TRIBOELECTRIC NANOGENERATORS (TENG): FACTORS AFFECTING ITS EFFICIENCY AND APPLICATIONS

The demand for energy is increasing tremendously with modernization of the technology and requires new sources of renewable energy. The triboelectric nanogenerators (TENG) are capable of harvesting ambient energy and converting it into electricity with the process of triboelectrification and electrostatic-induction. TENG can convert mechanical energy available in the form of vibrations, rotation, wind and human motions etc., into electrical energy there by developing a great scope for scavenging large scale energy. In this review paper, we have discussed various modes of operation of TENG along with the various factors contributing towards its efficiency and applications in wearable electronics

A CRITICAL REVIEW ON THE MATERIAL ASPECTS OF TRIBOELECTRIC NANOGENERATORS (TENG)

Triboelectric nanogenerators (TENG) take the advantage of coupling effect for harvesting energy in the area of electronics for various self-powered applications. These nanogenerators are capable of converting energy in our surroundings into electrical energy by using the process of electrostatic induction and contact electrification. Triboelectric layers of a TENG are formed basically with the use of various polymers, metals and other inorganic materials like PTFE (Poly tetra fluoro ethylene), PDMS (polydimethyl siloxane), FEP (Fluorinated ethylene propylene) and Kapton. Selection of different materials for the device fabrication is very important since it contribute towards the triboelectric effect and also forms the fundamental structure for the proposed TENG device. In this review article, we emphasis mainly on various triboelectric materials considering factors such as stability, flexibility, power density etc., to improve upon the electrical output of the devices for different applications

K∗(892)0\mathrm{K}^{*}(\mathrm{892})^{0} and ϕ(1020)\mathrm{\phi(1020)} production in p-Pb collisions at sNN\sqrt{s_{\rm NN}} = 8.16 TeV

The production of $\mathrm{K}^{*}(\mathrm{892})^{0}$ and $\mathrm{\phi(1020)}$ resonances has been measured in p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV using the ALICE detector. Resonances are reconstructed via their hadronic decay channels in the rapidity interval $-$0.5 $$ 8 GeV/$c$), the $R_{\rm pPb}$ values of all hadrons are consistent with unity within uncertainties. The $R_{\rm pPb}$ of $\mathrm{K}^{*}(\mathrm{892})^{0}$ and $\mathrm{\phi(1020)}$ at $\sqrt{s_{\rm NN}}$ = 8.16 and 5.02 TeV show no significant energy dependence

Forward rapidity J/ψ production as a function of charged-particle multiplicity in pp collisions at s \sqrt{s} = 5.02 and 13 TeV

International audienceThe production of J/ψ is measured as a function of charged-particle multiplicity at forward rapidity in proton-proton (pp) collisions at center-of-mass energies $\sqrt{s}$ = 5.02 and 13 TeV. The J/ψ mesons are reconstructed via their decay into dimuons in the rapidity interval (2.5 < y < 4.0), whereas the charged-particle multiplicity density (dN$_{ch}$/dη) is measured at midrapidity (|η| < 1). The production rate as a function of multiplicity is reported as the ratio of the yield in a given multiplicity interval to the multiplicity-integrated one. This observable shows a linear increase with charged-particle multiplicity normalized to the corresponding average value for inelastic events (dN$_{ch}$/dη/〈dN$_{ch}$/dη〉), at both the colliding energies. Measurements are compared with available ALICE results at midrapidity and theoretical model calculations. First measurement of the mean transverse momentum (〈p$_{T}$〉) of J/ψ in pp collisions exhibits an increasing trend as a function of dN$_{ch}$/dη/〈dN$_{ch}$/dη〉 showing a saturation towards high charged-particle multiplicities.[graphic not available: see fulltext

Inclusive quarkonium production in pp collisions at s=5.02\sqrt{s} = 5.02 TeV

This article reports on the inclusive production cross section of several quarkonium states, $\mathrm{J}/\psi$, $\psi {\rm (2S)}$, $\Upsilon\rm(1S)$, $\Upsilon\rm(2S)$, and $\Upsilon\rm(3S)$, measured with the ALICE detector at the LHC, in \pp collisions at $\sqrt{s} = 5.02$ TeV. The analysis is performed in the dimuon decay channel at forward rapidity ($2.5 < y < 4$). The measured cross sections, assuming unpolarized quarkonia, are: $\sigma_{\mathrm{J}/\psi} = 5.88 \pm 0.03 \pm 0.34\ \mu$b, $\sigma_{\psi {\rm (2S)}} = 0.87 \pm 0.06 \pm 0.10\ \mu$b, $\sigma_{\Upsilon\rm(1S)} = 45.5 \pm 3.9 \pm 3.5$ nb, $\sigma_{\Upsilon\rm(2S)} = 22.4 \pm 3.2 \pm 2.7$ nb, and $\sigma_{\Upsilon\rm(3S)} = 4.9 \pm 2.2 \pm 1.0$ nb, where the first (second) uncertainty is the statistical (systematic) one. The transverse-momentum ($p_{\rm T}$) and rapidity ($y$) differential cross sections for $\mathrm{J}/\psi$, $\psi {\rm (2S)}$, $\Upsilon\rm(1S)$, and the $\psi {\rm (2S)}$-to-$\mathrm{J}/\psi$ cross section ratios are presented. For the first time, the cross sections of the three $\Upsilon$ states, as well as the $\psi {\rm (2S)}$ one as a function of $p_{\rm T}$ and $y$, are measured at $\sqrt{s} = 5.02$ TeV at forward rapidity. These measurements also significantly extend the $\mathrm{J}/\psi$$p_{\rm T}$ reach with respect to previously published results. A comparison with ALICE measurements in pp collisions at $\sqrt{s} = 2.76$, 7, 8, and 13 TeV is presented and the energy dependence of quarkonium production cross sections is discussed. Finally, the results are compared with the predictions from several production models

Measurements of the groomed and ungroomed jet angularities in pp collisions at s \sqrt{s} = 5.02 TeV

International audienceThe jet angularities are a class of jet substructure observables which characterize the angular and momentum distribution of particles within jets. These observables are sensitive to momentum scales ranging from perturbative hard scatterings to nonperturbative fragmentation into final-state hadrons. We report measurements of several groomed and ungroomed jet angularities in pp collisions at $\sqrt{s}$ = 5.02 TeV with the ALICE detector. Jets are reconstructed using charged particle tracks at midrapidity (|η| < 0.9). The anti-k$_{T}$ algorithm is used with jet resolution parameters R = 0.2 and R = 0.4 for several transverse momentum {p}_{\mathrm{T}}^{\mathrm{ch}} ^{jet} intervals in the 20–100 GeV/c range. Using the jet grooming algorithm Soft Drop, the sensitivity to softer, wide-angle processes, as well as the underlying event, can be reduced in a way which is well-controlled in theoretical calculations. We report the ungroomed jet angularities, λ$_{α}$, and groomed jet angularities, λ$_{α,g}$, to investigate the interplay between perturbative and nonperturbative effects at low jet momenta. Various angular exponent parameters α = 1, 1.5, 2, and 3 are used to systematically vary the sensitivity of the observable to collinear and soft radiation. Results are compared to analytical predictions at next-to-leading-logarithmic accuracy, which provide a generally good description of the data in the perturbative regime but exhibit discrepancies in the nonperturbative regime. Moreover, these measurements serve as a baseline for future ones in heavy-ion collisions by providing new insight into the interplay between perturbative and nonperturbative effects in the angular and momentum substructure of jets. They supply crucial guidance on the selection of jet resolution parameter, jet transverse momentum, and angular scaling variable for jet quenching studies.[graphic not available: see fulltext

Measurement of beauty production via non-prompt D0{\rm D}^{0} mesons in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 5.02 TeV

The production of non-prompt ${\rm D}^{0}$ mesons from beauty-hadron decays was measured at midrapidity ($\left| y \right| 5~\mathrm{GeV}/c$ in the $0-10$% central Pb-Pb collisions. The data are described by models that include both collisional and radiative processes in the calculation of beauty-quark energy loss in the quark-gluon plasma, and quark recombination in addition to fragmentation as a hadronization mechanism. The ratio of the non-prompt to prompt ${\rm D}^{0}$-meson $R_{\rm AA}$ is larger than unity for $p_{\rm T} > 4~\mathrm{GeV}/c$ in the $0-10$% central Pb-Pb collisions, as predicted by models in which beauty quarks lose less energy than charm quarks in the quark-gluon plasma because of their larger mass

First measurement of the absorption of 3He‾^{3}\overline{\rm He} nuclei in matter and impact on their propagation in the galaxy

Antimatter particles such as positrons and antiprotons abound in the cosmos. Much less common are light antinuclei, composed of antiprotons and antineutrons, which can be produced in our galaxy via high-energy cosmic-ray collisions with the interstellar medium or could also originate from the annihilation of the still undiscovered dark-matter particles. On Earth, the only way to produce and study antinuclei with high precision is to create them at high-energy particle accelerators like the Large Hadron Collider (LHC). Though the properties of elementary antiparticles have been studied in detail, knowledge of the interaction of light antinuclei with matter is rather limited. This work focuses on the determination of the disappearance probability of \ahe when it encounters matter particles and annihilates or disintegrates. The material of the ALICE detector at the LHC serves as a target to extract the inelastic cross section for \ahe in the momentum range of $1.17 \leq p < 10$ GeV/$c$. This inelastic cross section is measured for the first time and is used as an essential input to calculations of the transparency of our galaxy to the propagation of $^{3}\overline{\rm He}$ stemming from dark-matter decays and cosmic-ray interactions within the interstellar medium. A transparency of about 50% is estimated using the GALPROP program for a specific dark-matter profile and a standard set of propagation parameters. For cosmic-ray sources, the obtained transparency with the same propagation scheme varies with increasing $^{3}\overline{\rm He}$ momentum from 25% to 90%. The absolute uncertainties associated to the $^{3}\overline{\rm He}$ inelastic cross section measurements are of the order of 10%$-$15%. The reported results indicate that $^{3}\overline{\rm He}$ nuclei can travel long distances in the galaxy, and can be used to study cosmic-ray interactions and dark-matter decays

First study of the two-body scattering involving charm hadrons

This Letter presents the first measurement of the interaction between charm hadrons and nucleons. The two-particle momentum correlations of $\mathrm{pD^-}$ and $\mathrm{\overline{p}D}^+$ pairs are measured by the ALICE Collaboration in high-multiplicity pp collisions at $\sqrt{s} = 13~\mathrm{TeV}$. The data are compatible with the Coulomb-only interaction hypothesis within (1.1-1.5)$\sigma$. Considering an attractive nucleon(N)$\overline{\mathrm{D}}$ strong interaction, in contrast to most model predictions which suggest an overall repulsive interaction, slightly improves the level of agreement. This measurement allows for the first time an estimation of the 68% confidence level interval for the isospin $\mathrm{I}=0$ inverse scattering length of the $\mathrm{N\overline{D}}$ state ${f_{0,~\mathrm{I}=0}^{-1} \in [-0.4,0.9]~\mathrm{fm^{-1}}}$, assuming negligible interaction for the isospin $\mathrm{I}=1$ channel

Investigating charm production and fragmentation via azimuthal correlations of prompt D mesons with charged particles in pp collisions at s=13\mathbf {\sqrt{ s} = 13} TeV

International audienceAngular correlations of heavy-flavour and charged particles in high-energy proton–proton collisions are sensitive to the production mechanisms of heavy quarks and to their fragmentation as well as hadronisation processes. The measurement of the azimuthal-correlation function of prompt D mesons with charged particles in proton–proton collisions at a centre-of-mass energy of $\sqrt{s} = 13$ TeV with the ALICE detector is reported, considering $\mathrm D^{0}$, $\mathrm D^{+}$, and $\mathrm D^{*+}$ mesons in the transverse-momentum interval $3 0.3$ GeV/$c$ and pseudorapidity $|\eta | < 0.8$. This measurement has an improved precision and provides an extended transverse-momentum coverage compared to previous ALICE measurements at lower energies. The study is also performed as a function of the charged-particle multiplicity, showing no modifications of the correlation function with multiplicity within uncertainties. The properties and the transverse-momentum evolution of the near- and away-side correlation peaks are studied and compared with predictions from various Monte Carlo event generators. Among those considered, PYTHIA8 and POWHEG+PYTHIA8 provide the best description of the measured observables. The obtained results can provide guidance on tuning the generators