PANCHROMATIC OBSERVATIONS OF THE TEXTBOOK GRB 110205A: CONSTRAINING PHYSICAL MECHANISMS OF PROMPT EMISSION AND AFTERGLOW

Zheng, W.,Shen, R. F.,Sakamoto, T.,Beardmore, A. P.,De Pasquale, M.,Wu, X. F.,Gorosabel, J.,Urata, Y.,Sugita, S.,Zhang, B.,Pozanenko, A.,Nissinen, M.,Sahu, D. K.,Im, M.,Ukwatta, T. N.,Andreev, M.,Klun IOP Publishing 2012 The Astrophysical journal Vol.751 No.2

<P>We present a comprehensive analysis of a bright, long-duration (T-90 similar to 257 s) GRB 110205A at redshift z = 2.22. The optical prompt emission was detected by Swift/UVOT, ROTSE-IIIb, and BOOTES telescopes when the gamma-ray burst (GRB) was still radiating in the gamma-ray band, with optical light curve showing correlation with gamma-ray data. Nearly 200 s of observations were obtained simultaneously from optical, X-ray, to gamma-ray (1 eV to 5 MeV), which makes it one of the exceptional cases to study the broadband spectral energy distribution during the prompt emission phase. In particular, we clearly identify, for the first time, an interesting two-break energy spectrum, roughly consistent with the standard synchrotron emission model in the fast cooling regime. Shortly after prompt emission (similar to 1100 s), a bright (R = 14.0) optical emission hump with very steep rise (alpha similar to 5.5) was observed, which we interpret as the reverse shock (RS) emission. It is the first time that the rising phase of an RS component has been closely observed. The full optical and X-ray afterglow light curves can be interpreted within the standard reverse shock (RS) + forward shock (FS) model. In general, the high-quality prompt and afterglow data allow us to apply the standard fireball model to extract valuable information, including the radiation mechanism (synchrotron), radius of prompt emission (R-GRB similar to 3 x 10(13) cm), initial Lorentz factor of the outflow (Gamma(0) similar to 250), the composition of the ejecta (mildly magnetized), the collimation angle, and the total energy budget.</P>

A SCS-CN-BASED MODEL INCORPORATING DIRECT USE OF ANTECEDENT RAINFALL IN RUNOFF EQUATION

SAHU R.K.,MISHRA S.K.,ELDHO T.I.,JAIN M.K. 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Parametric Resonance Characteristics of Laminated Composite Curved Shell Panels in a Hygrothermal Environment

Sahu, S.K.,Rath, M.K.,Datta, P.K.,Sahoo, R. The Korean Society for Aeronautical and Space Scie 2012 International Journal of Aeronautical and Space Sc Vol.13 No.3

The present study deals with the parametric resonance behaviour of laminated composite curved shell panels in a hygrothermal environment using Bolotin's approach. A simple laminated model is developed using first order shear deformation theory (FSDT) for the vibration and dynamic stability analysis of laminated composite shells subjected to hygrothermal conditions. A computer program based on the finite element method (FEM) in a MATLAB environment is developed to perform all necessary computations. Quantitative results are presented to show the effects of curvature, ply-orientations, degree of orthotropy and geometry of laminates on the parametric instability of composite curved shell panels for different temperature and moisture concentrations. The excitation frequencies of laminated composite panels decrease with the increase of temperature and moisture due to reduction of stiffness for all laminates.

Parametric Resonance Characteristics of Laminated Composite Curved Shell Panels in a Hygrothermal Environment

S.K Sahu,M.K.Rath,P.K Datta,R. Sahoo 한국항공우주학회 2012 International Journal of Aeronautical and Space Sc Vol.13 No.3

The present study deals with the parametric resonance behaviour of laminated composite curved shell panels in a hygrothermal environment using Bolotin’s approach. A simple laminated model is developed using first order shear deformation theory (FSDT) for the vibration and dynamic stability analysis of laminated composite shells subjected to hygrothermal conditions. A computer program based on the finite element method (FEM) in a MATLAB environment is developed to perform all necessary computations. Quantitative results are presented to show the effects of curvature, ply-orientations, degree of orthotropy and geometry of laminates on the parametric instability of composite curved shell panels for different temperature and moisture concentrations. The excitation frequencies of laminated composite panels decrease with the increase of temperature and moisture due to reduction of stiffness for all laminates.

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.

Quality control of Dalchini (Cinnamomum zeylanicum): a review

Arun K. S. Parihar,K. Kulshrestha Mayank,Umakant Sahu,K. S. Karbhal,S. R. Inchulkar,Kamal Shah,N. S. Chauhan 경희대학교 융합한의과학연구소 2023 Oriental Pharmacy and Experimental Medicine Vol.23 No.1

Dalchini bark (Cinnamomum zeylanicum) being a vast treasure of phytoconstitutents have a tremendous ethnomedicinal value. Dalchini (Cinnamomum zeylanicum) being a delicious spice with an impressive effects on health and metabolism. Cinnamon barks are available in the market in lot of varieties. So it’s difficult to identify and select dalchini adulterant by numerous substituent and exhausted drugs which are of fewer efficacies and have an harmful effects for human beings. Dalchini are adulterate with Cinnamon cassia, Cinnaniomon burmanii, Cinnaniomon loureirii with other spices and amurud (Psidium guajava, common guava, lemon guava) etc. The present chapter is an attempt to cater various techniques for the identified of the adulterants and substitutes to shot out deterioration of herb potential.

Survey Paper: Location Management in CDMA Network

N. P. Nath,S. R. Parija,P. K. Sahu,S. S. Singh 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.1

With the rapid increase in international roaming and highly growing number of cellular subscribers it is important to locate the subscriber both efficiently and accurately not only to reduce the cost but also to decrease the load on MSC and decrease the paging delay. The procedure used by the service provider for both collecting and analyzing the information regarding the subscribers’ location is called location management. Location management comprises of location update and paging schemes. This paper tried to highlight the different location management techniques and paging schemes that are used in CDMA network. This paper also compares their features, merits and demerits. Finally the paper discusses various techniques that are used in order to optimize the location update schemes by categorizing them into two broad groups’ i.e. static location update and dynamic location update. Each group enlists different techniques that are used to decide the update frequency of MS (Mobile System). This study has tried to summarize their underlying concepts and various pros and cons.

Experimental evidence of warm electron populations in magnetron sputtering plasmas

Sahu, B. B.,Han, Jeon G.,Kim, Hye R.,Ishikawa, K.,Hori, M. American Institute of Physics 2015 JOURNAL OF APPLIED PHYSICS - Vol.117 No.3

Temporal variations of black carbon in Guangzhou, China, in summer 2006

Verma, R. L.,Sahu, L. K.,Kondo, Y.,Takegawa, N.,Han, S.,Jung, J. S.,Kim, Y. J.,Fan, S.,Sugimoto, N.,Shammaa, M. H.,Zhang, Y. H.,Zhao, Y. Copernicus GmbH 2010 Atmospheric Chemistry and Physics Vol.10 No.14

<P>Abstract. In situ measurements of the mass concentration of black carbon (BC) and mixing ratios of carbon monoxide (CO) and carbon dioxide (CO2) were made at Guangzhou, an urban measurement site in the Pearl River Delta (PRD), China, in July 2006. The average ± standard deviation (SD) concentrations of BC, CO, and CO2 were 4.7± 2.3 μgC m−3, 798± 459 ppbv, and 400± 13 ppmv, respectively. The trends of these species were mainly controlled by synoptic-scale changes in meteorology during the campaign. Based on back trajectories, data are analyzed separately for two different air mass types representing northerly and southerly flows. The northerly air masses, which constituted ~25% of the campaign, originated mostly in the PRD and hence represent observations on regional scales. On the other hand, during southerly flow (~75%), the measurements were influenced by dilution due to cleaner marine air. The diurnal patterns of BC, CO, and CO2 exhibited peak concentrations during the morning and evening hours coinciding with rush-hour traffic. The ratios of OC/BC were lower during the morning hour peaks in the concentrations of primary pollutants due to their fresh emissions mainly from vehicular traffic in Guangzhou. The diurnal variations of BC observed in southerly air masses tended to follow the traffic patterns of heavy-duty vehicles (HDV) in Guangzhou, while the roles of other sources need to be investigated. The slopes of ΔBC/ΔCO, ΔBC/ΔCO2, and ΔCO/ΔCO2 observed during northerly flows were 0.0045 μgC m−3/ppbv, 0.13 μgC m−3/ppmv, and 49.4 ppbv/ppmv, respectively, agreeing reasonably with their respective emission ratios derived from regional emission inventories. </P>

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.