The impact of preanalytical variable like delay in sample transportation and post analytical variable like deep freezer temperature on combined Measurement Uncertainty.

2017 ◽  
Author(s):  
Dr.Kavita Rasalkar ◽  
◽  
Dr Suma HR ◽  
Keyword(s):  
Measurement Uncertainty ◽  
Analytical Variable ◽  
The Impact

scholarly journals Benefits of implementing IT tools and procedures for the estimation and measurement uncertainty in testing laboratories

2020 ◽  
Vol 2 (7) ◽  
pp. 317-323
Author(s):  
Maria Cristina Dijmarescu
Keyword(s):  
Measurement Uncertainty ◽  
Rapid Expansion ◽  
Market Demand ◽  
Destructive Testing ◽  
Continuous Increase ◽  
Testing Laboratories ◽  
Quality Of Products ◽  
The Impact ◽  
Non Destructive

Destructive and non-destructive testing of materials present a rapid expansion given by the increase in market demand caused by the desire to obtain an increasingly better quality of products. The continuous increase in quality demands leads directly to the need to implement and modernize the techniques, methods, and equipment used for quality control. Consequently, the need for product testing services has a rapid growth. This paper presents the strength and weaknesses of implementing IT tools for the estimation of the measurement uncertainty in testing laboratories and the impact of these tools on the economic part

scholarly journals Assessment the impact of samplers change on the uncertainty related to geothermalwater sampling

2018 ◽  
Vol 30 ◽  
pp. 01006
Author(s):  
Katarzyna Wątor ◽  
Anna Mika ◽  
Klaudia Sekuła ◽  
Ewa Kmiecik
Keyword(s):  
Measurement Uncertainty ◽  
Analysis Of Variance ◽  
Robust Statistics ◽  
Engineering Geology ◽  
Geothermal Water ◽  
Chemical Analyses ◽  
Water Sampling ◽  
Icp Oes ◽  
The Impact ◽  
Metasilicic Acid

The aim of this study is to assess the impact of samplers change on the uncertainty associated with the process of the geothermal water sampling. The study was carried out on geothermal water exploited in Podhale region, southern Poland (Małopolska province). To estimate the uncertainty associated with sampling the results of determinations of metasilicic acid (H2SiO3) in normal and duplicate samples collected in two series were used (in each series the samples were collected by qualified sampler). Chemical analyses were performed using ICP-OES method in the certified Hydrogeochemical Laboratory of the Hydrogeology and Engineering Geology Department at the AGH University of Science and Technology in Krakow (Certificate of Polish Centre for Accreditation No. AB 1050). To evaluate the uncertainty arising from sampling the empirical approach was implemented, based on double analysis of normal and duplicate samples taken from the same well in the series of testing. The analyses of the results were done using ROBAN software based on technique of robust statistics analysis of variance (rANOVA). Conducted research proved that in the case of qualified and experienced samplers uncertainty connected with the sampling can be reduced what results in small measurement uncertainty.

scholarly journals Correlated timing noise and high-precision pulsar timing: measuring frequency second derivatives as an example

2019 ◽  
Vol 488 (2) ◽  
pp. 2190-2201 ◽  
Author(s):  
X J Liu ◽  
M J Keith ◽  
C G Bassa ◽  
B W Stappers
Keyword(s):  
Measurement Uncertainty ◽  
High Precision ◽  
Power Law ◽  
Power Laws ◽  
Noise Model ◽  
Dispersion Measure ◽  
Pulsar Timing ◽  
Timing Noise ◽  
The Impact ◽  
Pulsar Timing Array

Abstract We investigate the impact of noise processes on high-precision pulsar timing. Our analysis focuses on the measurability of the second spin frequency derivative $\ddot{\nu }$. This $\ddot{\nu }$ can be induced by several factors including the radial velocity of a pulsar. We use Bayesian methods to model the pulsar times-of-arrival in the presence of red timing noise and dispersion measure variations, modelling the noise processes as power laws. Using simulated times-of-arrival that both include red noise, dispersion measure variations, and non-zero $\ddot{\nu }$ values, we find that we are able to recover the injected $\ddot{\nu }$, even when the noise model used to inject and recover the input parameters are different. Using simulations, we show that the measurement uncertainty on $\ddot{\nu }$ decreases with the timing baseline T as Tγ, where γ = −7/2 + α/2 for power-law noise models with shallow power-law indices α (0 < α < 4). For steep power-law indices (α > 8), the measurement uncertainty reduces with T−1/2. We applied this method to times-of-arrival from the European Pulsar Timing Array and the Parkes Pulsar Timing Array and determined $\ddot{\nu }$ probability density functions for 49  millisecond pulsars. We find a statistically significant $\ddot{\nu }$ value for PSR B1937+21 and consider possible options for its origin. Significant (95 per cent C.L.) values for $\ddot{\nu }$ are also measured for PSRs J0621+1002 and J1022+1001, thus future studies should consider including it in their ephemerides. For binary pulsars with small orbital eccentricities, such as PSR J1909−3744, extended ELL1 models should be used to overcome computational issues. The impacts of our results on the detection of gravitational waves are also discussed.

Measurement uncertainty of β-lactam antibiotics results: estimation and clinical impact on therapeutic drug monitoring

2020 ◽  
Vol 58 (2) ◽  
pp. 240-250 ◽  
Author(s):  
Raúl Rigo-Bonnin ◽  
Francesca Canalias ◽  
Cristina El Haj ◽  
María Cristina González-Hernando ◽  
Noelia Díaz-Troyano ◽  
...  
Keyword(s):  
Antibiotic Therapy ◽  
Measurement Uncertainty ◽  
Therapeutic Drug ◽  
Intermediate Precision ◽  
Simple Method ◽  
Uncertainty Sources ◽  
Clinical Laboratories ◽  
Potential Impact ◽  
The Impact ◽  
Single Laboratory

AbstractBackgroundDespite that measurement uncertainty data should facilitate an appropriate interpretation of measured values, there are actually few reported by clinical laboratories. We aimed to estimate the measurement uncertainty of some β-lactam antibiotics (β-LA), and to evaluate the impact of reporting the measurement uncertainty on clinicians’ decisions while guiding antibiotic therapy.MethodsMeasurement uncertainty of β-LA (aztreonam [ATM], cefepime [FEP], ceftazidime [CAZ], and piperacillin [PIP]) values, obtained by an UHPLC-MS/MS based-method, was estimated using the top-down approach called the single laboratory validation approach (EUROLAB guidelines). Main uncertainty sources considered were related to calibrators’ assigned values, the intermediate precision, and the bias. As part of an institutional program, patients with osteoarticular infections are treated with β-LA in continuous infusion and monitored to assure values at least 4 times over the minimal inhibitory concentration (4×MIC). We retrospectively evaluated the impact of two scenarios of laboratory reports on clinicians’ expected decisions while monitoring the treatment: reports containing only the β-LA values, or including the β-LA coverage intervals (β-LA values and their expanded measurement uncertainties).ResultsThe relative expanded uncertainties for ATM, FEP, CAZ and PIP were lower than 26.7%, 26.4%, 28.8%, and 25.5%, respectively. Reporting the measurement uncertainty, we identified that clinicians may modify their decision especially in cases where 4×MIC values were within the β-LA coverage intervals.ConclusionsThis study provides a simple method to estimate the measurement uncertainty of β-LA values that can be easily applied in clinical laboratories. Further studies should confirm the potential impact of reporting measurement uncertainty on clinicians’ decision-making while guiding antibiotic therapy.

scholarly journals Carbon dioxide and methane measurements from the Los Angeles Megacity Carbon Project – Part 1: calibration, urban enhancements, and uncertainty estimates

2017 ◽  
Vol 17 (13) ◽  
pp. 8313-8341 ◽  
Author(s):  
Kristal R. Verhulst ◽  
Anna Karion ◽  
Jooil Kim ◽  
Peter K. Salameh ◽  
Ralph F. Keeling ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Los Angeles ◽  
Measurement Uncertainty ◽  
Atmospheric Carbon Dioxide ◽  
Single Point ◽  
Calibration Method ◽  
Urban Environments ◽  
Uncertainty Estimates ◽  
Carbon Project ◽  
The Impact

Abstract. We report continuous surface observations of carbon dioxide (CO2) and methane (CH4) from the Los Angeles (LA) Megacity Carbon Project during 2015. We devised a calibration strategy, methods for selection of background air masses, calculation of urban enhancements, and a detailed algorithm for estimating uncertainties in urban-scale CO2 and CH4 measurements. These methods are essential for understanding carbon fluxes from the LA megacity and other complex urban environments globally. We estimate background mole fractions entering LA using observations from four extra-urban sites including two marine sites located south of LA in La Jolla (LJO) and offshore on San Clemente Island (SCI), one continental site located in Victorville (VIC), in the high desert northeast of LA, and one continental/mid-troposphere site located on Mount Wilson (MWO) in the San Gabriel Mountains. We find that a local marine background can be established to within  ∼  1 ppm CO2 and  ∼  10 ppb CH4 using these local measurement sites. Overall, atmospheric carbon dioxide and methane levels are highly variable across Los Angeles. Urban and suburban sites show moderate to large CO2 and CH4 enhancements relative to a marine background estimate. The USC (University of Southern California) site near downtown LA exhibits median hourly enhancements of  ∼  20 ppm CO2 and  ∼  150 ppb CH4 during 2015 as well as  ∼  15 ppm CO2 and  ∼  80 ppb CH4 during mid-afternoon hours (12:00–16:00 LT, local time), which is the typical period of focus for flux inversions. The estimated measurement uncertainty is typically better than 0.1 ppm CO2 and 1 ppb CH4 based on the repeated standard gas measurements from the LA sites during the last 2 years, similar to Andrews et al. (2014). The largest component of the measurement uncertainty is due to the single-point calibration method; however, the uncertainty in the background mole fraction is much larger than the measurement uncertainty. The background uncertainty for the marine background estimate is  ∼  10 and  ∼  15 % of the median mid-afternoon enhancement near downtown LA for CO2 and CH4, respectively. Overall, analytical and background uncertainties are small relative to the local CO2 and CH4 enhancements; however, our results suggest that reducing the uncertainty to less than 5 % of the median mid-afternoon enhancement will require detailed assessment of the impact of meteorology on background conditions.

Impact of Measurement Uncertainty in the Characteristic Maps of a Turbocharger on Engine Performance

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Holger Mai ◽  
Mathias Vogt ◽  
Roland Baar ◽  
Andreas Kinski
Keyword(s):  
Measurement Uncertainty ◽  
Process Simulation ◽  
Combustion Engine ◽  
Engine Performance ◽  
Engine Emissions ◽  
Engine Operation ◽  
Power Simulation ◽  
Systematic Uncertainties ◽  
Measurement Results ◽  
The Impact

The main goal of current engine development is to increase power density and efficiency and to minimize engine emissions. The idea is to obtain the desired power output with a highly charged combustion engine in combination with exhaust gas turbocharging and a very small engine displacement, which is known as downsizing. The selection of a turbocharger is based on the maps of the turbine and compressor, which are usually measured on a test bench. They also provide important boundary conditions on the engine process simulation of a supercharged engine with this turbocharger. In general, a very accurate measurement of the characteristic maps is desired to ensure the best possible matching. However, random and systematic errors have an impact on the measurement results. In order to assess the quality of the measured and calculated values, it is necessary to determine the uncertainties of the measurement variables as accurately as possible; particularly, the error propagation in calculating the efficiencies. The uncertainties are based on a systematic uncertainty component of the sensor and the confidence interval. In this way, the measurement uncertainty is estimated by linear and geometric combination of the calculated random and systematic uncertainties. After that, the respective uncertainty contributions and the identification of the relevant parameters that influence the resulting measurement uncertainty are evaluated. Knowing the measurement uncertainties of the characteristic maps of a turbocharger, the influence on engine operation will be determined with a one-dimensional engine process simulation model. Consequently, the determined measurement uncertainty will be applied as a deviation on the efficiencies and will be investigated in a GT POWER simulation. The impact of the measurement uncertainty on the engine performance is shown on the basis of load steps.

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