A distribution of particle sizes or particle size distribution (PSD) is a fundamental characteristic of cement powder. Accurate PSDs are required in computational efforts to model the hydration process and it is an important practical issue for the cement industry. Presently, the only available standard method for measuring the PSD of cement, namely ASTM C115, is limited in scope, with a lower size detection limit of 7.5 µm. Since there are no standard procedures that adequately cover the broad particle size range associated with portland cement powder, the implementation of different measurement techniques varies widely within the industry. Two ASTM-sponsored round robin tests were performed to (1) ascertain the techniques and methods currently used in the cement industry and (2) develop and refine a standard method or methods. The results have been incorporated into a best practice method based on the technique of laser diffraction. The aim of the current paper is to summarize the findings based on the data generated during the round robins and to summarize the various approaches available to measure the PSD of cement. A summary of the statistical analysis of the test results is described.

A distribution of sizes or particle size distribution (PSD) is an essential property of cement powder. The only standard method to measure the PSD of cement, namely ASTM C115 [ 11 is limited in scope; this standard only describes a method for determining "fineness" with a lower size detection limit of 7.5 pm. As there is no standard procedure covering the whole range of cement PSD, the implementation of different measurement methods varies widely within the industry. A first report [2] was prepared to examine the methods used in the cement industry. The high variability of the data led to the necessity for further research.ASTM committee C01.25.01 sponsored a second round-robin test to measure the PSD of cement. The aim of the current report is to analyze the data generated during that test and to summarize the various approaches available to measure the PSD of cement. The analysis of the data is conducted in two parts. In the first part, an attempt is made to establish a reference distribution using a standard cement powder (SRM 114p), improving the results already obtained from the first round-robin. This is followed by examination of the parameters and methodology used by the participants in order to initiate discussion on developing a standard test method for cement PSD to be submitted for ASTM consideration. The report provides all raw data collected during the round-robin tests, and the results of a statistical analysis of the collected data. AcknowledgementsThe authors would like to thank the ASTM Task Group CO1.25.01 for providing the opportunity for this round-robin. We would like to thank all participants of the round-robin (listed below by alphabetical order of the institution) for providing time and staff to perform the tests.Also, we would like to thank Robin Haupt and the staff of the Cement and Concrete Reference Laboratory (CCRL), who were instrumental in providing the samples to the round-robin participants.

The motion imagery community would benefit from the availability of standard measures for assessing image interpretability. The National Imagery Interpretability Rating Scale (NIIRS) has served as a community standard for still imagery, but no comparable scale exists for motion imagery. Several considerations unique to motion imagery indicate that the standard methodology employed in the past for NIIRS development may not be applicable or, at a minimum, require modifications. Traditional methods for NIIRS development rely on a close linkage between perceived image quality, as captured by specific image interpretation tasks, and the sensor parameters associated with image acquisition. The dynamic nature of motion imagery suggests that this type of linkage may not exist or may be modulated by other factors. An initial study was conducted to understand the effects target motion, camera motion, and scene complexity have on perceived image interpretability for motion imagery. This paper summarizes the findings from this evaluation. In addition, several issues emerged that require further investigation:The effect of frame rate on the perceived interpretability of motion imagery Interactions between color and target motion which could affect perceived interpretability The relationships among resolution, viewing geometry, and image interpretability The ability of an analyst to satisfy specific image exploitation tasks relative to different types of motion imagery clips Plans are being developed to address each of these issues through direct evaluations. This paper discusses each of these concerns, presents the plans for evaluations, and explores the implications for development of a motion imagery quality metric.

Particle size distribution (PSD) is an essential property of cement. The only standard method to measure the PSD of cement, namely ASTM C115 [1] is limited in scope; this standard describes a method for determining "fineness" with a lower size detection limit of 7.5 µm. As there is no standard procedure covering the whole range of cement PSD, the implementation of different measurement methods varies widely within the industry. In general, the round-robin results summarized here have demonstrated the high variability between participants using instruments based on the same physical principles. ASTM committee C01.25.01 sponsored a round-robin test to measure the PSD of cement. The aim of the current report is to analyze the data generated during those tests and to summarize the various approaches available to measure the PSD of cement. The analysis of the data is conducted in two parts. In the first part, an attempt is made to establish a reference distribution using a standard cement powder (SRM 114p). This is followed up by a comparison of the roundrobin data in order to initiate discussion on developing a standard test method for cement PSD to be submitted for ASTM consideration. The report provides all raw data collected during the round robin tests, and the results of a statistical analysis of the collected data.

The standard reference material (SRM) for fineness of cement, SRM 114, is an integral part of the calibration material routinely used in the cement industry to qualify cements. Being a powder, the main physical properties of cement, prior to hydration, are its surface area and particle size distribution (PSD). Since 1934, NIST has provided SRM 114 for cement fineness and it will continue to do so as long as the industry requires it. Different lots of SRM 114 are designated by a unique letter suffix to the SRM number, e.g., 114a, 114b, …. ,114q. A certificate that gives the values obtained using ASTM C204 (Blaine), C115 (Wagner) and C430 (45 µm sieve residue) is included with each lot of the material. The supply of SRM 114p, which was released in 1994, was depleted in 2004. Therefore, a new batch of SRM 114 needed to be developed. This process included selection of the cement, packaging the cement in small vials, and determination of the values for the ASTM tests reported. In this case, the Blaine, Wagner and 45 µm sieve residue were the tests used. Later the particle size distribution (PSD) will be added. The purpose of this report is to provide a detailed description of the process used to package and certify SRM 114q. All measurements used for the certifications are provided along with descriptions of the statistical analyses.