Hydrological variability and long-term floristic-structural modifications in different habitats of a tropical semi-deciduous forest

Author(s):  
Alisson Borges Miranda Santos ◽  
Vinicius Andrade Maia ◽  
Cléber Rodrigo de Souza ◽  
Natália de Aguiar-Campos ◽  
Aurélio de Jesus Rodrigues Pais ◽  
...  
2004 ◽  
Vol 188 (1-3) ◽  
pp. 197-210 ◽  
Author(s):  
Annett Wolf ◽  
Peter Friis Møller ◽  
Richard H.W. Bradshaw ◽  
Jaris Bigler

Ocean Science ◽  
2013 ◽  
Vol 9 (2) ◽  
pp. 301-324 ◽  
Author(s):  
K. Schroeder ◽  
C. Millot ◽  
L. Bengara ◽  
S. Ben Ismail ◽  
M. Bensi ◽  
...  

Abstract. The long-term monitoring of basic hydrological parameters (temperature and salinity), collected as time series with adequate temporal resolution (i.e. with a sampling interval allowing the resolution of all important timescales) in key places of the Mediterranean Sea (straits and channels, zones of dense water formation, deep parts of the basins), constitute a priority in the context of global changes. This led CIESM (The Mediterranean Science Commission) to support, since 2002, the HYDROCHANGES programme (http//www.ciesm.org/marine/programs/hydrochanges.htm), a network of autonomous conductivity, temperature, and depth (CTD) sensors, deployed on mainly short and easily manageable subsurface moorings, within the core of a certain water mass. The HYDROCHANGES strategy is twofold and develops on different scales. To get information about long-term changes of hydrological characteristics, long time series are needed. But before these series are long enough they allow the detection of links between them at shorter timescales that may provide extremely valuable information about the functioning of the Mediterranean Sea. The aim of this paper is to present the history of the programme and the current set-up of the network (monitored sites, involved groups) as well as to provide for the first time an overview of all the time series collected under the HYDROCHANGES umbrella, discussing the results obtained thanks to the programme.


2022 ◽  
Vol 9 ◽  
Author(s):  
Xavier Colin

This article deals with the long-term behaviour of radiation cured polymers. Among the wide variety of possible ageing modes, the attention is focused on two key processes for users of radio-cured polymers: humid ageing of polymer glasses and thermal oxidative ageing of rubbers. These two processes are illustrated by numerous results coming from literature or our own research works. In both cases, the consequences of the structural modifications on the use properties (in particular, on mechanical properties) are described. It is found that the ageings of radiochemically and thermally cured polymers are not so different. It is thus concluded that a great part of the very abundant literature published on the ageing of thermally cured polymers remains exploitable for radio-cured polymers.


2016 ◽  
Vol 228-229 ◽  
pp. 205-216 ◽  
Author(s):  
Ivano Fumagalli ◽  
Carsten Gruening ◽  
Riccardo Marzuoli ◽  
Stanislaw Cieslik ◽  
Giacomo Gerosa

Author(s):  
K. Ratkovská ◽  
J. Čerňan ◽  
M. Cúttová ◽  
K. Semrád

The operational issues of a small turbojet engine MPM – 20 are discussed. The engine was created by modifying the Soviet turbostarter TS – 20B/21 designed for short-term operation. It is necessary to make structural modifications that allow for the long-term operational premise of the engine. For this purpose, several analyses were focused on the thermally stressed parts. The first, a material analysis carried out on the outer casing of the combustion chamber and on the combustor liner reveals information about the mechanical properties of these structural nodes. It was necessary since there is no documentation of the engine with this information. Another analysis of the infrared emission spectra is important for monitoring operational conditions, especially from the temperature point of view. Subsequent stress analysis of the casing is based on results from previous analyses. It was used to observe the behaviour of the casing as operational conditions changed. This revealed a dangerous increase of thermally induced stress levels as temperature increased up to 150°C. Various structural modifications can be made in the future with these results, such as an application of a protective coating on the casing and combustor liner of the engine.


2021 ◽  
Vol 77 (2) ◽  
pp. e099
Author(s):  
Ibai Olariaga ◽  
Graciela Paz-Bermúdez ◽  
Javier Calvo ◽  
Javier Etayo ◽  
María Prieto

Lichens, as well as other organisms, should be considered important biodiversity components for the establishment of priorities in conservation biology. In this study, we report six new recent localities of the highly endangered, epiphytic macrolichen Pseudocyphellaria aurata in Spain: two in Navarra and four in A Coruña. Previous Spanish reports based on literature and herbarium specimens suggest a reduction of the distribution area of P. aurata and local extinction. Pseudocyphellaria aurata is known to be extinct in six localities, where it has not been observed since the middle of the 19th century (Cádiz, Pontevedra, Málaga). Four records reported for central Spain (Zaragoza, Salamanca, Teruel) are considered unplausible. The newly discovered populations are located in well-preserved patches of atlantic deciduous forest with strong oceanic influence, whose long-term ecological stability seems evident because of the presence of ancient trees. Nevertheless, these populations are small, fragmentary, and are threatened by habitat degradation, forestry and maybe fungal pathogens. Two populations, Intzola and Beba (Navarra and A Coruña, respectively), account for 75.7% of thalli. The localities with the highest number of trees colonized by P. aurata are Santa Leocadia and Beba in A Coruña. We reassessed the conservation status of this species concluding that conservation initiatives must be implemented to avoid its extinction in mainland Spain.


2020 ◽  
Vol 20 (4) ◽  
pp. 957-968
Author(s):  
ALINA MIHAELA CANTARAGIU ◽  
ANGELA STELA IVAN ◽  
PETRU ALEXE ◽  
CARMELIA MARIANA DRAGOMIR BALANICA ◽  
MARICICA STOICA

Coffee is one of the most widely consumed beverages. Roasting is a baseline step in coffee processing, being involved in the development of color, flavor and taste for which coffee is appreciated. In addition, the roasting treatment triggers several complex physical changes inside the coffee bean, resulting in density decrease owing to volume increase, increase of beans brittleness, changes in coffee color, loss of bean mass and water, porosity increase, and governs coffee bean behavior during storage, grinding, and brewing. It is essential to examine physical changes, as coffee production is seasonal, and a long-term coffee storage is required. In the present study, the visual and microstructural differences between green and roasted Arabica coffee beans were investigated. The study of microstructural differences was performed using scanning electron microscopy, and clearly showed significant structural differences between green Arabica coffee beans and roasted Arabica coffee beans. The physical and structural modifications of infused coffee with water were explained through chromatic evaluation and microscopic analysis, respectively as function of ground size of roasted coffee beans and infusion time.


2020 ◽  
Vol 24 (4) ◽  
pp. 1611-1631
Author(s):  
Rémy Bonnet ◽  
Julien Boé ◽  
Florence Habets

Abstract. The multidecadal hydroclimate variations of the Seine basin since the 1850s are investigated. Given the scarcity of long-term hydrological observations, a hydrometeorological reconstruction is developed based on hydrological modeling and a method that combines the results of a downscaled long-term atmospheric reanalysis and local observations of precipitation and temperature. This method improves previous attempts and provides a realistic representation of daily and monthly river flows. This new hydrometeorological reconstruction, available over more than 150 years while maintaining fine spatial and temporal resolutions, provides a tool to improve our understanding of the multidecadal hydrological variability in the Seine basin, as well as its influence on high and low flows. This long-term reconstruction allows analysis of the strong multidecadal variations of the Seine river flows. The main hydrological mechanisms at the origin of these variations are highlighted. Spring precipitation plays a central role by directly influencing not only the multidecadal variability in spring flows but also soil moisture and groundwater recharge, which then regulate summer river flows. These multidecadal hydroclimate variations in the Seine basin are driven by anomalies in large-scale atmospheric circulation, which themselves appear to be influenced by sea surface temperature anomalies over the North Atlantic and the North Pacific. The multidecadal hydroclimate variations also influence high and low flows over the last 150 years. The analysis of two particularly severe historical droughts, the 1921 and the 1949 events, illustrates how long-term hydroclimate variations may impact short-term drought events, particularly through groundwater–river exchanges. The multidecadal hydroclimate variations described in this study, probably of internal origin, could play an important role in the evolution of water resources in the Seine basin in the coming decades. It is therefore essential to take the associated uncertainties into account in future projections.


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