783 research outputs found
Preliminary note on the soils of Madeira
No presente trabalho dá-se uma informação preliminar sobre os solos que predominam na ilha da Madeira, adoptando-se para o efeito as unidades estabelecidas para a Carta de Solos do Mundo da FAO/UNESCO.
O trabalho começa por descrever de uma maneira muito sucinta o território madeirense, considerando-se, além do respectivo enquadramento geográfico, os seus aspectos geológico/litológico, morfológico, climático e vegetacional. Apresenta seguidamente a classificação e as características gerais dos principais tipos de solos que ocorrem na ilha. Por fim define as associações em que os diversos solos identificados se agruparam para fins cartográficos, mostrando a sua distribuição geográfica em esboço pedológico elaborado na escala de 1:150 000.
As unidades-solo dominantes na ilha da Madeira são Regossolos, Litossolos, Rankers, Vertissolos, Xerossolos, Faeosemes, Cambissolos e «Amorfissolos»info:eu-repo/semantics/publishedVersio
Aspectos micromorfológicos de solos de uma topossequência ocorrendo em zona tropical húmida (Superficie da Quibala - Angola)
info:eu-repo/semantics/publishedVersio
Exchangeable complex and taxonomy and management of ferrallitic soils from Angola
The cation exchange capacity, sum of exchangeable bases, and saturation base degree of Ferralitic soils from the Republic
of Angola, determined by the Mehlich and ammonium acetate methods, were compared to update their taxonomy;
also, the exchangeable acidity was determined for deeper insight in their classification. Fourty eight representative
pedons of subordens of those soils (Tipoferralic, Weakly Ferralic and Psamoferralic) were analysed. Values of sum
bases and exchangeable Ca2+ and Mg2+ by the two methods were strongly correlated; cation exchange capacity, base
saturation degree and exchangeable K+ showed weaker and variable correlations, according to soil type. Exchangeable
acidity largely corresponded to Al3+, but its content was mostly less than one cmolc kg-1; its percentage regarding the
effective cation exchange capacity was mostly higher than 60%. Study soils show in overall subsurface horizons with
the characteristics of a ferralic horizon; therefore, they are mostly Ferralsols, which can be separated at first level in geric,
vetic e haplic Ferralsols, according to the effective cation exchange capacity value; also, at second level they are largely
dystric and, in great proportion, alumic. The weakness of study soils regarding the low nutrient retention capacity can
be alleviated by organic matter additions and limin
Constitutintes minerais amorfos em solos mediterrâneos vermelhos de xistos paleozóicos
No presente trabalho determinam-se os produtos minerais amorfos
(Fe, AI e Si) nos horizontes A, B e C de três perfis típicos de
Solos Mediterrâneos Vermelhos de xistos paleozoicos, recorrendo-se
para isso ao método preconizado por Segalen. Nestes solos, as formas
não cristalinas dos constituintes referidos estão presentes em teores
relativamente baixos — praticamente não existe sílica e os produtos
aluminosos têm expressão quantitativa muito fraca, só o ferro se
encontrando significativamente representadoinfo:eu-repo/semantics/publishedVersio
The perspective of cyclists on current practices with digital tools and envisioned services for urban cycling
This is a preprint version of an accepted manuscript in WorldCist'21 -9th World Conference on Information Systems and TechnologiesAs cycling becomes increasingly important in sustainable mobility
policies, there is also an urge for new digital applications and services for urban
cycling. This new generation of cycling applications should be able to connect
cyclists with their local cycling ecosystem, promote cycling, and empower cyclists
to become active agents of urban mobility. In this work, we aim to explore
the new opportunity space of digital tools and applications designed specifically
for urban cycling. We pursue this goal by trying to uncover current practices associated
with digital tools that are already available and also by trying to uncover
new information needs, even those that cyclists are not yet able to fully express.
To explore these topics, we conducted 2 focus group sessions and 10 interviews
with cyclists. The result is a set of design opportunities for the development of
new applications, tools and methods for improving the cycling experience in the
context of urban mobility. We expect this contribution might help to better define
the design space of innovative digital tools for urban cyclists.This work is supported by: European Structural and Investment Funds in the FEDER
component, through the Operational Competitiveness and Internationalization Programme
(COMPETE 2020) [Project nº 039334; Funding Reference: POCI-01-0247-
FEDER-039334
Influence de la fertilisation azotée dans le complexe d'échange d'un sol brun acide derivé de granite
Estuda-se quantitativamente, num Solo Pardo Florestal Podzólico
derivado de granito, as modificações que sofre o complexo de troca
por influência de diferentes tipos de adubação azotada (sulfato de
amónio, sulfato de amónio com calcário, nitroamoniacal a 20,5 °/0
de N e cianamida cálcica aplicados em três doses), ao fim de dez anos
de cultura em caixas lisimétricasinfo:eu-repo/semantics/publishedVersio
Dosage gazométrique du carbone organique du sol par l'appareil de Strohlein
Neste trabalho comparam-se os resultados obtidos para o carbono
orgânico do solo pelo aparelho de Strõhlein (utilizado na determinação
do carbono no aço e no ferro) e pelo clássico método de combustão
lenta por via seca que se considerou como método padrão. Analisaram-
se 108 amostras pertencentes a vários tipos de solos tropicais
diferindo bastante quanto a teores em matéria orgânica e a outras
característicasinfo:eu-repo/semantics/publishedVersio
How to prepare a power system for 12% wind energy penetration: The Portuguese Case Study
The 2001/77/CE Renewable Energies European Directive together with Kyoto Protocol ratification supported by a Government vision and strong objective on the reduction of external oil dependence put Portugal in the front line to achieve one of the highest wind energy penetrations within ten years time. This paper gives a summarized overview of the Portuguese technical approaches and methodologies followed in order to plan and accomodate the ambitious wind power goals to 2010/2013, preserving the overall quality of the power system
Microbiological characterization of protected designation of origin Serra da Estrela cheese
Serra da Estrela is the oldest and most recognizable traditional protected designation of origin (PDO) cheese from Portugal. It has been extensively studied over the years, but the latest microbial characterization is 20 years old. Hence, this work aimed to perform an updated characterization of Serra da Estrela PDO cheeses and raw materials. Our analysis showed that lactic acid bacteria content on Serra da Estrela cheeses exceeded 8.8 log CFUsg−1 , in all analyzed samples, with lactococci, lactobacilli and Leuconostoc spp. predominating over enterococci strains. Moreover, lactococci and lactobacilli abundance increased across the production season, while enterococci dropped considerably in late manufactures. Lastly, Leuconostoc spp. content remained unchanged in all analyzed periods. A correspondence analysis showed that L. paracasei, L. lactis, E. durans, E. faecium and L. mesenteroides are transversal in Serra da Estrela cheese manufacturing and were closely associated with milk, curd and cheese matrices. Additionally, L. casei, L. plantarum and L. curvatus were specifically associated with cheese matrices, possibly active during ripening and contributing for the development of these cheeses’ organoleptic characteristics.9814-6B05-9C03 | Ricardo Miguel Pereira Pintoinfo:eu-repo/semantics/publishedVersio
Forestry covers and fertility recover in ferrallitic soils from Angola
Effects of different forestry covers - “mata de panda” (MP), Pinus patula (PP) Eucalyptus grandis (EG) and Grevillea robusta (GR) - installed between 1965 and 1968 in the Estação Experimental Agrícola da Chianga (Huambo, Angola), on chemical properties of Ferrallitic Soils were assessed up to 30 cm depth, as compared to those observed in nearby conventional agricultural fields. Only the soils of the areas with EG and GR showed a clear improvement in their reaction, content of organic carbon and of extractable non-acid cations and effective cation exchange capacity, usually up to 10 cm depth. The improvement associated with “mata de panda” was less pronounced and that of PP plantations was negligible or nil. The recover capacity of soil fertility may depend on the nature of tree cover as well as on the soil characteristics itself. Results also indicate that the low soil capacity to retain cations exhibited by soils of the Planalto Central of Angola can be increased through both acidity correction and increasing the content of soil organic matte
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