DESIGN, FABRICATION AND EXPERIMENTAL STUDY OF A FLAT PLATE COLLECTOR SIMULATOR

In this article, a flat plate collector simulator was designed and developed based on the use of electric heaters and a power control system. A computational algorithm aimed at determining the relationship between the incident solar energy on the collector absorber plate and the corresponding amount of power that must be supplied by the electrical resistance was developed. The variation in power is obtained by regulating the voltage fed through the assembly. With such regulation, simulating typical profiles of insolation over a day was possible. In the assessment of the average solar radiation data obtained by satellite imagery analysis (SWERA Project), the results showed that the thermal behavior of the simulator collector was close with a real behavior. Therefore, it can be used to determine the operating characteristics of auxiliary power systems as heat pumps, electrical systems or water heating systems. Different thermodynamic processes to determine the main losses of a collector evaluated the simulation parameters

SOCIO-ECONOMIC PERFORMANCE OF A SOLAR FLAT PLATE COLLECTOR BASED IN A HEAT PUMP WATER HEATING SYSTEM IN THE BRAZILIAN SOUTHEAST

By increasing renewable energy demand, the use of solar energy has been widely investigated over the recent years. Brazil is a privileged country in terms of the levels of receivable solar radiation in almost all over its territory. However, as there are days when there is a deficit in solar energy, because the day be cloudy or rainy days, and for this reason, solar collectors need a support to contribute to the water heating to the desired temperature. In this work, an experimental study of a heat pump operated with R-134a, as an ancillary equipment for a solar water heating system in Belo Horizonte city has been accomplished. For this project, is used a set of electrical resistances for by a power control step, simulate historical annual values of solar radiation. In the results, it was observed that is achieved through the collection of solar energy the temperature of 45°C in the reservoir only in January, and the other eleven months is necessary to use the heat pump to achieve reach that temperature. With the heat pump operating in conditions similar to real conditions gave an average annual consumption of 137.65 kWh and a cost of R$ 60.61

SOCIO-ECONOMIC PERFORMANCE OF A SOLAR FLAT PLATE COLLECTOR BASED IN A HEAT PUMP WATER HEATING SYSTEM IN THE BRAZILIAN SOUTHEAST

By increasing renewable energy demand, the use of solar energy has been widely investigated over the recent years. Brazil is a privileged country in terms of the levels of receivable solar radiation in almost all over its territory. However, as there are days when there is a deficit in solar energy, because the day be cloudy or rainy days, and for this reason, solar collectors need a support to contribute to the water heating to the desired temperature. In this work, an experimental study of a heat pump operated with R-134a, as an ancillary equipment for a solar water heating system in Belo Horizonte city has been accomplished. For this project, is used a set of electrical resistances for by a power control step, simulate historical annual values of solar radiation. In the results, it was observed that is achieved through the collection of solar energy the temperature of 45°C in the reservoir only in January, and the other eleven months is necessary to use the heat pump to achieve reach that temperature. With the heat pump operating in conditions similar to real conditions gave an average annual consumption of 137.65 kWh and a cost of R$ 60.61

Energy dependence of ϕ meson production at forward rapidity in pp collisions at the LHC

The production of $\phi$ mesons has been studied in pp collisions at LHC energies with the ALICE detector via the dimuon decay channel in the rapidity region $2.5< y < 4$. Measurements of the differential cross section $\mathrm{d}^2\sigma /\mathrm{d}y \mathrm{d}p_{\mathrm {T}}$ are presented as a function of the transverse momentum ($p_{\mathrm {T}}$) at the center-of-mass energies $\sqrt{s}=5.02$, 8 and 13 TeV and compared with the ALICE results at midrapidity. The differential cross sections at $\sqrt{s}=5.02$ and 13 TeV are also studied in several rapidity intervals as a function of $p_{\mathrm {T}}$, and as a function of rapidity in three $p_{\mathrm {T}}$ intervals. A hardening of the $p_{\mathrm {T}}$-differential cross section with the collision energy is observed, while, for a given energy, $p_{\mathrm {T}}$ spectra soften with increasing rapidity and, conversely, rapidity distributions get slightly narrower at increasing $p_{\mathrm {T}}$. The new results, complementing the published measurements at $\sqrt{s}=2.76$ and 7 TeV, allow one to establish the energy dependence of $\phi$ meson production and to compare the measured cross sections with phenomenological models. None of the considered models manages to describe the evolution of the cross section with $p_{\mathrm {T}}$ and rapidity at all the energies.publishedVersio

ϒ production in p–Pb collisions at sNN=8.16 TeV

ϒproduction in p–Pbinteractions is studied at the centre-of-mass energy per nucleon–nucleon collision √sNN=8.16TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 &lt;3.53and −4.46 &lt;−2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to ppcollisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pbcollisions at √sNN=5.02TeV and with theoretical calculations

Coherent psi (2S) photo-production in ultra-peripheral Pb-Pb collisions at root s(NN)=2.76TeV

We have performed the first measurement of the coherent psi(2S) photo-production cross section in ultraperipheral Pb-Pb collisions at the LHC. This charmonium excited state is reconstructed via the psi(2S) -> l(+)l(-) and ->(2S) -> J/psi pi(+)pi(-) decays, where the J/psi decays into two leptons. The analysis is based on an event sample corresponding to an integrated luminosity of about 22 mu b(-1). The cross section for coherent psi(2S) production in the rapidity interval -0.9 <y <0.9is d sigma(coh)(psi(2S))/dy = 0.83 +/- 0.19 (stat+syst) mb. The psi(2S) to J/psi coherent cross section ratio is 0.34(-0.07)(+0.08)(stat+syst). The obtained results are compared to predictions from theoretical models. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

Comparison of inclusive and photon-tagged jet suppression in 5.02 TeV Pb+Pb collisions with ATLAS

Parton energy loss in the quark–gluon plasma (QGP) is studied with a measurement of photon-tagged jet production in 1.7 nb−1 of Pb+Pb data and 260 pb−1 of pp data, both at √sNN = 5.02 TeV, with the ATLAS detector. The process pp → γ +jet+X and its analogue in Pb+Pb collisions is measured in events containing an isolated photon with transverse momentum (pT) above 50 GeV and reported as a function of jet pT. This selection results in a sample of jets with a steeply falling pT distribution that are mostly initiated by the showering of quarks. The pp and Pb+Pb measurements are used to report the nuclear modification factor, RAA, and the fractional energy loss, Sloss, for photon-tagged jets. In addition, the results are compared with the analogous ones for inclusive jets, which have a significantly smaller quark-initiated fraction. The RAA and Sloss values are found to be significantly different between those for photon-tagged jets and inclusive jets, demonstrating that energy loss in the QGP is sensitive to the colour-charge of the initiating parton. The results are also compared with a variety of theoretical models of colour-charge-dependent energy loss

Search for pair-produced resonances decaying to quark pairs in proton-proton collisions at root s=13 TeV

A general search for the pair production of resonances, each decaying to two quarks, is reported. The search is conducted separately for heavier resonances (masses above 400 GeV), where each of the four final-state quarks generates a hadronic jet resulting in a four-jet signature, and for lighter resonances (masses between 80 and 400 GeV), where the pair of quarks from each resonance is collimated and reconstructed as a single jet resulting in a two-jet signature. In addition, a b-tagged selection is applied to target resonances with a bottom quark in the final state. The analysis uses data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 35.9 fb(-1), from proton-proton collisions at a center-of-mass energy of 13 TeV. The mass spectra are analyzed for the presence of new resonances, and are found to be consistent with standard model expectations. The results are interpreted in the framework of R-parity-violating supersymmetry assuming the pair production of scalar top quarks decaying via the hadronic coupling lambda ''(312) or lambda ''(323) and upper limits on the cross section as a function of the top squark mass are set. These results probe a wider range of masses than previously explored at the LHC, and extend the top squark mass limits in the (t) over tilde -> qq' scenario.Peer reviewe