Novel Time-Domain Parameters for Detection and Classification of Flaws Using Pulsed Eddy Current Technique

K. Sambasiva Rao,T. V. Beatriceveena,C. S. Angani,Lucky Agarwal 한국자기학회 2020 Journal of Magnetics Vol.25 No.3

Pulsed eddy current (PEC) testing is an electromagnetic nondestructive evaluation (NDE) technique which is used for detection and classification of flaws. This paper presents an approach for the extraction of novel timedomain flaw parameters viz. amplitude ratio (V1/V0) and time constant (τ) for detection and classification of different flaws. Experiments are carried out on stainless steel (SS-316) plate with artificial EDM notches whose width (1.0 mm & 3.0 mm) and depth (1.0 mm to 6.0 mm) varied. The proposed approach can classify both surface and sub-surface flaws in an 8.0 mm thick SS plate. The advantage of the proposed approach is that it doesn’t require a reference signal subtraction or signal processing methodologies for the detection and classification of flaws.

Production of a Thermostable Nitrilase in a Lab Scale Stirred Tank Bioreactor

V. K. Nigam,A. K. Khandelwal,A. Agarwal,M. K. Mohan,A. S. Vidyarthi 보안공학연구지원센터 2012 International Journal of Bio-Science and Bio-Techn Vol.4 No.3

Kinetic Studies on Physical and Chemical Activation of Phenolic Resin Chars

Agarwal, Damyanti,Lal, Darshan,Tripathi, V.S.,Mathur, G.N. Korean Carbon Society 2003 Carbon Letters Vol.4 No.3

Granular Activated Carbon (GAC) has been proven to be an excellent material for many industrial applications. A systematic study has been carried out of the kinetics of physical as well as chemical activation of phenolic resin chars. Physical activation was carried out using $CO_2$ and chemical activation using KOH as activating agent. There are number of factors which influence the rate of activation. The activation temperature and residence time at HTT varied in the range $550{\sim}1000^{\circ}C$ and $\frac{1}{2}{\sim}8$ hrs respectively. Kinetic studies show that the rate of chemical activation is 10 times faster than physical activation even at much lower temperature. Above study show that the chemical activation process is suitable to prepare granular activated carbon with very high surface area i.e.$ 2895\;m^2/g$ in short duration of time i.e. 1 to 2 hrs at lower temperature i.e. $750^{\circ}C$ from phenolic resins.

Influence of Pyrolysis Conditions and Type of Resin on the Porosity of Activated Carbon Obtained From Phenolic Resins

Agarwal, Damyanti,Lal, Darshan,TripathiN, V.S.,Mathur, G.N. Korean Carbon Society 2003 Carbon Letters Vol.4 No.2

In polymer precursor based activated carbon, the structure of starting material is likely to have profound effect on the surface properties of end product. To investigate this aspect phenolic resins of different types were prepared using phenol, mcresol and formaldehyde as reactants and $Et_3N$ and $NH_4OH$ as catalyst. Out of these resins two resol resins PFR1 and CFR1 (prepared in excess of formaldehyde using $Et_3N$ as catalyst in the basic pH range) were used as raw materials for the preparation of activated carbons by both chemical and physical activation methods. In chemical activation process both the resins gave activated carbons with high surface areas i.e. 2384 and 2895 $m^2/g$, but pore size distribution in PFR1 resin calculated from Horvath-Kawazoe method, contributes mainly in micropore range i.e. 84.1~88.7 volume percent of pores was covered by micropores. Whereas CFR1 resin when activated with KOH for 2h time, a considerable amount (32.8%) of mesopores was introduced in activated carbon prepared. Physical activation with $CO_2$ leads to the formation of activated carbon with a wide range of surface area (503~1119 $m^2/g$) with both of these resins. The maximum pore volume percentage was obtained in 3-20 ${\AA}$ region by physical activation method.

Influence of Pyrolysis Conditions and Type of Resin on the Porosity of Activated Carbon Obtained From Phenolic Resins

Damyanti Agarwal,Darshan Lal,V.S. TripathiN,G.N. Mathur 한국탄소학회 2003 Carbon Letters Vol.4 No.2

In polymer precursor based activated carbon, the structure of starting material is likely to have profound effect on the surface properties of end product. To investigate this aspect phenolic resins of different types were prepared using phenol, mcresol and formaldehyde as reactants and Et3N and NH4OH as catalyst. Out of these resins two resol resins PFR1 and CFR1 (prepared in excess of formaldehyde using Et3N as catalyst in the basic pH range) were used as raw materials for the preparation of activated carbons by both chemical and physical activation methods. In chemical activation process both the resins gave activated carbons with high surface areas i.e. 2384 and 2895 m2/g, but pore size distribution in PFR1 resin calculated from Horvath-Kawazoe method, contributes mainly in micropore range i.e. 84.1~88.7 volume percent of pores was covered by micropores. Whereas CFR1 resin when activated with KOH for 2h time, a considerable amount (32.8%) of mesopores was introduced in activated carbon prepared. Physical activation with CO2 leads to the formation of activated carbon with a wide range of surface area (503~1119 m2/g) with both of these resins. The maximum pore volume percentage was obtained in 3-20 a region by physical activation method.

CAMP: Community Access MODIS Pipeline

Hendrix, V.,Ramakrishnan, L.,Ryu, Y.,van Ingen, C.,Jackson, K.R.,Agarwal, D. North-Holland ; Elsevier Science Ltd 2014 Future generations computer systems Vol.36 No.-

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument's land and atmosphere data are important to many scientific analyses that study processes at both local and global scales. The Terra and Aqua MODIS satellites acquire data of the entire Earth's surface every one or two days in 36 spectral bands. MODIS data provide information to complement many of the ground-based observations but are extremely critical when studying global phenomena such as gross photosynthesis and evapotranspiration. However, data procurement and processing can be challenging and cumbersome due to difficulties in volume, size of data and scale of analyses. For example, the very first step in MODIS data processing is to ensure that all products are in the same resolution and coordinate system. The reprojection step involves a complex inverse gridding algorithm and involves downloading tens of thousands of files for a single year that is often infeasible to perform on a scientist's desktop. Thus, use of large-scale resource environments such as high performance computing (HPC) environments are becoming crucial for processing of MODIS data. However, HPC environments have traditionally been used for tightly coupled applications and present several challenges for managing data-intensive pipelines. We have developed a data-processing pipeline that downloads the MODIS swath products and reprojects the data to a sinusoidal system on an HPC system. The 10 year archive of the reprojected data generated using the pipeline is made available through a web portal. In this paper, we detail a system architecture (CAMP) to manage the lifecycle of MODIS data that includes procurement, storage, processing and dissemination. Our system architecture was developed in the context of the MODIS reprojection pipeline but is extensible to other analyses of MODIS data. Additionally, our work provides a framework and valuable experiences for future developments and deployments of data-intensive pipelines from other scientific domains on HPC systems.

Kinetic Studies on Physical and Chemical Activation of Phenolic Resin Chars

Damyanti Agarwal,Darshan Lal,V.S. Tripathi,G.N. Mathur 한국탄소학회 2003 Carbon Letters Vol.4 No.3

Granular Activated Carbon (GAC) has been proven to be an excellent material for many industrial applications. A systematic study has been carried out of the kinetics of physical as well as chemical activation of phenolic resin chars. Physical activation was carried out using CO2 and chemical activation using KOH as activating agent. There are number of factors which influence the rate of activation. The activation temperature and residence time at HTT varied in the range 550~1000℃ and ½~8 hrs respectively. Kinetic studies show that the rate of chemical activation is 10 times faster than physical activation even at much lower temperature. Above study show that the chemical activation process is suitable to prepare granular activated carbon with very high surface area i.e. 2895 m2/g in short duration of time i.e. 1 to 2 hrs at lower temperature i.e. 750℃ from phenolic resins.

Enhanced recovery after surgery in liver resection: current concepts and controversies

Jigeeshu V. Divatia,Vandana Agarwal 대한마취통증의학회 2019 Korean Journal of Anesthesiology Vol.72 No.2

Enhanced recovery after surgery (ERAS) attenuates the stress response to surgery in the perioperative period and hastens recovery. Liver resection is a complex surgical procedure where the enhanced recovery program has been shown to be safe and effective in terms of postoperative outcomes. ERAS programs have been shown to be associated with lower morbidity, shortened postoperative stay, and reduced cost with no difference in mortality and readmission rates. However, there are challenges that are unique to hepatic resection such as safety after epidural catheterization and postoperative coagulopathy, intraoperative fluids and postoperative organ dysfunction, need for low central venous pressure to reduce blood loss, and non-lactate containing intravenous fluids. This narrative review briefly discusses these concerns and controversies and suggests revisiting some of the strong recommendations made by the ERAS society in light of the recent evidence.

Observation of dielectric relaxation modes in chiral smectic Cliquid crystal mixture

Rajbir Singh,V.K. Agarwal,K.K. Raina,B. Bahadur 한국물리학회 2005 Current Applied Physics Vol.5 No.6

The dielectric parameters in the frequency range 50Hz to 1MHz have been measured in a SmC* liquid crystal mixture in planaralignment. The relaxation frequency (fr), distribution parameter (a) and dielectric strength (de) have been evaluated and their cor-responding values were found to be 206.62Hz, 0.06 and 114.6 respectively. The Goldstone mode, domain mode, soft mode and anewrelaxation mode have been observed..

Neural Correlates of a Perspective-taking Task Using in a Realistic Three-dimmensional Environment Based Task: A Pilot Functional Magnetic Resonance Imaging Study

Sri Mahavir Agarwal,Venkataram Shivakumar,Sunil V. Kalmady,Vijay Danivas,Anekal C. Amaresha,Anushree Bose,Janardhanan C. Narayanaswamy,Michel-Ange Amorim,Ganesan Venkatasubramanian 대한정신약물학회 2017 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.15 No.3

Objective: Perspective-taking ability is an essential spatial faculty that is of much interest in both health and neuropsychiatric disorders. There is limited data on the neural correlates of perspective taking in the context of a realistic three-dimensional environment. We report the results of a pilot study exploring the same in eight healthy volunteers. Methods: Subjects underwent two runs of an experiment in a 3 Tesla magnetic resonance imaging (MRI) involving alternate blocks of a first-person perspective based allocentric object location memory task (OLMT), a third-person perspective based egocentric visual perspective taking task (VPRT), and a table task (TT) that served as a control. Difference in blood oxygen level dependant response during task performance was analyzed using Statistical Parametric Mapping software, version 12. Activations were considered significant if they survived family-wise error correction at the cluster level using a height threshold of p<0.001, uncorrected at the voxel level. Results: A significant difference in accuracy and reaction time based on task type was found. Subjects had significantly lower accuracy in VPRT compared to TT. Accuracy in the two active tasks was not significantly different. Subjects took significantly longer in the VPRT in comparison to TT. Reaction time in the two active tasks was not significantly different. Functional MRI revealed significantly higher activation in the bilateral visual cortex and left temporoparietal junction (TPJ) in VPRT compared to OLMT. Conclusion: The results underscore the importance of TPJ in egocentric manipulation in healthy controls in the context of reality- based spatial tasks.