Spin-polarized transport in ferromagnetic multilayered semiconductor nanostructures

The occurrence of inhomogeneous spin-density distribution in multilayered ferromagnetic diluted magnetic semiconductor nanostructures leads to strong dependence of the spin-polarized transport properties on these systems. The spin-dependent mobility, conductivity and resistivity in (Ga,Mn)As/GaAs,(Ga,Mn)N/GaN, and (Si,Mn)/Si multilayers are calculated as a function of temperature, scaled by the average magnetization of the diluted magnetic semiconductor layers. An increase of the resistivity near the transition temperature is obtained. We observed that the spin-polarized transport properties changes strongly among the three materials.Comment: 3 pages, 4 figure

Nonminimal Maxwell-Chern-Simons-O(3)-sigma vortices: asymmetric potential case

In this work we study a nonlinear gauged O(3)-sigma model with both minimal and nonminimal coupling in the covariant derivative. Using an asymmetric scalar potential, the model is found to exhibit both topological and non-topological soliton solutions in the Bogomol'nyi limit.Comment: 4 pages, 4 figures. Some typos corrected, two references changed. To appear in Physical Review

Características físico-químicas de raízes de mandioca brava (Manihot esculenta Crantz).

A caracterização e avaliação do Banco Ativo de Germoplasma (BAG) de mandioca é fundamental para a sua utilização mais eficiente nos trabalhos de melhoramento genético, portanto o objetivo deste trabalho foi caracterizar 15 genótipos de mandioca brava pertencentes ao BAG da Embrapa Amazônia Oriental. A caracterização físico-química é fator preponderante para a seleção de genótipos, pois permite definir quais genótipos apresentam características desejáveis. Após a colheita das raízes, estas passaram por lavagem, descasque e armazenamento até o momento de utilização nas analises físico-químicas percentual de proteínas variou de 0,1-0,7%; lipídios 0,3-2,1%; umidade 58,0- 65,2%; cinzas de 0,1-1,0%; fibras 0,9-1,9%, carboidratos 13,9-39,4%; acidez 1,1-2,7%; ph 6,3-6,8 e SST de 0,8-1,2. As diferenças encontradas nos resultados podem contribuir para seleção de genótipos promissores a serem utilizados em programas de melhoramento genético

Produções de bagas e de sementes de cultivares de mamoneira na região de Frei Paulo Sergipe.

bitstream/CPATC/19578/1/cot-63.pdfISSN 1678-1937

Bioactive peptides produced from the mussel mytilus galloprovincialis by enzymatic hydrolysis with corolase

Bioactive peptides have been produced from several marine sources since they can exhibit positive effects for humans and animals. Mytilus galloprovincialis is highly consumed in several countries and has a meat rich in proteins, which has been described as a source of bioactive peptides with relevant properties such as antioxidant, anti-hypertensive and antimicrobial activities. Mussel commercialization generates waste, since the small or broken mussels are discarded. Thus, in this work discarded mussels were used with the goal of producing water soluble extracts rich in proteins and bioactive peptides. The mussel meat was firstly minced, and then submitted to different conditions of enzymatic hydrolysis, using the protease corolase to generate peptides. The variable factors evaluated were temperature, incubation time and enzyme concentration. To achieve the optimal extraction conditions, a Box-Behnken experimental design was performed using statgraphic centurion software. Factorial design allowed the evaluation of the effects of the three factors on protein release, antioxidant and anti-hypertensive properties of the extracts. The protein content of each extract was determined by Kjeldahl, the antioxidant activity was determined by oxygen-radical absorbance-capacity (ORAC) assay and anti-hypertensive property was determined by the inhibition method of Angiotensin-I converting enzyme (ACE). The incubation of the minced mussel meat with 3% of enzyme, at 40 ºC for 3 hours, appears to be the best conditions to obtain the best results of protein extraction, and antioxidant and anti-hypertensive properties. With these conditions, the obtained extracts showed 48% of protein content, an antioxidant activity of 821 μmol TE / g of extract, and an ability of inhibiting the activity of ACE in 61% (using a concentration of 10 mg / mL). Thus, the factorial design allowed to confirm the combination of experimental factors that leads to the most efficient extraction of antioxidant and anti-hypertensive peptides of the mussel Mytilus galloprovincialis. In conclusion, the use of discarded mussels to produce functional ingredients for food, cosmetic and pharmaceutic industries contribute to valorise world waste in a circular economy context.info:eu-repo/semantics/publishedVersio

Desempenho de borregas da raça Santa Inês alimentadas com cana-de-açúcar e ramas de amoreira.

O desempenho de borregas alimentadas com dietas compostas de concentrado (20%) e volumoso (80%)a base de cana-de-açúcar( Saccharumo fficinarum cv RB 72-454)e ramas de amoreira (Morus spp.) foi avaliado. Os tratamentos foram: A- 80% de cana-de-açúcari B- 60% de cana-de-açúcaer 20%d e ramasd e amoreira e C- 40%d e cana-de-açúcaer 40%d e ramas de amoreira. O delineamento estatístico foi em blocos casualizados sendo os dados submetidos à análise de regressão. Foram utilizadas 24 fêmeas da raça Santa Inês, com iilade aproximada de cinco meses e peso vivo inicial de 18,3 J: 2,7kg. Avaliou-se o consumo voluntário de matéria seca, o ganho de peso vivo diário e total e a conversão alimentar. Constatou-se efeito linear significativo (P<0,05) para o consumo de matéria seca com o aumento do porcentual de ramas de amoreira na dieta, com conseqüentea umento linear (P<0,05)n o ganho de peso vivo total e diário. Houve redução linear (P<0,05) na conversão alimentar em função do aumento dos níveis de ramas de amoreira. Observaram-se valores mais elevados de fibra em detergente neutro, fibra em detergente ácido, ligninae menor valor de digestibilidade in vitro na cana-de-açúcaer em relação às ramas de amoreira. A cana-de-açúcar como volumoso exclusivo não possibilita desempenho a dequado de borregas, sendo que a associação com ramas de amoreira melhora o desempenho animal

Chemical Evolution of the Galactic Bulge as Derived from High-Resolution Infrared Spectroscopy of K and M Red Giants

We present chemical abundances in K and M red-giant members of the Galactic bulge derived from high-resolution infrared spectra obtained with the Phoenix spectrograph on Gemini-South. The elements studied are carbon, nitrogen, oxygen, sodium, titanium, and iron. The evolution of C and N abundances in the studied red-giants show that their oxygen abundances represent the original values with which the stars were born. Oxygen is a superior element for probing the timescale of bulge chemical enrichment via [O/Fe] versus [Fe/H]. The [O/Fe]-[Fe/H] relation in the bulge does not follow the disk relation, with [O/Fe] values falling above those of the disk. Titanium also behaves similarly to oxygen with respect to iron. Based on these elevated values of [O/Fe] and [Ti/Fe] extending to large Fe abundances, it is suggested that the bulge underwent a more rapid chemical enrichment than the halo. In addition, there are declines in both [O/Fe] and [Ti/Fe] in those bulge targets with the largest Fe abundances, signifying another source affecting chemical evolution: perhaps Supernovae of Type Ia. Sodium abundances increase dramatically in the bulge with increasing metallicity, possibly reflecting the metallicity dependant yields from supernovae of Type II, although Na contamination from H-burning in intermediate mass stars cannot be ruled out.Comment: ApJ in pres