extreme vortex events shows that they can be skilfully forecasted beyond 5 days and into the sub‐seasonal range (0–30 days) in some cases. Separate studies show that typical errors in forecasting a stratospheric extreme vortex event can alter tropospheric forecast skill by 5–7% in the extratropics on sub‐seasonal time‐scales. Thus understanding what limits stratospheric predictability is of significant interest to operational forecasting centres. Both limitations in forecasting tropospheric planetary waves and stratospheric model biases have been shown to be important in this context.</P>

Examining the Predictability of the Stratospheric Sudden Warming of January 2013 Using Multiple NWP Systems

Tripathi, Om P.,Baldwin, Mark,Charlton-Perez, Andrew,Charron, Martin,Cheung, Jacob C. H.,Eckermann, Stephen D.,Gerber, Edwin,Jackson, David R.,Kuroda, Yuhji,Lang, Andrea AMERICAN METEOROLOGICAL SOCIETY 2016 Monthly weather review Vol.144 No.5

<P>The first multimodel study to estimate the predictability of a boreal sudden stratospheric warming (SSW) is performed using five NWP systems. During the 2012/13 boreal winter, anomalous upward propagating planetary wave activity was observed toward the end of December, which was followed by a rapid deceleration of the westerly circulation around 2 January 2013, and on 7 January 2013 the zonal-mean zonal wind at 608N and 10 hPa reversed to easterly. This stratospheric dynamical activity was followed by an equatorward shift of the tropospheric jet stream and by a high pressure anomaly over the North Atlantic, which resulted in severe cold conditions in the United Kingdom and northern Europe. In most of the five models, the SSW event was predicted 10 days in advance. However, only some ensemble members in most of the models predicted weakening of westerly wind when the models were initialized 15 days in advance of the SSW. Further dynamical analysis of the SSW shows that this event was characterized by the anomalous planetary wavenumber-1 amplification followed by the anomalous wavenumber-2 amplification in the stratosphere, which resulted in a split vortex occurring between 6 and 8 January 2013. The models have some success in reproducing wavenumber-1 activity when initialized 15 days in advance, but they generally failed to produce the wavenumber-2 activity during the final days of the event. Detailed analysis shows that models have reasonably good skill in forecasting tropospheric blocking features that stimulate wavenumber-2 amplification in the troposphere, but they have limited skill in reproducing wavenumber-2 amplification in the stratosphere.</P>

Temperature and frequency depended structural, morphological, and electrical topographies of Bi2MnFeO6 double perovskite

Tripathy A.,Bhuyan Satyanarayan,Das S. N.,Choudhary R. N. P. 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.2

A double perovskite ceramic electronic sample of Bi2MnFeO6 has been formulated and synthesized using an ordinary solid-state sintering route from the metal oxides of bismuth, manganese, and iron. The crystallographic structure, morphological, dielectric, electrical, and current–voltage parameters have been analyzed for the fabricated sample. Room temperature XRD (X-ray diffraction) investigation confirms the monoclinic phase. The microstructure obtained from scanning electron microscope reveals compact grain structures with little or no voids. The impedance as well as its electrical properties have been appraised through the impedance analyzer (LCR meter) for a wide range of temperatures and frequencies (30–230 °C and 1 kHz–1 MHz). The negative temperature coefficient of the material is derived from the impedance analysis. The non-ohmic behavior of the sample was confirmed by the current versus voltage (V–I) characteristic of the sample. Most of the significant physical and chemical properties linked with this compound may be critical in the development of future peer group electrical and electronic devices.

Process Optimization of Vacuum-Assisted Solar Drying of Crush, Tear and Curl (CTC) Black Tea

K. R. Jolvis Pou,P. P. Tripathy 한국농업기계학회 2020 바이오시스템공학 Vol.45 No.1

Purpose This study was conducted to develop and evaluate the effects of vacuumassisted solar drying on the quality attributes of crush, tear and curl (CTC) black tea. Methods The influence of process parameters on the quality of tea was analyzed by using Design expert 7.1.1 software. The independent parameters namely vacuum level and loading rate were varied as per rotatable central composite design, and the responses were liquor colour (LC), aroma index (AI), drying time (t) and energy consumption (EC). Results The optimum drying condition was successfully found to be at a vacuum level of 570.71 mmHg and loading rate of 0.96 kg dry solid m−2. The LC redness and yellowness index, AI, t and EC were found to be 20.08, 11.65, 4.44, 140.66 min and 21450.7 kJ respectively in optimized condition. Two individual catechin, namely EGCG (epigallocatechin gallate) and ECG (epigallocatechin); four individual theaflavin like total theaflavins (TF), TF3MG (theaflavin-3-monogallate), TF3’MG (theaflavin-3′-monogallate) and TF3,3’DG (theaflavin-3,3′-digallate) and caffeine were detected in the made tea at the optimized conditions. Conclusions The predicted optimum drying conditions were in good term with the experimental results obtained. This optimum input parameters obtained from the present study would help to produce quality tea.

Structural, Morphological and Electrical Impedance Spectroscopy of Bi2MnCdO6 Double Perovskite Electronic Material

A. Tripathy,S. N. Das,S. Bhuyan,R. N. P. Choudhary 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.3

In this communication, the systematic studies of structural (basic crystal data, microstructure), and electrical (dielectric constant and loss, impedance, modulus, conductivity, etc.) properties of the double perovskite material Bi 2 MnCdO 6 have been reported. The compound has been synthesized by means of a high temperature route (a solid state reaction method). From the X-ray diff raction structural investigation, a stable phase of the orthorhombic crystal system has been recognized. The microstructure obtained from the scanning electron microscope shows uniform, dense and compact grain distribution. Detailed investigation of dielectric as well as electrical parameters of the fabricated compound through a broad frequency range (i.e. 1 kHz–1 MHz) and temperature (i.e., 25 °C to 300 °C) have provided many interesting data and results in order to understand its ferroelectric and electrical relaxation mechanism. It has been experimentally affi rm that this material (Bi 2 MnCdO 6 ) has more advantages like high relative dielectric constant and low tangent loss over Bi 2 MnCoO 6 material.

Structural, Morphological and Electrical Impedance Spectroscopy of Bi2MnCdO6 Double Perovskite Electronic Material

A. Tripathy,S. N. Das,S. Bhuyan,R. N. P. Choudhary 한국전기전자재료학회 2019 Transactions on Electrical and Electronic Material Vol.20 No.2

In this communication, the systematic studies of structural (basic crystal data, microstructure), and electrical (dielectric constant and loss, impedance, modulus, conductivity, etc.) properties of the double perovskite material Bi 2 MnCdO 6 have been reported. The compound has been synthesized by means of a high temperature route (a solid state reaction method). From the X-ray diff raction structural investigation, a stable phase of the orthorhombic crystal system has been recognized. The microstructure obtained from the scanning electron microscope shows uniform, dense and compact grain distribution. Detailed investigation of dielectric as well as electrical parameters of the fabricated compound through a broad frequency range (i.e. 1 kHz–1 MHz) and temperature (i.e., 25 °C to 300 °C) have provided many interesting data and results in order to understand its ferroelectric and electrical relaxation mechanism. It has been experimentally affi rm that this material (Bi 2 MnCdO 6 ) has more advantages like high relative dielectric constant and low tangent loss over Bi 2 MnCoO 6 material.

Micronutrients Dynamics in Soil And Grain Under Long Term Application of Fertilizer and Manurein a Tropical Rice-Rice System

Mohammad Shahid,Ak Nayak,P Bhattacharyya,R Tripathi,S Mohanty,A Kumar,B Lal,Priyanka Gautam,Bb Panda 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6