Error Of Measurement Values Research Articles

Determining an optimal run-off coefficient method for estimating peak discharge in the Lesti River catchment

The run-off coefficients provide vital hydrological data used for river discharge forecasts and flood risk management. Selecting an appropriate method to determine this coefficient is essential for accurately estimating peak discharge. This study compared the effectiveness of the Hassing, Cook, and U.S. Forest Service methods integrating GIS in estimating run-off coefficients in the Lesti River catchment area from 2013 to 2019. The findings revealed that the run-off coefficient was determined to be 0.188–0.243 using the U.S. Forest Service method, 0.194–0.213 using the Hassing method, and 0.466–0.480 using the Cook method. These results showed a rapid increase in the run-off coefficient within the Lesti River catchment area, signifying a heightened susceptibility to flooding. This is particularly concerning as the Lesti River is a primary tributary to the Brantas River. The comparison of estimated versus observed peak discharge emphasised the superiority of the runoff coefficient associated with the Hassing method over alternative methodologies when utilised as input data for peak discharge estimation. This was evident by the notable measurement error values of 11% for MAPE and 0.58 for MAE. The Hassing method emerged as the most appropriate and reliable for reflecting run-off characteristics in the Lesti River catchment area. Additionally, it proved to be the most accurate for estimating run-off coefficients in the Nakayasu process for peak discharge estimation. Consequently, applying the Hassing method offers a viable strategy for effectively mitigating flood risks in the Lesti catchment area.

The possibility of using the DKS-AT1123 dosimeter for radiation monitoring of medical electron accelerators with the energy of more than 10 MeV

In the Russian Federation, there is a constant increase in the number of radiation medical installations with electron accelerators. Over the past 4 years, their number has increased 2.5 times. These installations contain pulsed electron accelerators that generate pulsed bremsstrahlung radiation with a maximum energy from 6 to 21 MeV. Currently, there are no devices designed for dosimetry of the pulsed photon radiation with energy of more than 10 MeV in the state register of measuring instruments of the Russian Federation. The most widely used radiation monitoring device for pulsed electron accelerators is the DKS-AT1123 X-ray and gamma radiation dosimeter designed for dosimetry of pulsed bremsstrahlung radiation with an energy of up to 10 MeV. The purpose of this work is to evaluate the possibility of using this device for dosimetry of pulsed bremsstrahlung radiation with a maximum energy of up to 20 MeV. The authors calculated the energy spectra of bremsstrahlung radiation for a point source with a maximum energy of 20 MeV behind flat concrete screens with a thickness of 1 m, 2 m and 3 m by the Monte Carlo method using the GEANT4 calculation program. The energy dependence of the registration efficiency of the DKS-AT1123 dosimeter was extrapolated to the energy range of 10–50 MeV in the kerma-approximation without taking into account the energy transfer by secondary electrons. It was assumed that it corresponds to the energy dependence of the total mass attenuation coefficient for the absorbed energy of gamma quanta in water. Using conversion coefficients for converting the fluence of monoenergetic photons into the effective dose rate at an anterior-posterior radiation incidence on the human body, real dose rates were calculated, and using the energy dependence of the dosimeter readings, the predicted results of measuring the unit dose rate with the DKS-AT1123 dosimeter behind a concrete protection with a thickness of 1, 2 and 3 m were obtained. It is shown that the maximum expected underestimation of the measurement results will not exceed 40% and practically does not depend on the thickness of the concrete shield in the thickness range from 1 to 3 m. To account for this underestimation, it is necessary to use the value of additional measurement error due to the energy dependence of the sensitivity of this device for the photon radiation energy of more than 10 MeV, equal to 70%. This makes it possible to use the measurement results obtained using this dosimeter to adequately characterize the state of radiation safety during operation of pulsed electron accelerators with a maximum energy of up to 20 MeV. It is possible to use a correction factor to the measurement results equal to 1.63 ±0.04 to compensate for this underestimation. The proposed approach can be used to create a methodology for using this dosimeter for radiation monitoring of medical electron accelerators with the energy of up to 20 MeV, if there are correction factors for radiation protection configurations and radiation energies encountered in practice.

Development of a Low-Cost and Portable Device for Monitoring Heart Rate, Blood Oxygen Saturation, and Body Temperature in Infants Incubator

The risk of newborn infant mortality is commonly associated with hypothermia. Hypothermia is a health disorder and a leading cause of death in newborns, caused by an imbalance in the baby's body temperature. Hypothermia occurs due to a decrease in body temperature resulting from various conditions, especially high oxygen requirements and a decrease in room temperature. The purpose of this study is to monitor the health status of newborns. Monitoring the body temperature and oxygen saturation levels in newborns can help detect abnormalities in infants at an early stage. Oxygen saturation is considered a vital sign that is important in supplying oxygen to the body. This research is expected to assist patients using a baby cuve in providing care for newborns with hypothermia symptoms. The Baby Cuve utilizes the DS18B20 sensor for temperature measurement and the MAX3102 sensor for heart rate and oxygen saturation. The data is then processed using the ESP32 microcontroller, and the results are displayed on an LCD screen. The comparative tools used in this study are the standard thermometer and pulse oximeter. The results of this research indicate that the smallest measurement error value is found in the Spmeasurement of respondent 10, which is 0.1%. The largest measurement error value is found in the Spmeasurement of respondent 2, which is 5.6% based on the obtained data. However, the measurement results are still within the tolerance limit of ±10%.

The application of neural networks in the problem of radio monitoring with the use of a two-coordinate radio direction finder and the estimation of their efficiency

Problem statement. Measuring bases of two-coordinate phase direction finders (PDF), as a rule, are located along the same line, while bearing occurs in two planes independently. The procedure for determining the bearing in this case consists in restoring the true wave front and is quite computationally expensive. The study of PDF using a neural network with simultaneous use of information from all possible combinations of measurement bases is of particular interest from the point of view of evaluating the possibility of increasing the probability of correctly eliminating the ambiguity of bearing and increasing the accuracy of bearing, reducing computational costs and reducing the time to determine the bearing. Goal. Evaluation of the effectiveness of the use of artificial neural networks (NN) for direction finding of radio emission sources (RES) in solving radio monitoring problems using two-coordinate PDF, evaluation of the possibility of increasing the probability of correct elimination of ambiguity of bearing and increasing the accuracy of bearing when using all measuring bases of PDF. Results. A model of two-coordinate PDF based on NN has been developed, which makes it possible to evaluate the effectiveness of RES bearing in two planes with variations in model parameters and initial data. The obtained modeling results allow us to conclude that it is possible to create a two-coordinate PDF based on NN. The evaluation of the effectiveness of bearing shows that PDF based on NN has a commensurate accuracy of bearing and a high probability of eliminating ambiguity compared with PDF using classical methods and is somewhat inferior to them at high values of the phase measurement error in the receiving channels. Practical significance. The use of artificial neural networks (NN) for direction finding of radio emission sources (RES) in solving radio monitoring problems and further research on their development will improve the accuracy and reliability of measurements while reducing computational costs.

Estimation of population mean using ranked set sampling in the presence of measurement errors

Ranked set sampling is widely acknowledged for its superior efficiency compared with simple random sampling. Only a small amount of work has been conducted using ranked set sampling when measurement errors are present. This study introduces innovative estimators utilizing ranked set sampling to assess the population mean when faced with both correlated and uncorrelated measurement errors. The expressions for the bias and mean squared error of the proposed estimators are derived up to the first-order approximation, revealing their superior performance compared to the other examined estimators. The efficacy of the suggested estimators in handling measurement errors was demonstrated through numerical illustration and simulation study investigations. The recommended estimators are further compared to the existing ones using the percentage relative efficiency and mean squared error, and the impact of measurement errors on the results is highlighted through the percentage computation of measurement errors. The innovative estimators suggested were formulated by judiciously incorporating ratio, exponential, and log estimators. Numerical examples involving expenditure and income, as well as simulated data generated from a normal population using R software, affirm the superior performance of the proposed estimators over existing ones such as the usual mean estimator and those proposed by Vishwakarma and Singh (2022), as evidenced by the higher percent relative efficiency and lower mean squared error. The evaluation of the percentage contribution of measurement error values confirms the impact of measurement errors on the properties of the estimators.

Cross-cultural Adaptation, Translation, and Validation of Gujarati Version of Neck Disability Index in Patients with Chronic Neck Pain

Background and Aim: Specific to the population of Gujarat state, a need arises to have neck disability index (NDI) in the regional Gujarati language. The aim of present study is to translate NDI in Gujarati language and assess its validity for use in patient care. Materials and Methods: A total of 100 patients suffering from chronic neck pain and aged between 18 and 65 years participated in the study. In phase I, translation and cross-cultural adaptation of the original English version of NDI was performed according to the published guidelines. In phase II, all the patients were asked to complete a questionnaire booklet consisting of Gujarati version of NDI (NDI-G), Neck Pain and Disability (NPAD), and Beck’s depression inventory scales. The psychometric testing included evaluation of factor structure by exploratory factor analysis, reliability by test–retest reliability and internal consistency, agreement by Bland–Altman plots and value of measurement error (standard error of measurement and minimal detectable change), construct validity by assessing hypotheses of NDI-G correlations with the Gujarati version of Neck Pain and Disability (NPAD-G) and Gujarati version of BDI (BDI-G). A panel of 15 expert members assessed the content validity of NDI-G on a 7-point Likert scale for content equivalence, content relevance, and content representativeness. Test–retest reliability for the NDI-G was examined in 50 patients, twice with an interval of 48 h. Results: In phase I, the cross-cultural adaptation process of the NDI-G was successful, and less difficulty was experienced in achieving an acceptable translation. In phase II, the NDI-G showed strong psychometric properties. The translated version of the scale showed high internal consistency (Cronbach α = 0.82) and excellent test–retest reliability (Intra-class correlation coefficient = 0.982). Face and content validity of the NDI-G was well established with no floor and ceiling effects observed. In construct validity, convergent validity was confirmed by a high correlation of NDI-G with NPAD-G (r = 0.941, P < 0.01). Conclusion: The NDI-G was successfully translated into Gujarati, showing good psychometric properties. Its use is recommended for clinical and research purposes.

Self-Calibration Method for Circular Encoder Based on Two Reading Heads with Adjustable Positions

To improve the measuring accuracy of circular encoders in special applications, self-calibration of the circular encoder is necessary. The commonly used self-calibration method, namely the Equal Division Average (EDA) method, requires a large number of reading heads and cannot be used when the structural space is limited. In this paper, a self-calibration method for a circular encoder based on two reading heads with adjustable positions (TRAP) is proposed. This TRAP method uses two reading heads to simulate multiple reading heads, which can be used to achieve self-calibration of circular encoders in limited space. This paper investigates the principle of simulating multiple reading heads with two reading heads, designs and builds an experimental system, and obtains and analyzes experimental data. The experimental results show that the peak-valley value of the angle measurement error is reduced from 252.41″ to 18.82″ after self-calibration with the TRAP method, and the repeatability of multiple self-calibration experimental results is less than 0.75″. The TRAP method breaks through the limitation of the number of reading heads that can be installed during the self-calibration of the circular encoder and can effectively suppress the angle measurement error of the circular encoder.

Accuracy of coordinate measurements at phase modulation by digital raster

The development of optical-electronic instruments for measuring linear and angular quantities based on focal-plane array (photomatrices) using a digital phase analyzer (digital raster) is considered. It is shown that, unlike a phase raster with a mechanical drive, a digital raster provides the possibility of automation and increased measurement accuracy, reducing the weight and size characteristics of the measuring instrument. A method for constructing a digital raster is proposed, based on the use of photomatrices in combination with computer technologies. To ensure the required accuracy of the developed opto-electronic devices, the sources and components of the measurement error were investigated. The influence of the discrete structure of a digital raster on the error in measuring image coordinates has been studied. Mathematical expressions are obtained for calculating the limiting values of coordinate measurement errors caused by parasitic phase modulation that occurs when using a digital raster (sampling error). The dependence of these errors on image parameters and pixel size has been determined. It is shown that, based on the permissible maximum sampling error, it is possible to calculate the required dimensions of a photomatrix pixel, while the size of the sampling pixel can be larger than the size of the photomatrix pixel, which is very signifi cant from the point of view of energy relations. The results obtained will be useful in the development of optical-electronic means of angular and linear measurements with digital rasters.

Accuracy and reproducibility of two-dimensional computed tomography-based positioning of femoral component rotational alignment in preoperative planning for total knee arthroplasty

BackgroundPoor rotation of the femoral component in total knee arthroplasty (TKA) can result in various postoperative complications, underscoring the critical importance of preoperative planning.PurposeTo improve the accuracy of femoral component positioning during TKA, this study compared the accuracy and repeatability of different two-dimensional (2D) computed tomography (CT) measurement methods for measuring the posterior condylar angle (PCA) in preoperative TKA planning.MethodsA retrospective analysis was conducted on 75 patients (150 knees) who underwent bilateral lower extremity computed tomography angiography (CTA) at Fuyang People's Hospital from January 2021 to July 2021. Three different methods were used to measure the PCA based on 2D CT images (axial CT slices) and three-dimensional(3D) models (femoral models reconstructed from CT data) in this study. Method 1: Single-plane 2D CT measurement, measuring PCA in the most obvious single-plane CT slice of the surgical transepicondylar axis (sTEA); Method 2: multi-plane 2D CT measurement, identifying and locating anatomical landmarks in multiple 2D CT slices and measuring PCA; Method 3: 3D model measurement, measuring PCA in the reconstructed femur 3D model. Compare the differences in PCA measurements between the three measurement methods. A positive PCA measurement was recorded when the sTEA was externally rotated relative to the posterior condylar line (PCL). Any difference exceeding 3° between the PCA measurement in the 2D CT and the PCA reference value in the 3D model was classified as an outlier. The intraclass correlation coefficient (ICC) and Bland–Altman method were utilized to assess the intra- and inter-observer reproducibility of the three measurement methods.ResultsThe PCA measurement in the single-plane 2D CT was 1.91 ± 1.94°, with a measurement error of − 1.22 ± 1.32° and 12.7% of outlier values. In the multi-plane 2D CT, the PCA measurement was 2.96 ± 1.68°, with a measurement error of -0.15 ± 0.91° and 6.0% of outlier values. The PCA measurement in the 3D model was 3.12 ± 1.69°. The PCA measurement in single-plane 2D CT was notably smaller than that in multi-plane 2D CT and 3D models, with no significant difference between the latter two. The multi-plane 2D CT showed significantly lower measurement error and outlier values than the single-plane 2D CT. All three PCA measurement methods exhibited high reproducibility (ICC: 0.93 ~ 0.97).ConclusionsUsing of multi-plane 2D CT for measuring PCA in preoperative planning of TKA has high reproducibility and accuracy, with fewer outlier values. We recommend preoperative measurement of PCA using muti-plane 2D CT to improve the accuracy of positioning the femoral component rotational alignment during surgery.

Cross-cultural adaptation, reliability, and validity of the Turkish version of the Cumberland Ankle Instability Tool

ObjectivesThe objective of the study was to cross-culturally adapt and assess the validity and reliability of the Turkish version of the CAIT (CAIT-TR). MethodsThe CAIT was translated and adapted into Turkish according to accepted cross-cultural adaptation guidelines of self-reported measures. A total of 130 individuals, including healthy participants (n = 40) and with chronic ankle instability (CAI) (n = 90), were recruited in this study. The internal consistency and test-retest reliability of the CAIT-TR were assessed using Cronbach's alpha and intraclass correlation coefficients (ICC), respectively. To assess convergent validity, hypotheses were tested regarding expected correlations between CAIT-TR, Foot and Ankle Outcome Score (FAOS) subscales, and the Visual Analogue Scale (VAS). Discriminative validity was evaluated with the hypothesis that the CAIT-TR can distinguish between subjects with and without CAI and also calculated a cut-off score for CAI. The dimensional structure of the CAIT-TR was investigated with confirmatory factor analysis. Additionally, minimal detectable change (MDC), floor/ceiling effects, and measurement error values were determined. ResultsThe CAIT-TR demonstrated high Internal consistency (Cronbach's alpha = 0.854) and test-retest reliability (ICC = 0.919). Regarding convergent validity, the CAIT-TR exhibited a moderate-strong correlation with both the FAOS and VAS. The confirmatory factor analysis supported the unidimensional structure of the questionnaire. The identified cut-off value for the CAIT-TR was 25, and the MDC for individual-level CAIT-TR scores was determined to be 1.87. No floor or ceiling effects were observed. ConclusionThe CAIT-TR is a valid and reliable questionnaire for the assessment of ankle instability within the Turkish population.

A joint Bayesian framework for missing data and measurement error using integrated nested Laplace approximations.

Measurement error (ME) and missing values in covariates are often unavoidable in disciplines that deal with data, and both problems have separately received considerable attention during the past decades. However, while most researchers are familiar with methods for treating missing data, accounting for ME in covariates of regression models is less common. In addition, ME and missing data are typically treated as two separate problems, despite practical and theoretical similarities. Here, we exploit the fact that missing data in a continuous covariate is an extreme case of classical ME, allowing us to use existing methodology that accounts for ME via a Bayesian framework that employs integrated nested Laplace approximations (INLA) and thus to simultaneously account for both ME and missing data in the same covariate. As a useful by-product, we present an approach to handle missing data in INLA since this corresponds to the special case when no ME is present. In addition, we show how to account for Berkson ME in the same framework. In its broadest generality, the proposed joint Bayesian framework can thus account for Berkson ME, classical ME, and missing data, or any combination of these in the same or different continuous covariates of the family of regression models that are feasible with INLA. The approach is exemplified using both simulated and real data. We provide extensive and fully reproducible Supporting Information with thoroughly documented examples using R-INLA and inlabru.

Automated system for measuring electrophysical parameters of semiconductor structures

сThe article is devoted to the development of an automated information and measurement system for measuring the voltfarad characteristics of semiconductor structures, including structures based on transparent conductive coatings. The structure of the information-measuring system is proposed, the results of functional and metrological analysis of the measurement channel of complex conductivity are presented. In particular, as a result of functional analysis, the functions of converting complex conductivity into a digital code proportional to the capacitive component and the active component of conductivity are obtained. In the process of metrological analysis, a metrological structural model of the complex conductivity measurement channel has been compiled, which, unlike the functional model, takes into account additive, multiplicative errors of the links, as well as the quantization error of the analog-to-digital converter. Expressions are obtained for the real functions of converting complex conductivity into a digital code proportional to the capacitive and active component of conductivity, taking into account the instrumental errors of the links that make up the measuring channel. Metrological analysis makes it possible to solve both the direct problem of calculating the instrumental error of the measuring channel according to the known nominal parameters and errors of its constituent links, and the inverse problem, which consists in assigning requirements to the metrological characteristics of the links in the measuring channels to ensure the required value of the maximum measurement error. In particular, based on the metrological analysis performed, it was found that the limits of the permissible relative error of capacitance and conductivity measurements do not exceed ±3 %, which is confi rmed experimentally. The developed automated information and measurement system allows not only to measure the volt-farad characteristics of the studied semiconductor structures, but also to process measurements in order to determine the electrophysical parameters by an indirect method.

Determination of the code reliability of digital angle converters

To measure the angular motion parameters of various kinds of objects, digital angle converters are widely used, which differ in the output electrical interface using a parallel or serial method of code transmission. Currently, there is no single approach to the metrological assessment of the accuracy characteristics of these digital angle converters. Such an integral assessment can be the code reliability of the converter, which characterizes the probability that the value of the measured angle corresponds to the calculated quantum, the code of which is read. Now there is an analytical method for calculating the code reliability used for digital angle converters with parallel code transmission. The article proposes an algebraic method for calculating the code reliability. Unlike the analytical method, it lacks the disadvantages of approximating the error histogram of the digital angle converters by random variable distribution functions. The conducted studies have shown that the algebraic method of calculating the code reliability can be used for the digital angle converters, with parallel and serial code transmission. It is shown that in order to fi nd the unevenness of the angular scale of the digital angle converters using a dynamic goniometer with an incremental angle sensor, it is necessary to center the array of measured error values. The results obtained can be used in measuring technology and metrology for digital angle converters calibration. They are of interest to specialists working in the fi eld of metrology of angular measurements, measuring equipment, digital angle converters manufacturers.

Design And Development Of Spo2, Bpm, And Body Temperature For Monitoring Patient Conditions In Iot-Based Special Isolation Rooms

The use of batteries as the main power source in portable equipment systems has several drawbacks, including the percentage of battery power that must be monitored so that the system is always active. Analysis of battery power efficiency is needed to determine the resistance of portable systems. This study makes a portable system for monitoring the condition of patients with infectious diseases in a special isolation room that can measure heart rate, body temperature, and oxygen saturation. The design of this device uses a 2200mAH battery as a power source on the IC TTGO ESP32 to manage data and display measurement results, the MAX30102 sensor to measure oxygen saturation and heart rate, and the MCP9808 sensor to measure body temperature. The design of this device has been tested on respondents aged 25-40 years by placing the sensor on the fingertip then the measurement results are compared with a standard device that has been calibrated. The measurement results show that the device is feasible to use because the measurement error value is ±5%. Testing the efficiency of battery power in normal mode and save mode. In normal mode, the current used in the device is 154.9 mA, while the save mode by not activating the LCD TTGO ESP32 requires a current of 126.7 mA. The results of the analysis show that using the battery in normal mode can activate the device for up to ±14 hours and in save mode for ±17 hours. This designed method is useful for measuring power efficiency in different device modes and the user knows the battery charging time at regular intervals.

Talbot wavefront sensor measurement possibilities under gaussian illumination

Present paper deals with the measurement errors in Talbot wavefront sensor under Gaussian illumination conditions. The measurement possibilities of wavefront sensor based on the self-imaging phenomenon is investigated theoretically and based on the simulation results. A theoretical model based on Fresnel regime is used in order to determine the intensity distribution in the near field. The effect of Gaussian field is described in the terms of spatial spectrum of the grating image. On the basis of four different gratings was shown that Gaussian field affects on the spatial spectrum of the grating self-image if Gaussian waist is less than two grating periods and self-images of used gratings are almost the same. Four kinds of gratings are tested for their performance in the wavefront sensor. Simulation results show that binary gratings with square and circle unit cells show less value of measurement error in comparison with gratings that have cosine and Gaussian profiles.

Geographic information data processing and physical simulation for power transmission lines

To address the issue of traditional transmission line characteristic parameter testing methods being susceptible to external environmental interference. Proposed a method for processing geographic information data of transmission lines and physical simulation. Firstly, the parameters of the transmission line are tested, a model is established at both ends of the transmission line, and variable frequency signals are collected using 3D GIS technology to develop a lead control box for transmission line parameter testing. Then, the transmission line parameters are calculated online, and real-time voltage and current measurements are conducted at both ends of the transmission line. A zero sequence current simulation diagram of the transmission line is constructed, and circuit parameters are calculated based on the simulation results, Finally, measure the zero sequence parameters of the transmission line using electricity and obtain the zero sequence impedance value of the transmission line using the least squares method. The six zero sequence parameter values were measured in a disturbance environment. The results show that when the power line reaches a certain length, the error of the traditional method has reached 50%, and the testing error of the method studied by the author is less than 3%. The measurement error value of the transmission line characteristic parameter test method based on 3D GIS technology is less than that of the traditional method.

An Improved Combined Framework of Force Measurement With Friction Model for Harmonic Gear

To obtain accurate output torque of robot joint for torque control, a built-in torque sensor is designed in this paper. In order to enhance the performance of harmonic gear, it is urgent to deal with the key issues in terms of the errors of sensing and positioning, torque ripple interference. To handle these aforementioned key issues, four pairs of symmetrically distributed strain gauges are pasted on the bottom of the flexspline. Then, a precise positioning method based on laser marking is proposed to improve the positioning accuracy of the strain gauges. Moreover, Kalman filter is utilized to reduce torque ripple interference in the output signal of the strain gauges. Additionally, the designed device is evaluated by experimental tests which is conducted on prototype trial production. Synchronously, the relationship between the flexspline torque and the joint output torque is verified and the polynomial is used to represent the relationship of the measured torque for the built-in torque sensor and the standard torque sensor in the static and dynamic conditions. Finally, a friction model is presented and identified. Comprehensive comparative experiments is performed the performance of the build-in torque sensor in terms of estimation accuracy and control and it shows that the designed built-in torque sensor with friction compensation can be improved ten times in comparison with that of without friction compensation in terms of steady state mean error and mean value of measurement error. What is more, this designed build-in torque sensor holds tremendous potential for making the compact and light weight motion joint module, especially for cooperative robot and robotic supernumerary limb.

Measurement of oxygen concentration in atmospheric air using ultrasound time of flight with humidity compensation.

An absolute gas concentration can be measured from the variation in the speed of sound between two gases in principle. Owing to the small difference in the speed of sound between the atmospheric air and oxygen (O2) gas, measuring O2 concentration with high accuracy in the humid atmospheric air using ultrasound needs careful investigation. The authors show successfully a method to measure the absolute concentration of O2 gas in humid atmospheric air using ultrasound. It was possible to measure O2 concentration in the atmospheric air with accuracy by compensating for the influence of temperature and humidity by calculation. The O2 concentration was calculated from the conventional speed of sound equation by utilizing small mass variation for the change in moisture as well as temperature. This method using ultrasound enabled us to measure the O2 concentration in the atmospheric air as 21.0%, which is in agreement with the standard atmospheric dry air. The measurement error values after the humidity compensation are about 0.4% or less. Furthermore, this method takes only about a few ms for measuring O2 concentration and, thus, can be used as a high-speed portable O2 sensor for industrial, environmental, and biomedical instruments.

Signal acquisition analyzer based on MSP432

The system is based on digital signal processing technology, takes MSP432P401R single-chip microcomputer as the main controller, uses the on-board ADC to convert the input signal into a digital signal, and then carries out FFT transformation to obtain the amplitude of each harmonic component, so as to carry out spectrum analysis and calculate THD/ THDo/ Δ values for further signal processing. The system realizes the signal processing and the calculation of distortion and distortion measurement error and expands the functions of calculating the normalized amplitude of the fundamental wave and harmonic and recovering the input signal waveform. Distortion measurement error value Δ ≤3%, can process signal amplitude range 30mV~600mV, fundamental frequency range 1kHz~100kHz, and the calculation and processing time is less than 10 seconds.

Neutronics simulation of China Experimental Fast Reactor start-up tests using FARCOB and ERANOS 2.1 code systems

The neutronics analysis of selected start-up tests conducted from 2010 to 2011 in China Experimental Fast Reactor (CEFR) is carried out using in-house FARCOB and European ERANOS-2.1 code systems as a part of IAEA coordinated research project (CRP) on “Neutronics Benchmark of CEFR Start-Up Tests”. This exercise has the main objective of validation and verification of physical models, neutronics simulation methodology including cross-section libraries that is used for fast reactor core simulations. It is challenging to simulate such a small compact core of enriched uranium with high neutron leakage having stainless steel radial reflector by using 3-D diffusion theory codes. This benchmark analysis used a new simplified approach such as a 3-step method and experimental method for simulating temperature and sodium void reactivity coefficients. Net criticality, control rod worth, temperature and sodium void reactivity coefficients and swap reactivity could be predicted well within their measured error values. This exercise provided an additional validation of the FARCOB system against small sodium-cooled fast reactor (SFR) cores, and it can be confidently used for the design and analysis of small experimental reactor cores.