Authors:Zhongyu Wu, K. Inn, Zhichao Lin, and C. McMahon
One of the most critical elements of a performance evaluation (PE) program for radioactivity measurements is the traceability of the PE materials to the national standards. The requirements and criteria for the production of traceable environmental and radiobioassay PE materials have been defined by ANSI N42.22 and ANSI N13.30 standards. It is important to note that use of traceable source materials does not necessarily ensure the traceability of subsequently derived PE materials unless verification measurements exist in conjunction with the preparation processes. This paper describes the protocol currently used by NIST for the preparation and verification of air filter, acidified water, spiked soil, synthetic urine, and synthetic fecal PE materials for low-level radioactivity measurements. The process involves gravimetric dilutions and mixing of primary radionuclide NIST Standard Reference Materials (SRMs), addition of the derived master solution to sample matrices, and subsequent verification measurements. Several gamma-emitters were used to trace the gravimetric dilutions and spike addition through an unbroken chain of gamma comparison measurements. The massic activities of alpha- and beta-emitters in the diluted solutions and PE samples were also measured by radiochemical methods and compared with their gravimetric values. A correlation analysis demonstrated that the gamma emitters quantitatively followed 90Sr, 238U, 238Pu, and 241Am throughout the dilution and spiking and can be used as effective process monitors. The statistical results from t-tests, box plots, and normal probability tests suggested that traceability of radionuclides in the PE materials to their primary standards can be verified to within 1%, with an overall precision better than 2% (1s).
This paper reviews the history of research performance evaluation in the university sector of the Federal Republic of Germany over a fifteen-year period from 1975–88. While the first studies were rankings of entire institutions, recent studies have focused on performance differences between departments and individual researchers of the same discipline. Many different performance measures have been used to rank universities and departments within disciplines. Differences in conceptualization, data collection, counting and weighting procedures, however, make it very difficult to generalize findings across studies. This first generation of German research evaluation studies should, therefore, be viewed more as examplifying interesting methodological approaches than as offering definitive and clear-cut conclusions. Nevertheless some important lessons have been learnt from fifteen years of studies on university research performance evaluation.
The Radiological and Environmental Sciences Laboratory administers three separate programs that include the use of prepared
evaluation material to assess the performance of the participant laboratories. The performance materials include a simple
liquid matrix to soil containing organic compounds to synthetic excreta containing known concentrations of radionuclides.
The paper discusses the quality control associated with the preparation of these materials. The concept of synthetic-standard
enhancement of a natural matrix is briefly discussed to demonstrate homogeneity. The use of verified standards and the assurance
of homogeneity by preparation method and characterization are shown to be the necessary components of useful and accurate
performance evaluation materials. Because each of the performance programs is tailored to the specific needs of the participants,
a discussion of the acceptance criteria is also included.
Authors:A. Asha Monicka, T. Pandiarajan, and S. Ganapathy
. https://doi.org/10.15740/HAS/IJAE/9.1/12-18 . 10.15740/HAS/IJAE/9.1/12-18 Peleg , K. ( 1985 ). Produce handling, packaging and distribution . AVI Pub. Co. Inc , Connecticut . Shahir , S. and Thirupathi , V. ( 2009 ). Performanceevaluation of
Because of the demand for higher sensitivity radionuclide measurements,atom counting technology will become an increasingly used modality in geo-and bio-studies, and process control operations. It is anticipated that requestsfor standards, intercomparisons and performance evaluations services willsurge in the near future. In anticipation of such requests, the state-of-the-artneeded to be assessed for proactive planning purposes. The results of a workshopfocused on these issues indicated that there are several ongoing standards,intercomparisons and performance evaluations thrusts which are expected toexpand in the future. Furthermore, new projects were planned and the Councilon Ionizing Radiation Measurements and Standards (Public and EnvironmentalRadiation Protection subcommittee) was proposed as an information coordinator.
The preparation of performance testing (PT) materials for environmental and radiobioassay applications involves the use of natural matrix materials containing the analyte of interest, the addition (spiking) of the analyte to a desired matrix (followed by blending for certain matrices) or a combination of the two. The distribution of the sample analyte concentration in a batch of PT samples will reflect the degree of heterogeneity of the analyte in the PT material and/or the reproducibility of the sample preparation process. Commercial and government implemented radioanalytical performance evaluation programs have a variety of acceptable performance criteria. The performance criteria should take into consideration many parameters related to the preparation of the PT materials including the within and between sample analyte heterogeneity, the accuracy of the quantification of an analyte in the PT material and to what "known" value will a laboratory's result be compared. This manuscript discusses how sample preparation parameters affect the successful participation in performance evaluation (PE) programs having an acceptance criteria established as a percent difference from a "known" value or in PE programs using other acceptance criteria, such as the guidance provided in ANSI N42.22 and N13.30.
Data from seven Mixed Analyte Performance Evaluation Program studies have been used to identify specific problems with results
and/or laboratories. These data have never been used to determine the bias or variability in data reporting for these laboratories
in general. These historical analytical data were analyzed for accuracy and precision overall and separated by method of sample
preparation, method of sample pretreatment, method of detection and sample size. The calculated mean percent relative bias
was analyzed for the actinides (241Am, 238Pu, 239/240Pu, 234/233U, and 238U) in the soil and water standards. Results from most analysis methods were at least slightly negatively biased. For the water
standards, the overall 95% confidence interval for the mean percent relative bias was −1.6% to −0.5% indicating that the average
actinide results slightly underestimated the true concentration. For the soil standards, the overall 95% confidence interval
for the mean percent relative bias was −8.1% to −6.6% indicating that the average actinide results moderately underestimated
the true concentration.
Authors:Kuo-Liang Chang, Shang-Chia Chiou, and Jih-Lian Ha
The US dispatched a large quantity of troops to Taiwan in 1950 and constructed American Military Housing in Shilin District. The United States military in Taiwan provided military and economic assistance. The preference to the US increased with enhancing national living standards so that local economic and cultural development were greatly affected by the introduction of the US culture. By applying DEA to measuring the performance evaluation of local governments, appropriate input/output factors are selected to efficiently evaluate the performance of local governments. To integrate the selection of input/output factors with expert opinions, reduce input costs, and avoid fuzziness in the investigation process, Fuzzy Delphi Method is utilized for sieving input/output factors. The research results show the relative efficiency of 2 local governments being strong-form efficiency, with the efficiency = 1, revealing the better relative efficiency. The relative efficiency of 3 local governments, 25% of all DMUs, appears in 0.9–1, presenting the relative efficiency of such local governments being more easily enhanced. The efficiency of 7 local governments, 58% of all DMUs, is lower than 0.9, showing the distinct inefficiency.
Radioanalytical performance testing programs provide radioassay laboratories, regulators and the public performance-based
evidence that measurement capabilities are in control. Performance acceptance criteria that combine aspects of measurements
difference from a known value and the associated combined uncertainty establishes a quantitative statement of statistical
confidence. However, there is need for a reasonable upper limit of the reported measurement uncertainty. Evaluation of thousands
of historical U.S. DOE Mixed-Analyte Performance Evaluation Program measurement results for 17 radionuclides in soil and water
samples provides predictive expectations for future measurement results and a statistical basis for establishing reasonable
upper limits for reported measurement uncertainties for performance evaluation programs.