Primary Standard Research Articles

GET 203-2024 state primary special standard of complex refractive index and length in the field of measuring the thickness of optical coatings

GET 203-2024 state primary special standard of complex refractive index and length in the field of measuring the thickness of optical coatings

Practical realization of the watt from Planck’s constant using radiation pressure

Abstract A primary force standard is implemented to realize the watt through Planck’s constant by means of radiation pressure at the kilowatt level. The high amplification laser-pressure optic, or HALO, is a multiple reflection radiation pressure apparatus used for absolute radiometry of high-power lasers. In this work, a primary standard electrostatic force balance is used to measure the reflection-enhanced optical forces. With this configuration, the HALO is used to measure laser powers in the range of 100 W–5000 W from a 1070 nm fiber laser. The expanded uncertainty of the 5 kW measurement is 0.12%, which is both the lowest uncertainty multi-kW measurement and radiation pressure-based measurement to-date. The HALO result was validated against a thermal primary standard using a calibrated transfer standard at 2 kW. The degree of equivalence was 0.78% ± 1.12%, which demonstrates agreement within the uncertainties of these two primary standards.

Measurements of Low Optical Power with Cryostat-Based Predictable Quantum Efficient Detector at Liquid Nitrogen Temperature

Abstract We have validated optical power measurements with a Predictable Quantum Efficient Detector (PQED) at liquid nitrogen temperature (77 K) at low optical power from 130 fW to 3.3 pW. Two laser wavelengths at 514 nm and 785 nm were used. The lowest measured optical power corresponds to a photon flux of 0.5·106 photons per second (785 nm). The PQED’s responsivity is linear within the relative measurement uncertainties of 8% at 0.5·106 ph/s and 1.4% at 10·106 ph/s (95% confidence level), which enables the calibration of other low photon flux detectors directly against a primary standard of optical power.

Hardware Acceleration for High-Volume Operations of CRYSTALS-Kyber and CRYSTALS-Dilithium

Many high-demand digital services need to perform several cryptographic operations, such as key exchange or security credentialing, in a concise amount of time. In turn, the security of some of these cryptographic schemes is threatened by advances in quantum computing, as quantum computer could break their security in the near future. Post-quantum cryptography (PQC) is an emerging field that studies cryptographic algorithms that resist such attacks. The National Institute of Standards and Technology (NIST) has selected the CRYSTALS-Kyber Key Encapsulation Mechanism and the CRYSTALS-Dilithium Digital Signature algorithm as primary PQC standards. In this article, we present field-programmable gate array (FPGA)-based hardware accelerators for high-volume operations of both schemes. We apply high-level synthesis (HLS) for hardware optimization, leveraging a batch processing approach to maximize the memory throughput and applying custom HLS logic to specific algorithmic components. Using reconfigurable FPGAs, we show that our hardware accelerators achieve speedups between 3 \(\times\) and 9 \(\times\) over software baseline implementations, even over ones leveraging CPU vector architectures. Furthermore, the methods used in this study can also be extended to the new CRYSTALS-based NIST FIPS drafts, ML-KEM and ML-DSA, with similar acceleration results.

Verification of the results of the calibration of needle hydrophones on the measurement standard NDETU AUV-02-2018

The results of the verification of the calibration of needle hydrophones using the national primary measurement standard of the unit of ultrasonic pressure in the aquatic environment (NDETU AUV-02-2018) are presented. The main objective of the study was to confirm the accuracy of the calibration of needle hydrophones No. 2538 and No. 2515 by comparison with the calibration results obtained on the measurement standard at the Physikalisch-Technische Bundesanstalt (PTB), Germany. The paper describes the calibration methods used by laboratories to determine the sensitivity of hydrophones, including the two-transducer reciprocity method and the comparison method. The results of the calibration of needle hydrophones in the frequency range from 1 to 10 MHz obtained by the National Metrology Institute of Germany (PTB) and Ukraine (SE Research Institute “Systema”) were evaluated. Furthermore, the level of uncertainty of the calibration results was compared. The results of the study demonstrated a high degree of consistency in the measurement results. Added to this, the results confirmed the reliability of the results of the calibration of needle hydrophones using the NDETU AUV-02-2018 measurement standard by the calibration method selected and with the measurement equipment used. The conclusions confirmed the effectiveness of using the national measurement standard NDETU AUV-02-2018 and its conformity with international measurement standards, thus increasing the confidence in the results at the international level. Additionally, the study provides the ground for future international comparisons with measurement standards of other countries.

Shortened and simplified traceability chain for dimensional metrology based on self-traceable standards

Abstract Nanoscale measurement is an essential task of nanomanufacturing, and measurement traceability is a fundamental aspect of nanoscale measurement. High-precision nanoscale measurement instruments (e.g. atomic force microscopes (AFM) and scanning electron microscopes (SEM)) need to be calibrated by traceable standards to ensure their accuracy and reliability. However, due to the suboptimal accuracy, uniformity, and consistency of existing standards, they need to be calibrated by metrological instruments traceable to primary length standards (e.g. physical wavelength standards) before use. This results in a long traceability chain that leads to error accumulation and significantly reduces calibration efficiency. This paper proposes a novel shortened and simplified traceability chain, where the physical wavelength standard corresponding to the 7S3 → 7P4° transition frequency of chromium atoms is materialized into self-traceable gratings using the atom lithography technology. The self-traceable gratings can then be directly applied for calibrating measurement instruments. To verify this approach, the self-traceable gratings are calibrated using a metrological AFM of the Physikalisch-Technische Bundesanstalt. Measurement results confirmed the feasibility of the approach. Particularly, our results show that the self-traceable gratings have excellent uniformity over different measurement areas and consistency over different samples, both at 0.001 nm level. Finally, the application of the self-traceable gratings for the calibrations of a commercial AFM and SEM is demonstrated. The new traceability chain significantly simplifies the calibration process, providing a more reliable and higher efficient calibration approach for advanced nanomanufacturing than that of the state-of-the-art.

State primary standard of units of complex reflection coefficient and complex transmission coefficient in waveguide paths in the frequency range from 2.14 to 178.4 GHz GET 219-2024

Measurement of complex reflection coefficients and complex transmission coefficients of radio engineering devices in waveguide paths is widely used in radar and radio navigation in the development, production, testing and operation of microwave devices and components. These parameters characterize the quality of matching of transmit-receive paths at ultra-high frequencies. Before the introduction of the State primary standard of units of complex reflection coefficient and complex transmission coefficient in waveguide paths in the frequency range from 2.14 to 178.4 GHz GET 219-2024, metrological traceability of units of complex reflection coefficient and complex transmission coefficient in waveguide paths was ensured to the working standards developed in the 1980s. The operating frequency ranges and automation level of outdated standards did not meet modern requirements and did not fully provide a solution to modern measuring tasks. In order to ensure the uniformity of measurements of complex reflection coefficients and complex transmission coefficients, the State primary standard of units of complex reflection coefficient and complex transmission coefficient in waveguide paths in the frequency range from 2.14 to 178.4 GHz has been developed and approved. The standard provides reproduction, storage and transmission of units of complex reflection coefficient and complex transmission coefficient in 16 domestic and 22 foreign waveguide paths. The block diagram, technical and metrological characteristics of the standard are given. The research results confirmed that standard has comparable metrological characteristics with the standards of national metrological institutes of other countries.

Diagnostic accuracy of an exhaled breath test for TB in hospitalized patients with cough or risk.

<sec><title>INTRODUCTION</title>Closing the TB diagnostic gap is an urgent priority, for which non-sputum-based tests are needed. We evaluated the diagnostic accuracy of Aeonose, an exhaled breath test (EBT), as a TB triage test.</sec><sec><title>METHODS</title>Patients with cough or TB risk factors admitted to a tertiary hospital in Lima, Peru, were prospectively enrolled and underwent EBT. We evaluated EBT sensitivity and specificity for diagnosing pulmonary TB using culture and Xpert as primary and secondary reference standards and conducted stratified analyses based on risk factors.</sec><sec><title>RESULTS</title>EBT sensitivity was 85% (95% CI 72.9-93.4), and specificity was 51% (95% CI 46.0-56.6) in the training cohort (n = 417). EBT sensitivity was 70% (95% CI 47.1-86.8), and specificity was 54% (95% CI 44.8-63.6) in the validation cohort (n = 139) using the culture reference standard, with higher sensitivity (78%) when using the Xpert reference standard (n = 156). Sensitivity (60%) and specificity (48%) were lower when patients with prior TB were included. In a subset of participants randomly selected for interviews, 94% (15/16) preferred EBT to sputum-based testing.</sec><sec><title>CONCLUSIONS</title>EBT had moderate sensitivity and low specificity as a TB triage test in this hospitalised cohort with cough or risk factors. Diagnostic accuracy was lower in people with prior TB.</sec>.

Study of an electrochemical system with dual cathodes for the treatment of mariculture wastewater

The salinity properties of mariculture wastewater make it a suitable candidate for electrochemical treatment. In this study, an electro-Fenton synergistic electrocatalytic system was developed using a mixed metal oxide anode, often called Dimensionally Stable Anodes (DSA), and dual cathodes, an iron-carrying activated carbon sheet as the first cathode and a stainless-steel plate as the second cathode, to treat mariculture wastewater. The reaction conditions of the system were investigated and optimized. The chemical oxygen demand (COD) removal rate reached 100 % after 80 min under the optimal conditions: an applied voltage of 3.39 V, a plate spacing of 1.07 cm, and an aeration rate of 34.84 L·h−1. The system effectively removed COD and nitrogen from mariculture wastewater. Analyses using GC–MS, UV–visible spectroscopy, and Fourier-transform infrared spectroscopy showed that the system could degrade macromolecular organic pollutants in the wastewater. Mechanistic studies revealed that active chlorine and hydroxyl radicals play crucial roles in pollutant removal. The dynamic operation study indicated that the optimal operating conditions included a vertical water flow direction through the electrodes, and a flow rate of 10 mL·min−1. The oxidant reuse experiment determined a reflux ratio of 1:1 and a reaction time of 60 min, achieving effluent COD and NH3-N concentrations that met the primary discharge standards. The study on residual chlorine removal showed that the input amount of sodium thiosulfate was 0.36 kg, with a treatment cost of 0.32 yuan per ton of water, and the treated effluent met the discharge standards. These results provide a reference for the industrial application of electrochemical methods in treating mariculture wastewater.

High-Intensity Interval Training Decreases Circulating HMGB1 in Individuals with Insulin Resistance; Plasma Lipidomics Identifies Associated Cardiometabolic Benefits.

Background: Exercise is a fundamental primary standard of care for cardiometabolic health. Body Weight (BW) High-Intensity Interval Training (HIIT) is an effective strategy for reducing cardiometabolic markers in individuals with insulin resistance and Type-2 diabetes (T2D). High-mobility group box 1 (HMGB1), a ubiquitous nuclear factor, plays an ample role beyond an alarmin in T2D development and progression. Our group has described this novel role previously, showing the beneficial effect of whole body HMGB1 silencing in decreasing hyperglycemia in diabetic mice. In the present study we tested the hypothesis that BW-HIIT as an effective exercise training modality will decrease cardiometabolic risk with a concomitant decrease in circulating HMGB1 more prominently in insulin resistant individuals compared to non-insulin resistant individuals contrasting to what we can evidence in a preclinical murine model of insulin resistance; Methods: Human and mouse pre- and post-exercise serum/plasma samples were analyzed for Lipidomics as well as Metabolic and Cytokine Multiplex assays. Standard of care, as well as cardiometabolic parameters, was also performed in human subjects; Results: insulin resistant individuals had the most positive effect, primarily with a decrease in the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). as an index of insulin resistance as well as decreased HMGB1 post-exercise. Lipidomic analysis illustrated the highly beneficial effect of exercise training using a modified HIIT program, showing an enhanced panel of circulating lipids post-exercise exclusively in insulin resistant individuals. Plasma multiplex revealed significant translational heterogeneity in our studies with distinct metabolic hormone responses to exercise conditioning with a decrease in inflammatory markers in insulin resistant individuals; Conclusions: The current study demonstrated that 6-week BW-HIIT training improves cardiometabolic, anti-inflammatory markers, metabolic hormones, and insulin sensitivity in humans, strongly associated with decreased circulating HMGB1. Overall, these experiments reinforce the potential of HMGB1 as a marker of changes in insulin resistance and the positive effect of exercise training on insulin resistance possibly preventing the development of T2D and associated complications.

Technical note: Determination of for a miniature x-ray source using a soft x-ray ionization chamber calibrated in NIST reference beam qualities.

The formalism proposed by Watson etal. allows users of the INTRABEAM (Carl Zeiss Medical AG, Jena, Germany) electronic brachytherapy system to accurately determine the absorbed dose to water, in the absence of a primary dosimetry standard. However, all published values are for PTW 34013 ionization chambers calibrated in a TW30 reference beam, traceable to PTB (Germany). For North American users, it would be advantageous to have data for chambers calibrated in a kV reference beam maintained by the National Institute of Standards and Technology (NIST). In this work, we determine for a PTW 34013 chamber calibrated in three NIST-traceable reference beams: M30, L40, andL50. Using available photon spectra data for M30, L40, and L50 reference beam qualities, Monte Carlo simulations using EGSnrc were performed to calculate the ratio of the absorbed dose to the PTW 34013 chamber air cavity to air-kerma ( ) for these beams. From this ratio, as a function of depth in water was determined. The effect of the use of a buildup foil was also investigated. An uncertainty analysis considering both the Type A and Type B uncertainties in the calculation of was performed. The largest difference in was found between L50 and TW30, with a relative decrease of 1.4% (no buildup) to 1.6% (buildup). For M30 and L40, the differences were minimal compared with measurementuncertainties. We report values for three NIST-traceable kV reference beams. This study reinforces the feasibility of adapting the Watson etal. methodology using different kV reference beams, facilitating the use of INTRABEAM in North America and ensuring the continuity and accuracy of dosimetry standards in intraoperative radiationtherapy.

Evaluation of robotic-assisted navigation system for CT-guided thoracic and abdominal lesion puncture: A prospective clinical study.

The study aims to compare the accuracy and safety of robotic-assisted navigation puncture to freehand puncture during computed tomography (CT)-guided percutaneous needle insertion in the chest and abdomen. A total of 60 patients required percutaneous puncture procedures, with 40 involving the chest and 20 involving the abdomen. Eligible patients were randomly assigned to two groups. The test group punctured using a robotic-assisted navigation system, whereas the control group punctured manually. The primary outcome assessment standards are single puncture success rates, with the number of needle modifications and CT scan timings during the procedure serving as supplementary outcome evaluation standards. The Wilcoxon rank sum test is used for the comparison. The puncture procedure's success rates after just one puncture: The test group punctures accurately without adjusting the puncture needle, while the control group uses an average number of 1.73 ± 1.20 pins. The once-puncture success rate of robot navigation puncture is considerably higher than that of bare-handed puncture (P < 0.001). The times of CT scan are necessitated when the puncture is in place: the average times in the test group is 3.03 ± 0.18 times, while the control group is 4.70 ± 1.24 times. In conclusion, the robotic-assisted navigation system improves puncture accuracy while reducing the need for needle corrections during percutaneous puncture procedures. It also shortens CT scans and reduces radiation exposure from X-rays.

Study on O3-NOx-VOCscombined air pollution and ozone health effects in the Hexi Corridor.

In order to study the ecological and atmospheric recovery of the Hexi Corridor region, this paper analyzes the migration changes of land use characteristics and utilizes multivariate data and BenMAP-CE software to study the pollution characteristics of ozone and its precursors and the impact on human health in the Hexi Corridor region. The results showed that the increase of cultivated land area in the Hexi Corridor mainly originated from grassland. The MDA8-O3 concentrations met the primary and secondary standards of the Ambient Air Quality Standards on 43% and 99% of the days, respectively. NO2 showed a negative weekend effect with O3, and HCHO was opposite to it. Temperature, barometric pressure, and vegetation were highly correlated with O3-NO2-HCHO. Ozone pollution in the study area caused about 60% of all-cause premature deaths due to cardiovascular diseases. The study suggests that controlling exogenous transport in Wuwei City during the high ozone period (except August) is mainly dominated by the west and northwest, and that synergistic management of VOCs and NOx emissions can reduce O3 pollution and, consequently, reduce the risk to human health.

State primary special standard of complex refractive index and length in the field of measuring the thickness of optical coatings GET 203-2024

In many areas of science and technology, there is a task to measure the optical and geometric characteristics of thin fi lms. The need to ensure the uniformity of measurements in this area led to the creation of the State primary standard of complex refractive index units GET 203-2012. In it, the complex refractive index was measured using spectral ellipsometry by measuring ellipsometric angles. However, this standard did not provide metrological support for coating thickness measurements when measuring their complex refractive index. In the period 2020–2023, VNIIOFI GET 203-2012 improved and expanded its functionality in terms of reproducing the unit of length in the fi eld of thickness measurements of optical coatings. The improved standard has been approved as the State primary special standard for units of complex refractive index and units of length in the fi eld of thickness measurements of optical coatings GET 203-2024. GET 203-2024 ensures the unity of measurements of complex refractive index and units of length in the fi eld of optical thickness measurements in the range from 1 nm to 50 μm. The range expansion was achieved by introducing an ellipsometer with an infrared range wavelength range equipped with an FTIR Fourier spectrometer. This range expansion is important for such industries as optics, microelectronics, optoelectronics, integrated optics and other areas of science and technology. This article presents the composition, operating principle and main metrological characteristics of GET 203-2024.

Diagnostic accuracy of a prehospital electrocardiogram rule-based algorithm for ST-elevation myocardial infarction: results from a population-wide project.

This study reviewed the diagnostic accuracy of the prehospital electrocardiogram (PHECG) rule-based algorithm for ST-elevation myocardial infarction (STEMI) universally utilised in Hong Kong. This prospective observational study was linked to a population-wide project. We analysed 2210 PHECGs performed on patients who presented to the emergency medical service (EMS) with chest pain from 1 October to 31 December 2021. The diagnostic accuracy of the adopted rulebased algorithm, the Hannover Electrocardiogram System, was evaluated using the adjudicated blinded rating by two investigators as the primary reference standard. Diagnostic accuracy was also evaluated using the attending emergency physician's diagnosis and the diagnosis on hospital discharge as secondary reference standards. The prevalence of STEMI was 5.1% (95% confidence interval [CI]=4.2%-6.1%). Using the adjudicated blinded rating by investigators as the reference standard, the rule-based PHECG algorithm had a sensitivity of 94.6% (95% CI=88.2%-97.8%), specificity of 87.9% (95% CI=86.4%-89.2%), positive predictive value of 29.4% (95% CI=24.8%-34.4%), and negative predictive value of 99.7% (95% CI=99.3%-99.9%) [all P<0.05]. The rule-based PHECG algorithm that is widely used in Hong Kong demonstrated high sensitivity and fair specificity for the diagnosis of STEMI.

Detection of Inconsistencies in Isotope Ratios Certified in the Isotopic Primary Standards for Copper, Zinc and Nickel

Detection of Inconsistencies in Isotope Ratios Certified in the Isotopic Primary Standards for Copper, Zinc and Nickel

National programme for the reliability of ionizing radiation measurements based on inter-laboratory comparisons (ILCs): ILC n°2 ‘radiopharmaceutical activities’

A national Inter-Laboratory Comparisons (ILCs) programme was organized in Italy in 2022 by the Italian National Institute of Ionizing Radiation Metrology (INMRI), belonging to ENEA (Italian National Agency for New Technologies, Energy and Sustainable Economic Development), under the auspices of the Ministry of Enterprises and Made in Italy (Mimit ex MiSe). Within this ILCs programme, six inter-laboratory comparisons were organized, including the ILC-2 which focused on activity measurements carried out with radionuclide calibrators commonly used in the nuclear medicine departments of the participants.The focus was on three short-lived radionuclides - 99mTc, 18F, 177Lu - commonly employed in nuclear medicine for both diagnostic and therapeutic purposes. All presented results were compared with the reference values provided by ENEA-INMRI to ensure the traceability of measurements to the national primary activity standards. The observed deviation from the reference values of the measured activity were mainly within ± 10% (100% for 18F, 91.7% for 99mTc, 100% for 177Lu). The En statistical estimator was used to assess the participants’ ability to estimate uncertainty in the provided activity values. The obtained values revealed that, in certain instances, the involved laboratories did not achieve the correct results for En (with failure rates of 22.7%, 16.7%, 12.5% for 18F, 99mTc, 177Lu, respectively), despite deviations from the reference values falling within the ± 10%. The aim of ILC-2 was to harmonize the activity measurements in the country within the field of nuclear medicine for the specific radionuclides studied and enhance the measurement capabilities of the participants.

KV reference dosimetry in Australia and New Zealand: Survey results and trends.

To assess the number of radiotherapy kilovoltage (kV) units in service, their clinical utilization, and methodology and equipment used for absorbed dose determination across Australia and New Zealand. A survey was sent to 61 Australian and New Zealand radiotherapy providers in the second half of 2023. Fifty-seven responses were received, with 43 departments having kV units and providing beam quality data for 185 therapeutic kV beams 20-300kVp. Percentage depth dose curves were compared between five clinical beams with 100 kVp and 2.13-6.28mm Aluminum half value layers (HVLs), demonstrating large differences that can occur between beams with the same kVp. Eighteen departments provided clinical utilization data for their kV units, with a total of 4458 treatment courses and their corresponding kVp reported. All departments complied with national and international recommendations with respect to the equipment used for reference dosimetry of kV beams; 77% of ionization chambers used for absorbed dose determination were of Farmer-type, with the remaining 23% being plane parallel soft x-ray chambers. Methods of derivation of air-kerma calibration factors varied, with 73% of respondents using a draft document disseminated by the Australian Primary Standards laboratory, 23% using HVL alone, and 6% using other methods. The results of this survey provide a snapshot of kilovoltage radiation therapy use and the number of kV units across Australia and New Zealand. This data can be used as a point of reference for future investigations into clinical utilization and reference dosimetry methods across Australia and New Zealand or for comparisons with other countries, facilitating standardization of reference dosimetry practice for kilovoltage units.

Implementation of ICRU report 90 to re-evaluate the dosimetry standards in Taiwan

The purpose of this investigation is to re-evaluate primary dosimetry standards at the National Radiation Standard Laboratory (NRSL/INER) according to the recommendation of the International Commission on Radiation Units and Measurements Report 90 (ICRU Report 90). These standards are air kerma (Kair) in X-rays, 60Co and 137Cs beams, absorbed dose to water (DW) in 60Co beam, as well as reference air kerma (RAKR) in 192Ir beam for brachytherapy in Taiwan.However, the Consultative Committee for Ionizing Radiation (CCRI) summarized the expected changes in ICRU Report 90 to primary standards. These include modifications to the mean excitation energy of water (Iw) and graphite (Ig), the application of the density effect correction for graphite, new combined correction factors and the uncertainty related to the average energy required to create an ion pair in air (Wair), improved calculations of the stopping power, and the adoption of renormalized photoeffect cross-section. The recommendations of the CCRI were adopted for recalculation regarding correction factors and radiation-matter interaction constants for NRSL/INER primary standards. Furthermore, a newer version of Monte Carlo software and the alternative measurements with new ionization chambers (ICs) of a similar design were used to reassess the impact on the NRSL/INER standards. Consequently, the impact of the new ICRU recommendation on dosimetry standards ranged from -0.8% to 0.1%. The changes to the primary standards are in good correlation with similar changes implemented for the BIPM primary standards. For international comparisons of these standards, adoption of the ICRU Report 90 would not change significantly the degree of equivalence stated in the Asia-Pacific Metrology Programme (APMP) key and supplementary comparison database considering the impacts of the BIPM standards in the comparisons of APMP.RI(I)-K3, APMP.RI(I)-K1.1, APMP.RI(I)-K4, APMP.RI(I)-K8 and APMP.RI(I)-S3. Therefore, the NRSL/INER has formally implemented the re-evaluation standards on the 1st January 2024.

Implementation of the Profile Matching Method in a Football Player Position Decision Support

This study aims to overcome this issue by objectively determining the best positions of the soccer players through the application of the Profile Matching technique. The process consists of five steps: GAP values are first determined by comparing each player's unique traits to predetermined benchmarks. Next, compute the primary and secondary standards, establish weighted scores by utilizing the GAP values, compute the GAP values by contrasting specific player attributes with predetermined benchmarks, compute the overall scores, and order players according to their performance. A weighted combination of mental, physical, and skill criteria (30, 40%, and 30%, respectively) determines the final positions. The results demonstrate how effectively this rigorous technique scores the participants. This process offers a logical and objective approach to player selection, enhancing the precision and effectiveness of decision-making in soccer team management.