Ventilação natural e temperatura da superfície de pisos aquecidos em escamoteadores

This research had the objective of evaluating the influence of the natural ventilation on the surface temperature distribution of heated crates. The research used six crates from a farrowing room in a commercial swine production farm located in the state of São Paulo, Brazil. Three crates were heated using a heat mat while the other three had the environment heated by incandescent light bulbs (200W) fixed on the lateral wall. The surface temperature of the crate's floor (1.55x0.55m) was registered in 36 points, distributed in 18 quadrants (0.26x0.18m) using an infrared thermometer in three different conditions of the room's natural ventilation: opened, semi-opened, and closed lateral curtain. The isotherms and the temperature distribution of the floor heat were processed using the SURFER® (1995), and the statistical analysis was done using the MINITAB® (Statistical..., 2002). It was found that the room's natural ventilation had a significant influence on crate floor surface temperature distribution. The crate with a heat mat system provided higher temperatures and led to a more homogeneous surface temperature distribution.O objetivo deste trabalho foi avaliar a influência da ventilação natural sobre a distribuição da temperatura na superfície de pisos aquecidos em escamoteadores. Foram avaliados seis escamoteadores da maternidade de uma granja de suínos localizada no estado de São Paulo. Dentre os escamoteadores avaliados, três deles usavam piso aquecido para o acondicionamento dos leitões, e os outros usavam lâmpadas incandescentes (200W), fixadas na parede lateral do interior do escamoteador. A temperatura da superfície do piso (1,55x0,55m) foi registrada medindo-se 36 pontos distribuídos em 18 quadrantes (0,26x0,18m), por meio de um termômetro infravermelho, em três diferentes condições de ventilação natural: com cortina lateral aberta, semiaberta e totalmente fechada. As isotermas e a distribuição da temperatura sobre o piso aquecido foram processadas usando-se o software SURFER®. Verificou-se que a ventilação natural teve efeito sobre a distribuição da temperatura da superfície do piso dos escamoteadores. O escamoteador aquecido com manta térmica forneceu temperaturas mais altas e distribuição mais homogênea na superfície de contato com os leitões.47748

Blame Trees

We consider the problem of merging individual text documents, motivated by the single-file merge algorithms of document-based version control systems. Abstracting away the merging of conflicting edits to an external conflict resolution function (possibly implemented by a human), we consider the efficient identification of conflicting regions. We show how to implement tree-based document representation to quickly answer a data structure inspired by the “blame” query of some version control systems. A “blame” query associates every line of a document with the revision in which it was last edited. Our tree uses this idea to quickly identify conflicting edits. We show how to perform a merge operation in time proportional to the sum of the logarithms of the shared regions of the documents, plus the cost of conflict resolution. Our data structure is functional and therefore confluently persistent, allowing arbitrary version DAGs as in real version-control systems. Our results rely on concurrent traversal of two trees with short circuiting when shared subtrees are encountered.United States. Defense Advanced Research Projects Agency (Clean-Slate Design of Resilient, Adaptive, Secure Hosts (CRASH) program, BAA10-70)United States. Defense Advanced Research Projects Agency (contract #N66001-10-2-4088 (Bridging the Security Gap with Decentralized Information Flow Control))Danish National Research Foundation (Center for Massive Data Algorithmics (MADALGO)

Cache-Oblivious Persistence

Partial persistence is a general transformation that takes a data structure and allows queries to be executed on any past state of the structure. The cache-oblivious model is the leading model of a modern multi-level memory hierarchy.We present the first general transformation for making cache-oblivious model data structures partially persistent

Analysis of Passenger Car Turbocharged Diesel Engines Performance When Tested at Altitude and of the Altitude Simulator Device Used

[EN] According to current worldwide trends for homologation vehicles in real driving conditions is forced to test the engines in altitude and in highly dynamic driving cycles in order to approach nowadays and next future emissions standard. Up to now, there were two main options to perform this type of tests: round-robin tests of the whole vehicle or hypobaric chambers, both with high costs and low repeatability. In this paper a new device is described, which can emulate ambient conditions at whatever altitude between sea level and 5000m high. Even it can be used to emulate ambient conditions at sea level when test bench is placed up to 2000m high. The main advantages of the altitude simulation equipment are as follows: dynamic emulation of all the psychrometric variables affecting the vehicles during round-robin tests; lower space usage and low-energy consumption. The altitude simulator (AS) has been validated comparing with results from a hypobaric chamber at different altitudes. Previously a research about the dispersion in the measurements of both testing devices has been done for assessing the results of the comparison experiment. Final conclusion resulted in the same operating performance and emissions of the studied engine with both types of testing equipment for altitude simulation.FEDER, Government of Spain through Project TRA2016-79185-R (Funder ID: 10.13039/501100002924).Broatch, A.; Bermúdez, V.; Serrano, J.; Tabet, R.; Gómez, J.; Bender, S. (2019). Analysis of Passenger Car Turbocharged Diesel Engines Performance When Tested at Altitude and of the Altitude Simulator Device Used. Journal of Engineering for Gas Turbines and Power. 141(8):1-9. https://doi.org/10.1115/1.4043395S191418Hiroyasu, H., Arai, M., & Tabata, M. (1989). Empirical Equations for the Sauter Mean Diameter of a Diesel Spray. SAE Technical Paper Series. doi:10.4271/890464Gómez, J., 2018, “Development of an Altitude Simulator and Analysis of the Performance and Emissions of Turbocharged Diesel Engines at Different Altitudes,” Ph.D. thesis, Universitat Politècnica de València, Valencia, Spain.https://riunet.upv.es/bitstream/handle/10251/101284/G%C3%93MEZ%20-%20Development%20of%20an%20altitude%20simulator%20and%20analysis%20of%20the%20performance%20and%20emissions%20of%20tur....pdf?sequence=1Toff, W. D., Jones, C. I., Ford, I., Pearse, R. J., Watson, H. G., Watt, S. J., … Greaves, M. (2006). Effect of Hypobaric Hypoxia, Simulating Conditions During Long-Haul Air Travel, on Coagulation, Fibrinolysis, Platelet Function, and Endothelial Activation. JAMA, 295(19), 2251. doi:10.1001/jama.295.19.2251Bermúdez, V., Serrano, J. R., Piqueras, P., Gómez, J., & Bender, S. (2017). Analysis of the role of altitude on diesel engine performance and emissions using an atmosphere simulator. International Journal of Engine Research, 18(1-2), 105-117. doi:10.1177/146808741667956

Coherent States and Modified de Broglie-Bohm Complex Quantum Trajectories

This paper examines the nature of classical correspondence in the case of coherent states at the level of quantum trajectories. We first show that for a harmonic oscillator, the coherent state complex quantum trajectories and the complex classical trajectories are identical to each other. This congruence in the complex plane, not restricted to high quantum numbers alone, illustrates that the harmonic oscillator in a coherent state executes classical motion. The quantum trajectories are those conceived in a modified de Broglie-Bohm scheme and we note that identical classical and quantum trajectories for coherent states are obtained only in the present approach. The study is extended to Gazeau-Klauder and SUSY quantum mechanics-based coherent states of a particle in an infinite potential well and that in a symmetric Poschl-Teller (PT) potential by solving for the trajectories numerically. For the coherent state of the infinite potential well, almost identical classical and quantum trajectories are obtained whereas for the PT potential, though classical trajectories are not regained, a periodic motion results as t --> \infty.Comment: More example

The structure of typical clusters in large sparse random configurations

The initial purpose of this work is to provide a probabilistic explanation of a recent result on a version of Smoluchowski's coagulation equations in which the number of aggregations is limited. The latter models the deterministic evolution of concentrations of particles in a medium where particles coalesce pairwise as time passes and each particle can only perform a given number of aggregations. Under appropriate assumptions, the concentrations of particles converge as time tends to infinity to some measure which bears a striking resemblance with the distribution of the total population of a Galton-Watson process started from two ancestors. Roughly speaking, the configuration model is a stochastic construction which aims at producing a typical graph on a set of vertices with pre-described degrees. Specifically, one attaches to each vertex a certain number of stubs, and then join pairwise the stubs uniformly at random to create edges between vertices. In this work, we use the configuration model as the stochastic counterpart of Smoluchowski's coagulation equations with limited aggregations. We establish a hydrodynamical type limit theorem for the empirical measure of the shapes of clusters in the configuration model when the number of vertices tends to $\infty$. The limit is given in terms of the distribution of a Galton-Watson process started with two ancestors

Isovector part of nuclear energy density functional from chiral two- and three-nucleon forces

A recent calculation of the nuclear energy density functional from chiral two- and three-nucleon forces is extended to the isovector terms pertaining to different proton and neutron densities. An improved density-matrix expansion is adapted to the situation of small isospin-asymmetries and used to calculate in the Hartree-Fock approximation the density-dependent strength functions associated with the isovector terms. The two-body interaction comprises of long-range multi-pion exchange contributions and a set of contact terms contributing up to fourth power in momenta. In addition, the leading order chiral three-nucleon interaction is employed with its parameters fixed in computations of nuclear few-body systems. With this input one finds for the asymmetry energy of nuclear matter the value $A(\rho_0) \simeq 26.5\,$MeV, compatible with existing semi-empirical determinations. The strength functions of the isovector surface and spin-orbit coupling terms come out much smaller than those of the analogous isoscalar coupling terms and in the relevant density range one finds agreement with phenomenological Skyrme forces. The specific isospin- and density-dependences arising from the chiral two- and three-nucleon interactions can be explored and tested in neutron-rich systems.Comment: 14 pages, 7 figures, to be published in European Physical Journal

Metric versus observable operator representation, higher spin models

We elaborate further on the metric representation that is obtained by transferring the time-dependence from a Hermitian Hamiltonian to the metric operator in a related non-Hermitian system. We provide further insight into the procedure on how to employ the time-dependent Dyson relation and the quasi-Hermiticity relation to solve time-dependent Hermitian Hamiltonian systems. By solving both equations separately we argue here that it is in general easier to solve the former. We solve the mutually related time-dependent Schrödinger equation for a Hermitian and non-Hermitian spin 1/2, 1 and 3/2 model with time-independent and time-dependent metric, respectively. In all models the overdetermined coupled system of equations for the Dyson map can be decoupled algebraic manipulations and reduces to simple linear differential equations and an equation that can be converted into the non-linear Ermakov-Pinney equation

Nuclear energy density functional from chiral pion-nucleon dynamics: Isovector terms

We extend a recent calculation of the nuclear energy density functional in the framework of chiral perturbation theory by computing the isovector surface and spin-orbit terms: (\vec \nabla \rho_p- \vec \nabla \rho_n)^2 G_d(\rho)+ (\vec \nabla \rho_p- \vec \nabla \rho_n)\cdot(\vec J_p-\vec J_n) G_{so(\rho)+(\vec J_p-\vec J_n)^2 G_J(\rho) pertaining to different proton and neutron densities. Our calculation treats systematically the effects from $1\pi$-exchange, iterated $1\pi$-exchange, and irreducible $2\pi$-exchange with intermediate $\Delta$-isobar excitations, including Pauli-blocking corrections up to three-loop order. Using an improved density-matrix expansion, we obtain results for the strength functions $G_d(\rho)$, $G_{so}(\rho)$ and $G_J(\rho)$ which are considerably larger than those of phenomenological Skyrme forces. These (parameter-free) predictions for the strength of the isovector surface and spin-orbit terms as provided by the long-range pion-exchange dynamics in the nuclear medium should be examined in nuclear structure calculations at large neutron excess.Comment: 12 pages, 5 figure