Heat loss in one day old pullets inside a hatchery

After hatching, pullets are transported to brooding area and vaccinated. One day old chicks have not already developed thermoregulation ability; thus, brooding temperature variations may affect pullet quality leading to broiler meat production losses. This research aimed to calculate sensible heat loss in one day old pullets in hatching area and vaccination room. Ten one day old pullets were randomly selected from hatching area of a commercial hatchery. Infrared images were used to calculate bird surface temperature. Exposure areas for the two conditions were quantified, and both air temperature and wind speed was recorded. Total sensible heat loss was calculated as heat loss by radiation plus heat loss by convection. It was found that heat transfer occurs in different ways at different bird body parts. Total heat loss found for hatching baskets was equivalent to 0.81 J s-1 while for vaccination room was 1.16 J s-1. Pullet nutrition is based on energy loss from brooding to farm, and the overall pullet heat loss from hatchery to farm accepted is 13.95 J s-1. Thus, "starter feed" has relevant excess of energy input. These findings indicate that less energy can be used in initial feed, once heat loss is lower than assumed nowadays. Improved knowledge on these conditions may enhance broiler farm feeding strategies and economics during first rearing week.

Limit-feeding a high-energy diet to meet energy requirements in the dry period alters plasma metabolite concentrations but does not affect intake or milk production in early lactation

Limit-feeding dry cows a high-energy diet may enable adequate energy intake to be sustained as parturition approaches, thus reducing the extent of negative energy balance after parturition. Our objective was to evaluate the effect of dry period feeding strategy on plasma concentrations of hormones and metabolites that reflect energy status. Multiparous Holstein cows (n = 18) were dried off 45 d before expected parturition, paired by expected calving date, parity, and previous lactation milk yield, and randomly assigned to 1 of 2 dry-period diets formulated to meet nutrient requirements at ad libitum or limited intakes. All cows were fed the same diet for ad libitum intake after parturition. Prepartum dry matter intake (DMI) for limit-fed cows was 9.4 kg/d vs. 13.7 kg/d for cows fed ad libitum. During the dry period, limit-fed cows consumed enough feed to meet calculated energy requirements, and ad libitum-fed cows were in positive calculated net energy for lactation (NEL) balance (0.02 vs. 6.37 Mcal/d, respectively). After parturition, milk yield, milk protein concentration, DMI, body condition score, and body weight were not affected by the prepartum treatments. Cows limit fed during the dry period had a less-negative calculated energy balance during wk 1 postpartum. Milk fat concentration and yield were greater for the ad libitum treatment during wk 1 but were lower in wk 2 and 3 postpartum. Plasma insulin and glucose concentrations decreased after calving. Plasma insulin concentration was greater in ad libitum-fed cows on d -2 relative to calving, but did not differ by dietary treatment at other times. Plasma glucose concentrations were lower before and after parturition for cows limit-fed during the dry period. Plasma nonesterified fatty acid concentrations peaked after parturition on d 1 and 4 for the limit-fed and ad libitum treatments, respectively, and were greater for limit-fed cows on d -18, -9, -5, and -2. Plasma tumor necrosis factor-alpha concentrations did not differ by treatment in either the pre- or postpartum period, but tended to decrease after parturition. Apart from a reduction in body energy loss in the first week after calving, limit feeding a higher NEL diet during the dry period had little effect on intake and milk production during the first month of lactation.

Investigation of the relationship between load and loss factors for a Brazilian electric utility

With the considerable increase of the losses in electric utilities of developing countries, such as Brazil, there is an investigation for loss calculation methodologies, considering both technical (inherent of the system) and non-technical (usually associated to the electricity theft) losses. In general, all distribution networks know the load factor, obtained by measuring parameters directly from the network. However, the loss factor, important for the energy loss cost calculation, can only be obtained in a laborious way. Consequently, several formulas have been developed for obtaining the loss factor. Generally, it is used the expression that relates both factors, through the use of a coefficient k. Last reviews introduce a range of factor k within 0.04 - 0.30. In this work, an analysis with real life load curves is presented, determining new values for the coefficient k in a Brazilian electric utility. © 2006 IEEE.

Subdivision of Hysteresis Loss in Mn-Zn Ferrite Toroidal Cores

The hysteresis loss subdivision method proved to be a strong tool to help in the analysis of different energy dissipation mechanisms along the quasi-static hysteresis loop measured on electrical steels. This paper used the samemethod to discuss the mechanisms involving the energy loss dissipation in Mn-Zn ferrite toroidal cores. The samples, sintered under controlled atmosphere in industrial conditions, were measured under triangular waveform excitation at very low frequency (5 mHz) and peak flux densities varying from 0.05 T to 0.45 T. The results show a different behavior between the low inductions hysteresis loss (WLI) and the high induction hysteresis loss (WHI) which proves the existence of different energy dissipation mechanisms affecting these loss components.

Using the Franck-Hertz Experiment To Illustrate Quantization Energy States of the Neon Atom by Electron Impact

na provide students with motivation for the study of quantum mechanics. That microscopic matter exists in quantized states can be demonstrated with modem versions of historic experiments: atomic line spectra (I), resonance potentials, and blackbody radiation. The resonance potentials of mercury were discovered by Franck and Hertz in 1914 (2). Their experiment consisted of bombarding atoms by electrons, and detecting the kinetic energy loss of the scattered electrons (3). Prior to the Franck-Hertz experiment, spectroscopic work bv Balmer and Rvdbere revealed that atoms emitted radiatibn at discrete ekergiis. The Franck-Hertz experiment showed directly that auantized enerm levels in an atom are real, not jist optiEal artifacts. atom can be raised to excited states by inelastic collisions with electrons as well as lowered from excited states by emission of photons. The classic Franck-Hertz experiment is carried out with mercury (4-7). Here we present an experiment for the study of resonance potentials using neon.

Thermal Energy Storage for Solar Power Production

Solar energy is the most abundant persistent energy resource. It is also an intermittent one available for only a fraction of each day while the demand for electric power never ceases. To produce a significant amount of power at the utility scale, electricity generated from solar energy must be dispatchable and able to be supplied in response to variations in demand. This requires energy storage that serves to decouple the intermittent solar resource from the load and enables around-the-clock power production from solar energy. Practically, solar energy storage technologies must be efficient as any energy loss results in an increase in the amount of required collection hardware, the largest cost in a solar electric power system. Storing solar energy as heat has been shown to be an efficient, scalable, and relatively low-cost approach to providing dispatchable solar electricity. Concentrating solar power systems that include thermal energy storage (TES) use mirrors to focus sunlight onto a heat exchanger where it is converted to thermal energy that is carried away by a heat transfer fluid and used to drive a conventional thermal power cycle (e.g., steam power plant), or stored for later use. Several approaches to TES have been developed and can generally be categorized as either thermophysical (wherein energy is stored in a hot fluid or solid medium or by causing a phase change that can later be reversed to release heat) or thermochemical (in which energy is stored in chemical bonds requiring two or more reversible chemical reactions).

Simulation of the secondary electrons energy deposition produced by proton beams in PMMA: influence of the target electronic excitation description

We have studied the radial dependence of the energy deposition of the secondary electron generated by swift proton beams incident with energies T = 50 keV–5 MeV on poly(methylmethacrylate) (PMMA). Two different approaches have been used to model the electronic excitation spectrum of PMMA through its energy loss function (ELF), namely the extended-Drude ELF and the Mermin ELF. The singly differential cross section and the total cross section for ionization, as well as the average energy of the generated secondary electrons, show sizeable differences at T ⩽ 0.1 MeV when evaluated with these two ELF models. In order to know the radial distribution around the proton track of the energy deposited by the cascade of secondary electrons, a simulation has been performed that follows the motion of the electrons through the target taking into account both the inelastic interactions (via electronic ionizations and excitations as well as electron-phonon and electron trapping by polaron creation) and the elastic interactions. The radial distribution of the energy deposited by the secondary electrons around the proton track shows notable differences between the simulations performed with the extended-Drude ELF or the Mermin ELF, being the former more spread out (and, therefore, less peaked) than the latter. The highest intensity and sharpness of the deposited energy distributions takes place for proton beams incident with T ~ 0.1–1 MeV. We have also studied the influence in the radial distribution of deposited energy of using a full energy distribution of secondary electrons generated by proton impact or using a single value (namely, the average value of the distribution); our results show that differences between both simulations become important for proton energies larger than ~0.1 MeV. The results presented in this work have potential applications in materials science, as well as hadron therapy (due to the use of PMMA as a tissue phantom) in order to properly consider the generation of electrons by proton beams and their subsequent transport and energy deposition through the target in nanometric scales.

Observation Of D0 Meson Nuclear Modifications In Au+au Collisions At Sqrt[s(nn)] = 200 Gev.

We report the first measurement of charmed-hadron (D(0)) production via the hadronic decay channel (D(0) → K(-) + π(+)) in Au+Au collisions at sqrt[s(NN)] = 200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, N(bin), from p+p to central Au+Au collisions. The D(0) meson yields in central Au + Au collisions are strongly suppressed compared to those in p+p scaled by N(bin), for transverse momenta p(T) > 3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate p(T) is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

Efeitos de dietas contendo Leucaena leucocephala e Saccharomyces cerevisiae sobre a fermentação ruminal e a emissão de gás metano em bovinos

Este trabalho foi realizado com o objetivo de avaliar os efeitos do uso de leucena e levedura em dietas para bovinos sobre o metabolismo ruminal, incluindo o pH e as produções de ácido graxos voláteis (AGV), amônia e gás metano. Quatro bovinos machos com 800 kg e fistulados no rúmen foram mantidos em quadrado latino 4 × 4, em arranjo fatorial 2 × 2, composto de dois níveis de leucena (20 e 50% MS) e feno de capim coast-cross na presença ou ausência de levedura. Não houve influência das dietas nos valores médios de pH (média 6,82) e nas concentrações de amônia no rúmen, que variaram de 18 a 21 mg/100 mL. Houve interação entre níveis de leucena e levedura na concentração total de AGV. As dietas não diferiram quanto à concentração de ácido acético, mas os animais alimentados com a dieta com 50% de leucena e contendo levedura apresentaram maiores concentrações médias de ácido propiônico (média 19,14 mM). A emissão de metano reduziu em12,3% em relação à mesma dieta sem levedura e em 17,2% quando os animais foram alimentados com 20% de leucena com levedura. Verificou-se efeito associativo de leucena, quando fornecida em alto nível na dieta (50% MS), e levedura na redução da emissão de metano e na melhoria no padrão de fermentação no rúmen, o que pode reduzir as perdas de energia e melhorar eficiência energética do animal.

Azimuthal Anisotropy of pi(0) Production in Au plus Au Collisions at root s(NN)=200 GeV: Path-Length Dependence of Jet Quenching and the Role of Initial Geometry

We have measured the azimuthal anisotropy of pi(0) production for 1 < p(T) < 18 GeV/c for Au + Au collisions at root s(NN) = 200 GeV. The observed anisotropy shows a gradual decrease for 3 less than or similar to p(T) less than or similar to 7-10 GeV/c, but remains positive beyond 10 GeV/c. The magnitude of this anisotropy is underpredicted, up to at least similar to 10 GeV/c, by current perturbative QCD (PQCD) energy-loss model calculations. An estimate of the increase in anisotropy expected from initial-geometry modification due to gluon saturation effects and fluctuations is insufficient to account for this discrepancy. Calculations that implement a path-length dependence steeper than what is implied by current PQCD energy-loss models show reasonable agreement with the data.

Transition in Yield and Azimuthal Shape Modification in Dihadron Correlations in Relativistic Heavy Ion Collisions

Hard-scattered parton probes produced in collisions of large nuclei indicate large partonic energy loss, possibly with collective produced-medium response to the lost energy. We present measurements of pi(0) trigger particles at transverse momenta p(T)(t) = 4-12 GeV/c and associated charged hadrons (p(T)(a) = 0.5-7 GeV/c) vs relative azimuthal angle Delta phi in Au + Au and p + p collisions at root s(NN) = 200 GeV. The Au + Au distribution at low p(T)(a), whose shape has been interpreted as a medium effect, is modified for p(T)(t) < 7 GeV/c. At higher p(T)(t), the data are consistent with unmodified or very weakly modified shapes, even for the lowest measured p(T)(a), which quantitatively challenges some medium response models. The associated yield of hadrons opposing the trigger particle in Au + Au relative to p + p (I(AA)) is suppressed at high p(T) (I(AA) approximate to 0.35-0.5), but less than for inclusive suppression (R(AA) approximate to 0.2).

Suppression of away-side jet fragments with respect to the reaction plane in Au plus Au collisions at root s(NN)=200 GeV

Pair correlations between large transverse momentum neutral pion triggers (p(T) = 4-7 GeV/c) and charged hadron partners (p(T) = 3-7 GeV/c) in central (0%-20%) and midcentral (20%-60%) Au + Au collisions at root s(NN) = 200 GeV are presented as a function of trigger orientation with respect to the reaction plane. The particles are at larger momentum than where jet shape modifications have been observed, and the correlations are sensitive to the energy loss of partons traveling through hot densematter. An out-of-plane trigger particle produces only 26 +/- 20% of the away-side pairs that are observed opposite of an in-plane trigger particle for midcentral (20%-60%) collisions. In contrast, near-side jet fragments are consistent with no suppression or dependence on trigger orientation with respect to the reaction plane. These observations are qualitatively consistent with a picture of little near-side parton energy loss either due to surface bias or fluctuations and increased away-side parton energy loss due to a long path through the medium. The away-side suppression as a function of reaction-plane angle is shown to be sensitive to both the energy loss mechanism and the space-time evolution of heavy-ion collisions.

Photon-hadron jet correlations in p plus p and Au plus Au collisions at s(NN)=200 GeV

We report the observation at the Relativistic Heavy Ion Collider of suppression of back-to-back correlations in the direct photon+jet channel in Au+Au relative to p+p collisions. Two-particle correlations of direct photon triggers with associated hadrons are obtained by statistical subtraction of the decay photon-hadron (gamma-h) background. The initial momentum of the away-side parton is tightly constrained, because the parton-photon pair exactly balance in momentum at leading order in perturbative quantum chromodynamics, making such correlations a powerful probe of the in-medium parton energy loss. The away-side nuclear suppression factor, I(AA), in central Au+Au collisions, is 0.32 +/- 0.12(stat)+/- 0.09(syst) for hadrons of 3 < p(T)(h)< 5 in coincidence with photons of 5 < p(T)(gamma)< 15 GeV/c. The suppression is comparable to that observed for high-p(T) single hadrons and dihadrons. The direct photon associated yields in p+p collisions scale approximately with the momentum balance, z(T)equivalent to p(T)(h)/p(T)(gamma), as expected for a measurement of the away-side parton fragmentation function. We compare to Au+Au collisions for which the momentum balance dependence of the nuclear modification should be sensitive to the path-length dependence of parton energy loss.

Suppression Pattern of Neutral Pions at High Transverse Momentum in Au plus Au Collisions at root S(NN)=200 GeV and Constraints on Medium Transport Coefficients

For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, p(T), up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < p(T) < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e. g., <(q) over cap > in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.

Onset of pi(0) Suppression Studied in Cu plus Cu Collisions at root s(NN)=22.4, 62.4, and 200 GeV

Neutral pion transverse momentum (p(T)) spectra at midrapidity (|y| less than or similar to 0.35) were measured in Cu + Cu collisions at root s(NN) = 22.4, 62.4, and 200 GeV. Relative to pi(0) yields in p + p collisions scaled by the number of inelastic nucleon-nucleon collisions (N(coll)) the pi(0) yields for p(T) greater than or similar to 2 GeV/c in central Cu + Cu collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central Cu + Cu collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.