216 research outputs found
EFEITO DA UMIDADE E DA TEMPERATURA NO PROCESSAMENTO DE FARINHA DE BANANA VERDE (Musa acuminata, GRUPO AAA) POR EXTRUSÃO TERMOPLÁSTICA
Testou-se a utilização de farinha de banana da variedade
Nanicão no processo de extrusão termoplástico, visando
analisar as características dos produtos obtidos em função
das variáveis umidade e temperatura de extrusão. Os
experimentos variaram em torno dos pontos centrais de
umidade e temperatura de 20% e 150ºC, respectivamente,
observando-se o efeito conjugado dessas variáveis sobre
as características físicas e físico-químicas dos produtos
extrusados. O processo de extrusão propiciou grande
degradação do amido de banana e as amostras
apresentaram elevado grau de gelatinização em todas as
condições estudadas. O índice de solubilidade aumentou
com a elevação da temperatura e diminuição da umidade.
Verificou-se maior viscosidade de pasta a frio e a quente
com aumento da umidade da matéria-prima. As maiores
taxas de expansão foram obtidas com temperaturas mais
elevadas e umidades mais baixas. A energia mecânica
específica foi reduzida conforme o aumento da umidade e
da temperatura de extrusão. Confirmou-se a quebra da
molécula de amido sob as condições de extrusão pela
redução do conteúdo de amido das amostras
Localization of coated iron oxide (Fe3O4) nanoparticles on tomato seeds and their effects on growth
IFood demand due to the growing population globally has been stretching the agriculture sector to the limit. This demands the cultivation of plants in shrinking land areas which makes the search for highly effective systems for plant nutrition and pest control important. In this context, the application of nanoparticles (NPs) in agriculture can have a transformative effect on food production techniques as it can enable the delivery of bioactive agents (including growth factors, pesticides and fungicides) directly to plants. Herein we report the application of unfunctionalized as well as amine-functionalized and polycaprolactone-coated Fe3O4 nanoparticles (NP) to seed treatment and plant growth. The study reveals that the treatment has no side effects on plant germination and development. Furthermore, the penetration of NPs in tomato seeds (Solanum Lycopersicum) and their translocation in tomato seedlings post-treatment depends on the level of the NPs functionalization. The research also demonstrates that a fraction of NP is preferentially translocated to tomato seedling roots and shoots, however, uptake is lower for functionalized NPs (both amine and PCL). Thus, the results suggest that the functionalization of NPs can act as a versatile platform for delivering of active compounds, such as fungicides and growth factor agents
CCR5D32 mutation in three Brazilian populations of predominantly Sub-Saharan African ancestry
This study reports the frequencies of the CCR5D32 mutation of the beta-chemokine 5 gene and discusses the possible effects of past and recent gene flow in three quilombo remnants (Brazilians communities with anthropological African ancestry whose ancestors were escaped slaves): Rio das Rãs, Mocambo, and São Gonçalo in the northeastern region of Brazil. The CCR5D32 allele frequency of the Mocambo population was significantly higher (5.6%) than that found in the Rio das Rãs (1%) and São Gonçalo (0.9%) populations. These differences may reflect different proportions of parental populations in the founders individuals, a founder-effect and/or different histories of inter-ethnic contact. The frequency of the CCR5D32 allele in the Mocambo sample is similar to that found in those urban Brazilian populations which have a large amount of European genetic input, indicating a European contribution to the gene pool of this population and suggesting that, perhaps since its foundation, Mocambo has had a high level of admixture or experienced a founder-effect
Decoherence control in microwave cavities
We present a scheme able to protect the quantum states of a cavity mode
against the decohering effects of photon loss. The scheme preserves quantum
states with a definite parity, and improves previous proposals for decoherence
control in cavities. It is implemented by sending single atoms, one by one,
through the cavity. The atomic state gets first correlated to the photon number
parity. The wrong parity results in an atom in the upper state. The atom in
this state is then used to inject a photon in the mode via adiabatic transfer,
correcting the field parity. By solving numerically the exact master equation
of the system, we show that the protection of simple quantum states could be
experimentally demonstrated using presently available experimental apparatus.Comment: 13 pages, RevTeX, 8 figure
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