RESUMO Rentabilidade da produção de ovinos depende da resposta reprodutiva de ovelhas e do crescimento de seus cordeiros, o que pode ser melhorado por meio do genótipo masculino. O objetivo deste estudo foi avaliar o desempenho reprodutivo de ovinos Blackbelly (Bb), Pelibuey (Pb), Katadin (Kat) e Dorper (Dor) e o crescimento de cordeiros com carneiros Damara (Dam) e Dor. Para medir a porcentagem de partos simples e múltiplas (MLP), foram utilizados 234 ovelhas Bb, PB, Kat e Dor. Para medir o crescimento dos cordeiros, foram utilizadas 86 ovelhas Bb x Pb (BbPb) e 73 Kat x Dor (KatDOR). Quatro cordeiros Dor x BbPb, seis Dam x BbPb e seis Dam x KatDor foram sacrificados para avaliação de carcaça. MLP foi analisada com o procedimento CATMOD, considerando-se fatores como idade e raça. Dados de crescimento do cordeiro foram analisados com o procedimento MIXED, e as de características de carcaça com o procedimento GLM do SAS, utilizando-se peso ao sacrifício como covariável. MLP foi maior (P<0.05) em Bb do que em Dor. Os cordeiros Dor x BbPb foram mais pesados (P<0.05) no nascimento do que Dam x BbPb. Em partos simples e múltiplos, os cordeiros de ovelhas KatDor foram mais pesados (P<0.05) no momento do nascimento de cordeiros BbPb. As cordeiras de carneiros Dor apresentaram maior (P<0.05) ganho de peso após o desmame do que as de carneiros Dam. O rendimento de carcaça, a espessura da gordura subcutânea e o rendimento de corte primal não foram diferentes por efeito da raça de carneiro. Conclui-se que as ovelhas Bb são mais prolíficas do que as ovelhas Dor; cordeiros de carneiros Damara tiveram resposta de crescimento pós-desmame e rendimento de carcaça semelhantes aos dos carneiros Dor, embora Dorper cordeiras fossem mais pesadas do que as de Damara.

ABSTRACT Profitability of sheep production depends on the reproductive response of ewes and growth of their lambs, which can be improved through the ram genotype. The aim of this study was to evaluate the reproductive response of Blackbelly (Bb), Pelibuey (Pb), Katahdin (Kat) and Dorper (Dor) ewes crossed with Damara (Dam) and Dor rams and the growth of their offspring. To measure percentage of single and multiple lambings (MLP), 234 Bb, Pb, Kat and Dor ewes were used. To measure lamb growth, the offspring of 86 Bb x Pb (BbPb) ewes and 73 Kat x Dor (KatDOR) ewes were used. Four Dor x BbPb, six Dam x BbPb and six Dam x KatDor lambs were slaughtered for carcass assessment. MLP was analyzed with the CATMOD procedure considering the factors age and breed. Lamb growth data were analyzed with the MIXED procedure, and those of carcass characteristics with the GLM procedure of SAS, using weight at slaughter as covariable. MLP was higher (P<0.05) in Bb than in Dor. The Dor x BbPb lambs were heavier (P<0.05) at birth than Dam x BbPb. Of the lambs from single and multiple births, the KatDor lambs were heavier (P<0.05) at birth than BbPb lambs. The female lambs of Dor rams had higher (P<0.05) weight gain after weaning than those of Dam rams. Carcass dressing, subcutaneous fat, and primal cut yield were not different (P>0.05) by effect of ram breed. It is concluded that Bb ewes are more prolific than Dor ewes; male lambs of Dam rams had post-weaning growth response and carcass yield similar to those of Dor rams, although the female lambs of Dor rams were heavier than those of Dam rams.

Colloidal gold nanoparticles have been used as biomaterials since the 1970's. The main goal of developing biological sensors is to identify a number of human diseases and infections with high specificity and sensibility. Two of the most used methods to fabricate biofilms are the Langmuir-Blodgett and the Self-Assembled Monolayer techniques, which are used to obtain homogenous organic and inorganic monolayer films and thin films of organic compounds, respectively. We describe the fabrication of ring-structure colloidal gold nanofilms using both methods. Nanofilms were further characterized by X-Ray Diffraction, Fourier Transformed Infrared Spectroscopy, Ultraviolet-Visible Spectroscopy, and Atomic Force Microscopy.

A set of Ga xIn1-xAs ySb1-y quaternary layers were grown on (100) GaSb substrates using the liquid phase epitaxy technique (LPE). These layers were doped with tellurium and were characterized by Raman, Photoluminescence (PL) spectroscopy, and Secondary Ion Mass Spectroscopy (SIMS). Several optical modes were identified by performing Raman spectroscopy characterization at room temperature and observing the effect of the impurity concentration on the Raman mode frequencies. From secondary ion mass spectrometry the concentrations of Te in the liquid solutions and the electron densities present in the layers were obtained. Finally, these last results were compared with those obtained from low temperature photoluminescence spectroscopy measurements at low temperatures on this set of samples.

Colloidal dispersions of InP@ZnS nanoparticles were prepared using a single-step heating-up method relying at low temperature. The obtained particles are highly crystalline, monodisperse and exhibit size-dependent radiative emission in the range of 329−480 nm. By simply varying the concentration of the molecular precursor, the particles size can be controlled in the range from about 1.1 to 4.5 nm. The formation of InP nanocrystals has been confirmed using the techniques TEM, HRTEM, PL and UV-Vis spectroscopy.

In this work, we evaluated the effect of variation in concentration and the successive or simultaneously addition of reactants on size, dispersion and morphology of SiO2 nanospheres. Particles with different diameters were obtained by hydrolysis and condensation of TEOS in an ammonium hydroxide and alcohol solution. Simultaneously or successive addition of TEOS to different ammonium hydroxide solutions varying in concentration produced SiO2 nanoparticles with sizes ranging between 22 and 230 nm. Bigger and mono-dispersed particles were obtained at higher concentrations of ammonium hydroxide. However, when lower concentrations of ammonium hydroxide were employed, the particle size diminished but dispersion increased. The quantity of prepared sample had not a significant effect in structural properties of particles. The subsequent addition of TEOS produced SiO2 surfaces with increased roughness. Transmission electron microscopy was used to monitor the formation, size and morphology of SiO2 nanospheres. The samples was characterized with FT-IR spectroscopy we find that the nanospheres have a composition of SiO2 regardless of the experimental conditions used growth.

En este trabajo, evaluamos el efecto en el tamaño, dispersión y en la morfología de nanoesferas de SiO2 producido por la variación en la concentración y en la adición (sucesiva o simultanea) de reactantes. Partículas con diferentes diámetros fueron preparadas por hidrólisis y condensación de TEOS en una solución de hidróxido de amonio y alcohol. Con la adición simultánea y sucesiva del TEOS con diferentes contenidos de hidróxido de amonio se obtuvieron nanopartículas de SiO2 con tamaños en el rango entre 22-320 nm. Las partículas más grandes y monodispersas se obtuvieron con las mayores concentraciones de hidróxido de amonio. Sin embargo, cuando se prepararon concentraciones más bajas, el tamaño de las partículas disminuyó pero se incrementó la dispersión. La cantidad de muestra preparada no presentó efecto significativo en las propiedades estructurales de las partículas. Superficies con mayor rugosidad de SiO2 son resultado de la adición sucesiva de TEOS. Microscopia electrónica de transmisión fue empleada para monitorear la formación, tamaño y morfología de las nanoesferas de SiO2. Las muestras fueron caracterizadas por FT-IR mostrando que la composición de las nanoesferas es de SiO2 independientemente de las condiciones experimentales de crecimiento.

R6G dye with gold nanoparticles was prepared in water solution. Using a thermal lens experimental setup, the thermal diffusivity of R6G in presence of gold nanoparticles with Au different concentration was measured. The results show that, the thermal diffusivity of R6G dye mixed with gold nanoparticles increases with the increase of particle metallic concentration, enhancing the thermal diffusivity in the solution. The thermal diffusivity of the samples was studied for a constant concentration of R6G dye 0.1 g/L. The diffusivities were obtained by using the thermal lens aberrant model with lasers arranged in the mismatched mode. The characteristic time constant of the transient thermal lens was obtained by fitting the theoretical expression, for transient thermal lens, to the experimental data. UV-Vis spectroscopy and TEM were used to characterize the R6G dye gold nanoparticles.