Santosh Das - Academia.edu (original) (raw)

Papers by Santosh Das

Patan Prospective Journal

The objective of this work is to develop the mathematical model for the auxiliary field and inter... more The objective of this work is to develop the mathematical model for the auxiliary field and interlink the pair correlation in the external potential of the open quantum system of the 2D electron system. For this, we used 2D Hubbard Model with the action open quantum system Lindblad equation and then apply the saddle point condition to obtain the auxiliary field of the 2D system. The obtained pair correlation of quasiparticles was found symmetric in nature with cooper pairs electron paring angle. The pair correlation of 0K was found 0.1times, 1 time, 2 times, 3 times, 4 times, and 5 times greater when compared with 0.2K, 0.3K, 0.4K, 0.5K, and 0.6K, respectively at -1 radian and +1 radian copper pairs electron pairing angle which is maximum. In addition, with increasing the temperature, the pair correlation decrease and become minimum without loss of symmetry.

Current Science, 2021

The primordial matter of quarks and gluons, which filled our universe just after few micro-second... more The primordial matter of quarks and gluons, which filled our universe just after few micro-seconds of its creation through Big Bang, is expected to be created in the laboratory by colliding nuclei at relativistic energies. The ongoing nuclear collision programs at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) are two experimental facilities, where matter in the state of Quark-Gluon Plasma (QGP) can be created and characterized. Heavy quarks, mainly charm and bottom quarks, are considered as novel probes to characterize QGP, and hence the QCD matter. Heavy quark diffusion coefficients play a significant role to understand the properties of QCD matter. Experimental measurements of nuclear suppression factor and elliptic flow are able to constrain the heavy quark diffusion coefficients, which is a key ingredient for the phenomenological study and disentangle different energy loss models. We give a general perspective of heavy quark diffusion coefficient in QGP and discuss its potential as a probe to disentangle different hadronization mechanisms, as well as to probe the initial electromagnetic field produced in non-central collisions. Experimental perspective on future measurements are discussed with special emphasis on heavy-flavors as next generation probes.

International Journal of Innovations in Engineering Research and Technology, 2020

Power eminence controls the suitability of electrical power to user devices. A wireless sensor ne... more Power eminence controls the suitability of electrical power to user devices. A wireless sensor network is an arrangement collected of several computing and sensing devices distributed within an environment to be monitored. In this network saving power is a very serious issue, since sensor nodes are typically powered by batteries with an inadequate capacity. Since distribution is the main cause of power consumption in a sensor node, broadcast or response of data should be limited as much as possible. To this aim in this research paper, we propose an en ethics of reducing power consumption in wireless sensor networks using soft computing method.

-Nowadays electronic commerce services have risen to become more and more popular on Internet and... more -Nowadays electronic commerce services have risen to become more and more popular on Internet and Web environment. Exchange security on network is very important for e-commerce service and it is always the key factor that affects the success of electronic commerce (e-commerce). In this paper, we discuss some security related issues about traditional and new generation of e-commerce model, such as authentication, authorization, non-repudiation, and integrity in P2P model; moreover, we discuss some trust models in P2P e-commerce. By analyzing the main features of P2P e-commerce, we sum up some design principles of trust model in P2P e-commerce. We provide a thorough overview about the network security issues that surround e-commerce and e-commerce applications and propose a corresponding research framework for security in ecommerce. We believe that as long as the security issues are adequately addressed, the P2P e-commerce would achieve great success in the future e-commerce markets i...

Location forecasting of subscriber is critical in cellular network. Since many issues such as han... more Location forecasting of subscriber is critical in cellular network. Since many issues such as handoff, blocking probability, user prediction, etc., are greatly influenced by this location movement of mobile user. In this work, a comprehensive study of different artificial neural techniques and its wireless application, i.e., user forecasting, is presented. Three types of typical neural networks, namely back propagation (BP), Legendre (LN) and radial basis function (RBF), are extensively studied, investigated and analysed in the paper. The location user data used are the hourly mean mobile user data collected at sites in Chandrasekharpur, Bhubaneswar area. The performance is evaluated based on three metrics, namely training accurate, testing accuracy and processing time. The random user where the movement is frequent then conventional algorithms like multi-layer perceptron (MLP), radial basis function (RBF) do not outperform the Legendre neural network (LNN). For the best performance...

Materials Today: Proceedings, 2021

Abstract Over the years, traditional way of farming results in reduction of yield of crops due to... more Abstract Over the years, traditional way of farming results in reduction of yield of crops due to the changing climatic conditions and insufficient down pouring, to tackle this problem water usage in irrigation must be restricted and no wastages of this precious resource is tolerable. This paper discusses about the use of IoT in irrigation and the challenges expected to be faced when integrating technology with the conventional farming methods. The objective of this paper is to implement the technology of smart irrigation using IoT, to develop a system using a controller that processes not only the filed data from soil moisture sensor and but also analyze the condition of the future weather data from an open API, with these parameters the occurrence of rainfall is predicted and based on which irrigation is carried out. It results in water conservation and reduction in energy consumption. This technique can also be carried out in hydroponic system, is a method of growing crops without soil.

PURPOSE: To produce an Mg-base alloy dispersedly contg. fine intermetallic compds. and having exc... more PURPOSE: To produce an Mg-base alloy dispersedly contg. fine intermetallic compds. and having excellent strength and corrosion resistance by ultra-rapidly cooling molten metal which is formed by adding specific metallic elements to Mg and melting the mixture. CONSTITUTION: The melt 2 of the alloy having a component contg., by atomic %, <11% Al, <4% Zn and 0.5 to 4% at least one kind among Si, Ge, Co, Sn and Sb and total ratio of Al+Zn is 2 to 13% and balance is Mg or the Mg-base alloy having a compsn. formed by substituting the ratio up to 4% of the Al and Zn described above with at least one kind of Nd, Pr, Y, Ce and Mn or substituting up to 0.3% of Si, Ge, Co, Sn and Sb with Zr is extruded through a slotted nozzle defined by a first lip 3 and a second lip 4 onto the surface of a cooling body 1 moving at a high speed under pressurization, by which the molten metal is ultra-rapidly cooled. The molten metal is then peeled from the cooling body 1 in the protective gaseous atmosp...

Materials and Processing Report, 1990

On produit un composite a matrice metallique en formant un alliage a base d'aluminium rapidem... more On produit un composite a matrice metallique en formant un alliage a base d'aluminium rapidement solidifie auquel on donne la forme d'un fil. Le fil est pulverise a l'arc electrique sur au moins un substrat possedant en surface un materiau de renforcement comprenant des fibres, pour constituer une pluralite de preformes. Chacune des preformes possede une couche de l'alliage deposee sur ladite preforme, le materiau de renforcement comprenant des fibres etant present dans une proportion variant d'environ 0,1 a 75 pour-cent du volume. Les preformes sont assemblees pour former un profile technique.

The Egyptian Journal of Remote Sensing and Space Science, 2021

Abstract A quantitative analysis of the shoreline migration pattern at various timescales is impo... more Abstract A quantitative analysis of the shoreline migration pattern at various timescales is important to understand the coastal ecosystem and interaction behaviour between sea and land. The sea-level rise due to polar ice and glacier melting has directly affected the coastal environment. The present study attempts to analyze the potential migration characteristics of Jambudwip Island of the Sundarban biosphere in the Bay of Bengal. GIS, Remote Sensing and Statistical analyses have been utilized for this observation. Digital Shoreline Analysis System (DSAS) was used to assess the shoreline change over time span. Moreover, Linear Regression Rate (LRR) and End Point Rate (EPR) were used for statistical analysis to measure the rate of change of shoreline during 2011, 2013, 2015, and 2017. NDVI and single-band threshold method (IR band) has been applied on the Landsat-7 and OLI data to identify the shoreline position. The result showed that the Western part of the island was the most erosive zone and Eastern part is the most accretive zone. Overall, the maximum rate of erosion was 49.08 m/yr and accretion 122.4 m/yr. In consequence, shoreline length has also been changed between 2011and 2017, from approximately 11879.91m to 10374.42 m.

Journal of Physics: Conference Series, 2020

We study the correlations between light flavor and heavy quarks (HQs) flow harmonics at LHC energ... more We study the correlations between light flavor and heavy quarks (HQs) flow harmonics at LHC energy within a transport approach. We have investigated the role of transport coefficient in developing these anisotropic flows correlations. We suggest υ n h e a v y − υ n l i g h t correlation and the relative fluctuations of anisotropic flows συη /〈υn 〉 as novel observables to constrain the HQ transport coefficients in quark gluon plasma. Finally, very strong electro-magnetic (E.M.) fields are created in Ultra-relativistic Heavy-Ion Collision (HIC). We show within relativistic Boltzmann transport approach coupled with E.M. field that the strong e.m. field is responsible for a splitting of directed flow υ 1 of D and anti-D mesons of few percent, i.e. much larger compared to the observed charged particles. Moreover, we discuss the role played by the initial large bulk vorticity on the build up of rapidity odd HQs directed flow υ 1.

Proceedings of 52 International Winter Meeting on Nuclear Physics — PoS(Bormio2014), Oct 14, 2014

In this talk we review the basic concepts related with the study of the dynamics of the heavy qua... more In this talk we review the basic concepts related with the study of the dynamics of the heavy quarks in the quark-gluon plasma created in ultra-relativistic heavy-ion collisions. We discuss the relevant physical scale as well the difficulties of the present theoretical approach to have a self-consistent description of the experimental data at both RHIC and LHC. In the second part we challenge the assumption of brownian motion for charm quarks and compare the dynamical evolution of charm and bottom quarks in a Fokker-Planck approach and in a Transport Boltzmann one. We show that while for bottom the motion appears quite close to a Brownian one, this does note seems to be the case for charms quarks. In particular the solution of the full twobody collision integral shows that the anisotropic flows are larger respect to those predicted by a Langevin dynamics.

Physical Review C, 2019

Several transport models have been employed in recent years to analyze heavy-flavor meson spectra... more Several transport models have been employed in recent years to analyze heavy-flavor meson spectra in high-energy heavy-ion collisions. Heavy-quark transport coefficients extracted from these models with their default parameters vary, however, by up to a factor of five at high momenta. To investigate the origin of this large theoretical uncertainty, a systematic comparison of heavy-quark transport coefficients is carried out between various transport models. Within a common scheme devised for the nuclear modification factor of charm quarks in a brick medium of a quark-gluon plasma, the systematic uncertainty of the extracted drag coefficient among these models is shown to be reduced to a factor of two, which can be viewed as the smallest intrinsic systematical error band achievable at present time. This indicates the importance of a realistic hydrodynamic evolution constrained by bulk hadron spectra and of heavy-quark hadronization for understanding the final heavy-flavor hadron spectra and extracting heavy-quark drag coefficient. The transverse transport coefficient is less constrained due to the influence of the underlying mechanism for heavy-quark medium interaction. Additional constraints on transport models such as energy loss fluctuation and transverse-momentum broadening can further reduce theoretical uncertainties in the extracted transport coefficients.

Physical Review C, 2017

We describe the propagation of charm quarks in the quark-gluon plasma (QGP) by means of a Boltzma... more We describe the propagation of charm quarks in the quark-gluon plasma (QGP) by means of a Boltzmann transport approach. Non-perturbative interaction between heavy quarks and light quarks have been taken into account through a quasi-particle approach in which light partons are dressed with thermal masses tuned to lQCD thermodynamics. Such a model is able to describe the main feature of the non-perturbative dynamics: the enhancement of the interaction strength near Tc. We show that the resulting charm in-medium evolution is able to correctly predict simultaneously the nuclear suppression factor, RAA, and the elliptic flow, v2, at both RHIC and LHC energies and at different centralities. The hadronization of charm quarks is described by mean of an hybrid model of fragmentation plus coalescence and plays a key role toward the agreeement with experimental data. We also performed calculations within the Langevin approach which can lead to very similar RAA(pT) as Boltzmann, but the charm drag coefficient as to be reduced by about a 30% and also generates an elliptic flow v2(pT) is about a 15% smaller. We finally compare the space diffusion coefficient 2πT Ds extracted by our phenomenological approach to lattice QCD results, finding a satisfying agreement within the present systematic uncertainties. Our analysis implies a charm thermalization time, in the p → 0 limit, of about 4 − 6 f m/c which is smaller than the QGP lifetime at LHC energy.

Physical Review D, 2016

Momentum space anisotropy present in the quark and gluon distribution functions in relativistic h... more Momentum space anisotropy present in the quark and gluon distribution functions in relativistic heavy ion collisions induces Chromo-Weibel instability in the hot QCD medium created therein. The impact of the Chromo-Weibel instability on the dynamics of a heavy-quark (HQ) traversing in the QGP medium is investigated within the framework of kinetic theory by studying the momentum and temperature behavior of HQ drag and diffusion coefficients. The physics of anisotropy is captured in an effective Vlasov term in the transport equation. The effects of the instability are handled by making a relation with the phenomenologically known jet quenching parameter in RHIC and LHC. Interestingly, the presence of instability significantly affect the temperature and momentum dependences of the HQ drag and diffusion coefficients. These results may have appreciable impact on the experimental observables such as, the nuclear suppression factor, RAA(pT), and the elliptic flow, v2(pT), of heavy mesons in heavy ion collisions at RHIC and LHC energies which is a matter of future investigation.