Results 1 - 10 of 202
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[en] It presents a review on the determination of major types of organic pollutants in environmental samples by HPLC with diode array or fluorescence molecular detectors. Main objective has been to make a compilation of the analytical potential of the technique based on literature and our laboratory studies on the main aspects of analytical methodology used in the determination of these compounds. (Author) 53 refs.
[en] A preliminary study of literature review on the determination of carotenoids in microalgae samples by HPLC with diode array detector is presented. Main objective has been focused to compile data from literature and based on the main aspects of the analytical methodology used in the determination of these compounds. The work is structured as follows and affecting major analytical difficulties: Procurement and commercial availability of standard solutions. Stage of sample treatment. Chromatographic analysis. (Author) 19 refs.
[en] This paper compares different analytical methods for analysis of rigid inclusions with finite element modeling. First of all, the load transfer in the distribution layer is analyzed for its different thicknesses and different inclusion grids to define the range between results obtained by analytical and numerical methods. The interaction between the soft soil and the inclusion in the estimation of settlements is studied as well. Considering different stiffness of the soft soil, settlements obtained analytical and numerically are compared. The influence of the soft soil modulus of elasticity on the neutral point depth was also performed by finite elements. This depth has a great importance for the definition of the total length of rigid inclusion. (Author)
[en] A study on the comparison and evaluation of a miniaturized extraction method for the determination of selected PACs in sample filters is presented. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the intermediate precision. (Author)
[en] Pacific Gas and Electric Company (PG ampersand E) has been involved in photovoltaic (PV) research for more than a decade. PG ampersand E's efforts have ranged from basic cell research to the development of PV for utility-scale applications (PVUSA). These projects have covered a range of research designed to enhance technical understanding and speed commercialization of PV for utility use. Throughout, PG ampersand E has found PV to be a reliable, low maintenance, non-polluting energy producer that matches PG ampersand E's loads. Many in the PV community believe utility networks will eventually provide a large enough market to drive PV system costs down and thus establish PV as a significant power producing technology. Utilities have not found currently-available PV technology cost-effective, however, except for niche applications utilizing small off-grid power supplies
[en] The annual study of organic fraction of atmospheric aerosol in a rural area of Madrid is shown. Almost 90 organic compounds, among them aliphatic hydrocarbons, PAH and polar species such as alcohols and acids have been identified and quantified in PM2.5 fraction. Compounds concentration ranged between pg m-3 and ng m-3. The seasonal variability and also a comparison to others studies have been studied. (Author) 76 refs.
[en] The Positive Matrix Factorization (PMF) application to a set of PM2.5 data collected in a rural area of Madrid for a period of 1 year has been developed. Results has let describing the particulate faction of atmospheric aerosol collected in Chapineria according to 7 factor, among them fossil fuel combustion by traffic, wax plants, primary emissions of organic carbon, crustal material, and secondary organic aerosol. Five of these factors are related to primary particles; meanwhile only one factor has been associated to secondary particles. Finally, a factor has not been associated to any known source of particulate matter. (Author)