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The primary objective of the research reported here has been the development of a hybrid reference material (RM) to serve as a test of accuracy for elemental carbon (EC) isotopic (14C) speciation measurements. Such measurements are vital for the quantitative apportionment of fossil and biomass sources of "soot" (EC), the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust), showed a range of results, but since the "truth" was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC) of measurement validity (Currie et al., 2002). Components of the new Hybrid RM (DiesApple), however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically). NIST SRM 2975 (Forklift Diesel Soot) has little or no 14C, and its major compositional component is EC; SRM 1515 (Apple Leaves) has the 14C content of biomass-C, and it has little or no EC. Thus, the Hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C (char) from SRM 1515 in the EC isolate of the Hybrid RM, as well as a test for conservation of its dominant soot fraction throughout the isolation procedure. The secondary objective was to employ the Hybrid RM for the comparative evaluation of the thermal optical kinetic (TOK) and thermal optical transmission (TOT) methods for the isolation of EC for micro-molar carbon accelerator mass spectrometry (AMS). As part of this process, the relatively new TOK method was subjected to a critical evaluation and significant development. Key findings of our study are: (1) both methods exhibited biomass-C "leakage"; for TOT, the EC fraction isolated for AMS contained about 8% of the original biomass-C; for TOK, the refractory carbon (RC) isolated contained about 3% of the original biomass-C.; (2) the initial isothermal oxidation stage of the TOK method substantially reduced the transfer of artifact char to the RC fraction, improving isolation capabilities; (3) the Hybrid RM was not equal to the sum of its parts, with matrix interactions inducing premature loss of EC which, however, could be quantified and minimized; (4) the three-stage TOK method provided a superior capability for carbonate quantification at the submicromolar level, with "reagent-free" removal of carbonate- C from EC -- essential for low-level EC-14C AMS. [ABSTRACT FROM AUTHOR]

The primary objective of the research reported here has been the development of an hybrid reference material (RM) to serve as a test of accuracy for elemental carbon (EC) isotopic (14C) speciation measurements. Such measurements are critically important for the quantitative apportionment of fossil and biomass sources of "soot" (EC), the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust), showed a range of results, but since the "truth" was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC) of measurement validity (Currie et al., 2002). Components of the new Hybrid RM (DiesApple), however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically). NIST SRM 2975 (Forklift Diesel Soot) has little or no 14C, and its major compositional component is EC. SRM 1515 (Apple Leaves) has the 14C content of biomass-C, and it has little or no EC. Thus, the hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C from SRM 1515 in the EC isolate of the hybrid RM, together with testing for conservation of its dominant soot fraction through the isolation procedure. A secondary objective was the use of the hybrid RM for the comparative evaluation of the thermal optical transmission (TOT) and thermal optical kinetic (TOK) methods for the isolation of EC for micro-molar carbon accelerator mass spectrometry (AMS). Key findings were: that both methods exhibited biomass-C "leakage" into the fossil EC fraction, with substantially more for the TOT method; that the initial isothermal oxidation stage of the TOK method substantially reduced charring, improving isolation capabilities; that the hybrid RM was not equal to the sum of its parts, with matrix interactions yielding premature loss of EC which, however, could be quantified and minimized; and that the three-stage TOK method provided a superior capability for carbonate quantification at the sub-micromolar level, with "reagent-free" removal of carbonate-C from EC -- essential for low-level EC-14C AMS. [ABSTRACT FROM AUTHOR]

This review is based on findings from a postal survey undertaken between March and September 1993 to elicit information from nurses in four district health authorities regarding development and research activity in which they were involved. The objectives of the review were to obtain baseline information on the extent, variety and scope of work being carried out, to provide staff with a mechanism for networking good practice and to identify any areas of replication. A snowball sampling technique was used to obtain information from nursing personnel. A total of 141 responses were received out of which 4% (n = 5) reported no activity. Response rates varied between organizations and specialist groups but were similar in terms of the number of small-scale clinical practice developments undertaken without identified support or supervision. Fifty-five per cent (n = 75) of the reported developments related to the organization and management of services while 11% (n = 15) focused on consumer-related issues. Few studies identified dissemination strategies and there was generally a lack of clarity over expected benefits of the study in terms of measurable outcomes to the organization, nursing staff or patients. Funding for clinical practice development and research in nursing was found to be very sparse; the reasons for this were not identified. Overall the review confirmed statements from other sources (DoH, 1993a,b) that nursing development and research tends to be small scale and unsupported with nursing staff trying hard to implement research findings or be innovative in their practice without the necessary expertise and support. Such findings have implications for the current drive to implement research into practice. [ABSTRACT FROM AUTHOR]