Investigation of electron beam parameters in laser wakefield acceleration using skewed laser pulse and external magnetic field

Gopal K.,Gupta D.N.,Jain A.,Hur M.S.,Suk H. 한국물리학회 2021 Current Applied Physics Vol.25 No.-

We investigate the parameters of accelerated electron bunch in laser wakefield acceleration (LWFA), when a skewed laser pulse propagates through a plasma in the presence of a transverse magnetic field. Two dimensional particle-in-cell (2D-PIC) simulations have been performed under the consideration of pulse skewness parameter (sα = τl/τt) that is defined as the ratio of leading (τl) to trailing pulse edge (τt) duration. The injected charge is estimated as 23 pC for the laser strength parameter a0 = 2 when sα changes from 1 to 0.45 at a laser propagation distance of 1.5 mm with 50T magnetic field. The electron beam emittance reduces about 50% when leading edge of the pulse becomes two-fold sharper (sα = 0.45) with 50T magnetic field. Energy spread of accelerated electron bunch is also reduced from 18 to 6.6%. Hence, in the presence of a transverse magnetic field, the laser pulse skewness can significantly improve the quality of the accelerated electron bunch (i.e. charge, mean energy and emittance) in laser wakefield acceleration.

Object Based Fast Motion Estimation and Compensation Algorithm for Surveillance Video Compression

Gopal Thapa,Kalpana Sharma,M. K. Ghose 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.6

In surveillance systems, the storage requirements for video archival are a major concern because of recording of videos continuously for long periods of time, resulting in large amounts of data. Therefore, it is essential to apply efficient compression techniques for compressing surveillance video. The techniques used for the general video compression may not be the efficient technique for the compression of surveillance video because of the use of static camera as compared to moving camera in general purpose videos. Generally surveillance video consist of multiple objects, smaller in size as compared to the background and they have frequents occlusion with each other. In this paper a new object based motion estimation and compensation technique for surveillance video compression is proposed. Background differencing and summing technique (BDST) is used for the segmentation of the moving objects. This technique not only identifies moving object but also the maximum distance moved by the object in given group of frames. A bonding box is created based on the movement of the object in order to segment the moving objects. For exploiting the temporal redundancy, the motion estimation and compensation is carried out for the bonding box region only. The multiresolution property of discrete wavelet transform is used for the motion estimation and compensation. Experimental results show that the approach achieves high compression ratios compared to MPEG-2 compression.

Studies on the Anti-diarrheal Profiles of Bauhinia purpurea Linn Leaves (Fam . Caesalpiniaceae) Extract

Pulok K. Mukherjee,T. K. Gopal,T. subburaju,S. P. Dhanbal,B. Duraiswamy,K. Elango,B. Suresh 한국생약학회 1998 Natural Product Sciences Vol.4 No.4

To evaluate the anti-diarrheal potential of the leaves of Bauhinia purpurea Linn., investigations were performed on different animal models e.g. castor oil induced diarrhea in rats and gastrointestinal motility test by using charcoal meal. In both the models the ethanolic extract of the leaves showed significant activity when compared to control group. The group treated with standard anti-diarrheal agent also showed significant activity comparing with control. Thus this study establishes the efficacy of Bauhinia purpurea Linn. leaves as an anti-diarrheal as claimed in folklore.

Comparative Evaluation of Several Gene Targets for Designing a Multiplex-PCR for an Early Diagnosis of Extrapulmonary Tuberculosis

Promod K. Mehta,Ankush Raj,Netrapal Singh,Krishna B. Gupta,Dhruva Chaudhary,Aparna Yadav,Anil Chaudhary,Kshitij Agarwal,Mandira Varma-Basil,Rajendra Prasad,Gopal K. Khuller 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.1

Purpose: Diagnosis of extrapulmonary tuberculosis (EPTB) poses serious challenges. A careful selection of appropriate gene targetsis essential for designing a multiplex-polymerase chain reaction (M-PCR) assay. Materials and Methods: We compared several gene targets of Mycobacterium tuberculosis, including IS6110, devR, and genes encodingMPB-64 (mpb64), 38kDa (pstS1), 65kDa (hsp65), 30kDa (fbpB), ESAT-6 (esat6), and CFP-10 (cfp10) proteins, using PCR assayson 105 EPTB specimens. From these data, we chose the two best gene targets to design an M-PCR. Results: Among all gene targets tested, mpb64 showed the highest sensitivity (84% in confirmed cases and 77.5% in clinically suspectedcases), followed by IS6110, hsp65, 38kDa, 30kDa, esat6, cfp10, and devR. We used mpb64+IS6110 for designing an M-PCR assay. Our M-PCR assay demonstrated a high sensitivity of 96% in confirmed EPTB cases and 88.75% in clinically suspected EPTB cases with a high specificity of 100%, taking clinical diagnosis as the gold standard. Conclusion: These M-PCR results along with the clinical findings may facilitate an early diagnosis of EPTB patients and clinical management of disease.

Spatial Temporal Analysis of Freight Flow through Indian Major Seaport System

Prasanta K. Sahu,Abhishek PADHI,Gopal R. Patil,Gangadhar MAHESH,Ashoke K. SARKAR 한국해운물류학회 2019 The Asian journal of shipping and Logistics Vol.35 No.1

This paper analyzed the space time interactions among the freight flows through major Indian ports. Freight flow data at regular intervals in the form of spatial time series were collected for the twelve major ports located along the east and west coast of India. The system of freight flows was modeled through interactions both in time and space dimensions as a multivariate stochastic process. Effect of the neighbor port freight on a subject port was analyzed to understand the degree of dependency among the competing/non-competing ports. Demand elasticity analysis suggested that ports are more sensitive to changes in their own demand over time than the corresponding spatial changes indicating bulk of the demand dependency on hinterland economic activity. Interestingly, only two ports are found to be competing with each other as they share common hinterland. In general, it can be inferred that the interport relationship within Indian major port system is complimentary or co-operative. Proposed models can be used for assessing the impact of freight flow changes from one port to the nearest neighboring port. Study findings will help port authorities and policy makers for holistic development of port system by making right investments in required locations to promote balanced development. It has also implications towards formulating policies on port development considering Government of India's preferred mode of choice for infrastructure development is PPP, and policy formulation for this mode of development is required to address competition concerns considering the high sunk cost associated with ports development.

Error Free Butcher Algorithms for Linear Electrical Circuits

K. Murugesan,N.P. Gopalan,Devarajan Gopal 한국전자통신연구원 2005 ETRI Journal Vol.27 No.2

In this paper, an error-free Butcher algorithm is introduced to study the singular system of a linear electrical circuit for time invariant and time varying cases. The discrete solutions obtained using Runge-Kutta (RK)- Butcher algorithms are compared with the exact solutions of the electrical circuit problem and are found to be very accurate. Stability regions for the single term Walsh series (STWS) method and the RK-Butcher algorithm are presented. Error graphs for inductor currents and capacitor voltages are presented in a graphical form to show the efficiency of the RK-Butcher algorithm. This RK-Butcher algorithm can be easily implemented in a digital computer for any singular system of electrical circuits.

Neutral Integrodifferential Control Systems With Infinite Delay in Banach Spaces

( K. Balachandran ),( T. Nandha Gopal ) 한국산업응용수학회(구 한국산업정보응용수학회) 2004 한국산업정보응용수학회 Vol.8 No.1

Estimation of Freight Demand at Mumbai Port using Regression and Time Series Models

Gopal R. Patil,Prasanta K. Sahu 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.5

Forecasting future freight demand at a seaport is important for its planning and development. India has 13 major ports which handle 75% of the total seaport freight. Among the 13 major ports, Mumbai Port, ranked at number three in the country for the year 2013-14, handles about 11% of the total freight at major seaports in India. The focus of this paper is on developing inbound and outbound demand forecasting models for Mumbai Port. The models are developed using additive regression and time series techniques. In regression analysis economic indicators, Gross Domestic Product (GDP) and Crude Oil Production (CRLP) are found to be significant. The multivariate models performed better than the univariate models. The validation of time-series models resulted in error of less than 5%. Both multivariate regression and time-series models are used to forecast freight demand for the years 2014- 15 through 2017-18. The regression models are producing more optimistic forecasts than the time series models. The elasticity analysis suggested that Mumbai’s inbound freight will be growing almost with India’s GDP growth rate, the outbound freight, however, will experience slower growth than that of inbound.

Unusual chromosomal features in a child with gradual disappearance of right ulna (mono ostolic osteolysis)

Hit K,Goswami,Nirhhay Shrivastava,Shiv Kumar Gopal,Sanjay Sharna,Manoj Chandorkar,In Hwan Lee,Sung Ik Chang 대한의학유전학회 1997 대한의학유전학회지 Vol.1 No.1

A nine month old male child presenting degenerating right ulna (massive osteolysis) has been followed up for two years. The bone completely disappeared due to abscesses on the right forearm and without orthopedic or haematological complications. Repeated lymphocyte cultures showed somatic pairing (mostly chromosome pair 5), end to end association involving chromosome 14, 21, 21 and 16, and satellite enlargement in a high proportion of cells with an otherwise normal 46,XY karyotype. These observations are compared with 13 other types of orthopaedic patients, and we opine that cumulative picture of chromosomal aberrations appears to correspond with the present rare anomaly "Mono Ostolic Osteolysis" involving right ulna. None of the controls or any other orthopaedic anomaly studied hereunder exhibits this chromosomal picture.

Effects of counter ions on electrochromic behaviors of asymmetrically substituted viologens

Pande, Gaurav K.,Kim, Namhyeon,Choi, Jin Hui,Balamurugan, Gopal,Moon, Hong Chul,Park, Jong S. North-Holland 2019 Solar Energy Materials and Solar Cells Vol. No.

<P><B>Abstract</B></P> <P>We present effects of counter anions on electrochromic behavior of asymmetrically substituted viologens, 1-hexyl-1′-nonafluorohexyl viologens (HERFVs). For this purpose, two anions, hexafluorophosphate ([PF<SUB>6</SUB>]<SUP>–</SUP>) and bis(trifluorosulfonyl)imide ([TFSI]<SUP>–</SUP>), were employed for both HERFVs and 1-butyl-3-methylimidazolium ([BMIM]<SUP>+</SUP>)-based ionic liquids. The HERFV-containing electrochromic devices (ECDs) exhibited apparent dependence on the counter ions in terms of optical contrast, switching speed, long-term cyclic stability, coloration efficiency, and memory effect. Specifically, the ECDs based on [HERFV][PF<SUB>6</SUB>]<SUB>2</SUB> showed a redox response at −1.0 V with a color change from colorless to blue. Meanwhile, the coloration of [HERFV][TFSI]<SUB>2</SUB> appeared at −3.0 V, and a significantly long optical memory effect was observed with unstable cyclic repeatability. We attributed this discrepancy to the nature of counter ions, such as size and electronegativity, which may influence the electron transfer process during redox reactions. These results demonstrated that counter anions can exert a significant impact on the EC behaviors of asymmetrically substituted viologens. The presented approach suggests a potential tool for controlling EC properties of viologen derivatives for applications in transmissive windows and eye wear.</P>