6,971 research outputs found
DOE: high-pressure processing as a pre-treatment for production of raw ewe milk-cheese
info:eu-repo/semantics/publishedVersio
Morphodynamic modelling of a gravel beach at the NW Portuguese coast
Besides exhibiting an erosion trend for decades, the NW coastal zone of Portugal, since the
end of 20th century, was the stage of a new phenomenon. Between Lima and Cávado rivers, previously
dissipative, sandy beaches transformed in mixed sand-gravel beaches with gravelly beach cusps (by the
end of 80?s) and progressively convert in entire reflective gravel beaches (since 2000), though
maintaining the inherited dune systems on their backshore. This beach is being monitored since 2013
using DGPS, aerophotogrametic surveys and expedite gravel size characterization. Based on these
monitoring results a modeling work was carried out to simulate the beach morphodynamics, applying
XBeach-G software. The model was able to simulate the beach morphodynamics
The old and new therapeutic approaches to the treatment of giardiasis: Where are we?
Giardia lamblia is the causative agent of giardiasis, one of the most common parasitic infections of the human intestinal tract. This disease most frequently affects children causing abdominal pain, nausea, vomiting, acute or chronic diarrhea, and malabsorption syndrome. In undernourished children, giardiasis is a determining factor in retarded physical and mental development. Antigiardial chemotherapy focuses on the trophozoite stage. Metronidazole and other nitroimidazoles have been used for decades as the therapy of choice against giardiasis. In recent years many other drugs have been proposed for the treatment of giardiasis. Therefore, several synthetic and natural substances have been tested in search of new giardicidal compounds. This study is a review of drugs used in in vitro and in vivo tests, and also drugs tested in clinical trials (nonrandomized and randomized)
M.S.W. bottom ash : mechanical characterization for road pavement purposes
Neste trabalho são estudadas as propriedades mecânicas, tais como a rigidez e a resistência, de escórias provenientes da incineração de resíduos sólidos urbanos na incineradora da Valorsul, S.A.. Pretende-se avaliar, sob o ponto de vista geotécnico, a viabilidade de utilização deste material alternativo nas camadas estruturais de pavimentos rodoviários. Neste sentido, são
apresentados resultados provenientes dos seguintes ensaios laboratoriais: análise
granulométrica; ensaios C.B.R. e ensaio triaxial estático consolidado não drenado com medição das pressões intersticiais. Este estudo pretende contribuir para a valorização das escórias, cuja produção em Portugal, para 2006, se estima em cerca de 293 000 toneladas por ano. Para além de permitir reduzir a quantidade de resíduos a encaminhar para deposição final, o estudo
também implica a diminuição da exploração de agregados naturais.In this work the mechanical properties are studied, such as the stiffness and the strength, of bottom ashes from the incineration of municipal solid wastes in the Valorsul, S.A. incinerator. It is intended to evaluate, under the geotechnical point of view, the viability of using this alternative material in the structural layers of road pavements. In this direction, they are
presented results proceeding from the following laboratory tests: grain sized analysis; C.B.R. test and undrained consolidated static triaxial test with measurement of the pore water pressures.
This study intends to promote MSW bottom ashes, whose production for 2006, in Portugal, is estimated around 293 000 tons per year. Besides allowing reducing the amount of residues to final deposition, the study also implies the reduction of natural aggregate exploration
Dyeing of PA6.6 fibers - Effect of solvent and temperature on thermal properties
Dyeing fibers at low temperatures has many advantages such as savings in energy and avoiding alterations to the physical properties of the fibers being dyed or other fibers also present in blends, The problem of low temperature dyeing in synthetic fibers is that it difficults the dye diffusion into the fiber. In the case of polyamide 6.6 microfibers, by using benzyl alcohol as an auxiliary dyeing, it was shown that good diffusion was obtained for the dye exhaustion with metal complex dyes at temperatures more than 30°C below the normal dyeing temperature for the dye exhaustion with metal complex dyes. Using thermal analysis methods these results were shown to be caused by the lowering of the T g of the fiber when in the presence of benzyl alcohol.Fundação para a Ciência e a Tecnologia (FCT
Indicadores mineralógicos de drenagem ácida (ARD) em cortes de estrada em diferentes unidades litoestratigráficas
Construction of highways in some particular geological conditions exposes pyrite and other associated sulfides to oxidative weathering. This generates a process known as acid rock drainage. As a consequence, typical properties of acid drainage may develop, such as precipitation of soluble salts efflorescences. Also, acidic and metal-rich runoff from the exposed road cuts may pose concerns about the surface and groundwater contamination as well as regarding the structural robustness and the safety of the road slopes.
In the North of Portugal, particularly in the Minho region there are geological conditions that promote the development of natural acidic and metal contamination. Such acid rock drainage appears as an exuberant phenomenon in several highway cuts, where the sulfide-rich exposed rocks are suffering oxidation. The present work reveals the occurrence of acid rock drainage sites in road cuts in the north of Portugal, relating this process with the geology of the terrains. Thus, it describes the sources of acid and metals and the respective genesis conditions, and presents the mineralogical indicators of such a geochemical process, which are dominated by magnesium sulfates. Moreover, remediation measures are pointed out, some of them already implemented in some sites.A construção de infraestruturas viárias em certas condições geológicas pode expor minerais como os sulfuretos a mecanismos
de dissolução oxidativa. A complexa cadeia de reacções que se desencadeia gera um processo de drenagem ácida, que na
bibliografia anglo-saxónica é conhecida por “Acid Rock Drainage” (ARD). Como consequência, desenvolvem-se propriedades
típicas de uma contaminação ácida, idêntica à que se observa em contexto mineiro, tais como a precipitação de sais solúveis.
Para além desta manifestação mineralógica, as águas de escorrência criam preocupações ambientais, especificamente no que
respeita à qualidade do meio hídrico, mas também quanto à estabilidade dos taludes sujeitos a uma meteorização química
acelerada.
No Norte de Portugal, particularmente na região do Minho, existem condições geológicas favoráveis ao desenvolvimento deste
processo, que se manifesta de forma exuberante nalguns cortes de auto-estrada. O presente trabalho revela a ocorrênca de
sítios afectados, relacionando o processo com a geologia dos terrenos em que se implementaram estas vias. Descreve-se a
origem da drenagem ácida e apresentam-se indicadores mineralógicos da evolução geoquímica das rochas mais reactivas,
dominados pela presença de sulfatos de magnésio. Apontam-se ainda exemplos de medidas de remediação, algumas já
implementadas em certos sectores das vias afectadas.This work was co-funded by the EU, based on COMPETE 2020, project ICT (UID/GEO/04683/2013), reference POCI-01-0145-FEDER-007690, national funds provided by FC
Ocorrência de eflorescências sulfatadas na mina de São Domingos
The intense exploration of sulphide ore deposit in São Domingos mine, produced considerable amount of sulphide material that when are exposed to weathering generates acid mine drainage (AMD). The main goal of this paper is to study a specific occurrence regarding composition and morphology of the salts that arise at the end of the dry season. Soluble salts appear at the banks of the drainage channels and over the waste materials, exhibiting different colours and aspects. The obtained results showed by X-Ray diffraction and scanning electronic microscopy, that the mineralogy of salt efflorescences is dominated by sulphates, displaying different occurrence modes. Melanterite and copiapite are the main iron sulphates while minerals from the series of pickeringite-halotrichite dominate the aluminium sulphates. In addition, dehydration and dissolution laboratory experiments were carried out in order to simulate the transformations suffered by soluble salts and evaluate the environmental effect in aquatic system.Patrícia Gomes wishes to acknowledge FCT (Science and Technology Foundation, Portugal) by the research fellowship under the POCH (Programa Operacional Capital Humano) supported by the European Social Fund and National Funds of MCTES with reference SFRH/BD/108887/2015. This work was co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020
(Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/2013) with
reference POCI-01-0145-FEDER-007690 and national funds provided by FCT (Science and Technology Foundation, Portugal)
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