The Use of Spatial Statistics in Hydrography

This paper describes ongoing efforts by the Canadian Hydrographic Service to devise geostatistical techniques for optimizing the nominal line spacing used on bathymetric surveys. This survey planning parameter has a great impact on both the cost of a survey and the confidence that a mariner can have in the resulting chart. Current methodology establishes initial line spacing quite subjectively. The main advantage of the geostatistical method being implemented is that it can estimate both depths and an estimate of their variance for all points within the survey area, regardless of whether they lie on or between sounding profiles. The geostatistical software under development (called "Hydrostat") evaluates the roughness of local bathymetry using available data. It then computes and displays the additional sounding coverage required to map the area to any desired level of confidence. The ideal line spacing for each small zone within the survey area is computed after specifying a maximum allowable standard deviation for interpolated depths lying between the sounding profiles. Developing algorithms for estimating the standard deviation of interpolated depths and ground truthing their accuracy forms the bulk of the work being done. While conceptually identical to the age old rules of thumb used to select and examine shoals, the geostatistical routines being developed can lead to more objective data quality standards and a more efficient deployment of survey resources

Biosurfactants: Promising Molecules for Petroleum Biotechnology Advances

The growing global demand for sustainable technologies that improves the efficiency of petrochemical processes in the oil industry has driven advances in petroleum biotechnology in recent years. Petroleum industry uses substantial amounts of petrochemical-based synthetic surfactants in its activities as mobilizing agents to increase the availability or recovery of hydrocarbons as well as many other applications related to extraction, treatment, cleaning and transportation. However, biosurfactants have several potential applications for use across the oil processing chain and in the formulations of petrochemical products such as emulsifying/demulsifying agents, anticorrosive, biocides for sulphate-reducing bacteria, fuel formulation, extraction of bitumen from tar sands and many other innovative applications. Due to their versatility and proven efficiency, biosurfactants are often presented as valuable versatile tools that can transform and modernise petroleum biotechnology in an attempt to provide a true picture of state of the art and directions or use in the oil industry. We believe that biosurfactants are going to have a significant role in many future applications in the oil industries and in this review therefore, we highlight recent important relevant applications, patents disclosures and potential future applications for biosurfactants in petroleum and related industries

Anne Deguelle

Dagbert presents Deguelle's photographic compositions (sometimes accompanied by monochrome paintings) as reflexions on the reality of images and collective memory

Rôle enzymatique d'un biofilm sur la corrosion d'aciers inoxydables immergés en eau de mer naturelle

PARIS-BIUSJ-Thèses (751052125) / SudocCHATENAY MALABRY-Ecole centrale (920192301) / SudocPARIS-BIUSJ-Sci.Terre recherche (751052114) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Pattern Recognition and Geochemical Data: An Application to Monteregian Hills

The development of rapid and efficient methods of chemical analysis of major and minor elements in rocks has given rise to the production of large sets of data constituting a comprehensive 'picture' of the chemical composition of a rock unit or a rock group in a given area.The complex structure of this multidimensional picture is globally analyzed by 'correspondence analysis' as an interpretative method of pattern recognition. Significative trends of variation are determined and expressed in geological terms. Density distribution of representative points in the factor space is evaluated in search of homogeneous substructures inside the global one. The resulting 'natural clustering' is compared to an a priori partitioning of the structure on the basis of petrographic criteria.The whole analysis is performed by a computer program that can accommodate some 600 samples measured on more than 20 variables. The analysis of a chemical picture of the Monteregian petrographic province is given to illustrate the method. </jats:p