Rearing of Labeo bata in sewage-fed fish culture pond

Labeo bata is a highly priced fish which commanding good consumer preference, even if the size is very small (15 to 20 g each), especially in West Bengal. With a view to evaluating the culture potential of this fish, repeated experiments were conducted at the Wastewater Aquaculture Division of the Central Institute of Freshwater Aquaculture, Rahara, West Bengal, during 1991-93 in ponds fed with treated domestic sewage effluent. An average production of 1270.63 kg per ha was obtained within 6 to 10 months for a uniform stocking density of 50,000 seed per ha. The average size attained by the fish in the different sets of experiments varied from 23.3 to 37.9 g as against the initial weight of 0.096 to 0.193 g. Details of management, growth, survival, quantity of sewage used and pond nutrient status and productivity are dealt with in this communication

Waves Generated by Recreational Traffic on the Upper Mississippi River System

Movement of recreational boats in a waterway such as the Upper Mississippi River System (UMRS) generates waves that can impact the river biota and the stability of the shorelines. This report presents the results of a research project undertaken to determine the characteristics of waves generated by recreational craft within the UMRS. To meet the goals of the project, 246 controlled runs were made with 12 different boats at two sites, one on the Illinois River and the other on the Mississippi River. Data from the controlled runs indicated that recreational boats can generate from 4 to 40 waves per event, with a mean of about 10 to 20 waves. These waves can last from 6 to 40 seconds or more. Average wave heights for these controlled events varied from 0.01 to 0.25 meter, with a median of about 0.06 to 0.12 meter. The maximum wave height was as much as 0.6 meter. The wave data from the controlled runs were used to develop a regression equation for estimating maximum wave heights on the basis of the speed, draft, and length of the boats, and their distance from the measuring point. This relationship is now recommended for use in determining wave heights generated by recreational boats. Data from uncontrolled boating events on the Mississippi River indicated that as many as 704 boats passed a highly used area of the UMRS in a single day on a busy weekend. Up to 120 boats passed the site in a single hour. Sustained movement of recreational boats can generate essentially continuous waves, giving the appearance of random waves at or near the shoreline. During the day of heaviest boating activity at the Mississippi River site, the maximum wave height measured was 0.52 meter, and the average for the whole day was 0.065 meter. Analyses were also performed by partitioning the wave heights on an hourly basis. These analyses indicated that significant wave height can reach a magnitude of 0.4 meter or higher, and maximum wave height can reach 0.5 meter or higher. Calculations were also performed to show that for waves of 0.4 meter in height to develop at the Mississippi River site from wind alone, the wind would have to be blowing at a speed of about 26 meters per second (58 mph) across the measuring point. Wave energies were computed by partitioning the waves into five-minute intervals. These analyses showed that the shorelines are subjected to wave activity of fairly high intensity. No analyses were performed to determine the bank erosion potential or sediment resuspension characteristics of the waves generated by recreational boats. However, existing mathematical formulations can be used to analyze the stability of banks composed of noncohesive bank materials. Additional research should be initiated to determine the effects of recreational boats on the stability of cohesive and noncohesive banks, and the way in which wave activity resuspends bed materials.Ope

Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

Peer reviewe

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

The second-order Fourier coefficients (υ$_{2}$) characterizing the azimuthal distributions of Υ(1S) and Υ(2S) mesons produced in PbPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV are studied. The Υmesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb$^{-1}$. The scalar product method is used to extract the υ$_{2}$ coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < p$_{T}$ < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ$_{2}$ values for the Υ mesons are found to be consistent with zero

Measurement of prompt D0^{0} and D‾\overline{D}0^{0} meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at root SNN\sqrt{S_{NN}} = 5.02 TeV

The strong Coulomb field created in ultrarelativistic heavy ion collisions is expected to produce a rapiditydependent difference (Av2) in the second Fourier coefficient of the azimuthal distribution (elliptic flow, v2) between D0 (uc) and D0 (uc) mesons. Motivated by the search for evidence of this field, the CMS detector at the LHC is used to perform the first measurement of Av2. The rapidity-averaged value is found to be (Av2) = 0.001 ? 0.001 (stat)? 0.003 (syst) in PbPb collisions at ?sNN = 5.02 TeV. In addition, the influence of the collision geometry is explored by measuring the D0 and D0mesons v2 and triangular flow coefficient (v3) as functions of rapidity, transverse momentum (pT), and event centrality (a measure of the overlap of the two Pb nuclei). A clear centrality dependence of prompt D0 meson v2 values is observed, while the v3 is largely independent of centrality. These trends are consistent with expectations of flow driven by the initial-state geometry. ? 2021 The Author. Published by Elsevier B.V. This is an open access article under the CC BY licens

Performance of reconstruction and identification of τ leptons decaying to hadrons and vτ in pp collisions at √s=13 TeV

The algorithm developed by the CMS Collaboration to reconstruct and identify τ leptons produced in proton-proton collisions at √s=7 and 8 TeV, via their decays to hadrons and a neutrino, has been significantly improved. The changes include a revised reconstruction of π⁰ candidates, and improvements in multivariate discriminants to separate τ leptons from jets and electrons. The algorithm is extended to reconstruct τ leptons in highly Lorentz-boosted pair production, and in the high-level trigger. The performance of the algorithm is studied using proton-proton collisions recorded during 2016 at √s=13 TeV, corresponding to an integrated luminosity of 35.9 fb¯¹. The performance is evaluated in terms of the efficiency for a genuine τ lepton to pass the identification criteria and of the probabilities for jets, electrons, and muons to be misidentified as τ leptons. The results are found to be very close to those expected from Monte Carlo simulation

Performance of the CMS Level-1 trigger in proton-proton collisions at √s = 13 TeV

At the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13\TeV. During Run 2 (years 2015–2018) the LHC eventually reached a luminosity of 2.1× 10$^{34}$ cm$^{-2}$s$^{-1}$, almost three times that reached during Run 1 (2009–2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). The CMS Level-1 trigger was upgraded prior to 2016 to improve the selection of physics events in the challenging conditions posed by the second run of the LHC. This paper describes the performance of the CMS Level-1 trigger upgrade during the data taking period of 2016–2018. The upgraded trigger implements pattern recognition and boosted decision tree regression techniques for muon reconstruction, includes pileup subtraction for jets and energy sums, and incorporates pileup-dependent isolation requirements for electrons and tau leptons. In addition, the new trigger calculates high-level quantities such as the invariant mass of pairs of reconstructed particles. The upgrade reduces the trigger rate from background processes and improves the trigger efficiency for a wide variety of physics signals