R. Velo

• University of Santiago de Compostela

Ammonia (NH3) concentration has seldom been used for environmental control of weaner buildings despite its impact on environment, animal welfare, and workers’ health. This paper aims to determine the effects of setpoint temperature (ST) on the daily evolution of NH3 concentration in the animal-occupied zone. An experimental test was conducted on a...

An AutoRegressive Integrated Moving Average model was validated for the prediction of temperatures in the animal zone of conventional weaned piglet barn. The validation period covered seven cycles and recorded values at 10-min intervals for 292 days. Average weight was 5.75 ± 0.86 kg at the beginning of the production cycle and 18.41 ± 2.12 kg at t...

Passive infrared (PIR) detectors are widely used to measure animal activity, which is an increasingly relevant variable for livestock production insofar as activity is an indicator of animal welfare. This paper evaluates the agreement between two animal activity measurement methods: a PIR detector that uses the sensor's digital signal to perform me...

Carbon dioxide concentration is a major factor in air quality, animal welfare and air exchange rates inside livestock buildings. CO2 concentration series show a dynamic, non-linear and non-stationary behavior. This type of process can be handled by Wavelet Neural Network (WNN) models, which have been developed in recent years. The purpose of this p...

The activity level of weaned piglets provides a useful tool for farmers to control animal welfare and pollutant emissions. In addition, data for weaned piglet activity can be used as an input signal in real-time ventilation control systems because of its relation to temperature and CO2 levels. This paper characterises the daily activity pattern of...

Animal activity has a decisive influence on the concentration of gases in pig housing, accordingly, on animal welfare. Thus, the animal behaviour will condition the operation of air conditioning systems and energy consumption of farms. The aim is to characterize animal activity in a conventional farm of piglets of 20 kg live weight, and its relatio...

The aim of this study was to determine the effect of stocking density, light intensity and light color on broiler growth. The experiment consisted of four 35-day phases during each of which 320 chickens were surveyed. The research was performed at stocking densities of four and six birds/m(2) . Illuminances of 15 and 30 lx were obtained through com...

Wind speed knowledge is prerequisite in the siting of wind turbines. In consequence the wind energy use requires meticulous and specified knowledge of the wind characteristics at a location. This paper presents a method for determining the annual average wind speed at a complex terrain site by using neural networks, when only short term data are av...

This paper studies the behaviour of the voltage in steady state when fixed speed small wind turbines with induction generator are connected in distributed generation. Wind turbines used have horizontal axe, rotor located on the windward side and three-bladed and the power control is passive. A model of turbines and electric lines is created by MATL...

Heat transfer processes occurring in greenhouse cultivation substrates are very complex due to the high number of environmental and soil factors involved. Few estimation methods allow establishing the energy consumption of the heating elements as a function of the design parameters (depth and spacing) and of environmental and cultivation criteria,...

A method of estimating the annual average wind speed at a selected site using neural networks is presented. The method proposed uses only a few measurements taken at the selected site in a short time period and data collected at nearby fixed stations.The neural network used in this study is a multilayer perceptron with one hidden layer of 15 neuron...

This study presents a two-dimensional model of the thermal behavior of electric cable heating systems for substrates in greenhouses, developed in a transient state by using a general-purpose finite element code. In this model, the thermal properties of substrate can be introduced directly by layers or estimated by methods that allow the determinati...

The development of optimal control strategies in greenhouses requires precise models of energy transfer. A flexible model that enables the introduction of different substrate parameters and boundary conditions was developed for electric cable heating installations. The model is based on finite element analysis and is implemented by using a commerci...

Heat transfer processes occurring in greenhouse cultivation substrates are very complex due to the high number of environmental and soil factors involved. Few estimation methods allow establishing the capacity of the heating elements as a function of the design parameters (depth and spacing) and of environmental and cultivation criteria, such as th...