Standard Measurement Procedures Research Articles

Candidate reference measurement procedure for serum 17‐hydroxyprogesterone quantification via isotope dilution liquid chromatography–tandem mass spectrometry

AbstractBackgroundAccurate quantification of 17‐hydroxyprogesterone (17‐OHP) in serum is vital for clinical and research applications. However, inter‐laboratory variability in test results exists owing to the lack of a standardized reference measurement procedure (RMP). Therefore, in this study, we developed a highly accurate, cost‐effective, and user‐friendly candidate RMP (cRMP) for analyzing 17‐OHP in serum.MethodsWe quantified 17‐OHP in serum using a one‐step liquid–liquid extraction method with the addition of 17‐OHP‐13C3, followed by liquid chromatography–tandem mass spectrometry. The ability of these methods to suppress interference was evaluated by chromatographic analysis. We assessed accuracy, specificity, the lower limit of quantitation, linearity, and matrix effects by following the standards specified by the Clinical and Laboratory Standards Institute. The consistency between the developed cRMP and the chemiluminescence method was evaluated through experiments with 120 clinical samples.ResultsThe developed cRMP required only 8 min for accurate quantification of serum 17‐OHP without bias from matrix effects or interference from 19 metabolites added as potential interferents. The method exhibited favorable measurement performance, with a quantitation limit of 0.086 ng/mL, linear range of 0.1–400 ng/mL, a total imprecision of ≤2.90%, spike recovery of 100.1%–100.6%, and relative deviations from assigned target values (RfB Institution) of −2.91% to 1.10%. The cRMP demonstrated good consistency with the conventional assay (chemiluminescence method), with a correlation coefficient R of 0.96977.ConclusionA cRMP with high accuracy, cost‐effectiveness, and convenient operation was developed for quantifying 17‐OHP in serum. Its simplicity and robust performance make it an invaluable addition to the arsenal of analytical tools available for laboratories. This method can enhance the accuracy and reliability of 17‐OHP measurements across various laboratories.

ANALYTICAL PROCEDURES USING SEM/EDX EQUIPMENT FOR DETERMINING HEAVY METALS CONTENTS IN FLY ASH GENEREATED FROM DOMESTIC SOLID WASTE INCINERATORS: A CASESTUDY OF SOCSON WASTE-TO-POWER PLANT IN HANOI

The researching and establishing of as process for analyzing fly ash generated from a domestic solid waste treatment plant by SEM/EDX method were investigated. Three sampling series with twelve (12) fly ash samples collected at SocSon waste-to-power plant were used for: (i) analytical procedure establishment; (ii) standardization; and (iii) test analysis. At each measurement, a cross-check with one random sample using XRF method was carried out to verify the accuracy of the SEM/EDX measurements. As a result, a 6-step measurement procedure has been proposed, including: experimental preparation, sample weighting, liquid/solid phase separation, sample drying, sample measurement and data processing. And for procedure adjustment, liquid/solid phase separation were repeated twice while drying time was doubly increased from 24h to 48h to collect ll heavy metal contaminated residues. The proposed procedure could provide results in about 3-5 seconds without any requirement of sample digestion while most of the heavy metalspresent in fly ash, including low-content ones such as Ag, Cd and Cr were simultaneously displayed. The standardized measurement procedure was applied to test the hazardous properties of fly ash by comparing with QCVN 07:2009/BTNMT – National Technical Regulations on Hazardous waste thresholds. The results identified that fly ash could be primarily considered as hazardous waste with 5/14 heavy metal parameters exceed the limit from 1,7 to 9,5 times and needs to be collected and treated properly. This result is also quite similar to the studies that have been done in China, the US or Vietnam. Thus, SEM/EDX method could be used for analyzing heavy metal components in fly ash samples of solid waste treatment plants.

Ultrasensitive determination of selenium in food samples and its speciation in water and beverages using thiosemicarbazide-incorporated graphene and total-reflection X-ray fluorescence spectrometry

The paper presents a new analytical procedure for the determination and speciation of trace and ultratrace selenium in water, beverages, seafood, milk, and vegetables. The developed method is based on the dispersive micro-solid phase extraction with the use of new thiosemicarbazide-incorporated graphene as a solid sorbent, in combination of the total-reflection X-ray fluorescence spectrometry (TXRF). As a result, we have created an auspicious analytical tool for fast and sensitive analysis of samples with a complex matrix. Regardless of the specimen type, the method is characterized by a very low detection limit of 1.7 pg mL−1 and high precision. The developed strategy allowed us to solve common problems associated with selenium loss during the sample preparation for the TXRF measurement and also improve its performance toward the analysis of beverages and high saline/solid samples, which may even be impossible to perform using standard sample preparation procedures for a TXRF measurement.

Performances of low frequency impact sound in wooden buildings

Since 1999 Sweden has required an extended frequency range for sound insulation in residential buildings, using 50 Hz as the lower limit. This regulation update has driven the design and development of multi storey residential building systems with wooden structures in a positive direction. Already in the mid 1980'ies there existed scientific proof that it the perceived impact sound will improve if the frequency range was extended below the lower standard limit 100 Hz at that time. Lately, researchers have indicated that the perceived impact sound can be even further improved if the frequency range is extended below current lower standardized limit of 50 Hz. Assume that the frequency range for impact sound requirement will be further extended to include frequencies from 25 Hz, what would that mean for modern wooden apartment buildings? Acouwood and Kuster & Partner AG are collecting data from 20 Hz, no matter if the standard measurement procedure cannot be applied below 50 Hz. It gives a good overview of potential annoyance risk but also of acoustic performances of modern sustainable multifamily buildings and how they can be improved. This paper summarizes measurement results of impact sound from 20 Hz in several wooden buildings.

Policy recommendations for international regulations addressing air pollution from ships

Since 2015, Belgium has undertaken remote measurement activities to monitor SO2 and NOx emissions from ships to single out ships for on-board inspections in ports. One of the main challenges in enhancing the enforcement capabilities revolves around using these remote measurements as legal evidence. Previous studies have demonstrated that when an appropriate measurement uncertainty is taken into account, remote measurements can provide scientifically reliable evidence to verify compliance to fuel sulphur standards (FSC) and even to NOx emission limits described by MARPOL Annex VI. Nonetheless, remote SO2 and NOx measurements have so far not been used for direct legal action. In the first section of this article, the potential use of these remote measurements as legal evidence within international and national legal instruments is examined. Furthermore, while there are guidelines to enforce compliance with FSC standards in port, there are currently no recognized methods to enforce real-world NOx emissions at sea. In this context, standardized remote measurement procedures could potentially become a valuable tool in combination with specific vessel data (keel laying year, engine rated speed, power, …), in establishing an enforcement mechanism for NOx. This would require specific changes to the current NOx regulations. Within the Bonn Agreement, the MARPOL Annex VI Working Groups identified certain regulatory gaps that need to be addressed in order to effectively reduce emissions from ships and improve enforcement capacity. In the second part of this article a critical analysis of these recommendations and the results of these discussions towards new regulations is presented.

Critical Current Density Measurements of Argyrodite Li6PS5Cl Solid Electrolyte at Ambient Pressure

Sulfide electrolytes including the argyrodite family (Li6PS5X, X = Cl, Br, I) exhibit high ionic conductivities and transference numbers and are regarded as promising electrolytes for all-solid-state lithium batteries. Although high ionic conductivity is a necessary requirement for feasible battery operation, other parameters are equally important and have often been neglected in efforts to realize all-solid-state batteries. The so-called critical current density (CCD) is among the more relevant parameters for application and indicates the maximum current an electrolyte can sustain before breakdown. When Li metal electrodes are used, this breakdown is often initiated by heavy dendrite formation and subsequent growth through the electrolyte layer, resulting in internal shorting of the cell. Very promising CCD values are reported for the argyrodite family of >1 mA cm−2 at elevated temperatures and pressures. However, non-standardized cell setups and testing procedures are employed, which renders a proper comparison of values impossible. Thus, this work investigates the impact of these often-overlooked parameters and aims at establishing more standard measurement procedures for solid electrolytes under ambient or almost ambient pressure. Furthermore, an alternative method for evaluation of CCD values is presented adopted from Tafel analysis.

Waveform Similarity Analysis Using Graph Mining for the Optimization of Sensor Positioning in Wearable Seismocardiography.

A major concern with wearable devices aiming to measure the seismocardiogram (SCG) signal is the variability of SCG waveform with the sensor position and a lack of a standard measurement procedure. We propose a method to optimize sensor positioning based on the similarity among waveforms collected through repeated measurements. we design a graph-theoretical model to evaluate the similarity of SCG signals and apply the proposed methodology to signals collected by sensors placed in different positions on the chest. A similarity score returns the optimal measurement position based on the repeatability of SCG waveforms. We tested the methodology on signals collected by using two wearable patches based on optical technology placed in two positions: mitral and aortic valve auscultation site (inter-position analysis). 11 healthy subjects were enrolled in this study. Moreover, we evaluated the influence of the subject's posture on waveform similarity with a view on ambulatory use (inter-posture analysis). the highest similarity among SCG waveforms is obtained with the sensor on the mitral valve and the subject lying down. our approach aims to be a step forward in the optimization of sensor positioning in the field of wearable seismocardiography. We demonstrate that the proposed algorithm is an effective method to estimate similarity among waveforms and outperforms the state-of-the-art in comparing SCG measurement sites. results obtained from this study can be exploited to design more efficient protocols for SCG recording in both research studies and future clinical examinations.

Benchmarking methodology for stateful NAT64 gateways

The benchmarking of Network Address and Protocol Translation from IPv6 clients to IPv4 servers (stateful NAT64) gateways is challenging from a methodological point of view because the state of the art benchmarking standards have some requirements that are conflicting when applied to stateful NAT64 gateways. In this paper, several methodological gaps are pointed out and a benchmarking methodology is proposed, which is applicable for any stateful NATxy gateways, where x and y are in {4, 6}. It bridges all the gaps by reconciling the conflicting requirements and facilitating the execution of the industry standard benchmarking measurement procedures (throughput, latency, frame loss rate, packet delay variation) with stateful NATxy gateways. New performance metrics specific to stateful testing are also defined: maximum connection establishment rate, connection tear down rate, and connection tracking table capacity. The proposed methodology is suitable for examining the scalability of the stateful NATxy gateways, too. The methodology is validated by applying it to the benchmarking of three radically different stateful NAT64 implementations: Jool, tayga plus iptables, and OpenBSD Packet Filter (PF). The details of the measurements and their results are fully disclosed.

Abnormal Dynamic Reverse Bias Behavior and Variable Reverse Breakdown Voltage of ETL‐free Perovskite Solar Cells

Perovskite solar cells (PSCs) have shown an impressive power conversion efficiency of 26.1%, while their upcoming commercialization urgently needs to solve the stability problem. Among numerous stability issues of PSCs, little attention is paid to reverse bias stability. When some cells of the module are shaded by irresistible factors, this will cause the current of the illuminated part to flow through the shaded cells as a reverse current and force them to be under reverse bias. Herein, the breakdown mechanism dominated by different reverse bias regions of a prototype electron transport layer free PSCs is distinguished. And, it is confirmed that PSCs present a thought‐provoking dynamic reverse bias (DRB) behavior and variable reverse breakdown voltage (VRB), which is essentially distinct from classic solar cells. Specifically, VRB is significantly affected by voltage scan rate, range and direction, and illumination. The underlying mechanism is explained by drift‐diffusion modeling taking into account the electric field generated by directional ion migration. The latter can hinder the movement of charge carriers and cause the observed variable VRB and DRB behavior. Predictably, the understanding of the dynamic process is crucial to establish a standard VRB measurement procedure and further promote the commercialization of PSCs.

Analytical variation concerning total 25-hydroxyvitamin D measurement, where are we now? A DEQAS review of current assay performance

The Vitamin D External Quality Assessment Scheme (DEQAS) distributes serum samples globally, on a quarterly basis, to assess participants’ performance of specific methods for 25-hydroxyvitamin D (25OHD) and other vitamin D metabolites. In this review an assessment of the state of the art in the performance of 25OHD methods is presented. This assessment is based on an analysis of data submitted by scheme participants for the 2021/22 distribution cycle, which comprised of four distributions each containing five DEQAS samples. These distributions enabled the assessment of performance across a wide concentration range and included samples containing endogenous 25OHD2. Overall analytical performance continues to improve, but there is still significant method variation and bias in some automated methods. These automated methods continue to be challenged in measuring 25OHD at the extremes of the measuring range and in the presence of 25OHD2. LC-MS/MS methods still show superior performance with regards to bias, but are out-performed by some automated methods in terms of assay variability. Through participating in an accuracy based EQA scheme, such as DEQAS, laboratories are able to assess the accuracy of their methods in comparison to a gold standard reference measurement procedure. It is crucial for all laboratories to be aware of the performance and limitations of their 25OHD assays and to educate their users accordingly in order to ensure reliable assessment of vitamin D status.

Evaluation of End Effectors for Robotic Harvesting of Mango Fruit

The task of gripping has been identified as the rate-limiting step in the development of tree-fruit harvesting systems. There is, however, no set of universally adopted ‘specifications’ with standardized measurement procedures for the characterization of gripper performance in the harvest of soft tree fruit. A set of metrics were defined for evaluation of the performance of end effectors used in soft tree-fruit harvesting based on (i) laboratory-based trials using metrics termed ‘picking area’, which was the cross-sectional area in a plane normal to the direction of approach of the gripper to the fruit in which a fruit was successfully harvested by the gripper; ‘picking volume’, which was the volume of space in which fruit was successfully harvested by the gripper; and ‘grasp force’, which was the peak force involved in removing a fruit from the grasp of a gripper; (ii) orchard-based trials using metrics termed ‘detachment success’ and ‘harvest success’, i.e., the % of harvest attempts of fruit on tree (of a given canopy architecture) that resulted in stalk breakage and return of fruit to a receiving area, respectively; and (iii) postharvest damage in terms of a score based on the percentage of fruit and severity of the damage. Evaluations were made of external (skin) damage visible 1 h after gripping and of internal (flesh) damage after ripening of the fruit. The use of the metrics was illustrated in an empirical evaluation of nine gripper designs in the harvest of mango fruit in the context of fruit weight and orientation to the gripper. A design using six flexible fingers achieved a picking area of ~150 cm2 and a picking volume of 467 cm3 in laboratory trials involving a 636 g phantom fruit as well as detachment and harvest efficiency rates of 74 and 65%, respectively, in orchard trials with no postharvest damage associated with the harvest of unripe fruit. Additional metrics are also proposed. Use of these metrics in future studies of fruit harvesting is recommended for literature–performance comparisons.

Predicting the body core temperature of recreational athletes at the end of a 10 km self-paced run under environmental heat stress.

What is the central question of this study? The aim was to identify the factors predicting the body core temperature of athletes at the end of a 10km self-paced run in a hot environment. What is the main finding and its importance? Hyperthermia in athletes subjected to self-paced running depends on several factors, highlighting the integrated control of core temperature during exercise under environmental heat stress. Five of the seven variables that significantly predicted core temperature are not invasive and, therefore, practical for use outside the laboratory environment: heart rate, sweat rate, wet-bulb globe temperature, running speed and maximal oxygen consumption. Measurement of body core temperature (Tcore ) is paramount to determining the thermoregulatory strain of athletes. However, standard measurement procedures of Tcore are not practical for extended use outside the laboratory environment. Therefore, determining the factors that predict Tcore during a self-paced run is crucial for creating more effective strategies to minimize the heat-induced impairment of endurance performance and reduce the occurrence of exertional heatstroke. The aim of this study was to identify the factors predicting Tcore values attained at the end of a 10km time trial (end-Tcore ) under environmental heat stress. Initially, we extracted data obtained from 75 recordings of recreationally trained men and women. Next, we ran hierarchical multiple linear regression analyses to understand the predictive power of the following variables: wet-bulb globe temperature, average running speed, initial Tcore , body mass, differences between Tcore and skin temperature (Tskin ), sweat rate, maximal oxygen uptake, heart rate and change in body mass. Our data indicated that Tcore increased continuously during exercise, attaining 39.6±0.5°C (mean±SD) after 53.9±7.5min of treadmill running. This end-Tcore value was primarily predicted by heart rate, sweat rate, differences between Tcore and Tskin , wet-bulb globe temperature, initial Tcore , running speed and maximal oxygen uptake, in this order of importance (β power values corresponded to 0.462, -0.395, 0.393, 0.327, 0.277, 0.244 and 0.228, respectively). In conclusion, several factors predict Tcore in athletes subjected to self-paced running under environmental heat stress. Moreover, considering the conditions investigated, heart rate and sweat rate, two practical (non-invasive) variables, have the highest predictive power.

Integration of Distributed Streamflow Measurement Metadata for Improved Water Resource Decision-Making

Streamflow data are critical for monitoring and managing water resources, yet there are significant spatial gaps in our federal monitoring networks with biases toward large perennial rivers. In some cases, streamflow monitoring exists in these spatial gaps, but information about these monitoring locations is challenging to obtain. Here, we present a streamflow catalog for the United States Pacific Northwest that includes current and historical streamflow monitoring location information obtained from 32 organizations (other than the U.S. Geological Survey), which includes 2661 continuous streamflow gaging locations (22% are currently active) and 30,557 discrete streamflow measurements. A stakeholder advisory board with representatives from organizations that operate streamflow monitoring networks identified metadata requirements and provided feedback on the Streamflow Data Catalog user interface. Engagement with the water resources community through this effort highlighted challenges that water professionals face in collecting and managing streamflow data so that data are findable, accessible, interoperable, and reusable (FAIR). Over 60% of the streamflow monitoring locations in the Streamflow Data Catalog are not available online and are thus not findable through web search engines. Providing organizations technical assistance with standard measurement procedures, metadata collection, and web accessibility could substantially increase the availability and utility of streamflow information to water resources communities.

Defining the onset potential

The onset potential is a widely reported and generally accepted measure of electrocatalytic activity; however, there is no single and agreed definition, nor does the scientific community have a standard measurement procedure. This review starts by summarising the main definitions employed in the literature. However, regardless of how the measurement is undertaken, there are fundamental problems with the use of the onset potential as a figure of merit. Even if a defined threshold current density is used, the reported onset potential is inherently sensitive to the surface catalyst loading and the specific surface area of the catalytic material. A simple theoretical model is used to exemplify this problem and to further evidence why the mass-activity or the specific-activity of an electrocatalyst is a superior method for measuring the activity of a material.

Recommendations for soil sample preparation, pretreatment, and data conversion for texture classification in laser diffraction particle size analysis

With regard to the differences between soil particle size distribution (PSD) obtained by sieve-sedimentation methods (SSMs), e.g., the sieve-pipette method (SPM) and the laser diffraction method (LDM), usually, the clay fraction content in LDM measurements is lower than in SSM. Two groups of reasons can be identified for this. Firstly, differences resulting from the features of the methods themselves. Secondly, differences resulting from the soil sample preparation (after sampling) and pretreatment (disaggregation). These differences not only cause difficulties in the PSDs comparability but also make it difficult, and sometimes even impossible, to apply the LDM results to soil texture classification. The solution to this difficulty may be to use pedotransfer functions and standardization of measurement procedures. The aim of this work was to validate the pedotransfer function proposed by Makó et al. (2017) on a Polish soil physics database for recalculating the results from LDM to compare them with SPM results and assess how the soil preparation and pretreatment influenced the obtained PSD and resulting soil texture classification. Using the pedotransfer function, 74 % accuracy was achieved, which is comparable with the results of other pedotransfer functions reported in the literature. Comparing the PSD results for the methods of sample preparation found in the literature after sampling (analysis of fresh, air dry and oven-dried – in 105 °C – soil) and pretreatment before the measurement (breaking soil aggregates chemically and physically) allows recommending the conducting of LDM PSD measurements using air dry soils and soil ultrasound disaggregation.

Measurement of nuclear fuel assembly’s bow from visual inspection’s video record

The bow of the nuclear fuel assembly is a well-known phenomenon. One of the vital criteria during the history of nuclear fuel development has been fuel assembly’s mechanical stability. Once present, the fuel assembly bow can lead to safety issues like excessive water gap and power redistribution or even incomplete rod insertion (IRI). The extensive bow can result in assembly handling and loading problems. This is why the fuel assembly’s bow is one of the most often controlled geometrical factors during periodic fuel inspections for VVER when compared e.g. to on-site fuel rod gap measurements or other instrumental measurements performed on-site. Our proposed screening method uses existing video records for fuel inspection. We establish video frames normalization and aggregation for the purposes of bow measurement. The whole process is done by digital image processing algorithms which analyze rotations of video frames, extract angles whose source is the fuel set torsion, and reconstruct torsion schema. This approach provides results comparable to the commonly utilized method. We tested this new approach in real operation on 19 fuel assemblies with different campaign numbers and designs, where the average deviation from other methods was less than 2 % on average. Due to the fact, that the method has not yet been validated during full scale measurements of the fuel inspection, the preliminary results stand for that we recommend this method as a complementary part of standard bow measurement procedures to increase measurement robustness, lower time consumption and preserve or increase accuracy. After completed validation it is expected that the proposed method allows standalone fuel assembly bow measurements.

Тhe error of a standard air flow velocity measurement procedure in wind tunnels of low subsonic speeds

The standard air flow velocity measurement procedure has been developed in order to unify and standardize the measuring instruments used and data processing algorithms, reduce the development time and certify such standard methods. Sources of error in indirect measurements of air flow velocity in the range 3–105 m/s are investigated. The sources of instrumental error of indirect measurements are analyzed – pressure sensors with digital and analog output signals, pitot tube, temperature and relative air humidity sensors, atmospheric pressure sensors. It is shown that the greatest contribution to the instrumental error is made by measuring the pressure difference and atmospheric pressure. The errors of method, which depends on the measurement model, is considered. A new mathematical model of measurements is proposed, which includes optimal expressions for determining the density of moist air and corrections for compressibility and allows to reduce the methodological error, and requirements for the metrological characteristics of the measuring instruments used are developed, ensuring that the total error of indirect measurements of the flow velocity complies with the allowable limits of ±0,2 m/s. Recommendations are given on the use of measuring instruments and algorithms for processing measurement results, which make it possible to reduce the measurement error by 39 % and develop a standard air flow velocity measurement procedure. The standard procedure is relevant for aviation industry enterprises, where the air flow rate is measured by the pneumometric method.

Реализация единства измерений характеристик РАО при передаче на захоронение

The paper discusses the comprehensive measures implemented to ensure the uniformity of measurements as regards the RW characteristics demonstrating their compliance with waste acceptance criteria for disposal. Under this framework, the following regulations have been developed by JSC VNIINM: the Unified Industry Guidelines for the Measurements of Radiation Waste Characteristics, standard measurement and test procedures, as well as the standard of the State Corporation Rosatom for monitoring physical and chemical property indicators and characteristics of the RW form.

Fast orbit response matrix measurement via sine-wave excitation of correctors at Sirius

Sirius is the new 4th generation storage ring based synchrotron light source built and operated by the Brazilian Synchrotron Light Laboratory (LNLS). In this work, we report on the implementation at Sirius of a fast method for orbit response matrix (ORM) measurement which is based on sine-wave parallel excitation of orbit corrector magnets’ strength. This “AC method” has reduced the ORM measurement time from ∼ 25 minutes to 2.5–3 minutes and displayed increased precision if compared to the standard serial measurement procedure. When used as input to the Linear Optics from Closed Orbits (LOCO) correction algorithm, the AC ORM yielded similar optics corrections with less aggressive quadrupoles strength changes.

On Standardized Measurement in Behavioral Science.

That standardized measurement procedures are a sine qua non of "good" science is generally not questioned. Here we examine the meaning and use of standardized measurement in behavioral science. Procedures and methods of measurement that have served the physical sciences so well should not blindly be assumed to work in the same manner and with the same effectiveness in behavioral science. There seems to be general agreement that social/behavioral science is "different" among the sciences. Problems arising from how behavioral science is "different" begin, we believe, with measurement. We put forward the argument that the source of the difference is unique to animate objects and is first evident at the stage of measuring the behavioral attributes of interest. It is at that point in conducting scientific inquiry that the matters raised might be resolved by developing and applying alternatives to standardized measurement. One such alternative discussed is the idiographic filter (Nesselroade, Gerstorf, Hardy, & Ram, 2007).