4,582 research outputs found
Sistemas de cultivo para rendimento elevado em trigo e o desafio das correlações indesejadas.
bitstream/CNPT-2010/40666/1/p-do48.pd
Surface properties of extracts from cork black condensate
The insulation corkboard production generates black condensate
(BC), a paste-like solid waste. It is hydrophobic and
has the potential to be used as protective coating. To evaluate
this potential, coatings were prepared from BC extracts and
their surface behavior was evaluated by contact angle (CA)
measurements. The CA dynamics were recorded as a function
of time; advancing CAs were also registered; the
approaches were applied according to Fowkes, Owens-
Wendt-Rabel-Kaelble (OWRK), and Van Oss to determine
the surface energy (SE) for each coating. Depending on the
liquid probe, three phenomena were observed: water evaporation,
diiodomethane diffusion into the coating, and rearrangement
of the chemical groups on the coating surface,
when glycerol was dropped onto the surface. Based on the
results from the CA dynamics, the applicability of the coatings
against hydrophobic environments was limited owing to
its affinity to apolar compounds. The results show that the
coating prepared by the toluene BC extract was the best coating.
The key data were: water CA of 99.38, total SE (between
37.4 mN m-1 and 40.1 mN m-1), SE polar component
(0.1 mN m-1), and the acidic and basic characters were negligible.
It can be concluded that the BC extracts have potential
for coatings.R.P. acknowledges a post-doc research grant BPD/39333/2007 from the Portuguese Foundation for Science and Technology (FCT). We gratefully acknowledge Amorim Isolamentos S.A. for the supply of black condensate
Embrapa Trigo: carteira de projetos de pesquisa e desenvolvimento em 2010.
bitstream/CNPT-2010/41153/1/p-do120.pd
Embrapa Trigo: carteira de projetos de Pesquisa e Desenvolvimento em 2008.
bitstream/CNPT-2010/40710/1/p-do92.pd
Uma discussão sobre o conceito de hazards e o caso do furacão/ciclone Catarina.
bitstream/CNPT-2010/40654/1/p-do36.pd
Monitoramento de doenças fúngicas em cultivares de trigo no Rio Grande do Sul.
Orientador: João Leodato Nunes Maciel
Ensaio estadual de cultivares de trigo do Rio Grande do Sul, 2009.
bitstream/item/34686/1/ensaio-estadual-cultivares2009.pd
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