Temperature Correction Research Articles

A correlated multi-observable assessment for vanadium redox flow battery state of charge estimation — Empirical correlations and temperature dependencies

The efficient operation of vanadium redox flow batteries requires the half cell specific monitoring of the state of charge (SOC). Monitoring of the SOC is affected by temperature fluctuations, which need to be distinguished from the SOC signal. Several SOC monitoring approaches have been proposed in the literature and either been evaluated individually or compared to one other approach. The aim of this study is to contribute to SOC sensor development for VRFB by providing a first correlated assessment of several established and new SOC monitoring methods. We perform multi observable measurements of: half cell electrolyte potentials, electrolyte densities, electrolyte volumes, electrolyte viscosity related pressure drops, pH related potentials and UV/Vis absorbances. We determine SOC correlations of these observables in full charge/discharge cycles at constant temperature and derive temperature corrections in additional measurements over a range of 12°C to 32°C at 25%, 50% and 75% SOC. We compare the SOC and temperature sensitivity as well as the accuracy of these monitoring methods at constant and varied temperature. We find that the established half cell electrolyte potentials and UV/Vis absorbances can estimate the SOC at constant temperature with measurement errors of 1.7% and 4%, respectively and with slightly higher errors at varying temperatures. The viscosity related pressure drop and electrolyte density are both suitable for SOC estimation if temperature corrections are included. The pH related potentials for the positive half cell and both half cell electrolyte volumes could be used for a rough SOC estimate, but need accurate temperature corrections and further long term stability evaluation.

Bias Correction and Trend Analysis of Temperature and Rainfall in Eastern India

Bias Correction and Trend Analysis of Temperature and Rainfall in Eastern India

Impact of recurrent COVID-19 disease waves on acute myocardial infarction epidemics: results from a regional network

Aims To assess the impact of COVID-19 related public containment measures during recurrent COVID-19 waves on hospital admission rate for acute myocardial infarction (AMI). Methods and results: Clinical characteristics, reperfusion therapy modalities, COVID-19 status and in-hospital mortality of consecutive AMI patients who were admitted in a regional AMI network were recorded during one year starting in March 2020 and were compared with the year before. The COVID-19 study period encompassed two waves: the first in March-May 2020 and the second in October-December 2020. A total of 1349 AMI patients were hospitalised of which 725 during the pre-COVID period and 624 during the COVID period (incidence rate ratio of 1.16, p = 0,006). The impact was predominantly present in the first wave (32% reduction: n = 204 vs 152) and evanished during the second wave (3% increase (152 vs 156). A similar pattern was observed for ACS with cardiac arrest with a 92% reduction (n = 36 vs 3) during the first wave and no change during the second wave (18 vs 18). After correction for temperature and air quality, COVID-19 epidemic remained associated with a decrease of AMI hospitalisation (p = 0.046). Reperfusion strategy for AMI patients, were comparable between both study periods. The in-hospital mortality between the two periods was comparable (2.6% versus 1.9%), but COVID-19 positive ACS patients (n = 7) had a high mortality rate (14%). Conclusion COVID-19 related public containment measures resulted during the first wave in a 32% reduction of AMI hospitalisation, but this impact was not visible anymore during the second wave.

Enhanced heat flow assessment in Gulf of Hammamet and Pelagian Sea: Temperature corrections and conductivity adjustments

This study proposes new corrections of formation temperatures combined to correction of formation conductivities to reconstruct the heat flow map of the Gulf of Hammamet-Pelagian Sea, Eastern Tunisia. For that, a new linear Cross-Plot temperature correction approach, based on Bottom Hole Temperatures (BHT) and Drill Stem Temperatures (DST) of 63 drilled boreholes, was applied. In addition, and as temperature is transmitted from the substratum to the top of a stratigraphic column owing to the thermal conductivity, the latter was investigated according to a high appraisal of ±5 m and taking into account porosity variation with depth. The produced corrected thermal conductivity and geothermal gradient allowed to calculate the corrected heat flow in the Gulf of Hammamet – Pelagian Sea. Results show that the corrected geothermal gradient varies between 23 °C/Km and 58 °C/Km with a regional mean of about 39 °C/Km. The corrected heat flow rises from 49.5 to 119 mW/m2 with a regional mean of about 68 mW/m2. Variation of heat flow is dependent of the geodynamic evolution of the area where high heat flows follow folding structures and relatively low heat flows follow major trending faults. The major variations are E-W, N-S and NW-SE in direction following the major structural trends.

Non-Contact Measurement of Alcohol Content Based on Near Infrared Spectroscopy

In order to solve the influence of other external factors on the measurement concentration of alcohol solution, a non-contact measurement method based on near-infrared spectroscopy and BP neural network temperature correction method was proposed in this paper. This method takes into account the influence of temperature on the light intensity of alcohol liquid solution in the detection process, and trains it together with the measurement data as the input of neural network. At the same time, it is compared with the index fitting algorithm, which proves that the method has a good effect on the non-contact measurement of alcohol content.

Venous blood gases and electrolyte values of captive red foot tortoise (Chelonoidis carbonarius).

Blood gas analysis reflects the exchange of oxygen and carbon dioxide in the lungs. This test provides important information, since the relationship between these gases has a direct impact on the acid-basic balance in the body. Given the significance of blood gas analysis in Brazilian reptiles, this study set out to establish temperature-corrected and uncorrected reference intervals for venous blood gas measurements in Chelonoidis carbonarius, and to compare values between females and males. In this study, 19 animals were used, 8 males and 11 females. Blood samples were collected from the dorsal coccygeal vein, and the analyses were performed immediately after blood sample collection. The following parameters were measured: pH, PO2, HCO3-, TCO2, BEecf, Na, K, ICa, and Glu, and were compared between females and males. Additionally, pH, pCO2, and pO2 values were compared with and without temperature correction. Oxygen saturation and Na levels were significantly higher (p<0.05) in males. Furthermore, it was possible to infer that the lower the body temperature relative to the environmental temperature, the larger the difference in pH following temperature correction.

A half-cell reaction approach for pH calculation using a solid-state chloride ion-selective electrode with a hydrogen ion-selective ion-sensitive field effect transistor

Here, we explicitly define a half-cell reaction approach for pH calculation using the electrode couple comprised of the solid-state chloride ion-selective electrode (Cl-ISE) as the reference electrode and the hydrogen ion-selective ion-sensitive field effect transistor (ISFET) of the Honeywell Durafet as the hydrogen ion H+-sensitive measuring or working electrode. This new approach splits and isolates the independent responses of the Cl-ISE to the chloride ion Cl− (and salinity) and the ISFET to H+ (and pH), and calculates pH directly on the total scale pHtotalEXT in molinity (mol (kg-soln)−1) concentration units. We further apply and compare pHtotalEXT calculated using the half-cell and the existing complete cell reaction (defined by Martz et al. (2010)) approaches using measurements from two SeapHOx sensors deployed in a test tank. Salinity (on the Practical Salinity Scale) and pH oscillated between 1 and 31 and 6.9 and 8.1, respectively, over a six-day period.In contrast to established Sensor Best Practices, we employ a new calibration method where the calibration of raw pH sensor timeseries are split out as needed according to salinity. When doing this, pHtotalEXT had root-mean squared errors ranging between ±0.0026 and ±0.0168 pH calculated using both reaction approaches relative to pHtotal of the discrete bottle samples pHtotaldisc. Our results further demonstrate the rapid response of the Cl-ISE reference to variable salinity with changes up to ±12 (30 min)−1. Final calculated pHtotalEXT were ≤±0.012 pH when compared to pHtotaldisc following salinity dilution or concentration. These results are notably in contrast to those of the few in situ field deployments over similar environmental conditions that demonstrated pHtotalEXT calculated using the Cl-ISE as the reference electrode had larger uncertainty in nearshore waters. Therefore, additional work beyond the correction of variable temperature and salinity conditions in pH calculation using the Cl-ISE is needed to examine the effects of other external stimuli on in situ electrode response. Furthermore, whereas past work has focused on in situ reference electrode response, greater scrutiny of the ISFET as the H+-sensitive measuring electrode for pH measurement in natural waters is also needed.

Study on shrinkage and creep effect of steel truss-stiffened continuous rigid frame bridge considering variable temperature and relative humidity

In this study, indoor-outdoor comparison tests of shrinkage and creep were carried out in northwest China. The experimental results were compared with commonly used models of shrinkage and creep, some of which have adapted different methods for temperature and humidity correction. A finite element model for a continuous rigid-frame bridge with steel truss bracing was established. The calculated values from different shrinkage and creep models were then compared with the measured deflection values. An analysis was conducted to determine the influence of variable temperature and humidity on the long-term mechanical behavior of the steel truss-stiffened continuous rigid-frame bridge.The results show that when the concrete reaches the age of one year, the creep coefficient for the outdoor environment is 18.5% smaller than that in the indoor environment, while the outdoor shrinkage strain is 16.0% smaller. The CEB 90 model agrees best with the indoor test results. The corrected shrinkage and creep model (CSCM) is the closest to the outdoor test results, and the fib2010 model ranked second. The predicted values from CSCM exhibit the best agreement with the measured deflection values after the bridge completion. The CEB 90 model's predicted values for deflection of the main girder, longitudinal displacement of the pier, the maximum stress in steel trusses, and prestressing loss are lower than those in the CSCM after 20 years of construction, indicating that the influence of temperature and relative humidity variations on shrinkage and creep effect of the bridge can not be negligible.

Asphalt-related temperature correction of deflections measured in central FWD tests on a concrete-over-asphalt composite pavement

ABSTRACT This study focuses on the seasonal variations observed in five Falling Weight Deflectometer (FWD) tests conducted on a well-instrumented composite pavement. The main objective is to investigate the underlying mechanisms driving these seasonal variations and propose a method to facilitate the comparison of the different FWD tests. The stiffnesses of concrete, asphalt, and cement-stabilised layers are characterised individually. The stiffness of the subgrade is back-calculated using multi-layered simulations. These simulations also enable computation of deflections for different asphalt temperatures. The results allow for developing a method which converts measured deflections into corrected deflections referring to an asphalt reference temperature. Remaining seasonal variations of the corrected deflections refer to the subgrade. Corresponding k-values of the AREA4 method correlate well with seasonal variations of the stiffness of the subgrade. Finally, an alternative temperature-correction approach, requiring measured deflections only, is developed. Corrected deflections allow for quantifying seasonal stiffness variations of the subgrade.

Correction of Kerr-Sen Black Hole Temperature and Entropy by Lorentz Invariance Violation* *Supported by National Natural Science Foundation of China (Grant No.12373109) and the Natural Science Foundation of Shandong Province of China(Grant No.ZR202102220686).

In this paper, we modify the action of spin field in Kerr-Sen curved space-time through Lorentz invariance violation (LIV). The tunneling radiation rate of Fermion in the Kerr-Sen black hole and the correction of the black hole entropy are studied. In the curved space-time of the Kerr-Sen black hole, by considering the inclusion of LIV correction terms in the action of a spinor field, the modified form of the fermion dynamics equation, the tunneling radiation rate and Bekenstein-Hawking entropy of the black hole are obtained. In this paper, we further consider the modification of the results obtained under quantum perturbation theory and discuss the significance of the results obtained. We have used quantum perturbation theory to perform a more accurate correction of the above results.

Uncertainties originating from GCM downscaling and bias correction with application to the MIS-11c Greenland Ice Sheet

Abstract. The Marine Isotope Stage 11c (MIS-11c) interglacial is an enigmatic period characterized by a long duration of relatively weak insolation forcing, but it is thought to have been coincident with a large global sea-level rise of 6–13 m. The configuration of the Greenland Ice Sheet during the MIS-11c interglacial highstand is therefore of great interest. Given the constraints of limited data, model-based analysis may be of use but only if model uncertainties are adequately accounted for. A particularly under-addressed issue in coupled climate and ice-sheet modeling is the coupling of surface air temperatures to the ice model. Many studies apply a uniform “lapse rate” accounting for the temperature differences at different altitudes over the ice surface, but this uniformity neglects both regional and seasonal differences in near-surface temperature dependencies on altitude. Herein we provide the first such analysis for MIS-11c Greenland that addresses these uncertainties by comparing one-way coupled Community Earth System Model (CESM) and ice-sheet model results from several different downscaling methodologies. In our study, a spatially and temporally varying temperature downscaling method produced the greatest success rate in matching the constraints of limited paleodata, and it suggests a peak ice volume loss from Greenland during MIS-11c of approximately 50 % compared to present day (∼ 3.9 m contribution to sea-level rise). This result is on the lower bound of existing data- and model-based studies, partly as a consequence of the applied one-way coupling methodology that neglects some feedbacks. Additional uncertainties are examined by comparing two different present-day regional climate analyses for bias correction of temperatures and precipitation, a spread of initialization states and times, and different spatial configurations of precipitation bias corrections. No other factor exhibited greater influence over the simulated Greenland ice sheet than the choice of temperature downscaling scheme.

Temperature-Corrected Calibration of GS3 and TEROS-12 Soil Water Content Sensors

The continuous monitoring of soil water content is commonly carried out using low-frequency capacitance sensors that require a site-specific calibration to relate sensor readings to apparent dielectric bulk permittivity (Kb) and soil water content (θ). In fine-textured soils, the conversion of Kb to θ is still challenging due to temperature effects on the bound water fraction associated with clay mineral surfaces, which is disregarded in factory calibrations. Here, a multi-point calibration approach accounts for temperature effects on two soils with medium to high clay content. A calibration strategy was developed using repacked soil samples in which the Kb-θ relationship was determined for temperature (T) steps from 10 to 40 °C. This approach was tested using the GS3 and TEROS-12 sensors (METER Group, Inc. Pullman, WA, USA; formerly Decagon Devices). Kb is influenced by T in both soils with contrasting T-Kb relationships. The measured data were fitted using a linear function θ = aKb + b with temperature-dependent coefficients a and b. The slope, a(T), and intercept, b(T), of the loam soil were different from the ones of the clay soil. The consideration of a temperature correction resulted in low RMSE values, ranging from 0.007 to 0.033 cm3 cm−3, which were lower than the RMSE values obtained from factory calibration (0.046 to 0.11 cm3 cm−3). However, each experiment was replicated only twice using two different sensors. Sensor-to-sensor variability effects were thus ignored in this study and will be systematically investigated in a future study. Finally, the applicability of the proposed calibration method was tested at two experimental sites. The spatial-average θ from a network of GS3 sensors based on the new calibration fairly agreed with the independent area-wide θ from the Cosmic Ray Neutron Sensor (CRNS). This study provided a temperature-corrected calibration to increase the accuracy of commercial sensors, especially under dry conditions, at two experimental sites.

The Langley ratio method, a new approach for transferring photometer calibration from direct sun measurements

Abstract. This article presents a new method for transferring calibration from a reference sun photometer, referred to as the “master”, to a secondary sun photometer, referred to as the “field”, using a synergetic approach when master and field instruments have different spectral bands. The method was first applied between a precision filter radiometer (denoted PFR) instrument from the World Optical Depth Research and Calibration Center (WORCC), considered the reference by the WMO (World Meteorological Organization), and a CE318-TS photometer (denoted Cimel), the standard photometer used by AERONET (AErosol RObotic NETwork). These two photometers have different optics, sun-tracking systems, and spectral bands. The Langley ratio (LR) method proposed in this study was used to transfer calibration to the closest spectral bands for 1 min synchronous data for air masses between 2 and 5, and it was compared to the state-of-the-art Langley calibration technique. The study was conducted at two different locations, Izaña Observatory (IZO) and Valladolid, where measurements were collected almost simultaneously over a 6-month period under different aerosol regimes. In terms of calibration aspects, our results showed very low relative differences and standard deviations in the calibration constant transferred in IZO from the PFR to the Cimel: up to 0.29 % and 0.46 %, respectively, once external factors such as different fields of view between photometers or the presence of calibration issues were considered. However, these differences were higher in the comparison performed at Valladolid (1.04 %) and in the shorter-wavelength spectral bands (up to 0.78 % in IZO and 1.61 % in Valladolid). Additionally, the LR method was successfully used to transfer calibrations between different versions of the CE318-T photometer, providing an accurate calibration transfer (0.17 % to 0.69 %) in the morning LRs, even when the instruments had differences in their central wavelengths (Δλ up to 91 nm). Overall, our results indicate that the LR method is a useful tool not only for transferring calibrations but also for detecting and correcting possible instrumental issues. This is exemplified by the temperature dependence of the signal on the two Cimel UV spectral bands, which was estimated by means of the LR method, resulting in a signal rate of change of approximately -0.09×10-2 per degree in the case of 380 nm and approximately -0.03×10-2 per degree in the case of 340 nm. This estimation allowed us to implement the first operative temperature correction on ultraviolet (UV) spectral bands.

High-Resolution Gravity Measurements on Board an Autonomous Underwater Vehicle: Data Reduction and Accuracy Assessment

Gravity on Earth is of great interest in geodesy, geophysics, and natural resource exploration. Ship-based gravimeters are a widely used instrument for the collection of surface gravity field data in marine regions. However, due to the considerable distance from the sea surface to the seafloor, the spatial resolution of surface gravity data collected from ships is often insufficient to image the detail of seafloor geological structures and to explore offshore natural minerals. Therefore, the development of a mobile underwater gravimetry system is necessary. The GraviMob gravimeter, developed for a moving underwater platform by Geo-Ocean (UMR 6538 CNRS-Ifremer-UBO-UBS), GeF (UR4630, Cnam) and MAPPEM Geophysics, has been tested over the last few years. In this study, we report on the high-resolution gravity measurements from the GraviMob system mounted on an Autonomous Underwater Vehicle, which can measure at depths of up to several kilometres. The dedicated GraviMob underwater gravity measurements were conducted in the Mediterranean Sea in March 2016, with a total of 26 underwater measurement profiles. All these measurement profiles were processed and validated. In a first step, the GraviMob gravity measurements were corrected for temperature based on a linear relationship between temperature and gravity differences. Through repeated profiles, we acquired GraviMob gravity measurements with an estimated error varying from 0.8 to 2.6 mGal with standard deviation after applying the proposed temperature correction. In a second step, the shipborne gravity data were downward continued to the measurement depth to validate the GraviMob measurements. Comparisons between the corrected GraviMob gravity anomalies and downward continued surface shipborne gravity data revealed a standard deviation varying from 0.8 to 3.2 mGal and a mean bias value varying from −0.6 to 0.6 mGal. These results highlight the great potential of the GraviMob system in measuring underwater gravity.

Comparative of IEC 60891 and Other Procedures for Temperature and Irradiance Corrections to Measured I–V Characteristics of Photovoltaic Devices

The photovoltaic literature contains a wide range of methods for translating the I–V curves of a solar device to other conditions of irradiance and cell temperature, different from those under which the measurements were performed. Some of these translation methods are included as part of the International Standard IEC 60891. In this paper, these techniques are classified, reviewed, and implemented to perform a deep comparative analysis between them and to discuss their suitability for converting the I–V curves of photovoltaic modules under different scenarios of irradiance and temperature. From the analysis conducted, it can be seen that the interpolation method proposed in IEC 60891 achieves accurate results when it is applied to correct small and medium irradiance and temperature gaps. If no interpolation is possible and for large irradiance corrections, other procedures described in IEC 60891 can be applied. However, certain explicit methods based on the single-diode model or on the double-diode model can overcome the most well-known approaches proposed by the standard.

Near-infrared quality monitoring modeling with multi-scale CNN and temperature adaptive correction

Considering the impact of temperature on near-infrared spectroscopy (NIRS), a temperature adaptive correction neural network model called TI-CNN has been developed. This model takes into account the temperature influence. First, a multi-scale CNN model is established to extract the global features of NIRS. Then, by establishing the quantitative relationship between the sample and the modeling error of the neural network, the influence of temperature on the spectral features. Based on the degree of influence, the weight is adaptively adjusted to quantify the effect of temperature on near-infrared spectral features. Finally, to verify the model performance, EPO-PLSR, OSC-PLSR, CNN, and TA-CNN were used for comparison on the test set. The results showed that traditional temperature correction models performed poorly, with a coefficient of determination R2< 0.80. However, the neural network models based on multi-scale CNN, R2> 0.80. Of these, the TI-CNN based on multi-scale CNN and temperature adaptive correction, demonstrated the best performance with R2> 0.95. Therefore, the method proposed in this paper demonstrates superior performance compared to existing methods. It utilizes a multi-scale CNN to extract near-infrared spectral features and also incorporates temperature to adaptively correct the spectral features, resulting in superior model performance across various temperature conditions.

Non-destructive investigation of thermophysical properties on the China's space station: In-orbit experiment measurements and analysis

This paper discusses the current state of non-destructive research on the density, surface tension and viscosity of molten samples using the electrostatic levitation furnace (ELF) aboard the China Space Station (CSS). To address the challenges posed by the microgravity environment during the non-destructive testing process of containerless technology, we have developed several solutions. These include a temperature correction for infrared temperature measurement, a dual-camera position correction technique for density testing, a double electrode synchronous excitation, semi-frequency excitation and fine-sweeping approach for surface tension testing, and a signal demodulation method for viscosity testing. The uncertainties of the three thermophysical properties were 0.51 %, 3.10 %, and 9.78 %, respectively. This study highlights the feasibility and accuracy of measurements conducted in the ELF on the CSS, offering valuable insights into the behavior of molten materials under microgravity conditions. The findings from this study significantly contribute to our understanding of the thermophysical properties of molten materials.

Intelligent classifier for various degrees of coffee roasts using smart multispectral vision system

AbstractThis study proposes an innovative deep learning model for use in a multispectral vision system comprising a complementary metal‐oxide semiconductor image sensor and a spectrometer. To ensure accurate color recognition, the deep learning model includes an embedded adaptive automatic color temperature correction engine. By using this color temperature correction engine, the multispectral vision system can intelligently compensate for lighting and chromatic variations. To evaluate the performance of the system, we created a nine‐dimensional data set using the IT8.7/2 color target. We then used this data set to train the deep learning model. Our deep learning model outperformed other lightweight deep learning models in experiments, making it suitable for deployment on edge devices and embedded systems. We tested the ability of the multispectral vision system to classify adulterated coffee beans into their respective classes. The overall accuracy rate was more than 99.3%, indicating that out proposed multispectral vision system is effective in identifying color differences. Considering its capabilities in agricultural screening, we suggest incorporating our adaptive automatic multispectral vision system into agricultural machines for the realization of Agriculture 4.0.

Research on Correction of Temperature and Mineralization and Prediction of Water Holdup Based on Machine Learning

Research on Correction of Temperature and Mineralization and Prediction of Water Holdup Based on Machine Learning

Correction of the SMAP Sea Surface Brightness Temperature and Retrieval of Sea Surface Salinity Incorporating CYGNSS Observables

Correction of the SMAP Sea Surface Brightness Temperature and Retrieval of Sea Surface Salinity Incorporating CYGNSS Observables