177 research outputs found
Productive characterisation in iberian pig varieties. II: preliminar study of birht weihtg and preweaning weight
We have studied the behaviour of six varieties of the Iberian Pig breed in the preweaning period with a view to determine the preliminary productive characterisation of this breed. We have used a sampled formed by 2001 piglets (males and females) where the birth, 30 days and 60 days weight were collected. From our preliminary results we have concluded a mean birth weight of 1,37 kg a 30 days weight of 13,49 kg. And a 60 days weight of 20 kg standing out the Retinto variety as the population presenting the best growing capacity in this physiological period, even though we have to go deep in this study using a bigger sample.Se estudia el comportamiento de seis variedades del cerdo Ibérico en el periodo predestete con vistas a la caracterización productiva preliminar de la raza. Para ello se utilizó una muestra compuesta por 2001 lechones entre machos y hembras donde se estudió el peso al nacimiento y los pesos a los 30 y 60 días. De los resultados preliminares obtenidos concluimos un peso al nacimiento medio de 1,37 kg, un peso a los 30 días de vida en torno a 13,49 kg y un peso a los 60 días o peso de destete en alrededor de 20 kg, destacando la variedad Retinto como la población que presenta mejor capacidad de crecimiento en este periodo fisiológico, quedando a la espera de profundizar este estudio con una muestra animal más amplia
Caracterización de las variedades minoritarias del cerdo ibérico por la aptitud sexual del macho. Proyecto inicial
El presente proyecto se propone abordar un criterio absolutamente novedoso para la caracterización de los animales domésticos mediante la utilización de variables relacionadas con la aptitud reproductiva, algo que está especialmente relacionado con la productividad de los animales de ciclo corto dedicados a la producción cárnica. La metodología propuesta a continuación se aplicará a 24 animales en cada fase de estudio en que se utilizarán distintas variedades de cerdo ibérico. Actualmente estamos trabajando con el primer lote de animales, concretamente las variedades Manchado de Jabugo, Retinto y Torbiscal. La caracterización reproductiva abordará cuatro ópticas diferentes. Primeramente se realizarán evaluaciones de características anatómicas externas del aparato reproductor del macho (circunferencia escrotal, volumen, forma e implantación testicular). En segundo lugar se tipificarán los aspectos relacionados con el comportamiento sexual del macho referido tanto a sus actitudes para la monta natural como para la inseminación artificial. En tercer lugar se estudiarán las características del semen (aspectos físicos y morfológicos). Finalmente, se constituirá un banco de germoplasma de cerdos Ibéricos, donde se almacenarán dosis de semen de las diversas variedades de cerdo Ibérico para conservación o intercambio entre investigadores y ganaderos, así como su utilización en programas de inseminación artificial o mejora genética
Criopreservación de semen de las variedades minoritarias del cerdo ibérico: resultados preliminares de la fertilidad "in vivo"
Resumen de la comunicación presentada al III Congreso Ibérico sobre Recursos Genéticos Animale
Development of electrospun photocatalytic TiO2-polyamide-12 nanocomposites
Titanium dioxide (TiO2) in different forms such as films, fibers or particles are being extensively studied
for removal of contaminants from aquatic environments due to its outstanding photocatalytic activity.
This work reports the development of TiO2-polyamide 12 electrospun fiber mats. A systematic study on
the influence of electrospun processing parameters on polymer fiber morphology was performed. It was
observed that the average fiber diameter is mainly influenced by polymer concentration and average
fiber diameters between 404 ± 82 nm and 1442 ± 360 nm were obtained. Polyamide-12 (PA-12) was
used as a polymer matrix and electrospun with 0, 10 and 20 wt% of TiO2. It was observed that the filler
does not change the average fiber diameter, being similar to that observed for neat PA-12 fibers processed
under the same experimental conditions. The TiO2 were particles dispensed not only in the bulk
of the polymeric matrix but also on the surface of the fibers, especially for the samples with higher filler
contents. Neat and nanocomposite electrospun samples show a hydrophobic behavior and a degree of
crystallinity of ~25%.
The photocatalytic performance of the processed samples was measured by following the degradation
capability of a chosen dye, methylene blue (MB). Results show that the nanocomposite samples have a
remarkable photocatalytic activity, especially the one with a higher load of TiO2 particles (20 wt%), with
all MB being removed from the solution after 100 min.This work was supported by FEDER through the COMPETE
Program and by the Portuguese Foundation for Science and Technology
(FCT) in the framework of the Strategic Project PEST-C/FIS/
UI607/2014, and CNPq (Conselho Nacional de Desenvolvimento
Científico e Tecnol ogico e Brazil). The authors also thank funding
from “Matepro eOptimizing Materials and Processes”, ref. NORTE-
07-0124-FEDER-000037”, co-funded by the “Programa Operacional
Regional do Norte” (ON.2 e O Novo Norte), under the “Quadro de
Refer^encia Estrat egico Nacional” (QREN), through the “Fundo
Europeu de Desenvolvimento Regional” (FEDER). PM thanks the
FCT for the, SFRH/BD/98616/2013 grant. VS and SLM also thank
support from the COST Action MP1206 “Electrospun Nano-fibers for bio inspired composite materials and innovative industrial applications”.
VS thanks the EIS Faculty at UOW for the starting grant
Optical and structural analysis of solar selective absorbing coatings based on AlSiOx:W cermets
It is reported in this work the development and study of the optical and structural properties of a solar selective absorber cermet based on AlSiOx:W. A four-layer composite film structure, W/AlSiOx:W(HA)/AlSiOx:W(LA)/AlSiOx, was deposited on stainless steel substrates using the magnetron sputtering deposition method. Numerical calculations were performed to simulate the spectral properties of multilayer stacks with varying metal volume fraction cermets and film thickness. The chemical analysis was performed using X-ray photoelectron spectroscopy and the results show that in the high metal volume fraction cermet layer, AlSiOx:W(HA), about one third of W atoms are in the W-O oxidation state, another third in the Wx+ oxidation state and the last third in the W4+, W5+ and W6+ oxidation states. The X-ray diffractograms of AlSiOx:W layers show a broad peak indicating that both, W and AlSiOx, are amorphous. These results indicate that this film structure has a good spectral selective property that is suitable for solar thermal applications, with the coatings exhibiting a solar absorptance of 94-95.5% and emissivities of 8-9% (at 100 degrees C) and 10-14% (at 400 degrees C). The samples were subjected to a thermal annealing at 450 degrees C, in air, and 580 degrees C, in vacuum and showed very good oxidation resistance and thermal stability. Morphological characterizations were carried out using scanning electron microscopy and atomic force microscopy. Rutherford Backscattering experiments were also performed to analyze the tungsten depth profile.The authors acknowledge the support of the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013. The authors are also grateful to the financial support of FCT, POCI and PORL operational programs through the project POCI-01-0145-FEDER-016907 (PTDC/CTM-ENE/2882/2014), co-financed by European community fund FEDER. The authors also acknowledge GIST Japan for using the XPS-Kratos.info:eu-repo/semantics/publishedVersio
Resistência do solo à penetração e desenvolvimento do sistema radicular do milho (Zea mays) sob diferentes sistemas de manejo em um Latossolo Roxo
Structure of the parasite infracommunity of Sciades proops from the Japaratuba River Estuary, Sergipe, Brazil
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