In Vitro Antioxidant and Free Radical Scavenging Activity of Nardostachys jatamansi DC.

Surendra Kumar Sharma,Ajay Pal Singh 사단법인약침학회 2012 Journal of Acupuncture & Meridian Studies Vol.5 No.3

In this study, the antioxidative potential of a hydroalcoholic extract of Nardostachys jatamansi rhizomes (NJE) was evaluated by various antioxidant assays, including antioxidant capacity by the phosphomolybdenum method, total antioxidant activity in linoleic acid emulsion systems, 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide, hydroxyl radicals, nitric oxide (NO) scavenging, metal chelating and reducing power activity. These various antioxidant activities were compared to standard antioxidants such as butylated hydroxytoluene, tocopherol, catechin and L-ascorbic acid. Total phenolic and flavonoid content of NJE was also determined by a colorimetric method. The extract exhibited high reduction capability and powerful free radical scavenging, especially against DPPH and superoxide anions as well as a moderate effect on NO. Moreover, the peroxidation inhibiting activity of NJE was demonstrated in the linoleic acid emulsion system. The results obtained in the present study clearly established the antioxidative potency of Nardostachys jatamansi, which may account for some of the medical claims attributed to this plant.

A Multiband Shunt Hybrid Active Filter with Sensorless Control

Surendra Kumar S,Partha Sarathi Sensarma 전력전자학회 2008 JOURNAL OF POWER ELECTRONICS Vol.8 No.4

This paper proposes a Multiband Shunt Hybrid Active Filter (SHAF) with sensorless control. A plant is modeled in the discrete- time domain and a controller is designed using the Pole shifting law in the polynomial domain. This control approach is very useful for filtering the load harmonics with reduced sensor counts where a low cost solution like SHAF is required. Multiple Synchronous Reference Frames (MSRF) and low pass filters are used to measure the 5<SUP>th</SUP> and 7<SUP>th</SUP> harmonic components separately from the load and filter currents. Individual current controllers are designed for the 5<SUP>th</SUP> and 7<SUP>th</SUP> harmonic currents. Control is realized in the stationary, three-phase (abc) reference frame. Performance of the controller is validated through simulation, using realistic plant and controller models, as well as experimentally on a fullscale distribution system.

Performance Enhancing of Spray Formed Al/Graphite Alloy Composite by Rolling

Surendra Kumar Chourasiya,Gaurav Gautam,Devendra Singh 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

The present study outlines the effect of warm rolling on the Al/Graphite alloy composite to investigate its effect on mechanicalperformance. The Al/Graphite alloy composite has been fabricated by the spray forming process and has been subjectedto the rolling at 250 °C with varying reduction. The rolled composite has been studied under different characterizationtechniques such as X-ray fluorescence (XRF), optical microscopy, scanning electron microscopy with energy dispersivespectroscopy (EDS) and tensile tester. The XRF and EDS results indicate that the Al/Graphite alloy composite is successfullyformed. The microscopy results show that the grain size of α-aluminium and agglomeration of the particles refine byrolling and they continuously decrease with an increase in rolling reduction. The strength and percentage elongation of thecomposite improves by rolling and they continuously increase with an increase in rolling reduction. Further, the fracturesurface study has also been performed and it indicates that the fracture of the composite alters from brittle to ductile modewith an increase in rolling reduction. The appeared fracture surface of the composite has also been correlated with the producedmicrostructure and the tensile properties.

Effect of Genotype of Donor Plants on the Success of Anther Culture in Sweet Pepper (Capsicum annuum L.)

Surendra Lal Shrestha,강원희 한국자원식물학회 2009 한국자원식물학회지 Vol.22 No.6

To study the effect of genotype of donor plants on anther culture, anthers of nine hybrid cultivars (Derby, Special, Bossanova, Minipaprika, Fiesta, Boogie, Phenlene, Kufrah, and Clarity) of sweet pepper (Capsicum annuum L.) were cultured in a petridish containing C medium (Sibi, Dumas De Vaulx medium) supplemented with 0.1 mg/L 2,4-D and 0.1 mg/L kinetin, 3% sucrose and 0.32% Phytagel. The cultures were incubated in the dark at 35℃ for seven days, and then cultured at 25℃ with a photoperiod of 16 hr. daylength for 40 days. Frequency of callus formation and plant regeneration was varied among cultivars. Callus formation was ranged from 6% in Phenlene to 69.8% in Kufrah. The highest percentage of regenerated plantlets was obtained in cv. Phenlene (2.67%) followed by Bossanova (2.41%). Result of ploidy analysis; chromosome number observation and flowcytometry analysis, showed that haploid plants could be developed from all of these hybrid cultivars except cv. Fiesta, where highest percentage of haploid plants were obtained in Minipaprika (40%) followed by cv. Bossanova (36.1%). Haploid plants derived from these hybrid cultivars contained single set of chromosome (12 in numbers), higher stomata density (numbers), and smaller sized stomata as compare to diploid plants. The mean length of stomata was 26.9 ㎛ in haploid plants and 35.7 ㎛ in diploids.

Mesh distortion, locking and the use of metric trial functions for displacement type finite elements

Surendra Kumar,G. Prathap 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.29 No.3

The use of metric trial functions to represent the real stress field in what is called the unsymmetric finite element formulation is an effective way to improve predictions from distorted finite elements. This approach works surprisingly well because the use of parametric functions for the test functions satisfies the continuity conditions while the use of metric (Cartesian) shape functions for the trial functions attempts to ensure that the stress representation during finite element computation can retrieve in a best-fit manner, the actual variation of stress in the metric space. However, the issue of how to handle situations where there is locking along with mesh distortion has never been addressed. In this paper, we show that the use of a consistent definition of the constrained strain field in the metric space can ensure a lock-free solution even when there is mesh distortion. The three-noded Timoshenko beam element is used to illustrate the principles. Some significant conclusions are drawn regarding the optimal strategy for finite element modelling where distortion effects and field-consistency requirements have to be reconciled simultaneously.

Analysis of impact response and damage in laminated composite cylindrical shells undergoing large deformations

Surendra Kumar 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.35 No.3

The impact behaviour and the impact-induced damage in laminated composite cylindrical shell subjected to transverse impact by a foreign object are studied using three-dimensional non-linear transient dynamic finite element formulation. A layered version of 20 noded hexahedral element incorporating geometrical non-linearity is developed based on total Langragian approach. Non-linear system of equations resulting from non-linear strain displacement relation and non-linear contact loading are solved using Newton-Raphson incremental-iterative method. Some example problems of graphite/epoxy cylindrical shell panels are considered with variation of impactor and laminate parameters and influence of geometrical non-linear effect on the impact response and the resulting damage is investigated.

Agro-morphological Characterization of Anther Derived Plants in Sweet Pepper (Capsicum annuum L. cv. Boogie)

Surendra Lal Shrestha,Binod Prasad Luitel,강원희 한국원예학회 2011 Horticulture, Environment, and Biotechnology Vol.52 No.2

This study was conducted in sweet pepper ‘Boogie’ to produce the haploids and diploids via anther culture, and to characterize their plant and fruit characters. Anthers were cultured on Dumas de Vaulx medium, (C-medium) supplemented with 0.1 mg・L-1 kinetin and 0.1 mg・L-1 2, 4-D, and 3% sucrose and 0.32% phytagel. Cultures were first incubated in dark at 35℃ for one week and then transferred at 25℃ under 16 h photoperiod for 40 days. Regenerated plantlets including haploids and diploids were evaluated for their plant and fruit characters at Hwacheon in spring, 2007. Results revealed that 39.6 % callus was formed in total anthers (6100) whereas only 1.78% plants were regenerated among them. Ploidy analysis showed that 78.1% regenerants were diploids. Haploid plants were characterized by short plant height, narrow leaf size, short internode length, small flower bud size, and small fruit with low volume than diploid plants. Average fruit volume measured in diploids was 62.7% higher than haploids. Variation in plant and fruit characters was observed within the diploid population and pepper breeder could utilize such variation in breeding program. Based on this characterization and compared to original cultivar, SP94, SP117, SP148, SP171 and SP174 are found superior diploid lines and recommended them to evaluate for variety improvement in sweet pepper.

Heterosis and Heterobeltiosis Studies in Sweet Pepper (Capsicum annuum L.)

Surendra Lal Shrestha,Binod Prasad Luitel,강원희 한국원예학회 2011 Horticulture, Environment, and Biotechnology Vol.52 No.3

Twenty-five sweet pepper inbred lines were used to study the heterotic response of economic traits at Hwacheon during 2006/07-2007/08. Out of 25 inbred lines, 12 inbred lines (KNU1006, KNU1015, KNU1017, KNU2006, CO1234, 5AVS1, 5AVS2, 5AVS7, 5SAVS8, SP12, SP27 and SP46) were used as female parents whereas 13 inbred lines (SP9, SP14, SP22, SP25, SP30, SP32, SP34, SP36, SP38, SP43, SP45, SP48 and SP51) were used as male parents and single crosses were made to produce F1 hybrid in 2006/07. Twenty-three F1 hybrids, their parents and three standard varieties (Special, Fiesta and President) were evaluated based on their fruit and fruit quality traits at plastic house in 2007. Variation of fruit yield and fruit characters was observed among the F1 hybrids, their parents and standard varieties. Hybrids of 5AVS7 × SP32, SP12 × SP38, 5AVS7 × SP45, CO1234 × SP32, KNU1015 × SP32, 5AVS7 × SP34, 5AVS8 × SP51 and SP27 × SP25 expressed the highest positive heterosis on fruit number and yield per plant whereas highest positive heterobeltiosis was exhibited by the cross 5AVS7 × SP32 (87.2%) and SP12 × SP38 (119.3%). Hybrid of 5AVS7 × SP32 exhibited the highest heterosis for fruit number (104.0%) and yield (141.2%) per plant. Hybrids of 5AVS7 × SP45, 5AVS7 × SP32, and 5AVS8 × SP48 had highest positive standard heterosis on fruit yield per plant over Special, Fiesta and President. Highest positive standard heterosis had manifested on fruit yield per plant using SP32, SP45, and SP48 inbred lines, which can be used as the male parents with their counterpart female for commercial hybrid production.

Origin of Lα_1 X-Ray Satellites Spectra of 4d Transition Metals for Lead as Predicted by HFS Calculations.

Surendra Poonia 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.41

The X-ray satellite spectra arising due to 2p_(3/2)^(-1)3x^(-1)-3x^(-1)3d^(-1) (x = s, p, d) transition array, in elements with Z = 40 to 48, have been calculated, using available Hartree-Fock-Slater (HFS) data on 1s^(-1)-2p^(-1)3x^(-1) and 2p_(3/2)^(-1)-3x^(-1),3x'^(-1) Auger transition energies. The relative intensities of all the possible transitions have been estimated by considering cross - sections for the Auger transitions simultaneous to a hole creation and then distributing statistically the total cross sections for initial two hole states 2p_(3/2)^(-1)3x^(-1) amongst various allowed transitions from these initial states to 3x^(-1)3d^(-1) final states by Coster-Kronig (CK) and shake off processes. In both these processes initial single hole creation is the prime phenomenon and electron bombardment has been the primary source of energy. Each transition has been assumed to give rise to a Gaussian line and the overall spectrum has been computed as the sum of these Gaussian curves. The calculated spectra have been compared with the measured satellite energies in La1 spectra. Their intense peaks have been identified as the observed satellite lines. The peaks in the theoretical satellite spectra were identified as the experimentally reported satellites α3, α4, and α5, which lie on the high-energy side of the La1 dipole line. On the basis of agreement between the computed spectra and measured satellites, it is observed that the satellite α3 is observed due to intense transition, ^3F_4-^3F_4, in order of decreasing contribution of intensity. It has been found that the transition ^1F_4-^1G_4 is the main source of the emission of the satellite α4 in the elements _(42)Mo to _(48)Cd. The line α5, observed in the spectra of elements with Z = 40 - 48, has been assigned to the ^3D_3-^3F_4, ^3D_2-^3F_3, ^1P_1-^1D_2 and ^1F_3-^1D_2 transitions. Unfortunately no experimental data are available on the intensities, of these satellites.

Location Estimation of a GSM Mobile based on Received Signal Strength

Surendra Shrestha 한국디지털융합학회 2016 IJICTDC Vol.1 No.2

An optimization method that provides quick response using artificial immune system is proposed and is applied to a mobile robot for trajectory tracking in this paper. The study focuses on the immune theory to derive a quick optimization method that puts emphasis on immunity feedback using memory cells by the expansion and suppression of the test group rather than to derive a specific mathematical model of the artificial immune system. Various trajectories were selected to evaluate the performance of the proposed artificial immune system. The global inputs to the mobile robot are reference position and reference velocity, which are time variables. The global output of mobile robot is a current position. The tracking controller makes position error to be converged to zero. In order to reduce position error, compensation velocities on the track of trajectory are necessary. Input variables of fuzzy are position errors in every sampling time. The output values of fuzzy are compensation velocities. Immune algorithm is implemented to adjust the scaling factor of fuzzy automatically. The results of the computer simulation proved the system to be efficient and effective for tracing the trajectory to the final destination by the mobile robot.