Precision Estimates and Statements for Performance Indices from the Indirect Tensile Cracking Test at Intermediate Temperature

The Virginia Department of Transportation (DOT) has taken initiatives to implement the Balanced Mix Design (BMD) method to assure the long-term service life of its pavement network from a mixture quality standpoint. As part of this initiative, the cracking tolerance (CT) index obtained from the indirect tensile (IDT) test at intermediate temperature in accordance with ASTM D8225-19 was selected for evaluating the cracking potential of dense-graded surface asphalt mixtures. This prompted the need to generate the precision estimates (repeatability and reproducibility) for the test method for proper implementation during quality measurement practices. Thus, this interlaboratory study was undertaken to determine the precision estimates of the CT index calculated from the IDT test and to develop the associated precision statements. In addition, fracture strain tolerance (FST) and indirect tensile strength were included. Two asphalt mixes with significantly different CT index values were designed for the evaluation. Forty-six pairs of five replicate sets of compacted specimens (one set for each mix) were sent to 41 participating laboratories to be tested at 25°C. The test results were checked for data quality. The effects of loading rate and manufacturers on the indices were also evaluated. The test results indicated that one third of the sets were not tested in full accordance with the ASTM standard, indicating a need for training. The results also indicated that the specified loading rate of 50 ± 2 mm/min in ASTM D8225-19 for the IDT test may need revision. Finally, the precision estimates and associated statements for the three indices were presented.

Miriam Tildesley and the Anthropological Politics of Standardizing Racial Measurements

This article examines to what extent nationalist and sexist sentiment and international politics shaped attempts to universalize measurement practices in physical anthropology. On the one hand, racial scientists were interested in creating an international community with a universalized methodology and developing a global taxonomy of human races. On the other hand, they chauvinistically guarded their localized practices from outside influences. By following the standardization efforts of British biometrician Miriam Tildesley, a female racial scientist adamant on unifying a research field largely dominated by men from different countries, this article argues that intersecting forces of nationalism, internationalism, and sexism shaped anthropological practices in the early 20th century.

Four Problems in Sexting Research and Their Solutions

Despite over 10 years of research, we still know very little about people’s sexting behaviours and experiences. Our limited and, at times, conflicting knowledge about sexting is due to re-searchers’ use of inconsistent conceptual definitions of sexting, dubious measurement practices, and atheoretical research designs. In this article, we provide an overview of the history of sex-ting research and describe how researchers have contributed to the ‘moral panic’ narrative that continues to surround popular media discourse about sexting. We identify four key problems that still plague sexting research today: (1) imprudent focus on the medium, (2) inconsistent conceptual definitions, (3) poor measurement practices, and (4) a lack of theoretical frameworks. We describe and expand on solutions to address each of these problems. In particular, we focus on the need to shift empirical attention away from sexting and towards the behavioural domain of technology-mediated sexual interaction. We believe that the implementation of these solu-tions will lead to valid and sustainable knowledge development on technology-mediated sexual interactions, including sexting.

Insights from 20 years of temperature parallel measurements in Mauritius around the turn of the 20^th Century

There is considerable import in creating more complete, better understood, holdings of early meteorological data. Such data permit an improved understanding of climate variability and long-term changes. Early records are particularly incomplete in the tropics, with implications for estimates of global and regional temperature. There is also a relatively low level of scientific understanding of how these measurements were made and, as a result, of their homogeneity and comparability to more modern techniques and measurements. Herein we describe and analyse a newly rescued set of long-term, up to six-way parallel measurements, undertaken over 1884–1903 in Mauritius, an island situated in the southern Indian Ocean. Data include: i) measurements from a well-ventilated room, ii) a shaded Thermograph; iii) instruments housed in a manner broadly equivalent to a modern Stevenson Screen; iv) a set of measurements by a Hygrometer mounted in a Stevenson Screen; and for a very much shorter period v) two additional Stevenson Screen configurations. All measurements were undertaken within roughly 80 metre radius. To our knowledge this is the first such multidecadal multi-instrument assessment of meteorological instrument transition impacts ever undertaken, providing potentially unique insights. The intercomparison also considers the impact of different ways of deriving daily and monthly averages. The long-term comparison is sufficient to robustly characterise systematic offsets between all the instruments and seasonally varying impacts. Differences between all techniques range from tenths of a degree Celsius to in excess of a degree Celsius and are considerably larger for maximum and minimum temperatures than for means or averages. Systematic differences of several tenths of a degree also exist for the different ways of deriving average / mean temperatures. All differences bar two average temperature series pairs are significant at the 0.01 level using a paired t-test. Given that all thermometers were regularly calibrated against a primary Kew standard thermometer this analysis highlights significant impacts of instrument exposure, housing, siting and measurement practices in early meteorological records. These results reaffirm the importance of thoroughly assessing the homogeneity of early meteorological records.

Measurement practices in hallucinations research

Introduction: In several sub-fields of psychology, there has been a renewed focus on measurement practices. As far as we are aware, this has been absent in hallucinations research. Thus, we investigated (a) cross-study variation in how hallucinatory experiences are measured and (b) the reliability of measurements obtained using two tasks that are widely employed in hallucinations research.Method: In Study 1, we investigated to what extent there was variation in how the Launay-Slade Hallucination Scale (LSHS) has been used across 100 studies. In Study 2, we investigated the reliability of the measurements obtained through source monitoring and signal detection tasks, using data from four recent publications. Materials are available at doi: 10.17605/osf.io/d3gnk/.Results: In Study 1, we found substantial variation in how hallucinatory experiences were assessed using the LSHS and that descriptions of the LSHS were often incomplete in important ways. In Study 2, we reported a range of reliability estimates for the measurements obtained using source monitoring and signal discrimination tasks. Some measurements obtained using source monitoring tasks had unacceptably low levels of reliability. Conclusions: Our findings suggest that suboptimal measurement practices are common in hallucinations research and we suggest steps researchers could take to improve measurement practices.

“The Uncertain Method of Drops”: How a Non-uniform Unit Survived the Century of Standardization

This paper follows the journey of two small fluid units throughout the 19th century in Anglo-American medicine and pharmacy, explaining how the non-uniform “drop” survived while the standardized minim became obsolete. I emphasize two roles these units needed to fulfill: that of a physical measuring device, and that of a rhetorical communication device. First, I discuss the challenges unique to measuring small amounts of fluid, outlining how the modern medicine dropper developed out of an effort to resolve problems with the “minimometer,” which measured minim. Second, I explain how drops, utilized in “the open drop method” of administering general anesthesia, effectively communicated a gradual process and epistemically valuable heuristic to the audience of practitioners, whose attention to individual medical outcomes was important for verifying the proper dosage. The standardized minim was never able to achieve success as the drop’s intended replacement; the non-uniform drop better served the relevant epistemic goals within the practical contexts for which these units were designed. The surprising historical trajectory of drops should cause us to question the common equivocation of “standardization” with “progress” in the history and philosophy of measurement. This study also exemplifies how examining non-standard measurement practices can be instructive for better understanding the role and function of standardization within epistemology of measurement

Absorption instruments inter-comparison campaign at the Arctic Pallas station

Aerosol light absorption was measured during a 1-month field campaign in June–July 2019 at the Pallas Global Atmospheric Watch (GAW) station in northern Finland. Very low aerosol concentrations prevailed during the campaign, which posed a challenge for the instruments' detection capabilities. The campaign provided a real-world test for different absorption measurement techniques supporting the goals of the European Metrology Programme for Innovation and Research (EMPIR) Black Carbon (BC) project in developing aerosol absorption standard and reference methods. In this study we compare the results from five filter-based absorption techniques – aethalometer models AE31 and AE33, a particle soot absorption photometer (PSAP), a multi-angle absorption photometer (MAAP), and a continuous soot monitoring system (COSMOS) – and from one indirect technique called extinction minus scattering (EMS). The ability of the filter-based techniques was shown to be adequate to measure aerosol light absorption coefficients down to around 0.01 Mm−1 levels when data were averaged to 1–2 h. The hourly averaged atmospheric absorption measured by the reference MAAP was 0.09 Mm−1 (at a wavelength of 637 nm). When data were averaged for >1 h, the filter-based methods agreed to around 40 %. COSMOS systematically measured the lowest absorption coefficient values, which was expected due to the sample pre-treatment in the COSMOS inlet. PSAP showed the best linear correlation with MAAP (slope=0.95, R2=0.78), followed by AE31 (slope=0.93). A scattering correction applied to PSAP data improved the data accuracy despite the added noise. However, at very high scattering values the correction led to an underestimation of the absorption. The AE31 data had the highest noise and the correlation with MAAP was the lowest (R2=0.65). Statistically the best linear correlations with MAAP were obtained for AE33 and COSMOS (R2 close to 1), but the biases at around the zero values led to slopes clearly below 1. The sample pre-treatment in the COSMOS instrument resulted in the lowest fitted slope. In contrast to the filter-based techniques, the indirect EMS method was not adequate to measure the low absorption values found at the Pallas site. The lowest absorption at which the EMS signal could be distinguished from the noise was >0.1 Mm−1 at 1–2 h averaging times. The mass absorption cross section (MAC) value measured at a range 0–0.3 Mm−1 was calculated using the MAAP and a single particle soot photometer (SP2), resulting in a MAC value of 16.0±5.7 m2 g−1. Overall, our results demonstrate the challenges encountered in the aerosol absorption measurements in pristine environments and provide some useful guidelines for instrument selection and measurement practices. We highlight the need for a calibrated transfer standard for better inter-comparability of the absorption results.

In search of supplier flexibility performance measurement

PurposeThe purpose of this study is to identify, characterize and assess supplier flexibility measurement practices in the order-to-delivery process.Design/methodology/approachThe study involved a survey; participants were 224 purchasing managers at Swedish manufacturing companies that had more than 20 employees.FindingsScrutiny of the details of measurement practices revealed that most respondents actually do not specifically measure supplier flexibility. Instead they measure other measures like delivery reliability, conduct qualitative follow-ups, or cannot specify how supplier flexibility is measured. It was acknowledged that they measure different supplier flexibility aspects, and the applied measures were characterized, e.g. in terms of which flexibility dimension they represent.Research limitations/implicationsConceptual clarifications and adaptations to measuring supplier flexibility in the order-to-delivery process are provided. The identified measures can be a contribution in further developing literature on flexibility performance measurement.Practical implicationsPurchasing, logistics and supply chain managers in search of supplier flexibility performance measurement can find ways to measure and an extended flexibility vocabulary. This has the potential to improve flexibility in the supply chain.Originality/valueEven though flexibility is claimed as being an important competitive advantage, few empirical studies and operationalized measures exist, particularly in the order-to-delivery process.