bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite-key analysis for memory-assisted decoy-state quantum key distribution
Authors: Lorenzo Guillermo Currás , Razavi Mohsen
Published: August 2020

Memory-assisted quantum key distribution (MA-QKD) systems are among novel promising solutions that can improve the key-rate scaling with channel loss. By using a middle node with quantum storage and measurement functionalities, they offer the same key-rate scaling with distance as a single-node quantum repeater. However, the distance at which they can surpass the nominal key rate of repeaterless systems, in terms of bits per second, is typically long, owing to the efficiency and/or interaction time issues when one deals with quantum memories. This crossover distance can be a few hundred kilometres, for instance, when one relies on the exchange of infinitely many key bits for the key-rate analysis. In a realistic setup, however, we should account for the finite-key effects in our analysis. Here, we show that accounting for such effects would actually favour MA-QKD setups, by reducing the crossover distance to the regime where realistic implementations can take place. We demonstrate this by rigorously analysing a decoy-state version of MA-QKD, in the finite-key regime, using memory parameters already achievable experimentally. This provides us with a better understanding of the advantages and challenges of working with memory-based systems.
Role of crystalline and damping anisotropy to the angular dependences of spin rectification effect in single crystal CoFe film
Authors: Zeng Fanlong , Shen Xi , Li Yi , Yuan Zhe , Zhang Wei , Wu Yizheng
Published: August 2020

The angular dependence of the microwave-driven spin rectification (SR) effect in single crystalline Co0.5Fe0.5 alloy film is systematically investigated. Due to the strong current-orientation dependent anisotropic magnetoresistance (AMR), the SR effects in CoFe film strongly deviate from the ordinary sin 2φ
M cos φ
M relation with φ
M defined as the magnetization angle away from the current. A giant Gilbert damping anisotropy in the CoFe film with a maximum–minimum ratio of 520% is observed, which can impose a strong anisotropy onto magnetic susceptibility. The observed unusual angular dependence can be well explained by the theory including current-orientation dependent AMR and anisotropic magnetic susceptibility. Our work also suggests that the strong current-orientation dependent AMR in single crystalline CoFe film could exist up to the gigahertz frequency range.
Photometric investigation of eight ultra-short period eclipsing binaries from OGLE
Authors: Shanti Priya D. , Ravi Raja P. , Rukmini J. , Raghu Prasad M. , Thomas Vineet S.
Published: August 2020

We performed a detailed photometric analysis of eight ultra-short period eclipsing binaries (USPEBs) using the Wilson-Devinney method. We present the modeled light curves and derived photometric solutions. The USPEBs with period (P)≤0.21 d considered in our study belong to W-subtype having shallow contact factor (f) <∼20%, high mass ratio (q) >∼0.7 and later spectral types. The absolute parameters for these short-period binaries were derived applying empirical relations. We discuss the evolutionary stage of these USPEBs using the mass-radius, color-density and period-color diagrams. The objects showed poor metallicities, and some objects were even found to be existing around fully convective limits. The period distribution of USPEBs exhibited a sharp cut-off at 0.22 d; however, we observed significant deficits for our objects in the literature. We examined the statistics of USPEBs studied to date (in terms of the distribution of period, mass ratio and component temperatures of USPEBs) and observed that a dominant distribution of component temperatures for these USPEBs was towards lower temperatures.
Conditions for galaxy quenching at 0.5 < z < 2.5 from CANDELS: compact cores and environment
Authors: Ge Xue , Liu Feng-Shan , Gu Qiu-Sheng , Contini Emanuele , Gu Yi-Zhou
Published: August 2020

We investigate two classes of conditions for galaxy quenching at 0.5 < z < 2.5 based on the structural scaling relations of galaxies in the five Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) fields: the formation of a compact core and the environment. We confirm that in the entire redshift range, massive quiescent galaxies (M
* > 1010
M
⊙) have much higher stellar mass surface densities within the central 1 kpc (Σ1) and smaller sizes than star-forming galaxies in the same stellar mass range. In addition, the quiescent fractions significantly increase with the increase of Σ1 regardless of whether galaxies are centrals or satellites. In contrast, we find that the overall lower-mass quiescent galaxies (M
* <∼ 1010
M
⊙) have slightly higher Σ1 and comparable sizes compared to star-forming galaxies of the same mass and at the same redshift. At z < 1.5, satellites have higher halo masses and larger quiescent fractions than those of centrals at a given Σ1 (stellar mass). Our findings indicate that the significant growth of the galaxy cores is closely related to the quenching of massive galaxies since z ∼ 2.5, while the environmental effect plays an important role in the quenching of low-mass galaxies at z ≲ 1.5.
Propagating slow sausage waves in a sunspot observed by the New Vacuum Solar Telescope
Authors: Feng Song , Deng Zheng , Yuan Ding , Xu Zhi , Yang Xiao
Published: August 2020

A sunspot is an ideal waveguide for a variety of magnetohydrodynamic waves, which carry a significant amount of energy to the upper atmosphere and could be used as a tool to probe the magnetic and thermal structure of a sunspot. In this study, we used the New Vacuum Solar Telescope and took high-resolution image sequences simultaneously in both TiO (7058±10 Å) and H
α
(6562±2.5 Å) bandpasses. We extracted the area and total emission intensity variations of sunspot umbra and analyzed the signals with synchrosqueezing transform. We found that the area and emission intensity varied with both three and five minute periodicity. Moreover, the area and intensity oscillated in phase with each other, this fact hold in both TiO and H
α
data. We interpret this oscillatory signal as a propagating slow sausage wave. The propagation speed is estimated at about 8 km s−1. We infer that this sunspot’s umbra could have temperature as low as 2800–3500 K.
The dying accretion and jet in a powerful radio galaxy of Hercules A
Authors: Wu Lin-Hui , Wu Qing-Wen , Feng Jian-Chao , Lu Ru-Sen , Fan Xu-Liang
Published: August 2020

Hercules A (Her A) is one of a rare class of dying and transition-type objects, which has a pair of giant, powerful radio lobes and a weak radio core. We reduce and analyze the radio data of Her A that were observed by the Expanded Very Large Array (EVLA) during 2010-2011 at C band. The intensity distribution is very smooth along the edge of the lobe front and the intensity also sharply decreases at the edge, which supports that magnetic fields may play an important role in radio lobes. The spectrum of the weak core is very steep and the core flux becomes weaker by about ten percent when compared to what was observed twenty years ago, which suggest that the central engine is still dying quickly. Her A deviates a lot from the relation between [O III] luminosity and low-frequency 178 MHz luminosity (L
O III – L
178MHz) as defined by other FR I/II sources. However, when only radio core emission is considered, it roughly follows an L
O III – L
178 MHz correlation. This result supports that the black-hole accretion and large-scale jet in Her A did not evolve simultaneously, and indicates that although the large-scale jet is still powerful, the accretion and inner jet have changed into an inactive state. Based on the estimated Bondi accretion rate, we model the spectrum of Her A with a radiatively inefficient accretion flow and jet model.
A pilot study of catching high-z GRBs and exploring circumburst environment in the forthcoming SVOM era
Authors: Wang Jing , Qiu Yu-Lei , Wei Jian-Yan
Published: August 2020

Rapid spectroscopy of GRB afterglows is an important and hard task. Based on the archival XS-GRB spectral database, we here perform a pilot study on the afterglow’s spectroscopy in the forthcoming SVOM era in two aspects. First, our simulation indicates that the color acquired from the SVOM/VT blue and red channels is effective in discriminating between low-z (z ≲ 3) and distant GRB candidates until z ∼ 6. Second, by doubling the sample size, we find that the previously proposed global photoionization response of the circumburst gas to the prompt emission (i.e., the CIV/CII-

L

iso

/

E

peak

2

relationship) is roughly confirmed, although the confirmation is dissatisfactory at the large

L

iso

/

E

peak

2

end. We believe that this issue can be further addressed in the SVOM era by a larger spectroscopy sample, thanks to its capability of rapid identification of optical candidates of afterglow and its anti-solar pointing strategy.
Milky Way globular cluster dynamics: are they preferentially co-rotating?
Authors: Das Saikat , Roy Nirupam
Published: August 2020

The motion of baryonic components of the Milky Way is governed by both luminous and dark matter content of the Galaxy. Thus, the dynamics of Milky Way globular clusters (GCs) can be used as tracers to infer the mass model of the Galaxy up to a large radius. In this work, we apply the directly observable line-of-sight velocities to test if the dynamics of the GC population are consistent with an assumed axisymmetric gravitational potential of the Milky Way. For this, we numerically compute the phase space distribution of the GC population where the orbits are either oriented randomly or co-/counter- rotating with respect to the stellar disk. Then we compare the observed position and line-of-sight velocity distribution of ∼150 GCs with those of the models. We found that, for the adopted mass model, the co-rotating scenario is the favored model based on various statistical tests. We do the analysis with and without the GCs associated with the progenitors of early merger events. This analysis can be extended in the near future to include precise and copious data to better constrain the Galactic potential up to a large radius.
Mid-infrared atmospheric transmittance at 5100m-altitude Ali Observatory
Authors: Wang Fei-Xiang , Xu Fang-Yu , Guo Jie , Zhao Zhi-Jun , Hao Rui-Ting , Xiao Jian-Guo , Jia Yu-Chao , Huang Shan-Jie
Published: August 2020

Ali in Tibet, 5100 m above sea level, is one of the most suitable locations in the world for infrared spectral observations. The atmospheric transmittances at Ali Observatory and Mauna Kea Observatory were calculated by MODTRAN using radiosonde data. The results were 0.848 and 0.789 respectively which indicated better conditions at Ali Observatory. A self-made instrument with a 320×256-pixel HgCdTe infrared focal plane array and a 7.5-cm diameter telescope was utilized for the actual measurements. Without the help of standard stars, the on-site and real-time atmospheric transmittance can be obtained as 0.831 by fitting the relation between the measured atmospheric radiation intensity and the zenith angle based on radiation transfer equations. This paper firstly reports the atmospheric transmittance in the M’ band (4.605–4.755 μm) at the 5100 m-altitude Ali observatory by actual measurement. It shows that the high-altitude Ali observatory with sufficiently low water vapor content is suitable for observation in the mid-infrared bands.
Feasibility study of greater occipital nerve blocks by focused ultrasound – an animal study
Authors: Chiou Jiun-Yi , Abd-Elrehim Tamer , Lin Chou-Ching , Chen Gin-Shin
Published: August 2020

Objective. Greater occipital nerve (GON) block may provide substantial relief for headache in the occipital location. This study tested the feasibility of focused ultrasound (FUS) to induce the conduction block of GONs in rats. Approach. For in vitro experiments, the nerve was dissected and cut from C2 to the site near the ear of the rats and preserved in Ringer’s solution. Pulsed FUS was used for the block, and sensory action potentials were recorded in the GON. For in vivo experiments, the GONs of the rats were surgically exposed for precise ultrasonic treatment. All data are expressed as the mean ± the standard deviation. Main results. A single ultrasonic treatment temporarily suppressed the amplitude of action potentials of the in vitro nerves to 42 ± 14% of the baseline values, and the time to recovery was 55 min. The in vivo results showed that FUS acutely inhibited the amplitude of action potentials to 41 ± 8% of the baseline value in rat GONs, and the time to recovery was 67 min. Histological examination revealed no appreciable changes in the nerve morphology caused by FUS. Therefore, FUS reversibly blocked the conduction of the rat GON when the sonication parameters were appropriate. Significance. Noninvasive FUS may be a novel treatment paradigm for occipital headache by blocking the occipital nerve, and the procedure is repeatable if indicated.
MHD bioconvective flow of a thermally radiative nanoliquid in a stratified medium considering gyrotactic microorganisms
Authors: Eswaramoorthi S , Jagan K , Sivasankaran S
Published: August 2020

The impact of gyrotactic microorganisms of a stratified flow of a thermally radiative NL with heat absorption is highlighted. In addition, magneto NL with an inclined magnetic field is included. Suitable transformations are adopted to convert the governing PDEs into an nonlinear ODEs. Homotopy analysis method (HAM) is employed to solve these ODEs analytically. The impact of sundry parameters on VP, TP, NPVFP, MMDP, SFC, LNN and LDMM are graphically explained. We compare our results to available results in literature survey.
Bifurcation analysis in a discrete time square root response function of predator-prey system with fractional order
Authors: George Maria Selvam A , Janagaraj R
Published: August 2020

Stability and bifurcation analysis for a two spices discrete fractional order system by introducing square root response function of the form

x
(
j
+
1
)
=
x
(
j
)
+

h
α

Γ
(
1
+
α
)

[

μ
x
(
j
)
−
μ

x
2

(
j
)
−
σ

x
(
j
)
y
(
j
)

]

y
(
j
+
1
)
=
y
(
j
)
+

h
α

Γ
(
1
+
α
)

[

η

x
(
j
)
y
(
j
)

−
β
y
(
j
)

]

is examined in the closed first quadrant

ℝ
+
2

. The model parameters h, α, β, μ, σ, η are biologically feasible positive real numbers. Piecewise constant arguments method is applied to obtain the discrete fractional order system, particularly to study the rich dynamical behavior of the proposed system. Because the system has square root response function, the variation matrix of trivial and axial equilibrium states are in-determinant. In order to study the stability of the trivial and semi trivial equilibrium states, the change of variables x(j) = X
2(j) and y(j) = Y
2 (j) is considered. Moreover, we determine the criteria for stability of the interior equilibrium state using jury conditions. The numerical performance is shown for various parameter values and the time series and phase line diagrams are obtained. Bifurcation theory is applied to check whether the system undergoes periodic doubling bifurcations at its semi trivial and interior equilibrium states. Also we explore the periodic halving bifurcation which occurs for the fractional order as a bifurcation parameter. Numerical examples are presented to show the validity and feasibility of the obtained stability criterion in both species, including periodic doubling, periodic - 2, 4, 8, 16, periodic windows and Non periodic orbit (i.e., chaos).
Two dimensional second order Fibonacci summation formula with extorial functions
Authors: Sathinathan T , Britto Antony Xavier G , Vignesh K
Published: August 2020

This paper aims to obtain the extorial type solutions for Fibonacci difference equations on real valued function defined in two dimensional space having shift value ℓ. Using two dimensional second order Fibonacci nabla difference operator and its inverse, we derived Second order fibonacci summation formula of product of real valued polynomial. A function obtained by replacing polynomial into polynomial factorials in the expansion of exponential function is called extorial function. Using extorial functions defined in ℝ2, we obtain solution of certain type of two dimensional second order difference equations. Suitable examples and numerical verifications are given to validate the findings.
Ohmic dissipation effect of Walter’s-B fluids over a porous stretching sheet in the presence of inclined magnetic field
Authors: Munirathinam S , Ragavan C , Kalaivanan R , Ganga B
Published: August 2020

Present article intends to analyze the Ohmic dissipation effect on Walter’s-B fluid flow through porous medium over a stretching sheet with elastic deformation. Inclined magnetic field effects also considered. With the help of similarity transformations, the nonlinear ODEs are obtained from system of PDEs, and then solved analytically by using the confluent hypergeometric function. Results delineating the flow characteristics are presented through graphs and tables for the effect of various parameters. It is observed that thermal boundary layer enaches with increasing values of magnetic and angle parameters and opposite effect observed from elastic deformation parameter.
Prime cordial labeling of n-chain vertex merged staircase graphs
Authors: Antony Arockiasamy M , Manivasagam A
Published: August 2020

A prime cordial labeling of a graph G with vertex set V is a bijection h:V → {1,2,..|V|} such that, for each edgeuv, the label 1 is assigned, if g.c.d[h(u), h(y)] = 1, otherwise 0, and the total number of edges labeled as 0, and the total number of edges labeled as 1, differ atmost by 1. In this paper, we prove that n-chain vertex merged staircase graphs are prime cordial.
Exact and Asymptotic solution of a steady two dimensional boundary layer of a Micropolar fluid flow past a moving wedge
Authors: Kudenatti Ramesh B. , Vanitha V. R.
Published: August 2020

In this paper, we propose an analytic solution of a boundary value problem which models a steady, laminar, two dimensional, boundary layer flow of an incompressible and viscous micropolar fluid over a moving wedge. The governing non-linear partial differential equations are converted into highly non-linear ordinary differential equations using similarity transformations. An analytical exact solution obtained for particular values of parameters are then extended to obtain an exact solution for more general values of the parameters involved. We also propose asymptotic solution of the Micropolar boundary layer flow. The results thus obtained are compared with those of direct numerical solutions, which show a good agreement. The results are discussed in terms of velocity profiles and wall shear stresses for various physical parameters.
NS(WπG) closed sets in Neutrosophic topological spaces
Authors: Suresh R , Palaniammal S
Published: August 2020

Smarandache presented and built up the new idea of Neutrosophic concepts from Neutrosophic sets. Salama presented Neutrosophic topologicalspaces by utilizing the Neutrosophic sets. Point of this paper is we present and concentrate in NS(WπG)CS, NS(WπG)OS in NSTS. and its Properties are talked about subtleties
The minimum covering signless laplacian energy of graph
Authors: Permi Kavita , Manasa H S , Geetha M C
Published: August 2020

Gutman [5]has come out with the idea of graph energy as summation of numerical value of latent roots of the adjacency matrix of the given graph Γ. In this paper, we introduce the Minumum Covering Signless Laplacian energy

L
C
+

E
(
Γ
)

of a graph Γ and obtain bounds for it. Also we find

L
C
+

E
(
Γ
)

of some important class of graphs.
FCM labeling of some graphs and its line graph
Authors: Arockiaraj S , Rajesh Kannan A , Manivannan P , Durai Baskar A
Published: August 2020

A function f is called an F-centroidal mean labeling of a graph G(V, E) with p vertices and q edges if f : V(G) → {1, 2, 3, …, q + 1} is injective and the induced function g* : E(G) →{1, 2, 3, …, q} defined as

g
*
(
u
v
)
=

⌊

2

[

f

(
u
)

2

+
f
(
u
)
f
(
v
)
+
f

(
v
)

2

]

3

[

f
(
u
)
+
f
(
v
)

]

⌋
,

for all

u
v
∈
E
(
G
)

, is bijective. A graph that admits an F-centroidal mean labeling is called an F-centroidal mean graph. The line graph is one among the graph operations. In this paper, we try to analyse that the line graph operation preserves the F-centroidal mean property for the path Pn
, the cycle Cn
, the star graph Sn
, the complete graph Kn
, the graph Pn
o S
1, the triangular snake graph Tn
and the arbitrary subdivision of S
3.
Magnetohydrodynamic chemically reactive Sisko liquid flow through a stretching surface with nonlinear thermal radiation
Authors: Nagendramma V
Published: August 2020

Present article reveals results of steady 2D magnetohydrodynamic boundary layer flow of a chemically reactive Sisko liquid due to a stretching surface with nonlinear thermal radiation. The governing equations are computed with R-K 4th order method with BVP4C technique. Numerical evaluations have been accomplished for disparate values of physical constraints with abet of delineates. Additionally, the coefficient of drag force, local Nusselt and Sherwood numbers have been evaluated for disparate parameters and scrutinized for engineering interest.
Edge fault tolerant Hamiltonicity in Brick product graphs
Authors: Sumithra Devi M R , Girisha A
Published: August 2020

A connected graph G is Hamiltonian laceable if there is a Hamiltonian path exists among any two nodes in G at an odd number distance. G is Hamiltonian-t-laceable if there is a Hamiltonian path among any two nodes u and v with d(u,v) = t. In this article we extend the Hamiltonian-t-laceability of Brick product C(2n,1,r) for even t, 2 ≤ t ≤ diamG with a fault tolerant edge.
Minimum dominating signless laplacian graph energy
Authors: Permi Kavita
Published: August 2020

Minimum dominating graph energy was proposed by Rajesh Kanna et al.[11] in 2013. I propose the Minumum dominating signless laplacian graph energy

L
D
+

E
(
Γ
)

in this paper. Also obtain some bounds and discuss some important graph classes for the minimum dominating signless Laplacian energy.
Ricci operator in a Hopf real Hypersurfaces of complex space form
Authors: Manjulamma Uppara , Nagaraja H G , Kiran Kumar D L
Published: August 2020

We initiate the study of real hypersurface of a complex space form and it is proved that Lie parallelism of the Ricci operator in the direction of ξ, locally symmetric Ricci operator in a real hypersurface of a complex space form reduce the hypersurface to Hopf hypersurface.
Mild solutions for a coupled system of fractional differential equations with slit-strips type integral boundary conditions
Authors: Buvaneswari K , Karthikeyan P
Published: August 2020

In this present paper, we study the existence and uniqueness of solutions for a coupled system of fractional differential equations with Banach contraction mapping principle and Leray-Schauder alternative theorem. Examples are given to illustrate the applicability of the obtained results.
Buoyant convective transport of nanofluids in a non-uniformly heated annulus
Authors: Keerthi Reddy N , Sankar M.
Published: August 2020

This paper reports the influence of non-uniform thermal conditions on buoyancy-driven convection of water based nanofluids in a cylindrical annulus. Annular geometry is formed by two upright co-axial cylinders. In this analysis, two different non-uniform temperature profiles are applied at bottom boundary, while the side boundaries are kept at lower temperature and top boundary is taken as thermally insulated. For the first case, the bottom boundary is sinusoidally heated, while linear thermal profile is applied in the second case. The annular gap is filled with water based nanofluids with copper nanoparticle. Using ADI based finite difference technique, the model equations are solved for vast range of parametric values. Numerical simulation results reveal the bi-cellular flow pattern for both non-uniform thermal conditions at all range of Rayleigh numbers. Further, the heat transport rates are highly sensitive to non-uniform conditions supplied at the bottom wall. The results of this analysis could be utilized for applications involving non-uniform thermal conditions in an annular geometry.
Droplets of quark gluon plasma: PHENIX results on small systems at RHIC
Authors: Belmont R.
Published: August 2020

In these proceedings we discuss PHENIX results on small systems at RHIC, specifically those relating to collectivity and flow. We discuss the small systems geometry scan, which comprises collisions of p+Au, d+Au, and 3He+Au at

S

N
N

=
200

GeV

and is designed to exploit differences in intrinsic geometry. We also discuss the small systems beam energy scan, which comprises d+Au collisions at

S

N
N

=
200

GeV

, 62.4 GeV, 39 GeV, and 19.6 GeV and is designed to explore differences in system size and lifetime while keeping the geometry fixed. We find the data in nearly all cases are well-described by hydrodynamical calculations involving a QGP phase, suggestion formation of QGP droplets in a wide variety of collisions.
Production of hadronic resonances measured with ALICE at the LHC
Authors: Song Jihye
Published: August 2020

Measurements of short-lived hadronic resonances are used to probe the properties of the hadronic phase in ultra-relativistic heavy-ion collisions. Since these resonances have lifetimes comparable to that of the produced fireball, they are sensitive to the competitive rescattering and regeneration effects in the hadronic gas, which modify the observed particle momentum distributions and yields after hadronization. Having different masses, quantum numbers, and quark content, hadronic resonances can provide insight into processes that determine the shapes of particle momentum spectra, strangeness production, and the possible onset of collective effects in small systems.

We here present the latest results on ρ(770)0, K*(892), φ(1020), Σ(1385)±, Λ(1520), Ξ(1530)0 and Ξ(1820) production in pp, p–Pb, Pb–Pb and Xe–Xe collisions at different LHC energies. Results include system-size and collision-energy evolution of transverse momentum spectra, integrated yields, mean transverse momenta, particle ratios, and nuclear modification factors.
Exploring the QCD phase diagram via the collision energy dependence of multi-particle femtoscopy with PHENIX
Authors: Csanád Máté
Published: August 2020

Exploration of the rich structure of the QCD phase diagram is an important topic in the RHIC heavy ion program. One of the ultimate goals of this program is to search for the critical endpoint. Investigation of the space-time structure of hadron emissions at various phase transition points using Bose-Einstein correlations of identical bosons may provide insight on the location of the critical endpoint. PHENIX has performed comprehensive measurements of the Bose-Einstein correlation in Au+Au collisions at

S

N
N

=
15

, 19, 27, 39, 62.4, and 200 GeV, where we incorporated Lévy-type source functions to describe the measured correlation functions. We put particular focus on one of the parameters of the Lévy-type source functions, the index of stability α, which is related to one of the critical exponents (the so-called correlation exponent ɳ). We have measured its collision energy and centrality dependence. We have also extended our analysis from two-particle to three-particle correlations to characterize the nature of the hadron emission source. The three particle correlations confirmed the findings of the two-particle correlations, and also provide insight on the pion production mechanism beyond the core-halo model.
Characterizing the medium created in Pb–Pb collisions at

SNN=2.76TeV

by means of the evolution of two-particle transverse momentum correlations
Authors: González Víctor
Published: August 2020

Two-particle correlations are powerful tools for studying the medium produced in heavy-ion collisions. In particular, two-particle transverse momentum correlations enable measurements of the collision dynamics sensitive to momentum currents. Their evolution with collision centrality, which is related to the system lifetime, provides information about the shear viscosity, ɳ/S, and the system relaxation time,

τ
π

. We report on measurements of two-particle transverse momentum correlations as a function of centrality in Pb-Pb collisions using the ALICE detector at the LHC. The centrality dependence of the near-side peak of the correlation function, particularly in the longitudinal dimension, provides information about the shear viscosity and the system relaxation time of the produced medium. The data are compared to predictions from selected Monte Carlo models. The charge independent momentum correlator exhibits a longitudinal broadening from peripheral to central collisions that is qualitatively consistent with expectations from a model with viscous effects. We will discuss an interpretation of the observed broadening in the context of this model.
Exploring the partonic phase at finite chemical potential in and out-of equilibrium
Authors: Soloveva O. , Moreau P. , Oliva L. , Song T. , Cassing  , Bratkovskaya E.
Published: August 2020

We study the influence of the baryon chemical potential μB
on the properties of the Quark–Gluon–Plasma (QGP) in and out-of equilibrium. The description of the QGP in equilibrium is based on the effective propagators and couplings from the Dynamical QuasiParticle Model (DQPM) that is matched to reproduce the equation-of-state of the partonic system above the deconfinement temperature Tc
from lattice Quantum Chromodynamics (QCD). We calculate the transport coefficients such as the ratio of shear viscosity ɳ and bulk viscosity ¶ over entropy density s, i.e., η/s and ¶/s in the (T, μB
) plane and compare to other model results available at μB
= 0. The out-of equilibrium study of the QGP is performed within the Parton–Hadron–String Dynamics (PHSD) transport approach extended in the partonic sector by explicitly calculating the total and differential partonic scattering cross sections (based on the DQPM propagators and couplings) evaluated at the actual temperature T and baryon chemical potential μB
in each individual space-time cell of the partonic scattering. The traces of their μB
dependences are investigated in different observables for relativistic heavy-ion collisions with a focus on the directed and elliptic flow coefficients

υ
1

,

υ
2

in the energy range 7.7 GeV ≤

S

N
N

≤
200

GeV

.
3-Dimensional QCD Phase Diagrams for Strange Matter
Authors: Dexheimer V. , Aryal K. , Constantinou C. , Peterson J. , Farias R. L. S.
Published: August 2020

In this work, we examine in detail the difference between constraining the electric charge fraction and isospin fraction when calculating the deconfinement phase transition in the presence of net strangeness. We present relations among charge and isospin fractions and the corresponding chemical potentials and draw 3-dimensional QCD phase diagrams for matter out of weak equilibrium. Finally, we briefly discuss how our results can be applied to comparisons of matter created in heavy ion collisions and binary neutron star mergers.
Dilepton measurements with the ALICE experiment at the LHC
Authors: Meninno Elisa
Published: August 2020

The production of low-mass dielectrons and dimuons is a powerful tool for the understanding of the properties of the quark–gluon plasma (QGP) created in ultra-relativistic heavy-ion collisions. Since such pairs do not interact strongly and are emitted during all stages of the collisions, they provide information about the full time evolution and dynamics of the medium created. Measurements in pp and p–Pb collisions are the necessary reference for heavyion studies. In addition, they can be used to extract charm and beauty cross sections.

In this contribution, we present the latest measurements of e
+
e
− and µ
+
µ
− pair production in pp, p–Pb and Pb–Pb collisions performed by ALICE at different energies.
Far From Equilibrium Hydrodynamics and the Beam Energy Scan
Authors: Dore Travis , McLaughlin Emma , Noronha-Hostler Jacquelyn
Published: August 2020

The existence of hydrodynamic attractors in rapidly expanding relativistic systems has shed light on the success of relativistic hydrodynamics in describing heavy-ion collisions at zero chemical potential. As the search for the QCD critical point continues, it is important to investigate how out of equilibrium effects influence the trajectories on the QCD phase diagram. In this proceedings, we study a Bjorken expanding hydrodynamic system based on DMNR equations of motion with initial out of equilibrium effects and finite chemical potential in a system with a critical point. We find that the initial conditions are not unique for a specific freeze-out point, but rather the system can evolve to the same final state freeze-out point with a wide range of initial baryon chemical potential, µB
. For the same initial energy density and baryon density, depending on how far out of equilibrium the system begins, the initial µB
can vary by ΔµB
∼ 350 MeV. Our results indicate that knowledge of the out-of-equilibrium effects in the initial state provide vital information that influences the search for the QCD critical point.
Recent results on light (anti-)nuclei production with ALICE at the LHC
Authors: Bartsch Esther
Published: August 2020

The high-statistics and high-quality data samples in pp, p–Pb and Pb–Pb collisions at various collision energies collected by the ALICE Collaboration, and the excellent tracking and particle identification capabilities of the Inner Tracking System, the Time-Projection Chamber and the Time-of-Flight detector allow for the detection of rarely produced light (anti-)(hyper-)nuclei. The first (anti-)triton p
T spectra in Pb–Pb at the LHC as well as the first (anti-)4He p
T spectra are presented. Moreover, the p
T-integrated production yield ratios of deuteron over proton as well as 3He and triton over proton as a function of charged-particle multiplicity are shown. In addition coalescence parameters B
2 and B
3 as a function of p
T/A and charge particle multiplicity for several collision systems and energies are discussed. Furthermore, light-nuclei radial and elliptic flow are presented and compared to the flow of lighter particles. These various results are compared with statistical hadronization and coalescence model predictions to provide insight in the production mechanism of light (anti-)nuclei in heavy-ion collisions.
Sea Quark Chemistry and Correlations in the Initial Conditions of Heavy Ion Collisions
Authors: Sievert Matthew D.
Published: August 2020

QCD dynamics are directly studied in two different but intersecting contexts: high-temperature QCD in heavy-ion collisions and zero-temperature hadronic structure in electron-hadron collisions. The approaches to high-energy nuclear physics in these two contexts are very different, however, and bringing the two fields into dialogue can reveal new opportunities. In this paper I highlight one interesting intersection between the two: leveraging the sea quark chemistry of the proton to study charge transport in top-energy heavy-ion collisions.
From small to large x: toward a unified description of high energy collisions
Authors: Jalilian-Marian Jamal
Published: August 2020

Inclusive particle production at high pt
(equivalently intermediate to large x) in high energy hadronic collisions is successfully described by perturbative QCD, using the collinear-factorization formalism. On the other hand at very high energies and not so high pt
the Color Glass Condensate (CGC) formalism has been quite successful in describing particle production at small Bjorken x. Here we propose a way to unify the two approaches which enables one to apply it to particle production at all x (all pt
).
Magnetic effects of QCD parameters from fnite energy sum rules
Authors: Villavicencio Cristián , Dominguez C. A. , Loewe M.
Published: August 2020

One of the advantages of the fnite energy sum rules is the fact that every operator in the operator product expansion series can be selected individually by the use of an appropriate kernel function which removes other operator poles. This characteristic is maintained by QCD systems in the presence of external homogeneous magnetic feld, providing interesting information about the magnetic evolution of QCD and hadronic parameters. In this work fnite energy sum rules are applied on QCD in the light quark sector, combining axial and pseudoscalar channels in the presence of an external homogeneous magnetic feld, obtaining the magnetic evolution of the light quark masses, pion mass, the pion decay constant, the gluon condensate and the continuum hadronic threshold.
PHENIX Results on

J/ψ

Production in p+Al, p+Au and 3He+Au Collisions
Authors: Frawley Anthony D
Published: August 2020

Results are presented of measurements of the

J
/
ψ

modification in p+Au, d+Au and 3He+Au collisions at forward and backward rapidity

(

1.2
<
|
y
|
<
2.2

)

by the PHENIX experiment. The rapidity, transverse momentum and collision centrality dependence of the modifications are presented, and compared between the three light projectile collision systems. The modification for p+Al is found to be small. For p+Au it is depends strongly on collision centrality at forward rapidity. In both cases models describe the data well. The modifications for d+Au and 3He+Au are very similar to those for p+Au, although there is a hint of slightly increased suppression for 3He+Au over p+Au at backward rapidity.
Analysis and improvement of a mathematical turbine model
Authors: Reines A F , Svingen B
Published: August 2020

A mathematical turbine model is necessary for dynamic and transient analysis of hydro power plants, also in the early stages of a project. Such models can be based on a first principles approach or on empirical data, many models are a combination. A first principles approach is practical when specific laboratory data are unavailable, for example in the design phase of a new plant. These models can easily be simplified and linearized without losing physical correctness or generality, even though accuracy may vary when applied to a specific system.

The model studied in this work, was developed several years ago from the Euler turbine equation and the opening degree definition, and has later been modified and linearized for simple implementation into simulation software. The model captures losses for varying rotational speed quite well, but struggles to capture losses for varying flow rate. The hydraulic efficiency is over-predicted for flow far off the design point, because irreversible hydraulic loss phenomena such as 3D turbulence and dissipation are not inherently included in this 1D model. Empirical relations or Hill charts for exact fit to a measured turbine can be included, however generality is then lost.

This paper analyzes and discusses the mathematical model compared to laboratory measurements, highlighting its performance in predicting the efficiency off best efficiency point (BEP). A mathematical improvement based on turbine data is presented and implemented for three specific Francis turbines. The possibility to generalize the procedure is also discussed.
Technical investigation of Nepalese electricity market – A review
Authors: Sanjel Nawaraj , Baral Bivek
Published: August 2020

The article reviews the options of renewable energy technologies with the background of long-lasting power shortages that Nepal has been facing and examines the energy-related policies of Nepal and provisions to promote renewable energy technologies in Nepal and its regulatory framework. It analyses the pertinent energy policies related to energy generation and distribution. The research focuses on the context of the renewable energy sector of Nepal and its future. The research has found a positive role in renewable energy policies for adoption of renewable energy technologies and poses a positive impact on electricity generation. The article has also reviewed and analyzed the trend of electricity generation, peak demand and the resulted import to meet the gap. The almost linear electricity generation of Nepal Electricity Authority (including generation of Individual Power Producers against the steep gradient of peak power demand has ultimately increased the power purchase from India pushing towards unsustainability. It shows that energy policies are not up to the optimal. The research has further analyzed the impact of per capita GDP on electricity per capita by regression analysis. The analysis has found, higher the GDP per capita would increase the consumption of electricity per capita. The paper discusses issues and barriers for promotion of rural electrification and suggested economical, technical and geographical to be the three most pertinent barriers in developing countries.
An Experimental Investigation of PAT in Direct and Reverse Mode at Turbine Testing Lab
Authors: Rimal Samita , Sah Sanjay Pd. , Pokharel Nischal , Thapa Biraj Singh
Published: August 2020

PAT is typically employed as the electromechanical component, especially in the rural communities of developing countries in order to reduce the initial cost of a power plant. In the context of Nepal, there have been few researches about its feasibility but have given promising outcomes regarding its implementation. As a part of this continuation, this paper deals with the experimentation performed on end suction, KDS-520+ centrifugal pump of 3.5 kW on direct as well as reverse mode to study its performances. The main purpose of this study was to test the characteristic performance of the pump in turbine as well as pump mode to compare the variation in their efficiency in laboratory environment so as to shed light upon the importance of PAT in micro and mini hydropower and to study the prospect of replacing traditional water mills with PAT. The test rig for the operation of pump in turbine mode was developed as a part of the research and characteristic curves have been plotted on different flow rates. The efficiency of the centrifugal pump was found similar to the rated efficiency, 60.85% at the best efficiency point at the head of 17m and discharge of 17lps. In addition, performance of the same pump in turbine mode showed a maximum efficiency of 40.15% at flow of 11.5lps and head 10m which concluded that the centrifugal pump can operate in turbine mode without any modifications.
Numerical investigation of flow field and performance of the Francis turbine of Bhilangana-III hydropower plant
Authors: Thapa R , Sharma S , Singh K M , Gandhi B K
Published: August 2020

Computational fluid dynamics is an alternate tool to predict the performance as well as to investigate the flow field of a hydraulic turbine at different operating conditions. The objective of this paper is to analyze the flow field numerically and to predict the performance of Francis turbine of Bhilangana–III power plant. A numerical model of the prototype Francis turbine is undertaken to perform the simulation under the actual working condition of hydropower. The steady-state simulation has been performed at different operating conditions such as high load, part load, and best efficiency point using two turbulence model k-ω shear stress transport (SST) and standard k-ε with zero clearance gap and with a gap due to erosion. Based on computational results, an attempt has been made to compare the performance of the turbine under erosive wear conditions. The computational results are very close to the expected performance characteristics of the prototype turbine under no-gap condition. A difference of 0.24% and 1.71% in efficiency is observed between the numerical and prototype hill chart curve at the best efficiency point (BEP) and full load conditions, respectively. The simulation has also been performed with a clearance gap of 1.85 mm to study the effect of the gap, due to erosion, on the efficiency. The leakage flow-through 1.85 mm clearance gap has resulted in a decrease in the efficiency of the turbine. The efficiency drops around 5.73 % at BEP condition and 5.83% at full load condition. These computational results may be useful for further study of the turbine of Bhilangana–III power plant.
Opportunity for research and manufacturing of pump in Nepal
Authors: Pokharel N. , Ghimire A. , Thapa B. S. , Thapa B.
Published: August 2020

Pumps are the mechanical device used to increase the pressure energy of fluids. Pumps of different types and size are being used in Nepal, for different applications. Despite the wide spread applications of pumps not much have been done to manufacture pumps in Nepal. This study investigates the opportunity of manufacturing pumps in Nepal. It shows the history of usage of pumps in Nepal and also depicts the problems faced by the pumps used in different projects. It discusses about the current market trend related to the import of pumps from foreign countries and develops an argument to start a new business for manufacturing pumps. Role of research institutes like Turbine Testing Laboratory in design of pumps has been discussed as a future prospect for Nepalese academia and industry.
Volcanic eruptions, successive poor harvests and social resilience over southwest China during the 18–19th century
Authors: Hao Zhixin , Xiong Danyang , Zheng Jingyun , Yang Liang Emlyn , Ge Quansheng
Published: August 2020

Volcanic eruptions, climate changes and their influences on crop harvests and social development are of increasing concern in science communities. Using a dataset of crop harvest scores of southwest China from 1730 to 1910, which was derived from the memorials to the emperors in the Qing Dynasty of China, reconstructed climate proxies and the chronology of large volcanic eruptions occurring between 10°S and 15°N, we analysed possible relationships between crop harvests, climate changes and volcanic eruptions. In addition, some archives of policies and measures related to crops and social development extracted from the chronicles were used to analyse social resilience when faced with poor harvests. The results show that crop harvests in the study area generally increased with fluctuations when there were less low-latitude large volcanic eruptions from 1730 to 1810. However, from 1811 to 1910, volcanoes at low latitudes erupted more frequently, which contributed to concurrent low temperature and drought. Meanwhile, the crop harvests showed a step-down decrease during the following periods of 1810s, 1850s, 1870s and 1890s. Though, the local social system was certainly resilient in facing of such climate and agriculture disasters, i.e. the local society remained stable without significant famine, large-scale migration or social unrest until 1911. The strong resilience of local social systems owed largely to various relieving measures, such as, building barns, exempting or reducing local taxes, allocating farmland to immigrants, and central government dominated grain purchasing and distribution to alleviate disasters.
Light-induced In-situ Ti3+ Formation in TiO2 Nanosheets for Photocatalytic Hydrogen Evolution
Authors: Wierzbicka E , Osuagwu B , Denisov N , Fehn D , Meyer K , Schmuki P
Published: August 2020

TiO2 has been the benchmark semiconductor for the production of photocatalytic H2 from aqueous media (with and without sacrificial agent). On TiO2 surfaces, the photocatalytic H2 evolution reaction in aqueous environments is kinetically severely hampered. To overcome this limitation and reach reasonable H2 generation rates, a well-elucidated approach is the use of noble metal co-catalysts. In contrast to costly noble metal approaches, it recently has been reported that titania reduction treatments can lead to a noble-metal-free photocatalytic H2 generation. So-called “grey” titania due to Ti3+ states shows intrinsically activated photocatalytic H2 evolution [1–3]. The present work demonstrates the feasibility to use in-situ photoinduced reduction to create Ti3+ states that act as intrinsic catalyst and activate hydrothermal synthetized anatase nanosheets for H2 generation to mediate the transfer of photo-induced charge carriers to the electrolyte.