Assessing airflow rates of a naturally ventilated test facility using a fast and simple algorithm supported by local air velocity measurements

The high spatial and temporal variations of airflow patterns in ventilation openings of naturally ventilated animal houses make it difficult to accurately measure the airflow rate. This paper focuses on the development of a fast assessment technique for the airflow rate of a naturally ventilated test facility through the combination of a linear algorithm and local air velocity measurements. This assessment technique was validated against detailed measurement results obtained by the measuring method of Van Overbeke et al. (2015) as a reference. The total air velocity |u-|, the normal |Y-| and tangential velocity component |x-| and the velocity vector u- measured at the meteomast were chosen as input variables for the linear algorithms. The airflow rates were split in a group where only uni-directional flows occurred at vent level (no opposite directions of |Y-| present in the airflow pattern of the opening), and a group where bi-directional flows occurred (the air goes simultaneously in and out of the opening). For airflow rates with uni-directional flows the input variables u- and |Y-| yielded the most accurate results. For this reason, it was suggested to use the |Y-| instead of |u-| in ASHRAE’s formula of Q = E × A × |u-|. For bi-directional flows a multiple linear model was suggested where input variable u- gave the best results to assess the airflow rate

Methodology for airflow rate measurements in a naturally ventilated mock-up animal building with side and ridge vents

Currently there exists no generally accepted reference technique to measure the ventilation rate through naturally ventilated (NV) vents. This has an impact on the reliability of airflow rate control techniques and emission rate measurements in NV animal houses. As an attempt to address this issue a NV test facility was built to develop new airflow rate measurement techniques for both side wall and ridge vents. Three set-ups were used that differed in vent configuration, i.e. one cross ventilated set-up and two ridge ventilated set-ups with different vent sizes. The airflow through the side vents was measured with a technique based on an automatic traverse movement of a 3D ultrasonic anemometer. In the ridge, 7 static 2D ultrasonic anemometers were installed. The methods were validated by applying the air mass conservation principle, i.e. the inflow rates must equal the outflow rates. The calculated in - and outflow rates agreed within (5 ± 8)%, (8 ± 5)% and (−9 ± 7)% for the three different set-ups respectively, over a large range of wind incidence angles. It was found that the side vent configuration was of large importance for the distribution of the airflow rates through the vents. The ridge proved to be a constant outlet, whilst side vents could change from outlet to inlet depending on the wind incidence angle. The range of wind incidence angles in which this transition occurred could be clearly visualised

Coating quality as affected by core particle segregation in fluidized bed processing

[EN] Fluidized bed coating is an important technique in the food powder industry, where often particles of a wide size distribution are dealt with. In this paper, glass beads of different particle size distribution were coated with sodium caseinate in a top-spray fluid bed unit. Positron Emission Particle Tracking (PEPT) was used to visualize and quantify the particle motion in the fluidized bed. Confocal Laser Scanning Microscopy combined with image analysis were used to investigate the effect of core particle size and its distribution on the thickness and quality of the coating. Particle size significantly affected the thickness and quality of the coating, due to differences in the corresponding fluidization patterns, as corroborated by PEPT observations. As the particle size distribution becomes narrower, segregation is less likely to occur. This results in a thicker coating which is, however, less uniform compared to when cores of a wider particle size distribution are spray coated. (C) 2012 Elsevier Ltd. All rights reserved.The authors wish to thank the financial support received from the Fund for Scientific Research-Flanders (Belgium) (F.W.O.-Vlaanderen), as well as from the Programa de Apoyo a la Investigacion y Desarrollo from the Universitat Politecnica de Valencia.Atarés Huerta, LM.; Depypere, F.; Pieters, J.; Dewettinck, K. (2012). Coating quality as affected by core particle segregation in fluidized bed processing. Journal of Food Engineering. 113(3):415-421. doi:10.1016/j.jfoodeng.2012.06.012S415421113

The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour

Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect

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

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