Precise Measurements Research Articles

Dynamic mechanical behaviors of foamed concrete using modified viscoelastic SHPB

This study aims to investigate the dynamic mechanical behaviors of foamed concrete (FC) utilizing a modified viscoelastic split Hopkinson Pressure Bar (VE-SHPB). The VE-SHPB proposed in this study enables impedance matching between bars and FC, enhancing measurement precision. Dynamic mechanical behaviors of FC with different densities (400, 700, 1000, 1300 kg/m3) under various incident pressure (0.2, 0.5, 0.8, 1.1 MPa) are examined using the VE-SHPB. The failure modes of FC are categorized into Spalling (Mode I), Disintegration (Mode II), and Comminution (Mode III) based on fracture states of post-impact. The mechanism of strain rate and density on failure mode, dynamic strength, dynamic increase factor (DIF), and energy consumption density are discussed. The results show that FC's dynamic mechanical properties increase with increasing strain rate, but present different strain rate sensitivities at different densities. The dynamic mechanical properties of FC are determined by both the pore structure and matrix properties. Notably, Mode II shows better ability of energy consumption, specifically FC with a density around 700 kg/m³ demonstrates higher energy absorption density.

Accuracy compensation method with the combined dissimilar measurement devices for enhanced measurement quality: a digital aircraft assembly technology

PurposeThe pivotal aspect of aircraft assembly lies in precise measurement accuracy. While a solitary digital measuring tool suffices for analytical and small surfaces, it falls short for extensive synthetic surfaces like aircraft fuselage panels and wing spars. The purpose of this study is to develop a “combined measurement method” (CMM) that enhances measurement quality and expands the evaluative scope, addressing the limitations posed by singular digital devices in meeting measurement requirements across various aircraft components.Design/methodology/approachThe study illustrated the utilization of the CMM by combining a laser tracker and a portable arm-measuring machine. This innovative approach is tailored to address the intricate nature and substantial dimensions of aircraft fuselage panels. The portable arm-measuring machine performs precise scans of panel components, while common points recorded by the laser tracker undergo coordinate conversion to reconstruct the fuselage panel’s shape. The research outlines the CMM’s measurement procedure and scrutinizes the data processing technique. Ultimately, the investigation yields a deviation vector matrix and chromatogram deviation distribution, pivotal in achieving enhanced measurement precision for the novel CMM device.FindingsThe use of CMM noticeably enhances fuselage panel assembly accuracy, concurrently reducing assembly time and enhancing efficiency compared to conventional measurement systems.Practical implicationsThe research’s practical implication lies in revolutionizing aircraft assembly by mitigating accuracy issues through the innovative digital CMM for aircraft synthetic structure type product (aircraft fuselage panel). This ensures safer flights, reduces rework and enhances overall efficiency in the aerospace industry.Originality/valueIntroducing a new aircraft assembly accuracy compensation method through digital combined measurement, pioneering improved assembly precision. Also, it enhances aerospace assembly quality, safety and efficiency, offering innovative insights for optimized aviation manufacturing processes.

Clock with 8×10^{-19} Systematic Uncertainty.

We report an optical lattice clock with a total systematic uncertainty of 8.1×10^{-19} in fractional frequency units, representing the lowest uncertainty of any clock to date. The clock relies on interrogating the ultranarrow ^{1}S_{0}→^{3}P_{0} transition in a dilute ensemble of fermionic strontium atoms trapped in a vertically-oriented, shallow, one-dimensional optical lattice. Using imaging spectroscopy, we previously demonstrated record high atomic coherence time and measurement precision enabled by precise control of collisional shifts and the lattice light shift. In this work, we revise the black body radiation shift correction by evaluating the 5s4d ^{3}D_{1} lifetime, necessitating precise characterization and control of many body effects in the 5s4d ^{3}D_{1} decay. Last, we measure the second order Zeeman coefficient on the least magnetically sensitive clock transition. All other systematic effects have uncertainties below 1×10^{-19}.

Unlocking Single Particle Anisotropy in Real‐Time for Photoelectrochemistry Processes at the Nanoscale

AbstractThe key to rationally and rapidly designing high‐performance materials is the monitoring and comprehension of dynamic processes within individual particles in real‐time, particularly to gain insight into the anisotropy of nanoparticles. The intrinsic property of nanoparticles typically varies from one crystal facet to the next under realistic working conditions. Here, we introduce the operando collision electrochemistry to resolve the single silver nanoprisms (Ag NPs) anisotropy in photoelectrochemistry. We directly identify the effect of anisotropy on the plasmonic‐assisted electrochemistry at the single NP/electrolyte interface. The statistical collision frequency shows that heterogeneous diffusion coefficients among crystal facets facilitate Ag NPs to undergo direction‐dependent mass transfer toward the gold ultramicroelectrode. Subsequently, the current amplitudes of transient events indicate that the anisotropy enables variations in dynamic interfacial electron transfer behaviors during photothermal processes. The results presented here demonstrate that the measurement precision of collision electrochemistry can be extended to the sub‐nanoparticle level, highlighting the potential for high‐throughput material screening with comprehensive kinetics information at the nanoscale.

Unlocking Single Particle Anisotropy in Real-Time for Photoelectrochemistry Processes at the Nanoscale.

The key to rationally and rapidly designing high-performance materials is the monitoring and comprehension of dynamic processes within individual particles in real-time, particularly to gain insight into the anisotropy of nanoparticles. The intrinsic property of nanoparticles typically varies from one crystal facet to the next under realistic working conditions. Here, we introduce the operando collision electrochemistry to resolve the single silver nanoprisms (Ag NPs) anisotropy in photoelectrochemistry. We directly identify the effect of anisotropy on the plasmonic-assisted electrochemistry at the single NP/electrolyte interface. The statistical collision frequency shows that heterogeneous diffusion coefficients among crystal facets facilitate Ag NPs to undergo direction-dependent mass transfer toward the gold ultramicroelectrode. Subsequently, the current amplitudes of transient events indicate that the anisotropy enables variations in dynamic interfacial electron transfer behaviors during photothermal processes. The results presented here demonstrate that the measurement precision of collision electrochemistry can be extended to the sub-nanoparticle level, highlighting the potential for high-throughput material screening with comprehensive kinetics information at the nanoscale.

L-DNA-Based Melt Analysis Enables Within-Sample Validation of PCR Products.

The melt analysis feature in most real-time polymerase chain reaction (PCR) instruments is a simple method for determining if expected or unexpected products are present. High-resolution melt (HRM) analysis seeks to improve the precision of melt temperature measurements for better PCR product sequence characterization. In the area of tuberculosis (TB) drug susceptibility screening, sequencing has shown that a single base change can be sufficient to make a first-line TB drug ineffective. In this study, a reagent-based calibration strategy based on synthetic left-handed (L)-DNA, designated LHRM, was developed to confirm validation of a PCR product with single base resolution. To test this approach, a constant amount of a double-stranded L-DNA melt comparator was added to each sample and used as a within-sample melt standard. The performance of LHRM and standard HRM was used to classify PCR products as drug-susceptible or not drug-susceptible with a test bed of nine synthetic katG variants, each containing single or multiple base mutations that are known to confer resistance to the first-line TB drug isoniazid (INH). LHRM achieved comparable classification to standard HRM relying only on within-sample melt differences between L-DNA and the unknown PCR product. Using a state-of-the-art calibrated instrument and multiple sample classification analysis, standard HRM was performed at 66.7% sensitivity and 98.8% specificity. Single sample analysis incorporating L-DNA for reagent-based calibration into every sample maintained high performance at 77.8% sensitivity and 98.7% specificity. LHRM shows promise as a high-resolution single sample method for validating PCR products in applications where the expected sequence is known.

The influence of tibial length on radiographic posterior tibial slope measurement: How much tibia do we need?

PurposeThe purpose of this study was to determine whether significant differences exist when comparing posterior tibial slope (PTS) measured using increasing lengths of the tibia to determine the anatomical axis. MethodsPatients with full-length weight-bearing tibial radiographs were retrospectively identified from 2014 to 2022 at a single institution. Patients were excluded if there was any previous history of lower extremity fracture or osteotomy. The anatomical axis of the tibia was determined using the full length of tibial radiographs, and the “reference PTS” was measured using this axis. Using the same radiograph, the PTS was measured using four different anatomical axes at standardized tibial lengths. While the center of the proximal circle remained constant at 5-cm below the tibial plateau, the center of the distal circle was drawn at four points: a) overlapping circles; b) 10-cm distal to the tibial plateau; c) 15-cm distal to the tibial plateau; d) half the length of the tibia, measured from the tibial plateau to the tibial plafond. Bivariate correlation and frequency distribution analysis (measurements >2-degrees from reference PTS) were performed between the reference PTS and PTS measured at each of the four other lengths. ResultsA total of 154 patients (39.8 ± 17.4 years old, 44.2% male) were included in the final analysis. Measurements at each of the four tibial lengths were all significantly different from the reference PTS (p < 0.001). The correlation strength improved with increasing tibial length (overlapping: R = 0.681, 10-cm: R = 0.821, 15-cm: R = 0.937, and half-tibia: R = 0.963). The number of PTS measurements >2-degree absolute difference from the reference PTS decreased with increasing tibial length (overlapping: 40.3%, 10-cm: 24.0%, 15-cm: 26.0%, and half-tibia: 18.8%). ConclusionAssessment of PTS is dependent on the length of the tibia utilized to obtain the anatomical axis. Accuracy and precision of PTS measurements improved with increasing length of tibia used to determine the anatomical axis. Study designCase series.

Integrating the controlled evaporation mixer with cavity ring-down spectroscopy for enhanced water vapor isotope calibration

Accurate measurement of water vapor isotopes (δ18O and δ2H) is fundamental for advancing our understanding of the hydrological cycle and improving hydrological model accuracy. This study introduces an innovative calibration methodology using a controlled evaporation mixer (CEM) for determining stable isotopic ratios in atmospheric water vapor via cavity ring-down spectroscopy. The CEM technique reliably produces a stable water vapor stream, crucial for enhancing the precision and accuracy of isotopic measurements. Its rapid adaptation to changes in water vapor concentration and compatibility with different water standards enhance calibration reliability. Demonstrated reproducibility in generating water vapor across a broad concentration range from 900 to over 25,000 ppmv, coupled with a substantial reduction in memory effects, makes this approach highly effective in both laboratory and field settings. This calibration advancement greatly enhances research capabilities for continuous atmospheric water vapor analysis, providing deeper insights into hydrological processes and atmospheric dynamics.

Optical Biometry versus Ultrasound A-scan in Measuring Anterior Chamber Depth, Axial Length, and Lens Thickness in Patients Undergoing Cataract Surgery

Ocular biometry measurements use ultrasonography and optical biometry, offering high precision for noninvasive intraocular distance measurement in cataract surgery. This study aims to Compare agreement values between an optical biometry machine and an ocular ultrasound-based biometry device for axial length, anterior chamber depth, and lens thickness measurements. A study enrolled 64 eyes of 42 patients scheduled for cataract surgery at Benghazi Teaching Eye Hospital, Libya, from January 1st to February 1st, 2024. Patients' medical and ocular histories were taken, and slit lamp examinations were conducted. All eyes with visual impairment and good fixation were included. Axial length, anterior chamber depth, and lens thickness were measured using Aladdin optical biometer and an ellex eye-cubed ultrasonic contact biometer. The study involved 64 eyes with a mean age of 64.36 years, The most common type of cataract was posterior subcapsular cataract [46.9%], nuclear cataract [14.1%], and cortical cataract [14.1%]. Combined cataracts were also present in 31.3% of the participants. The ICC analysis showed a strong agreement [0.976] between the two measurement devices in assessing axial length. difference in measurements of the mean anterior chamber depth. ICC showed a high level of agreement between the two methods [0.545]. There was no significant difference in lens thickness as measured by optical biometry and A-scan ultrasound, with a medium positive correlation between lens thickness measurement by the two devices [P&lt;0.001]. The interclass correlation further supported these findings, with a strong correlation between lens thickness and cataract development [r = 0.753]. The study reveals consistency in the measurements between optical and ultrasound biometry, highlighting the need for future research, to address limitations like small sample size and potential biases.

Monitoring tides, currents, and waves along coastal habitats using the Mini Buoy

AbstractIntertidal habitats are shaped by the actions of tides and waves which are difficult to monitor in shallow water. To address this challenge, the “Mini Buoy” and associated open‐source App were recently developed for the low‐cost and long‐term monitoring of tidal inundation and current velocities simultaneously. The Mini Buoy is a bottom‐mounted float that measures tilt to infer near‐bed hydrodynamics. Here, we present significant updates to the Mini Buoy and App. Two new Mini Buoy designs were calibrated: the “Pendant” that requires minimal assembly for deployment, and the “B4+” that can also measure wave orbital velocity. Comparisons against industry‐standard water‐level and velocity sensors deployed in the field showed that each new design was effective at detecting tidal inundation (overall accuracy of 86–97%) and current velocities (R2 = 0.73–0.91; accuracies of ± 0.14–0.22 m s−1; detection limits between 0.02 and 0.8 m s−1). The B4+ could reasonably measure wave orbital velocities (R2 = 0.56; accuracies of ± 0.18 m s−1; detection limits between 0.02 and 0.8 m s−1). Reducing the sampling rate to prolong survey durations did not markedly reduce the precision of velocity measurements, except in the original Mini Buoy design (uncertainty increased by ± 2.11 m s−1 from 1 to 10 s sampling). The updated App enhances user experience, accepts data from any Mini Buoy design, is suitable for generic use across any tidal setting, and presents multiple options to understand and contrast local hydrodynamic regimes. Improvements to the Mini Buoy designs and App offer greater opportunities in monitoring hydrodynamics for purposes including ecosystem restoration and flood risk management.

Entanglement-enhanced quantum metrology: From standard quantum limit to Heisenberg limit

Entanglement-enhanced quantum metrology explores the utilization of quantum entanglement to enhance measurement precision. When particles in a probe are prepared into a suitable quantum entangled state, they may collectively accumulate information about the physical quantity to be measured, leading to an improvement in measurement precision beyond the standard quantum limit and approaching the Heisenberg limit. The rapid advancement of techniques for quantum manipulation and detection has enabled the generation, manipulation, and detection of multi-particle entangled states in synthetic quantum systems such as cold atoms and trapped ions. This article aims to review and illustrate the fundamental principles and experimental progresses that demonstrate multi-particle entanglement for quantum metrology, as well as discuss the potential applications of entanglement-enhanced quantum sensors.

Sensitivity Response Analysis of Optical Surface Monitoring Systems Using the Fitzpatrick Scale: A Phantom Study

PurposeOptical Surface Monitoring systems (OSMS) have gained substantial attention in modern radiotherapy, specifically in the context of Surface Guided Radiation Therapy (SGRT) which offers real-time patient surface monitoring, ensuring accurate and effective radiotherapy treatments. The aim of this paper is to evaluate the OSMS camera sensitivity towards different skin tones, categorized according to the Fitzpatrick scale, a universal classification of human skin tones, using a phantom. Methods and MaterialThe study utilized Catalyst and SentinelTM OSMS systems (C-Rad, Uppsala, Sweden). The Alderson RANDO Female Pelvis phantom, located at the isocenter in CT simulation and treatment rooms, served as an experimental subject. Eighteen skin tone matching cotton cloths, selected based on Von Luschan's chromatic and Fitzpatrick scales, were wrapped around the phantom for sensitivity evaluation. Camera sensitivity was optimized by adjusting threshold/gain (100-600%) and integration time during individual scans in both rooms. Temporal response analysis spanned two months, with sixteen measurements for each OSMS taken in varying light conditions. ResultsThe OSMS systems successfully detected the surface of cloth-covered phantoms with varying mean (standard deviation) integration times: 550 (34) to 950 (43) μs for the Sentinel system and 2300 (71) to12000 (400) μs for the Catalyst system. The sensitivity parameters differed for each skin tone, with lighter skin requiring shorter integration times and gain/threshold values. Darker skin tones necessitated higher parameters for optimal surface images. The reliability of the systems declined with excessive parameters, leading to noise and compromised accuracy in patient positioning. ConclusionsOptimized sensitivity parameters tailored to individual skin tones are crucial for effective real-time patient surface monitoring in radiation therapy, as variations in skin colour can affect the accuracy of measurements. The precision of skin colour measurements in OSMS relies on carefully adjusting camera sensitivity parameters. However, careful consideration is essential, as larger values are required for darker skin tones, compromising reliability. This suggests the need for exploring alternative image guidance methods for patients with darker skin tones.

Comparative analysis of AnaLig Sr01 and Sr Resin methods for 210Pb determination in tobacco using TriCarb 3100 TR spectrometry: a statistical approach to accuracy and efficiency

This study aims to statistically compare two methods for determining 210Pb in tobacco: the molecular recognition sorbent method (AnaLig Sr01) and the extraction chromatography sorbent method (Sr Resin). The TriCarb 3100 TR liquid scintillation spectrometer was used to measure and determine 210Pb activity in the tobacco solution. Statistical analysis confirmed the accuracy and precision of the 210Pb measurements, with high detection efficiencies of 82% for both AnaLig Sr01 and Sr Resin. The linear model demonstrated that the residuals followed the Gaussian model, without any autocorrelation or trend. Paired t tests showed consistent results across all methods, and all solid-phase extraction methods proved efficient for 210Pb separations in tobacco samples. These findings provide support for the suitability of both methods and lay a foundation for future articles on tobacco and cigarette samples.

Evaluation and clinical application of a bracketing calibration-based isotope dilution liquid chromatography-tandem mass spectrometry candidate reference measurement procedure for serum theophylline.

A candidate reference measurement procedure (RMP) for serum theophylline via isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. With a single-step precipitation pretreatment and a 6-min gradient elution, the method achieved baseline separation of theophylline and its analogs on a C18-packed column. A bracketing calibration method was used to ensure repeatable signal intensity and high measurement precision. The intra-assay and inter-assay imprecisions were 1.06%, 0.84%, 0.72% and 0.47%, 0.41%, 0.25% at concentrations of 4.22 µg/mL (23.40 µmol/L), 8.45 µg/mL (46.90 µmol/L), and 15.21 µg/mL (84.43 µmol/L), respectively. Recoveries ranged from 99.35 to 102.34%. The limit of detection (LoD) was 2 ng/mL, and the lowest limit of quantification (LLoQ) was 5 ng/mL. The linearity range extended from 0.47 to 60 µg/mL (2.61-333.04 µmol/L). No ion suppression and carry-over (< 0.68%) were observed. The relative bias for this candidate RMP that participated in 2023 External Quality Control for Reference Laboratories (RELA) conducted by the International Federation of Clinical Chemistry (IFCC) was within a range of 0.17 to 0.93%. Furthermore, two clinical immunoassay systems were compared with this candidate RMP, demonstrating good correlations. The results of the Trueness Verification Plan indicate significant differences among routine systems, highlighting the need for standardization efforts. The developed candidate RMP for serum theophylline serves as a precise reference baseline for standardizing clinical systems and assigning values to reference materials.

A Generalized Objective Function for Computer Adaptive Item Selection

AbstractComputer adaptive testing (CAT) is an increasingly common mode of test administration offering improved test security, better measurement precision, and the potential for shorter testing experiences. This article presents a new item selection algorithm based on a generalized objective function to support multiple types of testing conditions and principled assessment design. The generalized nature of the algorithm permits a wide array of test requirements allowing experts to define what to measure and how to measure it and the algorithm is simply a means to an end to support better construct representation. This work also emphasizes the computational algorithm and its ability to scale to support faster computing and better cost‐containment in real‐world applications than other CAT algorithms. We make a significant effort to consolidate all information needed to build and scale the algorithm so that expert psychometricians and software developers can use this document as a self‐contained resource and specification document to build and deploy an operational CAT platform.

Poster 105: MRI Demonstrates Similar Diagnostic Value to MR Arthrogram for Determining Labral Tear Extent up to 2 Weeks Following Shoulder Dislocation

Objectives: The aim of this study was to determine the comparative accuracy and precision of routine Magnetic Resonance Imaging (MRI) versus magnetic resonance (MR) arthrogram in measuring labral tear size as function of time from shoulder dislocation, and to identify a time threshold after which MR arthrogram supersedes MRI in diagnostic utility. Methods: We retrospectively evaluated consecutive patients who underwent primary arthroscopic labral repair between 2012 and 2021 and completed a preoperative MRI or MR arthrogram of the shoulder within 60 days of injury, and subsequently underwent arthroscopic repair within 6 months of imaging. Arthroscopic labral tear size and location was used as standard comparison. Three musculoskeletal radiologists independently interpreted tear extent using clock-face convention. Accuracy and precision of MR labral tear measurements were defined by location and size of the tear, respectively. Accuracy and precision were compared between MRI and MR arthrogram, as a function of time from dislocation. Results: Thirty-two MRI and 65 MR arthrogram (total n=97) were independently assessed by radiologists. Multivariate analysis demonstrated that intraoperative tear size, early imaging, and arthrogram status were associated with increased MR accuracy and precision (p&lt;0.05). Ordering surgeons preferred arthrogram for delayed imaging (p=0.018). For routine MRI, error in accuracy increased by 3.4° per day and error in precision increased by 2.3° per day (p&lt;0.001) from time of injury. MR arthrogram, however, was not temporally influenced (Figure 1). Significant loss of accuracy and precision of routine MRI compared to MR arthrogram occurs at 2 weeks after acute shoulder dislocation. Conclusions: For determining shoulder labral tear size after acute dislocation, routine MRI has similar diagnostic value for measuring labral tear extent as MR arthrogram up to approximately 2 weeks postacute shoulder dislocation, after which it significantly loses accuracy and precision, possibly due to resolving posttraumatic effusion. MR arthrogram accuracy and precision were not temporally influenced.

Mass calibration of DES Year-3 clusters via SPT-3G CMB cluster lensing

We measure the stacked lensing signal in the direction of galaxy clusters in the Dark Energy Survey Year 3 (DES Y3) redMaPPer sample, using cosmic microwave background (CMB) temperature data from SPT-3G, the third-generation CMB camera on the South Pole Telescope (SPT). Here, we estimate the lensing signal using temperature maps constructed from the initial 2 years of data from the SPT-3G 'Main' survey, covering 1500 deg2 of the Southern sky. We then use this lensing signal as a proxy for the mean cluster mass of the DES sample. The thermal Sunyaev-Zel'dovich (tSZ) signal, which can contaminate the lensing signal if not addressed, is isolated and removed from the data before obtaining the mass measurement. In this work, we employ three versions of the redMaPPer catalogue: a Flux-Limited sample containing 8865 clusters, a Volume-Limited sample with 5391 clusters, and a Volume&Redshift-Limited sample with 4450 clusters. For the three samples, we detect the CMB lensing signal at a significance of 12.4σ, 10.5σ and 10.2σ and find the mean cluster masses to be M 200m = 1.66±0.13 [stat.]± 0.03 [sys.], 1.97±0.18 [stat.]± 0.05 [sys.], and 2.11±0.20 [stat.]± 0.05 [sys.]×1014 M⊙, respectively. This is a factor of ∼ 2 improvement relative to the precision of measurements with previous generations of SPT surveys and the most constraining cluster mass measurements using CMB cluster lensing to date. Overall, we find no significant tensions between our results and masses given by redMaPPer mass-richness scaling relations of previous works, which were calibrated using CMB cluster lensing, optical weak lensing, and velocity dispersion measurements from various combinations of DES, SDSS and Planck data. We then divide our sample into 3 redshift and 3 richness bins, finding no significant discrepancies with optical weak-lensing calibrated masses in these bins. We forecast a 5.7% constraint on the mean cluster mass of the DES Y3 sample with the complete SPT-3G surveys when using both temperature and polarization data and including an additional ∼ 1400 deg2 of observations from the 'Extended' SPT-3G survey.

Model-based Roentgen Stereophotogrammetric Analysis (RSA) of polyethylene implants

Model-based Roentgen Stereophotogrammetric Analysis (RSA) is able to measure the migration of metallic prostheses with submillimeter accuracy through contour-detection and 3D surface model matching techniques. However, contour-detection is only possible if the prosthesis is clearly visible in the radiograph; consequently Model-based RSA cannot be directly used for polymeric materials due to their limited X-ray attenuation; this is especially clinically relevant for all-polyethylene implants. In this study the radiopacity of unicompartmental Ultra-High Molecular Weight Polyethylene (UHMWPE) knee bearings was increased by diffusing an oil-based contrast agent into the surface to create three different levels of surface radiopacity. Model-based RSA was performed on the bearings alone, the bearings alongside a metallic component held in position using a phantom, the bearings cemented into a Sawbone tibia, and the bearings at different distances from the femoral component. For each condition the precision and accuracy of zero motion of Model-based RSA were assessed. The radiopaque bearings could be located in the stereo-radiographs using Model-based RSA an accuracy comparable to metallic parts for translational movements (0.03 mm to 0.50 mm). For rotational movements, the accuracy was lower (0.1∘ to 3.0∘). The measurement accuracy was compared for all the radiopacity levels and no significant difference was found (p=0.08). This study demonstrates that contrast enhanced radiopaque polyethylene can be used for Model-based RSA studies and has equivalent translational measurement precision to metallic parts in the superior-inferior direction.

Euclid preparation

We investigate the accuracy of the perturbative galaxy bias expansion in view of the forthcoming analysis of the Euclid spectroscopic galaxy samples. We compare the performance of a Eulerian galaxy bias expansion using state-of-the-art prescriptions from the effective field theory of large-scale structure (EFTofLSS) with a hybrid approach based on Lagrangian perturbation theory and high-resolution simulations. These models are benchmarked against comoving snapshots of the flagship I N-body simulation at z = (0.9, 1.2, 1.5, 1.8), which have been populated with Hα galaxies leading to catalogues of millions of objects within a volume of about 58 h−3 Gpc3. Our analysis suggests that both models can be used to provide a robust inference of the parameters (h, ωc) in the redshift range under consideration, with comparable constraining power. We additionally determine the range of validity of the EFTofLSS model in terms of scale cuts and model degrees of freedom. From these tests, it emerges that the standard third-order Eulerian bias expansion – which includes local and non-local bias parameters, a matter counter term, and a correction to the shot-noise contribution – can accurately describe the full shape of the real-space galaxy power spectrum up to the maximum wavenumber of kmax = 0.45 h Mpc−1, and with a measurement precision of well below the percentage level. Fixing either of the tidal bias parameters to physically motivated relations still leads to unbiased cosmological constraints, and helps in reducing the severity of projection effects due to the large dimensionality of the model. We finally show how we repeated our analysis assuming a volume that matches the expected footprint of Euclid, but without considering observational effects, such as purity and completeness, showing that we can get constraints on the combination (h, ωc) that are consistent with the fiducial values to better than the 68% confidence interval over this range of scales and redshifts.

Development of new calibrating material for luminescence spectrometer from Eu3+ doped aluminum sodium calcium borate glass

The calibration standards are formulated to correct emissions spectra and systematically monitor sensitivity fluctuations in luminescence spectrometers. This study outlines the development of luminescence calibration standards utilizing glass doped with lanthanide ions, specifically focusing on Eu3+ ions chosen for their robust emission properties. Glasses composed of aluminum calcium sodium borate doped with Eu3+ ions were prepared using the melt-quenching technique, with varying compositions of 20Al2O3–20CaO–20Na2O–(40–x)B2O3–xEu2O3 (where x = 0.0, 0.5, 1.0, 3.0, 5.0, and 7.0 mol%). The intense red emission around 615 nm through the 5D0 to 7F2 transition of Eu3+ was detected. To ensure measurement reliability, this study conducted measurements under four different stimulations: ultraviolet–visible light (photoluminescence), X–ray (radioluminescence), proton (protonluminescence), and electron (cathodoluminescence), verifying consistent peak positions. The findings from this study validate the potential of aluminum sodium calcium borate glasses doped with Eu3+, particularly those containing 3.0 mol% of Eu2O3, as effective calibration materials for luminescence spectrometers. This highlights their capability for accurate and consistent calibration, emphasizing their importance in maintaining measurement precision in the luminescence spectrometer.