Search results for "Granulometry"

Investigation of characterizing methods for the microstructure of cement

2002

Volumetric, gravimetric, calorimetric, flow methods, mercury porosimetry and laser granulometry were used to investigate the surface structure and the sorption behavior of industrial cements and hydrated cement paste. The suitability of the measuring methods is assessed.

The open metastable structure of a collapsible sand: fabric and bonding

2015

This paper deals with the compositional and textural characteristics determining open metastable structures in the pleistocenic sand outcropping in the Agrigento district (Sicily). The aim of the study was to individuate the bonding types occurring between grains that could generate matric suction phenomena. The composition and microfabric were characterised by means of granulometry, porosimetry, permeability, optical and ESEM-EDS microscopy, thermogravimetry and XR diffractometry, electric conductivity, and ionic chromatography. The data thus acquired show that the skeleton of the sand is constituted mostly by bioclasts and microfossils, calcite and quartz monocrystalline grains. Moreover,…

Quantitative identification, distribution and source apportionment of anthropogenic trace metals in marine sediment of Milazzo gulf (N-E Sicily): pre…

2009

Temporal Changes in Mollusk and Polychaete Communities in the Soft Bottom of Cullera Bay (Western Mediterranean)

2007

Abstract This study identifies the most abundant and significant species—from an ecological point of view—in the soft bottom of Cullera Bay (Spain) in order to study the seasonal (summer–winter) variations in the local communities of polychaete annelids and bivalve mollusks. This paper presents the results of the analysis of samples taken during two field campaigns (July 2002 and February 2003) of a series of five campaigns carried out in 2002 and 2003. For these field observations, twelve sampling stations were set up in the bay along three transects. At these stations, macrobenthos was collected using a Ponar grab. Only polychaete annelids and bivalve mollusks were selected from the sampl…

Study of a plasma generated in metal surface treatment by laser ablation in air : characterisations of induced radiation and nanoparticules

2015

The interaction of a laser beam of short pulse duration with metallic materials such as aluminum, iron or titanium is characterized by the presence of a high energy and strongly ionized plume (plasma). The aim of this study is to understand the mechanisms involved in plasma, created when laser-target interaction, which lead to the formation of nanoparticles. We would generally consider the dynamic expansion in the air of the plasma plume formed with a nanosecond Nd:YAG laser to specify the conditions of formation of these particles and their morphological and structural characteristics. Thus, this work is divided onto two parts. In the first part, we present the experimental characterizatio…

GEOCHEMICAL AND MINERALOGICAL FINGERPRINTS OF THE SEDIMENTS SUPPLY AND EARLY DIAGENETIC PROCESSES IN THE BIZERTE LAGOON (TUNISIA)

2016

International audience; The Bizerte Lagoon (Tunisia) functions as a sedimentation environment characterized by receiving allochthonous sediments mainly transported by the Ben Hassine, Rharek and Guenich streams, as well as marine sediments from the Mediterranean Sea. It is subjected to significantenvironmental changes due to the natural and anthropic influences altering the natural patterns of circulation, extraction and/or deposition of mineralogical materials. The aim of this investigation is to analyze the sediments supply and early diagenetic processes in Bizerte Lagoon. Thephyicochemical parameter of the sediment pore water, as well as their texture, mineralogical composition (X-Ray di…

Alexandrium pacificum Litaker sp. nov (Group IV): Resting cyst distribution and toxin profile of vegetative cells in Bizerte Lagoon (Tunisia, Souther…

2015

International audience; A high spatial resolution sampling of Alexandrium pacificum cysts, along with sediment characteristics (% H2O, % organic matter (OM), granulometry), vegetative cell abundance and environmental factors were investigated at 123 study stations in Bizerte Lagoon (Tunisia). Morphological examination and ribotyping of cells obtained from a culture called ABZ1 obtained from a cyst isolated in lagoon sediment confirmed that the species was A. pacificum. The toxin profile from the ABZ1 culture harvested during exponential growth phase was simple and composed of the N-sulfocarbamoyl toxins C1 (9.82 pg toxin cell−1), the GTX6 (3.26 pg toxin cell−1) and the carbamoyl toxin Neo-S…

Selected physico-chemical parameters of forest soils of Smolnik partial reserve

2003

Quartz grains reveal sedimentary palaeoenvironment and past storm events: A case study from eastern Baltic

2018

Abstract Sediment record collected from the coastal lake serves as a powerful tool for reconstructing changes in palaeoenvironment and understanding the potential signals of past storminess. In this study, we use several proxies from sediment of the Holocene Thermal Maximum at coastal Lake Lilaste, Latvia. We focus on surface texture of quartz grains from the mineral inorganic fraction as indicators of depositional environments. We then use this as a proxy for potential storm transport and combine with information on granulometry, diatom stratigraphy and chronology to answer the question whether flux of quartz grains in the lake originated from the sea or from the land. Analyses in a binocu…

A new windstorm proxy from lake sediments: A comparison of geological and meteorological data from western Germany for the period 1965–2001

2009

[1] The feasibility of detecting windstorm layers in lake sediments is explored by comparing quartz grain size data from a freeze core obtained from the Schalkenmehrener Maar (Eifel region, western Germany) to recent meteorological wind data. The Schalkenmehrener Maar is appropriate for such a calibration study because the morphological settings of the lake allow the conservation of windstorm layers (in particular, there is no fluvial sediment inflow) and long-term wind measurements are available from nearby stations. The age model for the uppermost 30 cm of the sediment core is based on measurements of 137Cs and 210Pb concentrations. An ultra-high-resolution grain size analysis is performe…