Maximum Uncertainty Research Articles

Luminescence Thermometry on the Route of the Mobile-Based Internet of Things (IoT): How Smart QR Codes Make It Real.

Quick Response (QR) codes are a gateway to the Internet of things (IoT) due to the growing use of smartphones/mobile devices and its properties like fast and easy reading, capacity to store more information than that found in conventional codes, and versatility associated to the rapid and simplified access to information. Challenges encompass the enhancement of storage capacity limits and the evolution to a smart label for mobile devices decryption applications. Organic–inorganic hybrids with europium (Eu3+) and terbium (Tb3+) ions are processed as luminescent QR codes that are able to simultaneously double the storage capacity and sense temperature in real time using a photo taken with the charge‐coupled device of a smartphone. The methodology based on the intensity of the red and green pixels of the photo yields a maximum relative sensitivity and minimum temperature uncertainty of the QR code sensor (293 K) of 5.14% · K−1 and 0.194 K, respectively. As an added benefit, the intriguing performance results from energy transfer involving the thermal coupling between the Tb3+‐excited level (5D4) and the low‐lying triplet states of organic ligands, being the first example of an intramolecular primary thermometer. A mobile app is developed to materialize the concept of temperature reading through luminescent QR codes.

Response characterization of EBT-XD radiochromic films in megavoltage photon and electron beams.

The purpose of this study was to investigate the beam quality dependence of the EBT-XD radiochromic films for megavoltage photon and electron beam irradiations by studying their spectral response. Dose, dose rate, and interbatch dependencies were investigated as well. EBT-XD and EBT3 radiochromic films were cut into 5cm2 ×5cm2 pieces, placed between solid water phantoms, and irradiated with 6 and 15MV photon beams, 6 and 10MV flattening filter free photon beams, and 6 and 20MeV electron beams at dose levels between 0.5 and 50Gy. In order to measure the spectral response, the films were illuminated by a deuterium and tungsten-halogen lamp and net absorption was measured in 400-800nm spectral range using a fiber-coupled optical spectrometer. Film samples were then analyzed using a flatbed scanner in the red, green, and blue channel to obtain the optical density of the films. The net absorption spectra of the EBT-XD and EBT3 films showed two absorption bands centered at 635 and 585nm, characteristic of the EBT model. However, for a given dose, the EBT-XD films showed lower net absorbance compared to the EBT3 films. At a given dose level, the net absorption spectra and dose-response curves for EBT-XD films showed only slight variations across various beam qualities. When a calibration curve obtained from a given beam quality is used to measure dose from films irradiated with other beam qualities, the maximum uncertainty in the calculated dose, in ranges 5-40 and 8-50Gy for red and green channels, respectively, were ~3.1% and ~2.4%. The response of the EBT-XD films is dose rate independent but batch dependent. No significant beam quality dependence was observed in EBT-XD films in the dose range up to 50Gy.

Fast and Accurate Assessment of the “Well Stirred Condition” of a Reverberation Chamber From $S_{11}$ Measurements

This paper presents a method to determine the frequency where a reverberation chamber starts to be “well stirred” according to the number of stirring conditions (i.e., different positions of a mode stirrer for a mechanically stirred chamber) considered. The method, based on S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> measurements of an antenna inserted in the reverberation chamber to be characterized, requires a simple measurement setup, is fast (few minutes) while leading to an excellent level of accuracy (maximum uncertainty of 10%) as demonstrated by the measurement results shown in this paper. The method takes advantage of a reliable definition of the well stirred condition leading to threshold values theoretically justified. Clear measurement guidelines and recommendations on the post-treatment process (available on demand) are also given. The method, proposed to the community of users as an alternative calibration procedure, provides reliable information on the chamber performances in the “grey zone” between the lowest usable frequency defined by standards and the frequency when the chamber is actually well stirred.

Segmented gamma-ray assay of large volume radioactive waste drums containing plutonium lumps

Segmented gamma-ray scanning (SGS) is a traditional practice, globally, for the non-destructive assay of special nuclear materials (SNMs) in large volume radioactive waste drums. The conventional SGS is a relative two pass method and requires a standard drum of identical geometry. The present work is focused on identifying the limitations of traditional segmented gamma scanning methodology for the assay of waste drums containing plutonium lumps. It has been observed that, for drums containing Pu lumps, the conventional SGS methodology severely underestimates the assay results (~ 2–6 times depending on the gamma-ray energy) due to attenuation under-correction. An alternate single pass absolute efficiency approach following the principle of infinite energy extrapolation of apparent mass has been proposed for the assay of waste drums containing Pu lumps in various random and biased spatial distributions and has been found to agree within 1–10% with the actual value with a maximum uncertainty of 8%. The method has been further validated at higher collimator widths and it has been demonstrated that an increase in collimator width from 5.1 to 10.3 cm increases the throughput of the present system without much of losing the accuracy.

Compressibility factor measurement and simulation of five high-temperature ultra-high-pressure dry and wet gases

Five groups of high-temperature ultra-high-pressure natural gas samples (two dry gases and three wet gases) are collected from oilfields in northwestern China. The compressibility factors (Z-factors with a maximum uncertainty of 0.005) of these samples at their reservoir temperatures and different pressures are determined using a (high-pressure) pressure–volume–temperature apparatus. The experimental results indicate that the Z-factors of these natural gases under reservoir conditions are considerably higher than those of conventional natural gases. Moreover, the Z-factors decrease as the pressure decreases within the high pressure ranges considered in this investigation. A simple thermodynamic model based on the Soave–Redlich–Kwong equation of state and newly established binary interaction correlations is proposed to simulate the Z-factors of the gas samples investigated herein. Meanwhile, the performances of four Z-factor prediction empirical correlations and the Groupe Européen de Recherches Gazières (GERE) model reported in literature are compared. It is found that the thermodynamic model proposed in this work exhibits the best prediction accuracy; results show that the average absolute deviations in the calculations of the Z-factors of five natural gas samples are only 0.7%, 2.1%, 1.81%, 0.44%, and 0.92%. Furthermore, the high prediction accuracy of this thermodynamic model is verified by comparing the 428 Z-factor experimental data points of high-temperature ultra-high-pressure natural gases reported in literature.

Quantum correlations and quantum-memory-assisted entropic uncertainty relation in two kinds of spin squeezing models

We investigate thermal quantum correlations and the entropic uncertainty relation in the presence of quantum memory under two kinds of two-qubit spin squeezing models, namely the one-axis twisting model and two-axis countertwisting model. We provide the analytical expressions of quantum correlations and the entropic uncertainty relation in the ground state for these two models and we find a simple relationship between quantum discord and entropic uncertainty. It is found that there is a fully anti-correlated relationship between quantum correlations and entropic uncertainty. Also, the maximal quantum correlation and minimal uncertainty can be achieved when the spin squeezing parameters are large enough. Accordingly, these results may be significant in practical goals in which the maximum quantum correlation and minimum uncertainty are required such as in quantum key distribution and quantum computing.

Experimental study of cross flow and lateral pressure drop in a 5 × 5 rod bundle with mixing vane spacer grid

Cross flow and lateral pressure drop downstream a split-type mixing vane spacer grid in a 5 × 5 rod bundle were experimentally measured by particle image velocimetry (PIV) and differential pressure transmitter at the sub-channel Reynolds number (Re) of 13200. The geometrical parameters of the 5 × 5 rod bundle is as the same diameter (D = 9.5 mm) and pitch (P = 12.6 mm) as the real fuel rods of a typical pressurized water reactor (PWR), with sub-channel hydraulic diameter (Dh) 11.78 mm. With the aid of matched index of refraction (MIR) technique of transparent fluorinated ethylene propylene (FEP) tubes and water, the PIV measurements of cross flow covering all sixteen inner-sub-channels were conducted for cross sections at 1Dh, 4Dh, 8Dh and 16Dh downstream the spacer grid. With detailed error and uncertainty analysis, the uncertainty of the turbulent statistics is mainly determined by the out of plane error and sampling number error. The maximum standard uncertainty of statistical quantities normalized by the bulk velocity is less than 1%. The characteristics of cross flow were mainly determined by the mixing vanes of spacer grid in rod bundle. The mixing vanes generate strong cross flow and drastic turbulence flow downstream the spacer grid, enhancing the cross flow mixing and turbulent mixing between sub-channels. The lateral pressure drop was measured at 1Dh, 2Dh, 3Dh, 4Dh, 5Dh, 6Dh, 8Dh, 10Dh, 12Dh, 14Dh, 16Dh, 18Dh and 20Dh. The relative uncertainty level of lateral pressure drop is between 0.7% and 7.0%. Downstream the spacer grid, the lateral pressure drop increases from 1Dh to 2Dh. After 3Dh, the lateral pressure drop decays in exponential way with distance from spacer grid. After 16Dh, the lateral pressure drop almost keeps constant.

Convective heat transfer on a flat target surface impinged by pulsating jet with an additional transmission chamber

A series of experimental tests are performed for the pulsating jet impingement heat transfer by varying the Reynolds number (5000 ≤ Re ≤ 15000), operation frequency (5 Hz ≤ f ≤ 40 Hz) and dimensionless nozzle-to-surface distance (2 ≤ H/d ≤ 10) while fixing the duty cycle as DC = 0.5. The maximum uncertainty in the measurement of Nusselt number is estimated to be about ±7%. Meanwhile, numerical simulations are performed to demonstrate the instantaneous flow field of the pulsating jet impingement. Particular attention is paid to examine the influence of transmission chamber on the pulsating jet impingement heat transfer. The results show that by using an additional transmission chamber, the pulsating jet impingement heat transfer is enhanced. For example, the circumferentially-averaged Nusselt number around the stagnation point (x/d ≤ 2) is increased up 8%~16% by the adding of a transmission chamber in related to the baseline case under Re = 10000 and H/d = 6. Due to the presence of transmission chamber, the exiting jet velocity profile at the orifice outlet is varied. In related to the baseline case, the transmission chamber makes the time-averaged ejecting velocity in the central zone increase but decrease in the edge zone. As the peak velocity in the central zone of orifice outlet is effectively increased by the use of transmission chamber, the jet impinging velocity approaching to the target surface is also strengthened, resulting in a stronger jet impingement in the vicinity of the stagnation point.

Reducing uncertainties in flood inundation outputs of a two-dimensional hydrodynamic model by constraining roughness

Abstract. The consideration of uncertainties in flood risk assessment has received increasing attention over the last 2 decades. However, the assessment is not reported in practice due to the lack of best practices and too wide uncertainty bounds. We present a method to constrain the model roughness based on measured water levels and reduce the uncertainty bounds of a two-dimensional hydrodynamic model. Results show that the maximum uncertainty in roughness generated an uncertainty bound in the water level of 1.26 m (90 % confidence interval) and by constraining roughness, the bounds can be reduced as much as 0.92 m.

Algorithm for carrying out a procedure for verification of a spectrophotometric method for analysis of solid-dosed dosage forms according to the requirements of SPHU 2.0

Aim . The increase in the pharmaceutical market of Ukraine of the range of medicines leads to stricter requirements for their quality. According to the requirements of international standards ISO, ICH, GMP, current legislation of Ukraine and the State Pharmacopoeia of Ukraine, generic drugs must be equivalent, and the analytical methods used for quality control, validated or verified. One of the available methods of analysis used both in pharmacy conditions and in quality control laboratories at enterprises and in independent control and analytical laboratories is absorption spectrophotometry in the ultraviolet and visible areas. Materials and methods. The method of absorption spectrophotometry in the ultraviolet and visible areas is used to quantify the active pharmaceutical ingredients in finished tablet dosage forms when the quantitative determination performed and when conducting pharmaco-technological tests, such as Dissolution and Uniformity of dosage units. Results. To use the method of absorption spectrophotometry for the quantitative evaluation of active pharmaceutical ingredients in finished drugs, it is necessary to verify the proposed methods and examine such validation characteristics as specificity, linearity, accuracy and precision of the proposed methods. At the same time, the uncertainty of the results of the analysis D As ,, expressed as a one-sided confidence interval for the probability of 95 %, and which consists of the uncertainty of sample preparation (D Sp ) and the uncertainty of the final analytical operation (D FAO ), must not exceed the maximum permissible total uncertainty of the analysis (maxD As ). Conclusions. The approaches of the State Pharmacopoeia of Ukraine to the methods for determining the quantitative content of active ingredients in tablets during the tests Quantitative determination, Dissolution, Uniformity of dosage units were studied. The procedure has been proposed for verifying methods for quantitative determination of manufactured drugs using absorption spectrophotometry according to the requirements of the 2nd edition of the State Pharmacopoeia of Ukraine

Practical methodology for in situ measurement of micro flow rates using laser diode absorption sensors

A laser diode-based flowmeter based on the infrared absorption method that can measure in situ micro flow rates from 0.2 to 20 ml h−1 was developed. A 1450 nm laser absorbed in water was irradiated to form a heated spot at 0 mm, and the temperature was measured upstream and downstream of the heated spot. The flow rate was measured by the temperature difference obtained by two diode lasers and photodetectors upstream and downstream of the heated spot. We measured the temperature profile of the flow rate by changing the temperature measurement position and the heating laser energy upstream and downstream of the heated spot, and compared the measurements with the simulation results. As the flow rate increased, the temperature profile shifted downstream, and the measured temperature upstream and downstream were analyzed according to the flow rate. The flow measurement range was adjusted according to the temperature measurement position. Increasing the energy of the heating laser also improved the measurement accuracy in the lower flow range. The developed flowmeter was calibrated by the gravimetric method, and the deviation and measurement uncertainty according to the flow rate were obtained. The maximum measurement uncertainty was 6.8% at a 1 ml h−1 flow rate, and the minimum measurement uncertainty was 1.78% at 8 ml h−1. Thus, it was confirmed that the flow rate can be measured through the temperature difference gauged using a simple diode laser set. Using the laser diode-based flowmeter developed in this study, one can measure the flow rate in situ without injecting contaminants, such as particles, for measurements without cutting the piping. In addition, it can be manufactured in a miniaturized form at a low cost, and thus, it can be used for multi-drug infusion analysis, semiconductor process monitoring, etc.

Optimal estimation of spectral surface reflectance in challenging atmospheres

Optimal Estimation (OE) methods can simultaneously estimate surface and atmospheric properties from remote Visible/Shortwave imaging spectroscopy. Simultaneous solutions can improve retrieval accuracy with principled uncertainty quantification for hypothesis testing. While OE has been validated under benign atmospheric conditions, future global missions will observe environments with high aerosol and water vapor loadings. This work addresses the gap with diverse scenes from NASA's Next Generation Airborne Visible Infrared Imaging Spectrometer (AVIRIS-NG) India campaign. We refine atmospheric models to represent variable aerosol optical depths and properties. We quantify retrieval accuracy and information content for both reflectance and aerosols over different surface types, comparing results to in situ and remote references. Additionally, we assess uncertainty of maximum a posteriori solutions using linearized estimates as well as sampling-based inversions that more completely characterize posterior uncertainties. Principled uncertainty quantification can combine multiple spacecraft data products while preventing local environmental biases in future global investigations.

True random coding for Brillouin optical correlation domain analysis

A new technology for Brillouin optical correlation domain analysis (BOCDA) based on true random codes has been proposed, theoretically simulated, and experimentally demonstrated with high spatial resolution. The spatial resolution of 3.9 cm over a 1.1 km single mode fiber is experimentally achieved by using true random codes with 3Gbit/s rate. The numerical simulation shows that the higher spatial resolution of 1 cm can be further obtained by utilizing true random codes with a higher code rate of 10Gbit/s. Additionally, the maximum uncertainty of the local Brillouin frequency shift is ± 1.1 MHz and the temperature coefficient is 1.15 MHz/℃.

Granularity-based surrogate-assisted particle swarm optimization for high-dimensional expensive optimization

Surrogate-assisted meta-heuristic algorithms have won more and more attention for solving computationally expensive problems over past decades. However, most existing surrogate-assisted meta-heuristic algorithms either require thousands of expensive exact function evaluations to obtain acceptable solutions, or focus on solving only low-dimensional expensive optimization problems. In this paper, we attempt to propose a new method to solve high-dimensional expensive optimization problems, in which the population will firstly be granulated into two subsets, i.e., coarse-grained individuals and fine-grained ones, then different approximation methods are proposed for each category, and finally a new infill criteria is adopted to select solutions that have maximum uncertainty among all coarse-grained individuals and that among all fine-grained individuals, and the solution that has minimal approximated fitness value, to be re-evaluated using the exact objective function. Experimental results comparing the proposed algorithm with a few state-of-the-art surrogate-assisted evolutionary algorithms on benchmark problems with 50 and 100 dimensions show that the proposed algorithm is able to achieve better results when solving high-dimensional multi-modal expensive problems with a limited budget on exact fitness evaluations.

Quantitative measurement of binary-component fuel vapor distributions via laser absorption and scattering imaging

An ultraviolet-visible laser absorption-scattering technique (UV-LAS) was developed for obtaining the evaporation characteristics of binary-component fuel spray. P-xylene and fluorobenzene were selected as the substitutes for low and high boiling points components, respectively, in a binary fuel spray. The molar absorption coefficients (MAC) of p-xylene and fluorobenzene at 266 nm wavelength were measured with relative uncertainty of 2.8% in a calibration system, which was designed to facilitate control of the mixture temperature and vapor concentration. UV-LAS was applied to a quantitative detection of vapor concentration distributions of each component in a binary-component fuel spray injected into a high-temperature and high-pressure constant volume chamber. A difference in spatial stratification of each component fuel in the spray due to their volatility difference was observed. An uncertainty estimation of UV-LAS for binary-component fuel spray was performed, and the results show that the maximum uncertainty is less than 9.8% in measurement of vapor mass.

PIV measurement of turbulent flow downstream of mixing vane spacer grid in 5×5 rod bundle

Axial and cross flow downstream a split-type mixing vane spacer grid in a 5×5 rod bundle are measured with particle image velocimetry (PIV) at sub-channel Reynolds number (Resc) of 6600, 13,200, 26,400 and 39,600. The cross flow in the sixteen inner sub-channels are obtained at five elevations, i.e. 3Dh, 5Dh, 10Dh, 15Dh and 20Dh downstream of the spacer grid. The axial flow measurement is conducted in a plane parallel to the bundle axis. The satisfactory convergence of turbulent statistics is achieved with the sampling number of 2000. The maximum standard uncertainty of statistical quantities normalized by the bulk velocity for all the test conditions is less than 0.6%. The flow characteristics and structures were determined by the mixing vanes located on the upper edge of support grids in rod bundle, and the flow downstream the spacer grid can be divided into the advection zone, the reorganization zone and the dumping zone. And the maximum lateral velocity decreases from 44% of the bulk velocity (Wb) at 3Dh to 16%Wb at 20Dh. The mixing vanes generate drastic turbulence flow downstream the spacer grid, and the lateral root mean square (RMS) fluctuating velocity decays in exponential way. The maximum lateral RMS fluctuating velocity decays rapidly from 20%Wb at 3Dh to 9%Wb at 20Dh. The maximum lateral Reynolds stress decreases from 0.6%Wb2 at 3Dh to 0.3%Wb2 at 20Dh. The normalized mean velocity and turbulent statistics show similarity for the Reynolds above 13,200, while the low Reynolds number effect at Re = 6600 is observed for the axial mean velocity and axial RMS fluctuating velocity.

Design and benchmarking of a low-cost shape sensing spar for in situ measurement of deflections in slender lifting surfaces in complex multiphase flows

Shape sensing is a means by which to infer or reconstruct the deflections experienced by a flexible body. These deflections can be clear indicators of the operating conditions of the structure itself. The work presented in this paper proposes a robust, inexpensive, and accurate method for the shape sensing of a cantilevered body using a first-generation shape sensing spar. The shape sensing spar is benchmarked with static point loads and unsteady distributed loads in the context of a flexible hydrofoil. Results reveal maximum measurement error uncertainties of 0.2 cm in bending and 0.49° in twisting using a sampling rate of 500 Hz, making the proposed method competitive with optical methods for steady state measurements, and more suitable than optical methods for dynamic measurements because of the high sampling rate. Moreover, the shape sensing spar provides a method for deflection measurement in complex multiphase flows where optical methods do not perform well. Future improvements and applications for the shape sensing spar are outlined.

CFD modelling of pump-around jet mixing tanks: a reliable model for overall mixing time prediction

ABSTRACT Over the past two decades or so, computational fluid dynamics (CFD) has been employed to predict overall mixing times inside jet mixing tanks instead of non-universal mixing time correlations obtained by experiments. However, the numerical methods for jet mixing tank simulations were not clearly tested and the discretization errors of the previous CFD models were not assessed. So, in this paper, the suitable turbulence model and numerical methods for pump-around jet mixing tank simulations were investigated. Further, the discretization errors of the present CFD models were estimated with the help of grid convergence index (GCI). The results revealed that the realizable k-epsilon model, SIMPLE, second order upwind, and first order implicit were proper turbulence model and numerical methods for pump-around jet mixing tank simulations. From GCI analyses, the maximum discretization uncertainty in overall mixing time of the present CFD models was about ±0.08 s.

Application of a lower-fidelity surrogate hydraulic model for historic flood reconstruction

Two dimensional hydraulic models are useful to reconstruct maximum discharges and uncertainties of historic flood events. Since many model runs are needed to include the effects of uncertain input parameters, a sophisticated 2D model is not applicable due to computational time. Therefore, this papers studies whether a lower-fidelity model can be used instead. The presented methodological framework shows that a 1D-2D coupled model is capable of simulating maximum discharges with high accuracy in only a fraction of the calculation time needed for the high-fidelity model. Therefore, the lower-fidelity model is used to perform the sensitivity analysis. Multiple Linear Regression analysis and the computation of the Sobol’ indices are used to apportion the model output variance to the most influential input parameters. We used the 1926 flood of the Rhine river as a case study and found that the roughness of grassland areas was by far the most influential parameter.

Low-Cost Online Contact Resistance Measurement of Power Connectors to Ease Predictive Maintenance

With the increasing use of sensors and wireless communication systems, predictive maintenance is acquiring more and more importance to assess the condition of in-service equipment. Predictive maintenance presents promising cost savings, as it allows minimizing unscheduled power systems faults, which can have very costly and catastrophic consequences. Early stage detection of power system failure requires acquiring, monitoring, and periodically analyzing the condition of the elements involved, such as high-voltage power connectors, since they are critical devices which are often located in key points of power systems. This paper proposes a low-cost online system to determine the contact resistance of high-voltage direct current (dc) and alternating current (ac) power connectors, to determine their health condition in order to apply a predictive maintenance plan. The contact resistance is considered as a reliable indicator of the connector’s health condition. However, it cannot be directly measured, and the applied strategy differs between dc and ac power systems. The experimental results show a maximum uncertainty of 4.5%, thus proving the accuracy and feasibility of the approach presented in this paper, since the proposed limit of acceptable resistance increase is 20%. This approach can also be applied to many other power systems’ elements.