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The space-time evolution of the hot and dense fireball of quarks and gluons produced in ultra-relativistic heavy-ion collisions at non-zero baryonic chemical potential and temperature has been studied by using relativistic viscous causal hydrodynamics. For this purpose a numerical code has been developed to solve the relativistic viscous causal hydrodynamics in (3+1)-dimensions with the inclusion of QCD critical point (CP) through the equation of state and scaling behaviour of the transport coefficients. We have evaluated the transverse momentum spectra, directed and elliptic flow coefficients of pions and protons to comprehend the effect of CP on these observables by using this code. It is found that the integration over the entire space-time history of the fireball largely obliterates the effects of CP on the spectra and flow coefficients., Comment: 14 pages, 13 figures

The role of slow out of equilibrium modes (OEM), introduced to extend the validity of hydrodynamics near the QCD critical point on the power spectrum of dynamical density fluctuations has been studied. We have used the equation of motion of slow modes for the situation when the extensive nature of thermodynamics is not altered due to the introduction of OEM. We find that the extensivity condition puts an extra constraint on the coupling of OEM with the four divergence of velocity. The dynamic structure factor (Snn) in presence of the OEM shows four Lorentzian peaks asymmetrically positioned about $\omega (\text{frequency})=0$, whereas the dynamic structure factor without the presence of any OEM shows three well-known Lorentzian peaks. The width of the peaks are reduced in presence of OEM. We find that the asymmetric peaks originate due to the coupling of the out-of-equilibrium modes with the hydrodynamic modes. It is also shown that the OEM has negligible effects on Snn if first order hydrodynamics (relativistic Navier-Stokes) is used. The introduction of OEM reduces the width of the Rayleigh peak indicating the reduction in the decay rate of the fluctuation which leads to slowing down, a well-known characteristics of the critical end point (CEP)., Comment: 21 pages, 7 figures

Passing clouds and wind gusts can create unacceptable rapid voltage/power variations in power networks. Simulation results using a real Australian distribution feeder with real load demand and PV output profile show that with a high penetration of PV the voltage variations can increase beyond the allowable limit given by the standards. Similarly, wind gusts can create wind power output variations. This paper addresses the rapid voltage/power variations caused by solar or wind power outputs and presents a control strategy using the energy buffer in energy storage for their impact mitigation. By controlling the discharging/charging operation of the energy storage based on the available energy buffer in the storage unit, not only the rate of power output variations can be maintained at the desired level, but also the voltage variations can be controlled within acceptable limits. An experimental setup, consisting of a PV emulator, inverter, and grid simulator, demonstrates the potential threat of unacceptable voltage variations. The proposed mitigation strategy using energy buffer in the storage for smoothing the power outputs of solar/wind is tested and validated through simulation. Simulation results show that with the proposed control, the fast variations of the voltage/power variations instigated by solar/wind can be maintained within the acceptable limits.

The value proposition for energy storage systems (ESSs) is a key topic for creating and advancing its acceptance within the electric power sector, particularly for electric utilities. Although ESS as a technology is gaining popularity within the electric utility industry, its anticipated value streams are not fully understood, quantified, and demonstrated. The unavailability of suitable demonstration sites/projects, the lack of a deep understanding of available economic opportunities, and the deployment complexities associated with pursuing those opportunities are some of the reasons that complicate its value demonstration. The lessons learned from holistic demonstration projects covering key steps, e.g., economic value stream identification, evaluation, and its subsequent realization via suitable control strategies, could help electric utilities learn to manage ESS adoption challenges better.

Objectives: The motive of this research study is to evaluate the influence and attractiveness of Social Networking Sites (SNSs) in the amidst the full time working journalists and the part time media practitioners, located in Hyderabad and Karachi practicing on SNSs in their professional field of work. This study examines individual approach, comfort ability, usefulness, and inclination towards the most popular SNSs. Method: The statistics of this research work were congregated through Web-based Questionnaire Survey. That was dispended among the journalists of Hyderabad and Karachi region in Sindh Province, Pakistan. The data were collected through an online Google Docs form out of 386,309; valid questioners were selected for this research and evaluated in SPSS Software. This research work has focused on acceptance of the Technology Acceptance Model (TAM) proposed by Davis (1986) for diversified description of information system and communication technologies. This research examines individual inclination towards Social Media in a Media Profession. Findings: The pronouncement has been shown in Tables and then illustrated and interpreted to perceive the SNSs e.g. Facebook, Twitter, Instagram, Whatsapp, etc. and their acceptance and adoption by full time journalists and part time media practitioners. In this approach, it was recognized that the journalists have a great inclination towards SNSs which enables them to exchange information promptly with ease and confidently practice in the field of journalism. Novelty: In the era of technology, SNSs like; facebook, Instagram, Bebo, Twitter, and Whatsapp are widely used by professional journalists as well as active citizens for journalistic purposes which highlight the untold stories. Keywords: Social Network Sites, TAM, Facebook, Twitter, Whatsapp, Journalists.

The discovery and characterization of hot and dense QCD matter, known as Quark Gluon Plasma (QGP), remains the most international collaborative effort and synergy between theorists and experimentalists in modern nuclear physics to date. The experimentalists around the world not only collect an unprecedented amount of data in heavy-ion collisions, at Relativistic Heavy Ion Collider (RHIC), at Brookhaven National Laboratory (BNL) in New York, USA, and the Large Hadron Collider (LHC), at CERN in Geneva, Switzerland but also analyze these data to unravel the mystery of this new phase of matter that filled a few microseconds old universe, just after the Big Bang. In the meantime, advancements in theoretical works and computing capability extend our wisdom about the hot-dense QCD matter and its dynamics through mathematical equations. The exchange of ideas between experimentalists and theoreticians is crucial for the progress of our knowledge. The motivation of this first conference named "HOT QCD Matter 2022" is to bring the community together to have a discourse on this topic. In this article, there are 36 sections discussing various topics in the field of relativistic heavy-ion collisions and related phenomena that cover a snapshot of the current experimental observations and theoretical progress. This article begins with the theoretical overview of relativistic spin-hydrodynamics in the presence of the external magnetic field, followed by the Lattice QCD results on heavy quarks in QGP, and finally, it ends with an overview of experiment results., Comment: Compilation of the contributions (148 pages) as presented in the `Hot QCD Matter 2022 conference', held from May 12 to 14, 2022, jointly organized by IIT Goa & Goa University, Goa, India

We study the causality and stability of relativistic hydrodynamics with the inclusion of the spin degree of freedom as a hydrodynamic field. We consider two specific models of spin-hydrodynamics for this purpose. A linear mode analysis for static background shows that a first-order dissipative spin-hydrodynamics remains acausal and admits instabilities. Besides, it is found that the inclusion of the spin field in hydrodynamics leads to new kinds of linear modes in the system. These new modes also exhibit instability and acausal behavior. The second model of the spin-hydrodynamics that we have considered here is equivalent to a particular second-order conventional hydrodynamics with no dissipative effects. For a static background, it is found that the linear modes of this model support the sound waves only. However, when the background has constant vorticity, then the model admits instability and acausality in certain situations. It is found that the spin-dynamics have an effect on the hydrodynamic response of the fluid. These findings point toward the need for a causal and stable theory with spin as a hydrodynamic field to describe the spin-polarized fluid., Comment: 32 pages

The COVID19 infection is known to disseminate through droplets ejected by infected individuals during coughing, sneezing, speaking and breathing. The spread of the infection and hence its menace depend on how the virus-loaded droplets evolve in space and time with changing environmental conditions. In view of this, we investigate the evolution of the droplets within the purview of the Brownian motion of the evaporating droplets in the air with varying weather conditions under the action of gravity. We track the movement of the droplets till either they gravitationally settle on the ground or evaporate to aerosols of size 2$\mu$m or less. Droplets with radii $2 \mu$m or less may continue to diffuse and remain suspended in the air for long time. The effects of relative humidity and temperature on the evaporation are found to be significant. We note that under strong flowing conditions droplets travel large distances. It is found that the bigger droplets fall on the ground due to the dominance of gravity over the diffusive force despite the loss of mass due to evaporation. The smaller evaporating droplets may not settle on the ground but remain suspended in the air due to the dominance of the diffusive force. The fate of the intermediate size droplets depends on the weather conditions and play crucial roles in the spread of the infection. These environment dependent effects indicate that the maintenance of physical separation to evade the virus is not corroborated, making the use of face mask indispensable., Comment: 13 pages, one text file with seven figures

The drag and diffusion coefficients of heavy quarks propagating through quark–gluon plasma (QGP) have been estimated by shielding the infra-red divergences using electric and magnetic screening masses. The electric-type screening in perturbative quantum chromodynamics (pQCD) has been widely studied and used in evaluating the diffusion coefficient of heavy quarks (HQs). The impact of magnetic screening on diffusion coefficients of HQs is not studied before to the best of our knowledge. We explore the effect of magnetic screening mass on the drag and diffusion coefficients of HQs and found it to be non-negligible. Therefore, the effect of magnetic screening should be taken into consideration to characterize hot and dense matter formed in the collisions of nuclei at ultra-relativistic energies. We estimate the suppression of heavy flavored mesons in heavy ion collisions compared to proton+proton collisions at high transverse momenta and found that the suppression is less with the inclusion of magnetic screening. The value of the magnetic screening mass is not known exactly because of its nonperturbative nature. Moreover, it may not be possible to single out the effect of magnetic mass because of the uncertainties in other parameters involved in the diffusion process of HQs. Still it is important to include the effects of magnetic screening because of its physical origin in QCD.

Results from proton-proton ($pp$) collisions have routinely been used as a baseline to analyze and understand the production of QCD matter expected to be produced in nuclear collisions. But recent studies of small systems formed in $pp$ collisions at the LHC energies hint at the possibility of producing medium with collective behavior. Therefore, results from $pp$ collisions required more careful investigation to understand whether QCD matter is produced in high multiplicity $pp$ collisions. With this motivation, the Glauber model traditionally used to study the heavy-ion collision dynamics at high energy is applied here to understand the dynamics of $pp$ collisions. We have used anisotropic and inhomogeneous quark/gluon-based proton density profile, a realistic picture obtained from deep inelastic scattering results and this model explains the charged particle multiplicity distribution of $pp$ collisions at LHC energies very well. Collision geometric properties like impact parameter and mean number of binary collisions ($\langle N_{coll} \rangle$), mean number of participants ($\langle N_{part} \rangle$) at different multiplicities are determined for $pp$ collisions. We further used these collision geometric properties to estimate average charged-particle pseudorapidity density ($\langle dN_{ch}/d\eta \rangle$) and found it to be comparable with the experimental results. Knowing $\langle N_{coll} \rangle$, we have obtained nuclear modification-like factor ($R_{pp}$) in $pp$ collisions which has not been done before to the best of our knowledge., Comment: Presented in LHCP-2021. To appear as PoS. Slightly modified version with corrected references

The multiplicity, finite system size and collision energy dependencies of heat capacity ($C_V$), conformal symmetry breaking measure (CSBM) and speed of sound ($c_s$) have been investigated using ALICE data for $p+p$ collisions at $\sqrt{s}$ = 7 TeV. The aim of this study is to ascertain the possibility of formation of a thermalized medium in such collisions. We find that there is a threshold in charged particle multiplicity beyond which $C_V$, CSBM and $c_s$ attain plateau. The presence of such threshold in multiplicity is further reflected in the variation of these quantities with center-of-mass energy ($\sqrt{s_{NN}}$). In order to have a grasp on experimentally obtained results, variation of $\langle p_T \rangle$ with multiplicity has also been studied. The experimental results have been contrasted with PYTHIA8 and it is found that PYTHIA8 is inadequate to explain the features reflected in these quantities, thereby indicating the possibility of thermalization in such small system. It is also observed that the finite size effects alone cannot explain the non-extensive nature of particle spectra in $p+p$ collisions., Same as the published version

Summary Despite extensive research in the past five years and several successfully completed and on-going pilot projects, regulators are still reluctant to implement peer-to-peer trading at a large scale in today's electricity market. The reason could partly be attributed to the perceived disadvantage of current market participants such as retailers due to their exclusion from market participation—a fundamental property of decentralized peer-to-peer trading. As a consequence, recently, there has been growing pressure from energy service providers in favor of retailers' participation in peer-to-peer trading. However, the role of retailers in the peer-to-peer market is yet to be established, as no existing study has challenged this fundamental circumspection of decentralized trading. In this context, this perspective takes the first step to discuss the feasibility of retailers' involvement in the peer-to-peer market. In doing so, we identify key characteristics of retail-based and peer-to-peer electricity markets and discuss our viewpoint on how to incorporate a single retailer in a peer-to-peer market without compromising the fundamental decision-making characteristics of both markets. Finally, we give an example of a hypothetical business model to demonstrate how a retailer can be a part of a peer-to-peer market with a promise of collective benefits for the participants., Graphical abstract, Energy resources; Energy policy; Energy systems; Energy management; Energy flexibility

The impact of the QCD critical point on the propagation of nonlinear waves has been studied. The effects have been investigated within the scope of second-order causal dissipative hydrodynamics by incorporating the critical point into the equation of state, and the scaling behaviour of transport coefficients and of thermodynamic response functions. Near the critical point, the nonlinear waves are found to be significantly damped which may result in the disappearance of the Mach cone effects of the away side jet. Such damping may lead to enhancement in the fluctuations of elliptic and higher flow coefficients. Therefore, the disappearance of Mach cone effects and the enhancement of fluctuations in flow harmonics in the event-by-event analysis may be considered as signals of the critical endpoint., One LaTex file for text and 6 pdf files for figures

The high-multiplicity pp collisions at the Large Hadron Collider energies with various heavy-ion-like signatures have warranted a deeper understanding of the underlying physics and particle production mechanisms. It is a common practice to use experimental data on the hadronic transverse momentum ($p_T$) spectra to extract thermodynamical properties of the system formed in heavy ion and high multiplicity pp collisions. The non-availability of event topology dependent experimental data for pp collisions at $\sqrt{s}$ = 13 TeV on the spectra of non-strange and strange hadrons constrains us to use the PYTHIA8 simulated numbers to extract temperature-like parameters to study the event shape and multiplicity dependence of specific heat capacity, conformal symmetry breaking measure (CSBM) and speed of sound. The observables show a clear dependence on event multiplicity and event topology. Thermodynamics of the system is largely governed by the light particles because of their relatively larger abundances. In this regards, a threshold in the particle production, $\rm N_{ch} \simeq$ (10-20) in the final state multiplicity emerges out from the present study, confirming some of the earlier findings in this direction. As for heavier hadrons with relatively small abundances, a similar threshold is observed for $\langle \rm N_{ch} \rangle \simeq$ 40 hinting towards formation of a thermal bath where all the heavier hadrons are in equilibrium., Same as the published version

An effective action for “soft” gluons has been constructed by integrating out hard thermal modes of topologically massive vector bosons at one loop order. The gluons are equally massive in the non-Abelian topologically massive model due to a quadratic coupling B∧F where a 2-form field B is coupled quadratically with the field strength F of the Yang-Mills (YM) field. This non-Abelian model provides the same asymptotic freedom of strong coupling which is found in massless YM theory at zero temperature. The presence of a gauge-invariant infrared cutoff plays the role of magnetic mass. Thus, in the model, it can be used to get the transport coefficients in the perturbative regime.

Recent studies reveal that at high energies, collisions of small system like $p+p$ gives signatures similar to that widely observed in heavy ion collisions hinting towards a possibility of forming a medium with collective behaviour. With this motivation, we have used the Glauber model, which is traditionally applied to heavy ion collisions, in small system using anisotropic and inhomogeneous density profile of proton and found that the proposed model reproduces the charged particle multiplicity distribution of $p+p$ collisions at LHC energies very well. Collision geometric properties like mean impact parameter, mean number of binary collisions ($\langle N_{coll} \rangle$) and mean number of participants ($\langle N_{part} \rangle$) at different multiplicities are determined. Having estimated $\langle N_{coll} \rangle$, we have calculated nuclear modification-like factor ($R_{HL}$) in $p+p$ collisions. We also estimated eccentricity and elliptic flow as a function of charged particle multiplicity using the linear response to initial geometry., Same as published version

We have used second order relativistic hydrodynamics equipped with equation of state which includes the critical point to study the propagation of perturbation in a relativistic QCD fluid. Dispersion relation for the sound wave has been derived to ascertain the fate of the perturbation in the fluid near the QCD critical end point (CEP). We observe that the threshold value of the wavelength of the sound in the fluid diverges at the CEP, implying that all the modes of the perturbations are dissipated at this point. Some consequences of the suppression of sound near the critical point have been discussed., Comment: To be published in Physical Review C

After a century of relative stability of the electricity industry, extensive deployment of distributed energy resources and recent advances in computation and communication technologies have changed the nature of how we consume, trade, and apply energy. The power system is facing a transition from its traditional hierarchical structure to a more deregulated model by introducing new energy distribution models such as peer-to-peer sharing for connected communities. The proven effectiveness of P2P sharing in benefiting both prosumers and the grid has been demonstrated in many studies and pilot projects. However, there is still no extensive implementation of such sharing models in today's electricity markets. This paper aims to shed some light on this gap through a comprehensive overview of recent advances in the P2P energy system and an insightful discussion of the challenges that need to be addressed in order to establish P2P sharing as a viable energy management option in today's electricity market. To this end, in this article, we provide some background on different aspects of P2P sharing. Then, we discuss advances in P2P sharing through a systematic domain-based classification. We also review different pilot projects on P2P sharing across the globe. Finally, we identify and discuss a number of challenges that need to be addressed for scaling up P2P sharing in the electricity market followed by concluding remarks at the end of the paper., Comment: 33 pages, 6 figures, 4 tables

The spread of COVID19 through droplets ejected by infected individuals during sneezing and coughing has been considered as a matter of key concern. Therefore, a quantitative understanding of the propagation of droplets containing virus assumes immense importance. Here we investigate the evolution of droplets in space and time under varying external conditions of temperature, humidity and wind flow by using laws of statistical and fluid mechanics. The effects of drag, diffusion and the gravity on droplets of different sizes and ejection velocities have been considered during their motion in the air. In still air we found that bigger droplets traverse larger distance but the smaller droplets remain suspended in the air for longer time. So, in still air the horizontal distance that a healthy individual should maintain from an infected one is determined by the bigger droplets but the time interval to be maintained is determined by the smaller droplets. We show that in places with wind flow the lighter droplets travel larger distance and remain suspended in the air for longer time. Therefore, we conclude that both temporal and the geometric distance that a healthy individual should maintain from an infected one is determined by the smaller droplets under flowing air which makes the use of mask mandatory to prevent the virus. The maintenance of only stationary separation between healthy and infected individuals is not substantiated. The quantitative results obtained here will be useful to devise strategies for preventing the spread of other types of droplets also containing microorganisms., Comment: To be published in Physics of Fluid

The ability to define the potential value that energy storage systems (ESSs) could generate through various applications in electric power systems, and an understanding of how these values change due to variations in ESS performance and parameters, market structure, utility structures, and valuation methodologies is highly important in advancing ESS deployment. This paper presents a taxonomy for assigning benefits to the use cases or services provided by ESSs, defines approaches for monetizing the value associated with these services, assigns values, or more precisely ranges of values, to major ESS applications by region based on a review of an extensive set of literature, and summarizes and evaluates the capabilities of several available tools currently used to estimate value for specific ESS deployments.

Battery energy storage systems (BESS) are forecasted to play a vital role in the future grid system, which is complex but incredibly important for energy supply in the modern era. Currently, Li-ion batteries are the most widely deployed BESS for a wide range of grid services but need substantial understanding and improvement for effective market creation. Hence, the main purpose of this review is to provide a comprehensive overview of the current status and challenges of Li-ion battery energy storage systems for grid application from various aspects based on real-world projects.

In this paper, the applicability of marine renewable energy (MRE) for potential grid applications is presented. We show that many of the unique value streams from marine-based electricity generation resources stem from their inherent temporal characteristics, especially when compared to wind and solar. Specifically, in this work, we evaluate the timing value for three types of MRE resources: (a) tidal, (b) wave, and (c) ocean currents. First, through a suite of novel metrics, such as resource availability, persistence, and versatility, we evaluate the temporal value characteristics of these resources. Second, through a more grid-oriented numerical study, we comment on the potential ramifications of those temporal characteristics in context of energy balancing and effective load carrying capability for one marine-based resource i.e., wave. Finally, we further our understanding of the relative advantages that may be leveraged by operating wave-based generation in tandem with more established renewable resources, such as wind and solar. Our results indicate that compared to wind and solar, MRE resources are consistently more available and persistent on an hourly level throughout an entire year of operation. In addition, wave resources are also seen to reduce the balancing requirements within the power system. Our work focuses on sites specific to the United States (US) and a parallel study for a location in Great Britain (GB). Results are found to be consistent for sites in both the US and GB, implying that the grid benefits discussed in this work could apply to a number of locations globally.

Classical and quantum Tsallis distributions have been widely used in many branches of natural and social sciences. But, the quantum field theory of the Tsallis distributions is relatively a less explored arena. In this paper, we derive the expression for the thermal two-point functions in the Tsallis statistics with the help of the corresponding statistical mechanical formulations. We show that the quantum Tsallis distributions used in the literature appear in the thermal part of the propagator much in the same way the Boltzmann–Gibbs distributions appear in the conventional thermal field theory. As an application of our findings, we calculate the thermal mass in the [Formula: see text] scalar field theory within the realm of the Tsallis statistics.

Ultra-relativistic Heavy-Ion Collision (HIC) generates very strong initial magnetic field ($\vec B$) inducing a vorticity in the reaction plane. The high $\vec{B}$ influences the evolution dynamics that is opposed by the large Faraday current due to electric field generated by the time varying $\vec{B}$. We show that the resultant effects entail a significantly large directed flow ($v_1$) of charm quarks (CQs) compared to light quarks due to a combination of several favorable conditions for CQs, mainly: (i) unlike light quarks formation time scale of CQs, $\tau_f \simeq \, 0.1 \rm fm/c$ is comparable to the time scale when $\vec B$ attains its maximum value and (ii) the kinetic relaxation time of CQs is similar to the QGP lifetime, this helps the CQ to retain the initial kick picked up from the electromagnetic field in the transverse direction. The effect is also odd under charge exchange allowing to distinguish it from the vorticity of the bulk matter due to the initial angular momentum conservation; conjointly thanks to its mass, $M_c >>\Lambda_{QCD}$, there should be no mixing with the chiral magnetic dynamics. Hence CQs provide very crucial and independent information on the strength of the magnetic field produced in HIC., Comment: 7 pages, 5 figures, Accepted for publication in Physics Letters B

As the energy sector experiences a paradigm shift towards cleaner and greener generation sources, the need for evaluating the applicability of marine energy for grid-based applications has intensified. This is because marine energy (ocean, wave and tidal) may be utilized to provide unique benefits to electric grid operations, especially in conjunction with other established renewable technologies (such as wind and solar) or technologies like energy storage. In this work, we focus our attention on some specific characteristics of one type of marine energy resources i.e. tidal based resources. Specifically, we perform a comprehensive temporal analysis using a suite of metrics on resource data to characterize the inherent predictability of the resource across various time scales of interest. We also investigate the correlation of tidal power generation profiles with energy demand and comment on the effectiveness of having such resources in the overall generation portfolio.