Search Results
Abstract
The article presents environmental analysis of a detached house in terms of its life cycle. The analysis is simplified in order to compare the built and operational energy of the building whereas the operational energy is described using computer aided building performance simulation. The input data related to the built (embodied) energy are based on information from classical works on life cycle analysis. The article also justifies the simplification of environmental analysis, which aims to build pragmatically on existing standardization and legislation on energy performance of buildings. The final section provides some considerations concerning the environmental assessment of buildings.
Abstract
The aim of the present review is to evaluate, on the basis of published papers, the real potential of XRF technique for environmental analysis. Special attention is given for the determination of heavy metal pollution in water. Results of numerous papers for various samples are presented. Some details of the technique and preconcentration methods employed are also discussed.
Abstract
An overview of Compton suppression neutron activation analysis (NAA) is given. The basic theory of the technique, its experimental design, uniqueness, and limitations are discussed. Experimental data showing its usefulness for the low level determination of several key elements in environmental samples that can not be obtained using conventional non-destructive neutron activation is deliberated.
Abstract
Sediments of the Kitajukkengawa River (Sumida-ku, Tokyo, Japan) were analyzed by activation analyses. Concentrations of 36 elements for each sample were determined by instrumental neutron activation analysis (INAA) and neutron induced prompt gamma-ray analysis (PGA). Based on the correlation matrix between the elements in vertical distribution, principal component analysis (PCA) was performed. The degree of chemical weathering of silicate minerals was highest in the middle layer of the Kitajukkengawa River sediment and that adsorbed amount of trace metals such as Cd and Cr was increased along with chemical weathering.
Abstract
Sampling and preparatory treatment of environmental objects is discussed from the view of their information content, functional speciation of the pollutant, statistical distribution treatment and uncertainty assessment. During homogenization of large samples, a substantial information may be lost and validity of environmental information becomes vague. Isotope dilution analysis (IDA) is discussed as the most valuable tool for both validity of analysis and evaluation of samples variance. Data collection for a non-parametric statistical treatment of series of "non-representative" subsamples, and physico-chemical speciation of analyte may actually better fulfill criteria of similarity and representativeness. Large samples are often required due to detection limits of analysis, but the representativeness of environmental samples should be understood not only by the mean analyte concentration, but also by its spatial and time variance. Hence, heuristic analytical scenarios and interpretation of results must be designed by cooperation of environmentalists and analytical chemists.
Abstract
Reference materials are necessary to improve or to maintain a high quality of analysis. To avoid bias as far as possible, the BCR certifies reference materials on the basis of results of different methods used by different laboratories. A proper selection of good methods and laboratories makes it possible to obtain excellent agreement and narrow confidence intervals. Neutron activation techniques are suited for many key elements; their results are in good agreement with those of other techniques.
Fundamental differences between Cry1Ab-based Bt-bioinsecticides and MON 810 maize varieties render these technologies not equivalent. While the former contain at least five different crystalline (Cry) toxins, the latter produce a single Cry1Ab toxin as active ingredient. Moreover, the lectin type toxin protein produced by these plants is a truncated version of microbial Cry1Ab. The majority of the results reported for Cry1Ab content is, therefore, subject to correction between microbial Cry1Ab protoxin and plant-expressed preactivated Cry1Ab toxin, and the latter is not a registered insecticide active ingredient. Cry1Ab toxin is produced continuously and not at the highest concentration in those plant parts, where the pest occurs. In turn, MON 810 maize does not comply with IPM principles, as control cannot be limited to the period of pest damage above threshold level. The target insect, Ostrinia nubilalis is a practically inconsiderable pest in Hungary, therefore, the use of MON 810 maize is mainly groundless. Pollen settling on Urtica dioica, Rubus spp. or Datura stramonium near or in maize fields may exert toxicity on caterpillars of protected butterflies, e.g. the peacock butterfly (Nymphalis io). Decaying Bt-maize material potentially affect other non-target organisms. Occurrence of Cry1 toxin resistance in pests is facilitated by the fact that MON 810 maize produces only a single Cry protein, preactivated Cry1Ab toxin.
Summary
Stir bar sorptive extraction (SBSE) is an extraction technique for enrichment of organic compounds from aqueous and gaseous matrices. This technique is based on sorptive extraction, whereby the solutes are extracted into a polymer coating on magnetic stirring rod. SBSE has been used in various types of analytical procedures and wide variety of matrices. However, a limitation of SBSE lies in the fact that only polydimethylsiloxane (PDMS)-coating material is commercially available and that PDMS predominantly extracts non-polar compounds with K o/w higher than 10. In this survey, a review on non-PDMS stir bar sorptive extraction coatings and their applications to the analysis of environmental, food, and biomedical samples is given.
Abstract
Integrated microchemical systems on microchips, which are based on continuous microflows, are expected to become important tools for analysis and chemical synthesis applications for biological sciences and technologies. For these purposes, general integration concepts have been developed, including microunit operations (MUOs) and continuous-flow chemical processing (CFCP) to create fully functional systems for various chemical processing applications. The general methodology has enabled analysis, synthesis, and fabrication of chemical systems on microchips, and these microsystems have demonstrated superior performance (e.g., rapid, simple, easy operation, and highly efficient processing) compared to conventional methodologies. Microchemical technology has now entered the phase of practical application. In this review, we discuss the methods for integration of continuous flow-based chemical process on microchips, relevant technologies, and applications.
Abstract
INAA results of 11 standard reference materials used in archaeometric investigations of pottery as well as in environmental analysis are presented. The values obtained for 24 elements are compared with the certificate values as well as with the analytical data of other investigators. The accuracy of analysis is discussed.
