2,428 research outputs found
Length-weight relationships of demersal fishes from the upper continental slope off Colombia
Parameters of the length–weight relationship of the form W=aLb are presented for 45 demersal fish species caught on the upper continental slope of the Caribbean Sea off Colombia. The b values varied between 2.13 and 4.97, with the mean b = 3.042 (95% CI, 2.887- 3.196)
Review of Measures to Control Airborne Pollutants in Broiler Housing
Broiler housing is a significant source of airborne pollutants from animal
production, which lead to degradation of indoor air quality and outdoor emissions,
particularly ammonia, nitrous oxide, carbon dioxide, methane, hydrogen sulphide,
odours and particulate matter. In this chapter, we first analyse the current state of the
art on the consequences of these pollutants on broiler farming, farm workers, and the
environment. This includes the factors affecting pollutants generation, quantification, and mitigation measures suppressing airborne pollutants. Next, we describe
different best available techniques for environmental protection and sustainability
of broiler production, namely feeds and feeding management, feed supplements,
bedding management and treatment of exhaust air. Thus, broiler farms should select
mitigation strategies based on several considerations, such as location, climate conditions, environmental policies and financial resourcesinfo:eu-repo/semantics/publishedVersio
Microscopic Approach To Irreversible Thermodynamics. I. General Theory
In this paper we show how an extension of the nonequilibrium-statistical- operator method, relying upon the maximum-entropy principle set up by Jaynes [Am. J. Phys. 33, 391 (1965)], may be used to describe the time evolution of an arbitrary many-body system. The Gibbs space of the observables describing the macrostates of the system is extended to include not only the conserved variables, but additional ones whose origin is directly related to the microscopic nature of the system manifested in its Hamiltonian. This allows us to go beyond linear irreversible thermodynamics and enter into the domain of what is now known as extended irreversible thermodynamics (EIT). Transport equations for the extended basic set of macrovariables are derived, showing that the Maxwell-Cattaneo-Vernotte equations of EIT are obtained. The relaxation times and transport coefficients contained therein can be calculated from the microscopic dynamics of the system averaged over an appropriate nonequilibrium coarse-grained probability density. Other outstanding features of the methods are emphasized and related to already-established results for nonequilibrium systems. © 1991 The American Physical Society.43126622663
A Bag of Features Based Approach for Classification of Motile Sperm Cells
The analysis of sperm morphology remains an essential process for diagnosis and treatment of male infertility. In this paper, a novel framework based on image processing is proposed to classify sperm cell images affected by noise due to their movement. This represents a challenge, articularly because the cells are not fixed or stained. The proposed framework is based on Speeded-Up Robust Features (SURF) combined with Bag of Features (BoF) models to quantise features computed by SURF. Support Vector Machines (SVMs) are used to classify the simplified feature vectors, extracted from sperm cell images, into normal, abnormal and noncell categories. The performance of this framework is compared to a similar model where the Histogram of Oriented Gradients (HOG) is used to extract features and SVMs is applied for their classification. The proposed framework allows to achieve classification results with an average accuracy of 90% with the SURF approach compared to 78% with the HOG approach
Resonance expansions in quantum mechanics
The goal of this contribution is to discuss various resonance expansions that
have been proposed in the literature.Comment: 10 pages and 1 figure; presented at the Istanbul workshop on
pseudo-Hermitian Hamiltonian
On the nature of the so-called generic instabilities in dissipative relativistic hydrodynamics
It is shown that the so-called generic instabilities that appear in the
framework of relativistic linear irreversible thermodynamics, describing the
fluctuations of a simple fluid close to equilibrium, arise due to the coupling
of heat with hydrodynamic acceleration which appears in Eckart's formalism of
relativistic irreversible thermodynamics. Further, we emphasize that such
behavior should be interpreted as a contradiction to the postulates of linear
irreversible thermodynamics (LIT), namely a violation of Onsager's hypothesis
on the regression of fluctuations, and not as fluid instabilities. Such
contradictions can be avoided within a relativistic linear framework if a
Meixner-like approach to the phenomenological equations is employed.Comment: 13 pages, no figures. Accepted for publication in GR
Review of Measures to Control Airborne Pollutants in Broiler Housing
Broiler housing is a significant source of airborne pollutants from animal production, which lead to degradation of indoor air quality and outdoor emissions, particularly ammonia, nitrous oxide, carbon dioxide, methane, hydrogen sulphide, odours and particulate matter. In this chapter, we first analyse the current state of the art on the consequences of these pollutants on broiler farming, farm workers, and the environment. This includes the factors affecting pollutants generation, quantification, and mitigation measures suppressing airborne pollutants. Next, we describe different best available techniques for environmental protection and sustainability of broiler production, namely feeds and feeding management, feed supplements, bedding management and treatment of exhaust air. Thus, broiler farms should select mitigation strategies based on several considerations, such as location, climate conditions, environmental policies and financial resources
Dynamically generated resonances from the vector octet-baryon decuplet interaction
We study the interaction of the octet of vector mesons with the decuplet of
baryons using Lagrangians of the hidden gauge theory for vector interactions.
The unitary amplitudes in coupled channels develop poles that can be associated
with some known baryonic resonances, while there are predictions for new ones
at the energy frontier of the experimental research. The work offers guidelines
on how to search for these resonances
Scaling Flows and Dissipation in the Dilute Fermi Gas at Unitarity
We describe recent attempts to extract the shear viscosity of the dilute
Fermi gas at unitarity from experiments involving scaling flows. A scaling flow
is a solution of the hydrodynamic equations that preserves the shape of the
density distribution. The scaling flows that have been explored in the
laboratory are the transverse expansion from a deformed trap ("elliptic flow"),
the expansion from a rotating trap, and collective oscillations. We discuss
advantages and disadvantages of the different experiments, and point to
improvements of the theoretical analysis that are needed in order to achieve
definitive results. A conservative bound based on the current data is that the
minimum of the shear viscosity to entropy density ration is that eta/s is less
or equal to 0.5 hbar/k_B.Comment: 32 pages, prepared for "BCS-BEC crossoverand the Unitary Fermi Gas",
Lecture Notes in Physics, W. Zwerger (editor), Fig. 5 corrected, note added;
final version, corrected typo in equ. 9
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