This paper compares the approach and resultant outcomes of item response models (IRMs) and classical test theory (CTT). First, it reviews basic ideas of CTT, and compares them to the ideas about using IRMs introduced in an earlier paper. It then applies a comparison scheme based on the AERA/APA/NCME 'Standards for Educational and Psychological Tests' to compare the two approaches under three ge...

In isotope ratio mass spectrometry (IRMS), any sample (S) measurement is performed as a relative-difference (δi) from a working-lab-reference (W), but the result is evaluated relative to a recommended-standard (D): δi. It is thus assumed that different source specific results (δi, δi ...) would represent their sources (S1, S2 ...), and be accurately intercomparable. However, the assumption has ...

Abstract Indigenous Research Methodologies (IRMs) for considering cultural values of water are a missing component and wetlands management in Australia. On this dry, flat ancient continent Traditional Knowledge has been passed on from generation to millennia. The profound knowledge surface groundwater critical ensuring the survival peoples driest inhabited continent, through finding, re-finding...

δ13C and δ18O values of carbonate in organic-rich samples such as soils, biofilms, lake sediments have been scarcely used so far paleo-environmental, biomineralization, or diagenetic studies because organic matter high proportions is suspected to alter isotope analysis. Yet, with the improvement analytical capabilities particular use CF-IRMS, this may not be an issue anymore. To evaluate this, ...

In our earlier publications we proposed the possibility of using new EIM–IRMS ® instrumental technique and analytical parameter δD n wine ethanol, which represents δ 2 H value non-exchangeable hydrogen stable isotope ratio in to improve detection illegal production practices such as addition sugar and/or water grape must prior alcoholic fermentation. This article shows a comparative performance...

This study aimed to characterize the carbon isotopic signatures ( ? 13 C-CH 4 ) of several methane waste sources, predominantly in UK, and during field campaigns Netherlands Turkey. CH plumes emitted from sources were detected mobile surveys using a cavity ring-down spectroscopy (CRDS) analyser. Air samples collected for subsequent isotope analysis by gas chromatography ratio mass spectrometry ...

High-precision analysis of the 17O / 16O isotope ratio in water and water vapor is of interest in hydrological, paleoclimate, and atmospheric science applications. Of specific interest is the parameter 17Oexcess (117O), a measure of the deviation from a linear relationship between 17O / 16O and 18O / 16O ratios. Conventional analyses of 117O of water are obtained by fluorination of H2O to O2 th...

A commercial interface coupling liquid chromatography (LC) to a continuous-flow isotope ratio mass spectrometry (CF-IRMS) instrument was used to determine the δ(13) C of dissolved organic carbon (DOC) in natural waters. Stream and soil waters from a farmland plot in a hedgerow landscape were studied. Based on wet chemical oxidation of dissolved organics the LC/IRMS interface allows the on-line ...

Studies are conducted on silver metal oxide contacts on a purposed built apparatus to investigate the extent of contact erosion under opening (break) operations. The contacts are opened between 0.1 and 0.8 ms 1 at particular point-on-wave, tPOW, of the ac waveform. Current loading of up to 30 A rms, Irms, is investigated. Contact material deposition, as well as mass loss, is observed and is fou...