346 research outputs found
Thermal Behaviour and Refrigeration of High-Temperature Superconducting Fault Current Limiters and Microlimiters
Approach to a classification of construction typologies of pig facilities: case study Antioquia – Colombia
Received: January 31th, 2021 ; Accepted: March 27th, 2021 ; Published: April 30th, 2021 ; Correspondence: [email protected] facilities foro confined production in tropical countries such as Colombia does not
specify, in the present moment a typological classification that allows researchers to carry out
evaluations related to animal comfort and environmental impacts according to the type of
accommodation. To achieve the objective of this research were developed a survey to a panel of
experts, a decision sensitivity analysis and the hierarchical analytical method AHP. Parameters
that allowed to describe the concept of a technified pig farm were obteined, where the most
relevant were: biosecurity measures, measurement of zootechnical parameters, training for
workers and legal fulfilment. Additionally, ranges were defined to establish the production size
in small, medium and large according to the number of animals. The results obtained per group
were: 1) breeding small (50–200), medium (201–1,000) and large (1,001–5,000); 2) growth small
(60–200), medium (201–800) and large (801–5000); and 3) finishing stage small (50–500),
medium (501–1,000) and large (2,001–5,000). A total of 948 typological combinations were
initially determined. Finally, the construction characteristics with the greatest technical and
operational feasibility were prioritized for each group achieving 36 typologies that can represent
the typological pig facilities not only in the state of Antioquia but also in many others states in
Colombia
Thermal environment in two broiler barns during the first three weeks of age
The objective of this research was to evaluate the internal thermal environment of two broiler barns featuring different ventilation systems representative of Brazilian and South American poultry production industry: (a) a negative-pressure tunnel and (b) a positive- pressure lateral ventilation system. Environmental parameters such as dry bulb temperature, relative humidity and temperature-humidity index were assessed; temperature maps for day and night average conditions were determined for the first three weeks of life. Better uniformity of the thermal environment and comfort conditions inside the negative-pressure tunnel were found
Thermal comfort assessment in a typological non-isolated maternity pig sheds with different types of farrowing systems
Received: February 1st, 2021 ; Accepted: May 8th, 2021 ; Published: May 19th, 2021 ; Correspondence: [email protected] facilities in tropical climates, especially the maternity, have worked with
typological systems that have been little studied to determine the influence of the type of
farrowing on microenvironmental conditions and its effect on both the sows and the piglets'
physiological parameters. Therefore, the aim of the research was evaluate the thermal
environment (Temperature Humidity Index - THI and Radiant Thermal Load - RTL) and its
influence on some physiological parameters (respiratory frequency - RF and rectal temperature -
TRectal) in the sows and piglets in two different types of farrowing systems (Traditional and
Slatted), in a typological swine facility located in tropical climates in Colombia. The findings
showed that in the two systems, both for sows and piglets, the type of farrowing system did not
generate significant differences in the physiological responses RF and TRectal. Also, the RTL
did not show significant differences in the two types of farrowing system at the piglets and the
sows’ level, without exceeding the maximum allowed levels. Temperature-Humidity Index was
above the threshold during all experimental time, being slightly higher at the piglets' level with
Slatted systems. These results show that the type of floor has little impact on the conditions of
animal thermal comfort at the sows and piglets’ level. However, variables like low-temperature,
low radiant energy exchange, and high humidity, which were found mainly at the piglets’ level,
could have the highest incidence for not achieving a suitable microenvironment. This means that
almost all Colombian pig farming facilities require a redesign of their farrowing system to
guarantee better thermal conditions for both piglets and sows
Assessment of the methane emission for different typologies of fattening swine facilities in the department of Antioquia – Colombia
The explosive growth of swine production at high stocking densities in confinement
farming worldwide, has raised concerns the environmental impact, health and livestock
productivity and the production of associated gases in this type of large-scale farms. The aim of
this paper was to study the methane gas concentration and emissions of ten different typologies
of swine production installations. The facilities were in the department of Antioquia - Colombia,
they were located between 800–2,300 meters above sea level (m.a.s.l.) of heights, they mainly
employed natural ventilation as refrigeration strategy and they were used for pigs in fattening
stage. Methane measurements were taken at animal height. Sensors were located at intermediate
points of the ventilation inlet and outlet areas. The behaviour of methane concentration and
emission of the facilities were analysed along with the correlation and temporal evolution of
climatic variables, comfort indices and construction typologies. The information was analysed
using descriptive statistics, analysis of variance (ANOVA) and principal component analysis
(PCA). Were found an average of CH4 Emission Rate (ER) per facility (kg year-1
) of 607.9,
Global Warming Potential (GWP) per facility (kg year-1
) of 15,197.42 and significant correlations
between ER and cleaning frequency (CF), animal unit (AU), air flow (Q), animal density(AD)
and relative humidity (RH) were evidenced. This is the first research reported in Colombia, that
will be important to create some governmental policies
Assessment of a low-cost solar water heating systems in farrowing facilities
ArticleThe objective of this study was to develop a prototype solar heater using alternative materials and then to compare its thermal efficiency against that of two other commercial solar heating systems when heating the floor of piglet housing. To evaluate the thermal heaters, temperature sensors were installed in the inlet and outlet of each floor and the thermal reservoir. The results showed good performance, however the thermal efficiency of the alternative heater was lower than the conventional systems. However, due to the construction of this solar collector with alternative materials its cost was relatively low and its operation is easier than the other conventional heater, therefore this heater is a good alternative to use for small livestock producer
The mineralizing effect of zinc oxide-modified hydroxyapatite-based sealer on radicular dentin
Objective To evaluate the remineralization ability of three endodontic sealer materials at different root dentin regions.
Material and methods Cervical, medial and apical root dentin surfaces were treated with two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite); an epoxy resin-based canal sealer, AH Plus; and gutta-percha. Remineralization, at the inner and outer zones of dentin disk surfaces, was studied by nanohardness (Hi) and Raman analysis. Nano-roughness and collagen fibrils width measurements were performed. Numerical data, at 24 h or 12 m, were analyzed by ANOVA and Student-Newman-Keuls (P<0.05).
Results At the outer and inner zones of cervical dentin treated with oxipatite, the highest Hi after 12 m of immersion was achieved. The same group showed the highest intensity of phosphate peak, markers for calcification and crystallinity. Nanoroughness was lower and fibrils diameter was higher at the inner zone of dentin treated with oxipatite. Dentin mineralization occurred in every region of root dentin treated with oxipatite and calcypatite, especially at inner zone of dentin after 12 m.
Conclusions Oxipatite, reinforced the inner root zone at any third of radicular dentin, by increasing both nanohardness and remineralization. When using calcypatite, the highest nanohardness was found at the apical third of the inner root dentin, but the lowest mechanical performance was obtained at the cervical and the medial thirds of the roots. Therefore, application of oxipatite as sealing cement of root canals is recommended.
Clinical relevance Oxipatite, when used as endodontic sealing material, strengthens radicular dentin.Project MAT2017-85999-P MINECO/AEI/FEDER/UE supported by the Ministry of Economy and Competitiveness (MINECO) and European Regional Development Fund (FEDER)
Work conditions assessment in manufacturing organizations in the colombian caribbean region
Deficient work conditions have been linked with an epidemic of injury and illness in low and middle-income countries. A group of 22 companies from different sectors was selected in order to carry out a diagnosis related to work conditions in Colombia. To do so, an instrument was designed based on the International Labour Organization (ILO) standards. This information allowed identifying potential problems in work conditions such as work environments, physical load, noise and social welfare. Some low cost measures were discussed as suggestions to improve work conditions. Such measures are expected to generate both an increase in productivity and an enhancement in the employees' attitude
DESARROLLO DE UN AMBIENTE SEMIAUTOMATIZADO PARA LA ENSEÑANZA Y APRENDIZAJE DE CONCEPTOS DE PRODUCCIÓN APLICADOS A LA INDUSTRIA DE CONFECCIONES
This article presents the result of a research project whose objective was the design, development and implementation of a semi-automated environment for teaching and learning production processes in confection, formed with the use of a conveyor belt with discrete movements controlled by PLC, buttons at each station and software SCADA supervision. The environment allows Sena apprentices to be taught clothing, with a greater appropriation of concepts and useful manufacturing techniques slender, in a practical, playful and didactic way. The environment serves as a laboratory and is a reference as a production model for the clothing industry in Medellin. This model breaks paradigms of the use of automation in a sector in which productivity and quality depend largely on the ability of the operator, and in which the product reference changes are continuous due to in fashion.En este artículo se presenta el resultado de un proyecto de investigación cuyoobjetivo fue el diseño, desarrollo e implementación de un ambiente semiautomatizadode enseñanza y aprendizaje de procesos de producción enconfección, conformado con el uso de una banda transportadora con movimientosdiscretos controlados por PLC, botones en cada estación y softwarede supervisión SCADA. El ambiente permite enseñar a los aprendices del Sena de confecciones,con una mayor apropiación de conceptos y técnicas útiles de manufacturaesbelta, de una manera práctica, lúdica y didáctica. El ambiente sirve de laboratorio yes referente como un modelo de producción para la industria de las confecciones enMedellín. Con este modelo se rompen paradigmas del uso de la automatización en unsector en el que, la productividad y calidad, dependen en gran medida de la habilidaddel operario, y en el cual los cambios de referencia de producto son continuos debidoa la moda
A CFD based approach for determination of ammonia concentration profile and flux from poultry houses with natural ventilation
The understanding of concentration and emissions distribution of gases such as ammonia (NH3) in agricultural installations is of growing importance due to its effect on health and productivity of animals and workers. The objective of this study was to use validated Computational Fluid Dynamics (CFD) model as a tool to predict NH3 concentration distribution and mass fluxes in a non-insulated broiler chicken installation with natural ventilation, typically found in subtropical and tropical contries. Results from this study indicated that simulation with CFD can be used to predict NH3 concentration distribution and mass flux inside similar installations with incident winds from different directions of entrance at the lateral opening of the installation. The most direct application of the proposed mode would be to help improving the existing buildings and also to help in the conception of new ones, and may also apply the model to help in the development of NH3 emission inventories
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