109 research outputs found
Cloud water interception in the high altitude tree heath forest (Erica arborea L.) of Paul da Serra Massif (Madeira, Portugal)
Cloud water interception (CWI) occurs when cloud droplets are blown against the forest canopy, where they are retained on
the vegetation surface, forming larger water droplets that drip into the forest floor. CWI was measured from 1 October 1997
to 30 September 1999, on a first-line tree heath (Erica arborea), at Bica da Cana, Madeira Island. Rainfall was corrected
for wind-loss effect and compared with throughfall and other climatological normals. The CWI depletion rate along a forest
stand transect was also analysed during three distinct fog events in 2008. Cloud water was 28 mm day 1, corresponding to
68% of total throughfall and 190% of the gross precipitation. Cloud water correlates directly with monthly normals of fog
days and wind speed and correlates inversely with the monthly air temperature normal. CWI has an exponential correlation
with monthly relative humidity normal. Cloud water capture depletion along the stand shows a logarithmic decrease. Although
a forest stand does not directly relate to a first-line tree heath, this study shows that CWI is a frequent phenomenon in the
Paul da Serra massif. Restoration and protection of high altitude ecosystems in Madeira should be a priority, not only for
biodiversity, ecological and economical purposes but also for its role in regional water resources.info:eu-repo/semantics/publishedVersio
L'interception de l'eau des nuages dans la forêt tempérée de lauriers de l'Ile de Madère
A cloud belt frequently forms on the windward side of Madeira Island, between 800 and 1600 m a.s.l.,
as a result of adiabatic cooling of the northeastern trade winds that are forced upward. Temperate laurel forest is
the most common vegetation inside that cloud belt altitudinal range. Cloud water interception was estimated by
comparing precipitation and throughfall during a hydrological year. It totalled 200 mm (8% of rainfall) during
65 days (3 mm d-1) and seems to constitute a larger fraction of water input during drier months. Multiple linear
regression between gauge standard deviation and throughfall throughout rain events shows that cloud interception
is common before the onset of rainfall. Its role in the ecohydrology of laurel forest and in the island’s hydrology
should be acknowledged. Further studies on this issue should be a priority in order to better understand these
dynamics and provide tools for the correct management of this protected forest and the island’s groundwater
resources.Une ceinture de nuages se forme fréquemment sur le côté au vent de l’île de Madère, entre 800 et
1600 m d’altitude, à la suite du refroidissement adiabatique des alizés de Nord-Est qui sont poussés en altitude.
La forêt tempérée de lauriers est la végétation la plus courante dans cette fourchette d’altitude de la ceinture de
nuages. L’interception de l’eau des nuages a été estimée en comparant les précipitations et le pluviolessivat au
cours d’une année hydrologique. Ce dernier s’élève à 200 mm (8% des précipitations) pendant 65 jours (3 mm
jour−1) et semble constituer une partie importante de l’apport d’eau pendant les mois les plus secs. La régression
linéaire multiple entre l’écart-type des précipitations et le pluviolessivat pendant les épisodes de pluie montre que
l’interception de l’eau des nuages est fréquente avant le début des pluies. Son rôle dans l’écohydrologie du laurier
et sur l’hydrologie de l’île devrait être reconnu. La poursuite des études sur cette question devrait être une priorité
afin de mieux comprendre cette dynamique, et de pouvoir fournir des outils pour une bonne gestion de cette forêt
protégée et des ressources en eau souterraine de l’île.info:eu-repo/semantics/publishedVersio
Improved Generation of Identifiers, Secret Keys, and Random Numbers From SRAMs
This paper presents a method to simultaneously improve the quality of the identifiers, secret keys, and random numbers that can be generated from the start-up values of standard static random access memories (SRAMs). The method is based on classifying memory cells after evaluating their start-up values at multiple measurements in a registration phase. The registration can be done without unplugging the device from its application context, and with no need for a complex laboratory setup. The method has been validated experimentally with standard low-power SRAM modules in two different application specific integrated circuits (ASICs) fabricated with the 90-nm TSMC technology. The results show that with a simple registration the length of the identifiers can be reduced by 45%, the worst case bit error probability (which defines the complexity of the error correcting code needed to recover a secret key) can be reduced by 64%, and the worst case minimum entropy value is improved, thus reducing the number of bits that have to be processed to obtain full entropy by 81%. The method can be applied to standard digital designs by controlling the external power supply to the SRAM using software or by incorporating simple circuitry in the design. In the latter case, a module for implementing the method in an ASIC designed in the 90-nm TSMC technology occupies an active area of 42, $025~mu text{m}^{mathrm {mathbf {2}}}
Reply to comment on Prada et al. 2012. ‘Cloud water interception in the high altitude tree heath forest (Erica arboreaL.) of Paul da Serra Massif (Madeira, Portugal)’. Hydrological Processes 26: 202-212
info:eu-repo/semantics/publishedVersio
Geologia e recursos hídricos subterrâneos da Ilha da Madeira
Nesta tese da especialidade de Hidrogeologia, é apresentado um primeiro
levantamento vulcano-estratigráfico da ilha da Madeira. Os trabalhos de campo
permitiram definir, até agora, sete unidades geológicas principais, descritas da mais
antiga para a mais recente:
1- Complexo Vulcânico Antigo (CA)
2- Calcários Marinhos dos Lameiros - S. Vicente (CM)
3- Depósito Conglomerático-Brechóide (CB)
4- Complexo Vulcânico Principal (CP)
5- Complexo Vulcânico S. Roque/Paul (SRP)
6- Episódios Vulcânicos Recentes (VR)
7- Depósitos de Vertente (dv), Fajãs (fj), Quebradas (q), Depósitos de Enxurrada
Recentes (dr), Areias de Praia (ap), Dunas Fósseis (df), Terraços (t), e Aluviões (a)
A caracterização climática da ilha da Madeira foi feita com base nos dados
recolhidos em 27 pontos de observação climatológicos, dos quais 14 são estações
meteorológicas e 13 são postos udométricos, o que representa uma densidade de 1
ponto de observação/27 km2. Constatou-se que a variação da precipitação com a
altitude não era linear e dependia da orientação das vertentes.
Efectuou-se o balanço hídrico sequencial diário, com base nos valores de
precipitação média diária, registados no Paul da Serra, durante os últimos 15 anos
hidrológicos.
Pretendeu-se quantificar a precipitação oculta na vegetação típica da ilha da
Madeira, de modo a poder avaliar a contribuição daquele tipo de precipitação para
os recursos hídricos subterrâneos, e, ainda, determinar qual o potencial daquele
recurso natural, como contribuição importante às fontes tradicionais de abastecimento de água à ilha. Para o efeito, procedemos a dois tipos principais de
medição: medição directamente sob a vegetação de altitude da Madeira, o urzal, que
se desenvolve entre os 1200 e os 1600 m de altitude, e construção de aparelhos
constituídos por obstáculos artificiais, de modo a interceptarem as gotículas de água
contidas no nevoeiro. Pela sua importância, os resultados obtidos justificam o
desenvolvimento futuro deste estudo.
A caracterização hidrodinâmica das formações da ilha da Madeira baseou-se nas
observações feitas no interior das galerias e túneis em escavação, na análise dos
registos de caudais de galerias e nascentes e na interpretação de ensaios de
bombeamento dos furos de captação. Os dados evidenciam a grande
heterogeneidade e anisotropia características do meio vulcânico. As
transmissividades vão desde 11 m2/d até 25 766 m2/d.
A caracterização hidrogeoquímica permitiu identificar um grupo de 5 águas termais,
emergentes em falhas, no Complexo Antigo, com características muito próprias,
bastante distintas das restantes, que representam, quer em quantidade, quer em
volume de caudais captados, a grande maioria das águas da ilha da Madeira. O
principal fenómeno mineralizador das águas é a hidrólise de minerais silicatados,
verificando-se, nas águas dos furos, nas das nascentes de altitude e nas situadas
próximo do litoral, o efeito da contaminação de sais de origem marinha.
A partir dos dados hidrogeológicos obtidos, foi possível elaborar um modelo
conceptual de funcionamento hidrogeológico para a ilha da Madeira, que, apesar de
possuir alguns elementos comuns, é, no seu conjunto, diferente dos modelos
conhecidos para outras ilhas vulcânicas, nomeadamente, Canárias, Reunião, Havai e
Polinésia Francesa
Fog precipitation and rainfall interception in the natural forests of Madeira Island (Portugal)
Situated in the Atlantic Ocean, Madeira is a within-plate volcanic island, approximately 600 km
northwest of the Western African coast. Cloud cover formed mainly of orographic origin persists on
Madeira for more than 200 days per year between 800 m and 1600 m altitude. Since vegetation occupies
2/3 of the island’s surface, fog precipitation, which occurs when fog droplets are filtered by the forest
canopy and coalesce on the vegetation surfaces to form larger droplets that drip to the forest floor, is an
important hydrological input. Rainfall interception and fog precipitation data were collected between
1996 and 2005 in the natural forests of Madeira. Six throughfall gauges were placed under the canopy of
three different types of forest: high altitude tree heath forest (1580 m), secondary tree heath forest
(1385 m) and humid laurisilva forest (1050 m). Fog precipitation is higher under high altitude heath
forest (average canopy interception was 225% of gross precipitation) and dependent both on altitude
and vegetation type, due to different tree architecture and leaf shape. Although results are conservative
estimates of fog precipitation, they point towards the importance of fog-water as a source of
groundwater recharge in the water balance of the main forest ecosystems of Madeira.info:eu-repo/semantics/publishedVersio
Update of the therapeutic planning of irrigation and intracanal medication in root canal treatment. A literature review
The success of endodontic treatment derives from the complete elimination of microorganisms capable of causing an intraradicular or extraradicular infection. To achieve a more effective eradication of these microorganisms, endodontic instrumentation must always be implemented with abundant irrigation, which has to achieve chemical, mechanical and biological effects. The irrigators most used today are NaOCl, CHX and EDTA, released into the ducts through different techniques such as syringe, manual agitation, positive or negative apical pressure, sonic or ultrasonic activation, PIPS and PDT. The objective of this review is to update the different irrigating solutions and intracanal disinfection drugs, as well as to establish an irrigation protocol in the endodontic treatment. Systematic search of scientific articles in the databases PubMed, Medline and Google Scholar, with the following keywords Endodontic, Infection, Failure, Irrigation, Retreatment and Irrigation protocol. The exclusion criteria were ?case report? articles and articles with a publication date prior to 2000. 48 articles that met the inclusion criteria were analyzed. Comparing the different articles it can be seen that the NaOCl is the ?gold standard? in terms of immediate antimicrobial efficacy, followed by the CHX that has a long-term antibacterial effect. As an intra-conductive drug it is advisable to use the combination of Ca(OH)2 with CPMC. The most adequate irrigation protocol consists of using 2.5% NaOCl activated with ultrasound followed by a final wash with 7% MA or 0.2% CTR combined with 2% CHX
The impact of baryons on dark matter haloes
We analyse the dark matter (DM) distribution in a approx 10^12 M_sun halo
extracted from a simulation consistent with the concordance cosmology, where
the physics regulating the transformation of gas into stars was allowed to
change producing galaxies with different morphologies. Although the DM profiles
get more concentrated as baryons are collected at the centre of the haloes
compared to a pure dynamical run, the total baryonic mass alone is not enough
to fully predict the reaction of the DM profile. We also note that baryons
affect the DM distribution even outside the central regions. Those systems
where the transformation of gas into stars is regulated by Supernova (SN)
feedback, so that significant disc structures are able to form, are found to
have more concentrated dark matter profiles than a galaxy which has efficiently
transformed most of its baryons into stars at early times. The accretion of
satellites is found to be associated with an expansion of the dark matter
profiles, triggered by angular momentum transfer from the incoming satellites.
As the impact of SN feedback increases, the satellites get less massive and are
even strongly disrupted before getting close to the main structure causing less
angular momentum transfer. Our findings suggest that the response of the DM
halo is driven by the history of assembly of baryons into a galaxy along their
merger tree.Comment: 5 pages, 5 figures, accepted for publication in MNRA
47- #1142 ALGORITMO GENÉTICO PARA EL PROBLEMA DE FLOWSHOP DISTRIBUIDO Y PERMUTADO CON ETAPA DE ENSAMBLE CONSIDERANDO TIEMPOS DE ALISTAMIENTO DEPENDIENTES DE LA SECUENCIA, Y FÁBRICAS HETEROGÉNEAS
Entre las estrategias corporativas, la adecuada gestión de la producción tiene una relevanciasignificativa en las empresas de manufactura debidoa que, se enfocan en alinear factores como la calidad,velocidad, flexibilidad y costos de los procesos conlos objetivos organizacionales.
De los problemas de optimización de procesos productivos existentes, el Flowshop es consideradoimportante, por su objetivo de minimizar los tiempos deproducción; dado lo anterior, se encuentran diferentesvariaciones de este problema, en donde se consideranparámetros y características diferentes para su estudio.De esta manera, como lo propone Hatami, Ruiz, &Andrés-romano (2015),el Flowshop Distribuido yPermutado con Etapa de Ensamble considerandotiempos de alistamiento dependientes de la secuencia(DAPFSP-SDST), es una adaptación del problemabase que se caracteriza por tener dos etapas, en laprimera etapa o etapa de procesamiento (DAPFSP),existen f fábricas con m máquinas que procesan ntrabajos y elaboran todas los componentes que debenpasar a la segunda etapa o etapa de ensamble (SDST),donde una máquina M es la encargada de ensamblarestos componentes con el fin de obtener el productofinal j. Considerando que, en la actualidad, laelaboración del producto final requiere delfuncionamiento de más de una fábrica, en la presenteinvestigación se aborda el DAPFSP-SDSTcontemplando fábricas heterogéneas(CorreaGonzález, Ortíz Delgado, & Garavito Hernández,2017), es decir, tiempos de alistamiento y produccióndistintos para cada una de las fábricas que componenel sistema productivo. Para dar solución al problema encuestión se desarrolla un Algoritmo Genético codificadoen el software MATLAB, validado haciendo uso deinstancias adaptadas de la literatura y finalmente,evaluado mediante análisis estadístico de losresultado
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