Search Results

You are looking at 1 - 6 of 6 items for :

  • "Concentration order" x
  • All content x
Clear All

This paper presents several indices to describe multivariate diversity and evenness. Multivariate generalizations of the Gini-Simpson index and the Rosenbluth index are proposed tomeasure diversity. A multivariate Gini ratio is also presented to measure evenness. These indices extend the usual univariate measures; they reflect not only the diversity of marginal distributions but also the dependence structure of abundance. The indices fulfill desirable measurement properties and are consistent with certain orderings of multivariate distributions. An order of concentration surfaces and a majorization order are also surveyed shortly.

Restricted access

Abstract  

Instrumental neutron activation analysis (INAA) was performed for measurement of extractable organohalogens (EOX) in blubber samples of Weddell seals (Leptonychotes weddelli) from Antarctica. EOX were detected in all the analyzed samples. The concentration order of EOX was: extractable organochlorine (EOCl)>extractable organobromine (EOBr)>extractable organoiodine (EOI). Their levels increased gradually with aging as with other man-made persistent organic pollutants (POPs) such as PCBs and DDTs.

Restricted access

Abstract  

Instrumental neutron activation analysis (INAA) was conducted for the analysis of extractable organohalogens (EOX) in the blubber samples of harbour porpoise (Phocoena phocoena) and whole body samples of Atlantic herring (Clupea harengus) from the Baltic Sea. The concentration order of EOX was: extractable organochlorine (EOCl) > extractable organobromine (EOBr) > extractable organoiodine (EOI). As the results of investigation into the biomagnification properties of EOX, EOBr in low molecular weight fraction was the highest among the organic halogens investigated, suggesting the presence of high persistent organic bromine compounds in the marine environment, and accumulation through food chains.

Restricted access

Abstract  

Instrumental neutron activation analysis was performed to measure the levels of extractable organohalogens (EOX) in the organisms from the Antarctic marine ecosystem. The results show that EOX (EOCl, EOBr and EOI) were found in all the samples analyzed. The highest concentration was determined in the ascidian sample. The concentration order of EOX was mainly EOCl>EOBr>EOI with the exception of nemertine, ascidian, fish and adelie penguin samples. The concentrations of man-made organochlorines (DDTs and CHLs) were analyzed by GC-MS, and the results were compared with the concentrations of EOX determined in the same samples. The results show that the contribution of known man-made organochlorines in EOCl was less than 3%. This means that a large amount of unknown organochlorine compounds is present in Antarctic marine organisms.

Restricted access

Abstract  

Procedures and results of CH3 131I absorption in water and ethanol solutions have been studied. These are: 1%, 5%, 15%, 30%, 50% or saturated solutions Na2S2O3, C6H5–OH, Hg2(NO3)2, AgNO3, K4(Fe(CN)6), KI, NaOH, KOH and (COOH)2. Methyl iodide was carried with the laboratory air stream through five bubblers filled with a selected solution. The CH3 131I released from the last bubbler was absorbed in 2 cartridges in series filled with 5% TEDA impregnated charcoal. Efficiency of CH3 131I absorption was studied in dependences of the kind of solutions, their concentrations, order of bubblers and CH3 131I concentration in the carrier air. Results of these experiments are discussed.

Restricted access

Time taken for signal detection decreases as culture concentration is increased. Bacterial growth in sample was observed even for low concentrations (10 CFU/mL) within a 5-h period. Maximum peaks appear following a relative concentration order

Restricted access