scholarly journals Is the Consensus Value of ANU Sucrose (IAEA C-6) Too High?

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 866-874 ◽  
Author(s):  
Xiaomei Xu ◽  
Matthew S Khosh ◽  
Kevin C Druffel-Rodriguez ◽  
Susan E Trumbore ◽  
John R Southon
Keyword(s):  
Primary Standard ◽  
Laboratory Data ◽  
Weighted Average ◽  
Secondary Standard ◽  
Data Quality Control ◽  
Unequal Variance ◽  
Consensus Value ◽  
Average Value ◽  
Consensus Values ◽  
Primary And Secondary Standards

Primary and secondary standards are essential in radiocarbon analyses for the purpose of reporting and comparing data among laboratories, as well as for internal laboratory data quality control. ANU sucrose is one of the IAEA-certified 14C standards (C-6) with a consensus value of 1.5061 ± 0.0011 fraction modern (Fm). All of our measurements of ANU sucrose (n = 351) as a secondary standard over the last 7 yr result in an average value of 1.5016 ± 0.0005 Fm (2-σ standard error). After applying the same outlier tests used for IAEA reference standards, a weighted average value of 1.5016 ± 0.0002 Fm (n = 294) was calculated. This value is significantly lower than the IAEA C-6 consensus value (t test with unequal variance; p = 0.023). In contrast, our measurements of other secondary standards over the same time period are in excellent agreement with their respective consensus values. Since ANU is the only secondary standard measured in our lab that does not agree with the consensus values, and we have measured a larger number analyses compared to what went into the definition of the consensus value, we suggest that the consensus value of ANU sucrose might be too high by ∼0.0045 ± 0.0011 Fm. Given that some labs routinely use ANU sucrose as a primary standard, our results suggest that revisiting the consensus value of ANU sucrose may be necessary.

scholarly journals Considerations of the Scale of Radiocarbon Offsets in the East Mediterranean, and Considering a Case for the Latest (Most Recent) Likely Date for the Santorini Eruption

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 449-474 ◽  
Author(s):  
Sturt W Manning ◽  
Bernd Kromer
Keyword(s):  
Time Horizon ◽  
Weighted Average ◽  
17Th Century ◽  
Data Sets ◽  
East Mediterranean ◽  
Average Value ◽  
Accuracy And Precision ◽  
Wide Range ◽  
The Impact ◽  
East Mediterranean Region

The debate over the dating of the Santorini (Thera) volcanic eruption has seen sustained efforts to criticize or challenge the radiocarbon dating of this time horizon. We consider some of the relevant areas of possible movement in the14C dating—and, in particular, any plausible mechanisms to support as late (most recent) a date as possible. First, we report and analyze data investigating the scale of apparent possible14C offsets (growing season related) in the Aegean-Anatolia-east Mediterranean region (excluding the southern Levant and especially pre-modern, pre-dam Egypt, which is a distinct case), and find no evidence for more than very small possible offsets from several cases. This topic is thus not an explanation for current differences in dating in the Aegean and at best provides only a few years of latitude. Second, we consider some aspects of the accuracy and precision of14C dating with respect to the Santorini case. While the existing data appear robust, we nonetheless speculate that examination of the frequency distribution of the14C data on short-lived samples from the volcanic destruction level at Akrotiri on Santorini (Thera) may indicate that the average value of the overall data sets is not necessarily the most appropriate14C age to use for dating this time horizon. We note the recent paper of Soter (2011), which suggests that in such a volcanic context some (small) age increment may be possible from diffuse CO2emissions (the effect is hypothetical at this stage and hasnotbeen observed in the field), and that "if short-lived samples from the same stratigraphic horizon yield a wide range of14C ages, the lower values may be the least altered by old CO2." In this context, it might be argued that a substantive “low” grouping of14C ages observable within the overall14C data sets on short-lived samples from the Thera volcanic destruction level centered about 3326–3328 BP is perhaps more representative of the contemporary atmospheric14C age (without any volcanic CO2contamination). This is a subjective argument (since, in statistical terms, the existing studies using the weighted average remain valid) that looks to support as late a date as reasonable from the14C data. The impact of employing this revised14C age is discussed. In general, a late 17th century BC date range is found (to remain) to be most likelyeven ifsuch a late-dating strategy is followed—a late 17th century BC date range is thus a robust finding from the14C evidence even allowing for various possible variation factors. However, the possibility of a mid-16th century BC date (within ∼1593–1530 cal BC) is increased when compared against previous analyses if the Santorini data are considered in isolation.

CHANGES IN THE TECHNICAL AND TECHNOLOGICAL LEVEL OF STEAM CULTIVATORS IN THE XXI CENTURY

2021 ◽  
Vol 2 (143) ◽  
pp. 174-183
Author(s):  
Andrey Yu. Nesmiyan ◽  
◽  
Anastasiya S. Kaymakova ◽  
Yuliya S. Tsench ◽  
Keyword(s):  
Weighted Average ◽  
Specific Weight ◽  
Research Purpose ◽  
Utilization Rate ◽  
Average Value ◽  
Technological Level ◽  
Short Test ◽  
Specific Material ◽  
The Cost

Most modern agricultural machines and tools consist of components, the main parameters, design features of which were justified in the first half of the twentieth century. Slowly and evolutionarily, these technical means are developing. (Research purpose) The research purpose is in identifying general trends in the technical and technological level of steam cultivators in the first quarter of the XXI century. (Materials and Methods) For the study there was analyzed the data of the short test reports of the selected machines. The production of steam cultivators in the Russian Federation is gradually increasing. (Results and discussion) For ten years of the beginning of the XXI century, only 27 machines were provided for testing, and from 2014 to 2017 – more than 40, while for "old" cultivators, the weighted average value of the tractor traction class was 2.8, for new ones it is about of four. For the study period (on average 10 years) the quality of soil cultivation in terms of such parameters as deviation from the specified depth of cultivation, crumbling and combing of the field surface has not changed much. The productivity of cultivator units increased by 7-21 percents, which is explained not only by an increase in the power of tractors, but also by an increase in the utilization rate of charge time on average from 0.72 to 0.77. The specific weight of the "new" cultivators was on average 22 kilogram-meters less than that of the "old" analogues, which can be explained by the evolution of their designs. (Conclusions) Increasing the class of tractors by one "level" the specific material consumption of the cultivators aggregated with them increases by about 58 kilogram-meters for both "old" and " new " cultivators. With an increase in the width of the tools from 4 to 16 meters, their weight will increase by 8 times, which affects the cost and operational and environmental characteristics of wide-reach cultivators.

ACCURACY OF OPTICAL PYROMETRY IN THE RANGE 800 °C TO 4000 °C

1958 ◽  
Vol 36 (10) ◽  
pp. 1397-1408 ◽  
Author(s):  
D. R. Lovejoy
Keyword(s):  
Standard Deviation ◽  
Temperature Scale ◽  
Primary Standard ◽  
Secondary Standard ◽  
Optical Pyrometer ◽  
Optical Pyrometry ◽  
International Temperature Scale ◽  
International Temperature ◽  
Carbon Arc ◽  
Temperature Standard

A pair of secondary standard tungsten strip lamps have had a luminance temperature – current calibration, in the range 800 °C to 2200 °C, at a number of national laboratories. An analysis of the calibration results confirms estimates of the accuracy of optical pyrometry in the range 800 °C to 2200 °C and supports the extension of these estimates to 4000 °C. The standard deviation uncertainty of optical pyrometry is shown to be about 1 °C at 800 °C rising to 2 °C at 2200 °C and 10 °C at 4000 °C, being about double this for the calibration of commercial pyrometers unless certain described precautions are taken.The reliability of the secondary standard lamps, when used under well-defined conditions, is confirmed and it is shown that they have a standard deviation calibration uncertainty of about 1 °C for the vacuum-type lamps in the range 800 °C to 1500 °C and 2 °C for the gas-filled lamps in the range 1500 °C to 2200 °C. Most of this uncertainty is due to primary standard optical pyrometer calibration errors. Attention is drawn to the fact that a carbon arc fulfills the requirements of a secondary luminance temperature standard at about 3514 °C.Recent determinations of the gold point and the second radiation constant indicate that the 1948 International Temperature Scale is lower than the thermodynamic scale by an amount varying from 0.8 °C at 800 °C to 12 °C at 4000 °C. This is already greater than the calibration errors of optical pyrometry and, in view of the still greater accuracies presaged by photomultipliers, a revision of the International Temperature Scale is suggested.

scholarly journals Quantitive Evalution of Involvement of Countries of the World in the International Open Access Movement

2018 ◽  
pp. 216-221
Keyword(s):  
Open Access ◽  
Quantitative Evaluation ◽  
Weighted Average ◽  
Average Value ◽  
The World

The article presents the developed method for the quantitative evaluation of involvement of countries of the world in the international open access movement. It consists in the identification of eight country open access indicators initially connected with the open access initiatives and instruments, their weighing, normalization and aggregation in the form of a weighted average value. In a second more strict approximation the number of indicators has been reduced up to six for the account of discarding the data duplicated in ROAR and Open DOAR. Budapest initiative and Berlin declaration were considered as the ОА-initiatives, and data from the international registers DOAJ, SHERPA/RoMEO, ROAR MAP and the Webometrics ОА-repositories ranking was considered as the instruments. The calculation is done on the basis of the developed method for 133 countries.

scholarly journals High-resolution Data Based Groundwater Recharge Estimations of Aynalem Well Field

2021 ◽  
Vol 13 (1) ◽  
pp. 1-20
Author(s):  
Abdelwassie Hussien ◽  
Tesfamichael Gebreyohannes ◽  
Miruts Hagos ◽  
Gebremedhin Berhane ◽  
Kassa Amare ◽  
...  
Keyword(s):  
Land Use ◽  
High Resolution ◽  
Water Balance ◽  
Groundwater Recharge ◽  
Groundwater Level ◽  
Weighted Average ◽  
Level Fluctuation ◽  
Average Value ◽  
Well Field ◽  
Groundwater Level Fluctuation

Due to the ever-increasing demand for water in Aynalem catchment and its surrounding, there has been an increased pressure on the Aynalem well field putting the sustainability of water supply from the aquifer under continuous threat. Thus, it is vital to understand the water balance of the catchment to ensure sustainable utilization of the groundwater resource. This in turn requires proper quantification of the components of water balance among which recharge estimation is the most important. This paper estimates the groundwater recharge of the Aynalem catchment using high-resolution hydro-meteorological data. Daily precipitation and temperature measurement data for years 2001-2018; groundwater level fluctuation records collected at every 30 minutes; and soil and land use maps were used to make recharge estimations. In the groundwater level fluctuation, three boreholes were monitored, but only two were utilized for the analysis because the third was under operation and does not represent the natural hydrologic condition. Thornthwaite soil moisture balance and groundwater level fluctuation methods were applied to determine the groundwater recharge of the Aynalem catchment. Accordingly, the annual rate of groundwater recharge estimated based on the soil-water balance ranges between 7mm/year and 138.5 mm/year with the weighted average value of 89.04 mm/year. The weighted average value is considered to represent the catchment value because the diverse soil and land use/cover types respond differently to allow the precipitation to recharge the groundwater. On the other hand, the groundwater recharge estimated using the groundwater level fluctuation method showed yearly groundwater recharge of 91 to 93 mm/year. The similarity in the groundwater recharge result obtained from both methods strengthens the acceptability of the estimate. It also points out that the previously reported estimate is much lower (36 to 66 mm/year).

scholarly journals Temporal distribution of size and weight of fattened Bluefin tuna (Thunnus thynnus l.) from Tunisian farms: (2005-2010)

2013 ◽  
Vol 15 (1) ◽  
pp. 115 ◽  
Author(s):  
A. HATTOUR ◽  
W. KOCHED
Keyword(s):  
Fork Length ◽  
Weighted Average ◽  
Temporal Distribution ◽  
Bluefin Tuna ◽  
Thunnus Thynnus ◽  
Length Frequency ◽  
Average Value ◽  
Atlantic Bluefin Tuna ◽  
Straight Line ◽  
The Mean

The present study analysis size and weight-frequency composition of Atlantic bluefin tuna (Thunnus thynnus thynnus) fattened in Tunisian farms for the period 2005-2010 and compare these morphometric parameters with those from wild bluefin tuna landed on 2001 at Sfax port (Tunisia). A total of 6,757 wild and fattened bluefin tuna were measured as straight-line fork length and 49,962 were weighted. Average value of K for wild BFT was 1.59 and respectively 2.43, 2.32, 2.15, 1.61, 1.79 and 1.90 for Fattened BFT after 5-6 months from 2005 to 2010. Length frequency of fattened bluefin showed clearly a substantial increase in juvenile rate. The percentage which was 21.4% in 2005 reached 31.3% in 2009. For weight distribution, 73.3% of the fish caught in 2001 are below the annual mean (75.7 kg), while means 71 to 72% of fattened fish were under annual mean weight. Year 2009 is exceptional because only 57% of fattened fish were under the mean weight. This demonstrates that the fish caught are becoming increasingly small. Mean weight for fattening period (77 to 124 kg) are obviously higher than those of the wild fish (75,7kg).This study showed an increment in the amount of specimen under first sexual maturity which will not have the chance to spawn.

scholarly journals Determination of the Key Comparison Reference Value from Multiple Field Calibration of Sentinel-2B/MSI over the Baotou Site

2020 ◽  
Vol 12 (15) ◽  
pp. 2404
Author(s):  
Caixia Gao ◽  
Yaokai Liu ◽  
Jinru Liu ◽  
Lingling Ma ◽  
Zhifeng Wu ◽  
...  
Keyword(s):  
Weighted Average ◽  
Reference Value ◽  
Atmospheric Conditions ◽  
Key Comparison ◽  
Field Calibration ◽  
Average Value ◽  
True Value ◽  
Chi Squared ◽  
Calibration Samples ◽  
Relative Differences

Field calibration is a feasible way to evaluate space-borne optical sensor observations via natural or artificial sites on Earth’s surface with the aid of synchronous surface and atmospheric characteristic data. Since field calibration is affected by the coupled effects of surface and atmospheric characteristics, the single calibration results acquired under different surface and atmospheric conditions have different biases and different uncertainties, making it difficult to determine the consistency of these multiple calibration results. In view of this, by assuming that the radiometric performance is invariant during field calibration and the calibration samples are independent of each other, the surface–atmosphere invariant Key Comparison Reference Value (KCRV) is essentially derived from various calibration results. As the number of calibration samples increases, the uncertainty in the KCRV should decrease, and the KCRV should approach the “true” value. This paper addresses a novel method for estimating a weighted average value from multiple calibration results that can be used to compare each calibration result, and this value is accepted as the KCRV. Furthermore, this method is preliminarily applied to the field calibration of the Multispectral Instrument (MSI) onboard the Sentinel-2B satellite via the desert target at the Baotou site, China. After employing a chi-squared test to verify that 12 calibration samples are independent from each other, the KCRV of the 12 calibration samples at the Baotou site is derived, which exhibits much lower uncertainty than a single sample. The results show that the KCRVs of the relative differences between the simulated and observed at-sensor reflectance are 3.75%, 5.11%, 6.09%, and 5.03% for the four bands of Sentinel-2B/MSI, respectively, and the corresponding uncertainties are 1.84%, 1.87%, 1.90%, and 1.93%. It is noted that the KCRV uncertainty obtained with only 12 calibration samples is reduced significantly, and in the future, more samples in other instrumented sites will be used to validate this method thoroughly.

Carrier Detection In Haemophilia A By Measurement Of Factor VIII Clotting Antigen (VIIICAg) And Factor VIII Related Antigen (VIIIRAg

1981 ◽  
Author(s):  
I R Peake ◽  
R G Newcombe ◽  
B L Davies ◽  
R A Furlong ◽  
C A Ludlam ◽  
...  
Keyword(s):  
Factor Viii ◽  
Laboratory Data ◽  
Carrier Detection ◽  
Clotting Factor ◽  
Haemophilia A ◽  
Immunoradiometric Assay ◽  
Plasma Samples ◽  
Severe Haemophilia ◽  
Likelihood Ratios ◽  
Unequal Variance

In order to assess the value of measurement of VIIICAg in the detection of carriers of haemophilia A, plasma samples were obtained on three separate occasions from each of 23 obligate carriers of mild and severe haemophilia, and 26 normal females. At each visit each sample was divided into three and each aliquot was then assayed for VIIICAg (immunoradiometric assay), clotting factor VIII (VIIIC) (two stage assay) and VIIIRAg (Laurell immu noelectrophoresis). After calculating median values at each visit, and for the three visits, a comparison of the ratios VIIIC/VIIIRAg and VIIICAg/VIIIRAg was made. Likelihood ratios (of being a carrier) were calculated using an unequal variance predictive method for both ratios. These showed that laboratory data calculated on the median of the three-visit medians had greater discriminatory power than a single-visit median value. Using the median of three visits both VII IC/VIIIRAg and VIIICAg/VIIIRAg gave the same proportional misclassification of carriers as normals (4 of 23- 17%). However the ratios VII ICAg/VIIIRAg were more discriminatory due to the greater reproducibility between visits of VIIICAg results than those of VIIIC. There was no statistically significait difference between VII ICAg/VIIIRAg (or VII IC/VIIIRAg) ratios obtained from carriers of mild or severe haemophilia. The ratio VII ICAg/VIIIRAg was therefore shown to be the method of choice for carrier detection except theoretically in the rare CRM+ families.

scholarly journals Practical learnings from an epidemiology study on TDI-related occupational asthma: Part I—Cumulative exposure is not a good indicator of risk

2020 ◽  
Vol 36 (11) ◽  
pp. 876-884 ◽  
Author(s):  
Patrick M Plehiers ◽  
Anne H Chappelle ◽  
Mark W Spence
Keyword(s):  
Occupational Asthma ◽  
Weighted Average ◽  
Toluene Diisocyanate ◽  
Cumulative Exposure ◽  
Respiratory Protection ◽  
Epidemiology Study ◽  
Average Value ◽  
Asthma Incidence ◽  
Anonymized Data ◽  
Epidemiology Studies

The anonymized data of an epidemiology study on incidence of toluene diisocyanate (TDI)-related occupational asthma in three US-based TDI production facilities have been reanalyzed to identify where to best focus exposure reduction efforts in industrial practice to reduce the risk of sensitization to TDI. Since the induction of sensitization has sometimes been attributed to cumulative exposure, this relationship was examined first. Gross cumulative exposure values (i.e. not taking into account whether respiratory protection was used or not) and net cumulative exposure values (i.e. accounting for the use of respiratory protection) per participant were calculated based on the duration of their study participation and the average time-weighted average value of the exposure group to which they belonged. These two sets of cumulative exposure data were compared with asthma incidence using logistic regression. Incidence was zero among workers who rarely come into contact with open plant systems (e.g. during maintenance or spills). Notwithstanding, no statistically significant relationship between asthma incidence and either gross or net cumulative exposure could be determined. This is shown to be consistent with the results of several other epidemiology studies on TDI-related occupational asthma. In conclusion, cumulative exposure values are not a good indicator of the risk of developing TDI-related occupational asthma.

Thread Friction Torque in Bolted Joints

2005 ◽  
Vol 127 (4) ◽  
pp. 387-393 ◽  
Author(s):  
Sayed A. Nassar ◽  
Payam H. Matin ◽  
Gary C. Barber
Keyword(s):  
Friction Coefficient ◽  
Current Practice ◽  
Weighted Average ◽  
High Accuracy ◽  
Friction Torque ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Average Value ◽  
Highly Sensitive

In this paper, formulas are developed for the calculation of the effective thread friction radius in fasteners, in order to determine the thread friction torque component. Due to the lack of exact formulas in the literature, current practice uses the average value of the minor and major thread radii, as an approximation, for determining the thread friction torque component. Results provided by these formulas are compared with those given by the current practice that uses the average value of the minor and major thread radii, instead of the exact value. It is well known that the torque-tension relationship in threaded fastener applications is highly sensitive to the friction torque components: between threads, and under the turning fastener head or nut. Even moderate variations or inaccuracies in determining the friction torque components would significantly impact the fastener tension and the joint clamp load. High accuracy in the estimation of the friction torque components is critical, as it directly affects the reliability, safety, and the quality of bolted assemblies. This analysis focuses on the thread friction torque component. The new formulas for the thread friction radius are developed for a mathematical model of a bolted joint using five assumed scenarios of the contact pressure between male and female threads. Because of the fact that the variation in the sliding speed of various points on a thread surface is insignificant, a uniform thread friction coefficient is used in the analysis. However, a contact area weighted average value is used for the thread friction coefficient. Numerical results and error analysis are presented in terms of a single nondimensional variable, namely, the ratio between the major and minor thread radii.

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