Search results for "WATER"
showing 10 items of 9348 documents
A physical model for the interaction between unsaturated soils and retaining structures
2020
Temporary and permanent retaining structures interact with soils that are usually in unsaturated conditions. In this work, a 1g-scale physical model is presented to investigate the interactions between retaining walls and unsaturated soils. The physical model is equipped with a water-filled hydraulic cylinder connected to a pressure-volume controller to measure the horizontal component of the later earth thrust and high capacity tensiometers to measure soil matric suction. A system of low-friction linear guideways has been installed at the base of the wall-model. The failure surface is observed through a 3 cm thick glass wall on one side of the container. A series of images are acquired dur…
Hygrothermal conditions in Cross Laminated Timber (CLT) dwellings
2020
The use of CLT has been increasing the last decade, and a subsequently focus on documentation of the accompanying indoor climate and exposed wooden surfaces on human well-being. This study presents the results of a measurement campaign conducted over one year of a CLT apartment building in Grimstad, Norway. The apartment building consists of three floors with 35 apartments and comply with the Norwegian passive house standard and energy grade A. Measurements of the relative humidity (RH), indoor air temperature and wood moisture content (MC) were performed in the exposed CLT spruce panels in three apartments in two different floors. The results from the three apartments show a relatively sma…
BEST-2K Method for Characterizing Dual-Permeability Unsaturated Soils with Ponded and Tension Infiltrometers
2019
This study presents a new method (BEST-2K) that extends the existing BEST methods for use in characterizing the water retention and hydraulic conductivity functions of matrix and fast-flow regions in dual-permeability soils. BEST-2K requires input information from two water infiltration experiments that are performed under ponded (Beerkan) and unsaturated (tension infiltrometer) conditions at the surface. Other required inputs include water content measurements and the traditional BEST inputs (particle size distribution and bulk density). In this study, first, a flowchart of the BEST-2K method was developed and illustrated with analytically generated data for a synthetic dual-permeability s…
Sedimentary humic substances from lakes in Latvia
1997
Humic and fulvic acids, isolated from sediments of lakes in different trophic states (Latvia) were studied. The humic substances (HS) were characterized by their elemental and functional composition, their spectral properties, and molecular mass. The humus properties strongly depend on the origin of the sedimentary HS. Substantial similarity between sedimentary HS from oligotrophic and dystrophic water bodies was found, unless the biology of these lakes greatly differs. Humic molecules from sediments of oligotrophic and dystrophic lakes are smaller, more uniform, and contain lower amounts of carboxyl- and hydroxyl-groups than HS from meso- and eutrophic water bodies. On the other hand, sedi…
Screening of halogenated aromatic compounds in some raw material lots for an aluminium recycling plant
2004
Four samples of scrap raw materials for an aluminium recycling plant were screened for the occurrence of persistent halogenated aromatic compounds. The samples contained waste from handling of electric and electronic plastics, filter dust from electronic crusher, cyclone dust from electronic crusher and light fluff from car shredder. In our screening analyses, brominated flame retardants were observed in all samples. Polybrominated diphenyl ethers (PBDE) were identified in all samples in amounts of 245–67450 ng/g. The major PBDE congeners found were decabromo- and pentabromodiphenyl ethers. 1,1-bis(2,4,6-tribromophenoxy)ethane, hexabromobenzene, ethyl-pentabromobenzene, tetrabromobisphenol-…
Pyriproxyfen, a juvenoid hormone analog, does not induce male production in parthenogenetic lineages of Eucypris virens (Crustacea: Ostracoda)
2007
Analogs of juvenoid hormones are increasingly recommended for controlling insect pests in agriculture. One of these analogs, pyriproxyfen, was found to be very potent in inducing male production in Daphnia under laboratory conditions, even after acute exposure. Other studies also demonstrated a major role of juvenoid hormones for the sex determination in arthropods that have sex chromosomes. We exposed parthenogenetic lineages of the freshwater ostracod Eucypris virens to a wide range of pyriproxyfen concentrations, and compared mortality and fecundity between treated and control animals. Animals exposed to the highest concentrations of pyriproxyfen (3-30 nM) experienced a higher mortality …
Erosión costera y cambio ambiental en el humeral de Cabanes-Torreblanca (Castelló). Datos para una gestión sostenible
2014
A progressive increase in salinity and marine influence, related to local subsidence characterize the evolution of the lagoon of Cabanes Torreblanca. Relative sea level rise, caused saltwater intrusion and landward migration of the barrier. This barrier is recessive (60-20 m in the last 50 years) and its current processes show a sedimentary deficit that can lead to rapid and irreversible changes. The information shown by this research can help to achieve a sustainable management.
First record of Hemidiaptomus (Gigantodiaptomus) superbus (Schmeil, 1895) in Italy, with notes on distribution and conservation status (Copepoda, Cal…
2011
Hemidiaptomus (Gigantodiaptomus) superbus (Schmeil, 1895) was found in a temporary pool in the Pineta di Classe coastal pine-wood (Ravenna, northern Italy). This is the first official record of a species belonging to the subgenus Gigantodiaptomus of Italian fauna, and it widens the known distribution of this rare diaptomid to the Mediterranean basin. In order to supply data on this rare and poorly known species, original drawings for the Italian population have been provided, and some overlooked morphological features have been highlighted. In light of the growing evidence of the existence of a number of cryptic species in the Diaptomidae family, and considering the variability observed in …
Decadal oscillations of the aquatic chemistry of river waters in Latvia
2018
Abstract. Water quality changes of surface waters can be used to assess human impact intensity, but of importance is to consider also impacts of climate change/variability and naturally occurring changes of environmental quality. In Latvia, during the recent decades a major reduction of anthropogenic pressure has happened due to restructuring of economy and industrial production, resulting in major decrease of loading of many groups of pollutants. However, trends and driving factors for other groups of substances have not been much studied. Long term (1980–2012) results of hydrochemical monitoring, performed in rivers of Latvia, are analysed during this study in connection with long-term se…
Magnetic Susceptibility in the Soils Along Communication Routes in the Town of Opole
2019
Magnetic susceptibility measurements were taken in eight selected streets of Opole, with diversified vehicle traffic intensity. The experiment surfaces were marked on every street, with two separate zones: A – a strip directly adjacent to the road and B – a strip 1 m away from the road edge. The carried out research indicated considerable influence of communication-generated pollution, with simultaneous influence of other local emission sources. The relation of magnetic anomalies was indicated, which may be the result of ferromagnetic materials aggregation, originating mainly from combustion processes. The road structure, including the surface condition, the main construction material and s…