Fitting Parameters Research Articles

Study of grain orientation effect on the corrosion behavior of biocompatible magnesium alloy Mg–2Zn-0.5Ca

In recent years, biocompatible magnesium alloys have garnered extensive attentions because of their wide applications in clinical medicine. Their excellent biocompatibility allows the avoidance of secondary surgeries for removal. However, magnesium-based biocompatible alloys are still suffering from some shortcomings such as rapid corrosion rate, causing limited service time. Among the factors that influence the corrosion resistance, the grain orientation (GO) is a primary factor influencing its corrosion behavior. Since the surface energy differs among various grains with different orientations, the corrosion sensitivity is anisotropic. Based on the 10T samples, we have established a functional relationship between the reciprocal of corrosion rate and the percentage of each grain orientation. The fitting parameters for the grain orientations of (0001), (1–100), and (11–20) are 0.133, 0.034, and −0.0287, respectively. This intuitively demonstrates that different grain orientations exhibit varying sensitivity to corrosion, with (0001) showing the highest corrosion resistance, while (11–20) has a negative impact on improving corrosion resistance. Furthermore, when we applied this formula to another set of 3T samples, we found that the calculated results matched well with the actual measurements, indicating that this formula has a certain degree of accuracy in quantifying the relationship between corrosion rate and grain orientation.(3T and 10T represent for the annealing treatment made at 400 °C for 3 and 10 min respectively.)

Global fit to b→cτν anomalies as of Spring 2024

Recently, several new experimental results of the test of lepton flavor universality (LFU) in B→D(*) semileptonic decays were announced: the first result of RD from the LHCb run 1 data, the first results of RD and RD* from the LHCb run 2 data, and the first result of RD* from the Belle II collaboration. Including these new data, a global analysis still prefers the violation of the LFU between the tau and light leptons. A new world average of the data from the , LHCb, Belle, and Belle II collaborations is RD=0.342±0.026 and RD*=0.287±0.012. Including this new data, we update a circumstance of the b→cτν¯ measurements and their implications for new physics (NP). Incorporating recent developments for the B→D(*) form factors in the Standard Model, we observe a 4.4σ deviation from the Standard Model prediction. Our updates also include model-independent NP formulas for the related observables and the global fittings of parameters for leptoquark scenarios as well as single NP operator scenarios. Furthermore, we show future potential to indirectly distinguish different NP scenarios with the use of the precise measurements of the polarization observables in B→D(*)τν¯ at the Belle II and the high-pT flavored-tail searches at the LHC. We also discuss an impact on the LFU violation in ϒ→l+l−. Published by the American Physical Society 2024

Radiation shielding transmission data for modern digital radiography.

Radiography is one of the most widely used x-ray imaging modalities. In National Council on Radiation Protection and Measurements (NCRP) Report No. 147, transmission data for radiographic systems were evaluated on those installed before 2000. For x-ray systems (except intraoral dental) manufactured on or after June 10, 2006, the U.S. required minimum half-value layer (HVL) was increased; for example, 2.9 (2.3) mm Al at 80kV, where the value in parenthesis denotes the earlier requirement before the above date. To calculate the transmission of the broad x-ray beam of modern digital radiography (DR) through shielding materials. X-ray beam HVLs on two DR systems (Agfa DR 600, GE Revolution XR/d) were measured in 10kV increments between 60 and 120kV, with a calibrated ionization chamber (Radcal model 10×5-60) and varying thickness of aluminum 1100 plates. Monte Carlo (Geant4) simulation was performed to calculate the transmission of broad x-ray beams through lead, concrete, gypsum, and steel, with x-ray HVLs matching those of the DR 600 at two beam filtrations (default, 1mm Al plus 0.1mm Cu added filtration). The transmission data were fitted to the Archer equation. HVLs on two DR systems with default beam filtration were consistent (median difference, 2.1%; maximum difference, 5.5%). An additional beam filtration option (1mm Al plus 0.1mm Cu) on the DR 600 substantially increased HVLs by 45.2%-61.2%. Transmission fitting parameters were provided for seven tube voltages (60-120kV) at two beam filtrations. This work presents transmission data for modern DR systems, indicating increased x-ray beam filtration compared to the primary x-ray beam in NCRP Report No. 147. The updated transmission data can enhance structural shielding evaluations at individual tube voltages or with a workload distribution.

Cosmology in f (R, T) modified gravity : unified dark matter and dark energy model constrained by current observations

The proposed cosmological model deals with modified Chaplygin gas (MCG) in f(R, T) = R + ξ(T) gravity, where R is the Ricci Scalar and T is the trace of energy-momentum tensor. The function ξ(T) is chosen as the linear combination of power law and logarithmic form under flat Friedmann-Lemaitre-Robertson-Walker space-time. The model is compatible with current observational data (Pantheon Type Ia Supernova) and confronts the deceleration and state parameters effectively. The model can predict the Big Rip in future infinity and can also tackle the difficulties related to the fine-tuning and the coincidence problem practically. Further, we have numerically solved the modified Friedmann equations in f(R, T) gravity and also performed a Markov Chain Monte Carlo analysis to obtain the best fit parameters of this current cosmological model. These best parameters are then used to compute the cosmographic parameters, i.e., the deceleration parameter, the jerk parameter and the snap parameter. Significantly, the cosmographic test has given valuable insights into the dynamics of the current cosmological model and also enriched us to understand about the cosmic evolution of the accelerated Universe. Additionally, the Statefinder diagnostics and O m diagnostics have provided deeper insights into the dynamics of the cosmic expansion and also provided information to distinguish between both the cosmological frameworks. Furthermore, these tests also reveal that at late times, the current model goes beyond the phantom region. Again, the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) have provided enough support for the current model under consideration, indicating that the present model exhibits a plausible explanation. However, the ΛCDM model has emerged with the lowest AIC value which suggests its relatively superior fit compared to the current model. Finally, our current model aligns well with several recent observations and unveils various intriguing features about the late time accelerated Universe.

Parameter estimation from an Ornstein-Uhlenbeck process with measurement noise.

We investigate the impact of noise on parameter fitting for an Ornstein-Uhlenbeck process, focusing on the effects of multiplicative and thermal noise on the accuracy of signal separation. To address these issues, we propose algorithms and methods that can effectively distinguish between thermal and multiplicative noise and improve the precision of parameter estimation for optimal data analysis. Specifically, we explore the impact of both multiplicative and thermal noise on the obfuscation of the actual signal and propose methods to resolve them. First, we present an algorithm that can effectively separate thermal noise with comparable performance to Hamilton Monte Carlo (HMC) methods, but with significantly improved speed. We then analyze multiplicative noise and demonstrate that HMC is insufficient for isolating thermal and multiplicative noise. However, we show that with additional knowledge of the ratio between thermal and multiplicative noise, we can accurately distinguish between the two types of noise when provided with a sufficiently large sampling rate or an amplitude of multiplicative noise that is smaller than the thermal noise. Thus, we demonstrate the mechanism underlying an otherwise counterintuitive phenomenon: when multiplicative noise dominates the noise spectrum, one can successfully estimate the parameters for such systems after adding additional white noise to shift the noise balance.

Effects of Bulgarian bag training on bio-motor fitness, physiological, haematological, and performance in young adult male Kabaddi players

Kabaddi demands high bio-motor fitness and physiological robustness in players. The Bulgarian Bag, known for its dynamic training potential, offers multi-planar movements to enhance strength, endurance, and coordination. However, its impact on Kabaddi players still needs to be explored. To assess the effects of Bulgarian Bag training (BBT) on bio-motor fitness, physiological, hematological, and performance measures in young adult Kabaddi players. A total of 30 participants were randomly assigned to either the BBT Group (BBTG) (n = 15; age = 20.73 ± 1.83 years; weight = 72.56 ± 7.27 kg; height = 175.20 ± 6.03 cm) or the active Control Group (CG) (n = 15; age = 20.80 ± 1.69 years; weight = 71.86 ± 4.75 kg; height = 171.46 ± 6.06 cm). The training intervention lasted 12 weeks and was conducted during the in-season period. All outcome parameters tests were conducted before and after the intervention, including agility (AG), explosive strength (ES), shoulder strength (SS), muscular strength (MS), resting heart rate (RHR), VO2max, red blood cells (RBC), white blood cells (WBC), hemoglobin (HG), and playing ability (PA). The ANCOVA analysis revealed significant between-group differences in all physical fitness measures at post-test. Specifically, the BBTG showed significant improvements in AG, ES, SS, MS, RHR, VO2Max, RBC, WBC, HG, and PA (d = 0.75 to 3.28; Δ0.50% to 16.37%). Moreover, the BBTG group significantly reduced resting heart rate (d = 0.75; Δ-3.31%). In contrast, no significant changes were reported in the Control Group (CG) between pre- and post-tests (d = 0.00 to 0.78; Δ-0.08% to 4.59%). Integrating BBTG into the training program of young adult male Kabaddi players yielded beneficial effects across multiple parameters of bio-motor fitness, physiological, hematological, and playing ability. The findings reveal the potential of BBTG as a valuable training method for enhancing Kabaddi performance and overall athletic conditioning. Keywords: Kabaddi Player, Bulgarian bag training, bio motor, physiological, haematological

POROELASTICITY AND ROCK PHYSICS TEMPLATES

Two common rock physics templates (RPTs) that are used to identify geological facies and fluid trends derived from well log or pre-stack inverted seismic data involve cross-plotting VP/VS ratio against acoustic impedance, IP (the product of P-wave velocity, VP, and density) and mu-rho against lambda-rho, where mu and lambda are the Lam矣oefficients extracted from P and S-wave velocity, called the LMR, or LambdaMuRho, method. Using well log examples from an Alberta gas well and a deeper North Sea oil well, we show how to superimpose constant mu-rho and lambda-rho curves on a VP/VS versus IP cross-plot, which produce orthogonal trends of stiffness or porosity (from mu-rho) and fluid saturation (from lambda-rho) that match the data trends reasonably well. We then consider the related technique of KMR, or KMuRho, where K represents bulk modulus, and show how to superimpose constant K-rho trends on a VP/VS versus IP cross-plot. Again, we get orthogonal trends of stiffness or porosity (from mu-rho) and fluid saturation (from K-rho), but the fit to our real data examples is less accurate than with LMR. Using Biot-Gassmann poroelasticity theory, we generalize the LMR and KMR approaches into a technique we call FMR (Fluid-Mu-Rho). In the FMR techniques we introduce two new fitting parameters, f and d, where f is a fluid term derived from Biot-Gassmann theory, and d is the dry rock VP/VS ratio squared. When we superimpose fluid trends from the FMR technique on our two well log datasets, and adjust the f and d parameters, we achieve accurate fits to the datasets. Finally, we apply the FMR technique to a seismic case study from the Gulf of Mexico. In an appendix, we compare the FMR technique to the empirical Curved Pseudo-Elastic impedance, or CPEI, and Pseudo-Elastic Impedance for Lithology, or PEIL, methods.

Direct extraction of optical constants of organic semiconductors in ultrastrongly coupled microcavities and their application in antireflection design for polariton devices.

The strongly bound Frenkel excitons in organic semiconductors enable strong or even ultrastrong exciton-photon coupling in room-temperature cavities, with the resulting polariton states typically resolved through reflectance measurements. This paper demonstrates that the distinct features of exciton and polariton modes in the reflectance spectra of strongly/ultrastrongly coupled organic microcavities can be effectively utilized to extract the optical constants and physical thickness of the embedded organic semiconductor. We investigate metal-clad microcavities based on two prototype conjugated polymers, poly[2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly(3-hexylthiophene) (P3HT), both exhibiting ultrastrong coupling characteristics. The (n,k) spectra and thickness of these polymer films are determined by fitting the normal incidence reflectance spectra of organic microcavities, using Kramers-Kronig transformation and transfer-matrix calculations with varying optical and thickness parameters. We also examine the individual effects of the main fitting parameters on the spectrum, establishing a close correlation with the underlying polariton properties. Moreover, we analyze the optical admittance at exciton and polariton modes to understand reflectance variations with different parameters, which facilitates precise control of optical properties at specific modes through cavity design. Finally, using the extracted optical constants of MDMO-PPV and P3HT, we propose optimized microcavity designs that exhibit antireflection at the lower polariton mode for potential luminescence and photodetection device applications.

Electromagnetic |GE/GM| ratios of hyperons at large timelike q2

In recent years, it has become possible to measure not only the magnitude of the electric (GE) and magnetic (GM) form factors of spin 12 baryons, but also to measure the relative phases of those quantities in the timelike kinematic region. Aiming to interpret present |GE/GM| data on hyperons of the baryon octet, as well as to predict future data, we present model calculations of that ratio for large invariant 4-momentum square q2 in the timelike region (q2>0). Without any further parameter fitting, we extend to the timelike region a covariant quark model previously developed to describe the kinematic spacelike region (q2≤0) of the baryon octet form factors. The model takes into account both the effects of valence quarks and the excitations of the meson cloud which dresses the baryons. This application to the timelike region assumes an approximation based on unitarity and analyticity that is valid only in the large q2 region. Using the recent data from BESIII we establish the regime of validity of this approximation. We report here that our results for the effective form factor (combination of |GE| and |GM|) are in good agreement with the data already for q2 values above 15 GeV2. In addition, a more conservative onset of the validity of the approximation is provided by the newly available |GE/GM| data which suggest that our predictions may be compared against data for q2≥ 20 GeV2. This is expected in the near future, when the range of the present measurements is expanded to the 20–50 GeV2 region.

Impact of Multicomponent Training Frequency on Health and Fitness Parameters in Postmenopausal Women: A Comparative Study.

Menopause induces physiological changes in women, including increased risks of obesity, cardiovascular diseases, and muscle loss, which can be mitigated by physical exercise. This study aimed to evaluate the effects of a 12-week multicomponent exercise programme, performed 2 or 3 days per week, on health and fitness parameters in postmenopausal women. Eighty-three postmenopausal women (aged 50-65 years) were randomly assigned to three groups: control group (CG, n = 27), 2 days/week exercise group (EG2, n = 28), and 3 days/week exercise group (EG3, n = 28). The intervention included strength, balance, aerobic, and flexibility exercises. Anthropometric measurements (body weight, BMI, waist-to-hip ratio, lean body mass, body fat percentage), lipid profile, and isometric strength were assessed pre- and post-intervention. Data were analysed using a repeated-measures ANOVA, with p < 0.05 considered significant. Significant reductions in body weight, BMI, and waist-to-hip ratio were observed in EG2 and EG3 compared to CG. Lean body mass increased significantly in both EG2 (p < 0.001, ES = 1.37) and EG3 (p < 0.001, ES = 1.50). EG3 showed a greater reduction in body fat percentage than EG2 (p = 0.049). Strength and balance improved significantly in both experimental groups compared to CG, with no significant differences between EG2 and EG3. EG3 also showed superior improvements in lipid profile compared to EG2 and CG. A multicomponent exercise programme, particularly with higher frequency (3 days per week), improves body composition, strength, balance, and lipid profile in postmenopausal women.

Characterization, modeling and prediction of foam-formed softwood fiber sound absorption

The transition towards building materials with low or negative carbon-dioxide footprint is a pressing topic in nowadays society. Materials for thermal and acoustic insulation are among those attracting a growing number of research publications. Commonly used materials in the building sector are mostly mineral wools which demand huge amounts of energy during production by melting sand or stone. Cellulose-based materials are a promising substitute for the current market leaders. These materials are able to reach negative carbon footprints due to low embodied energy and their ability to store carbon dioxide in buildings for decades. Predicting the sound absorption behavior prior to manufacturing can further improve their usability. This study delves into the prediction and characterization of wood-based pulp fiber foams and their acoustic properties. By comparing analytical models, semi-phenomenological models and experimental measurements the prediction of sound absorption based on fiber diameter and bulk density is evaluated. The findings reveal that refining a recent analytical model for natural fibers through parameter fitting to non-acoustic parameters yields improved accuracy in predicting sound absorption curves. While the accuracy declines towards higher densities, this work lays the groundwork to create environmentally sustainable sound absorbers with carefully tailored sound absorption properties.

Physical fitness, psychological characteristics, and game performance in youth male soccer players of different levels of competition

ABSTRACT This cross-sectional study examined the differences and associations regarding physical fitness, psychological characteristics, and game performance between elite (n = 64), sub-elite (n = 82), and non-elite (n = 97) youth male soccer players aged 16.2 ± 0.5 years. Physical fitness parameters were assessed using field tests, psychological characteristics were evaluated using validated questionnaires and technical – tactical data were recorded during a competitive soccer match using a multicamera, semiautomatic optical tracking system. Elite players demonstrated superior performance in cardiorespiratory fitness, countermovement jump (CMJ), 10 m sprint, and agility, compared to the sub-elite and the non-elite players. Also, the elite and sub-elite players had faster 40 m sprints than the non-elite players. Game performance was significantly better in the elite group than the other groups and was associated with coping with the adversity and coachability, tension-anxiety, anger-hostility, and fatigue-inertia subscales. Among the physical fitness parameters examined, only agility and CMJ were associated with game performance. In conclusion, elite youth soccer players performed significantly better in various physical fitness and psychological parameters and demonstrated a higher game performance indicator score compared to their sub-elite and non-elite peers. Results suggested that physical fitness and psychological parameters are essential predictors of game performance.

Accurate measurements of delayed neutron data for reactor applications: methodology and application to 235U(nth,f)

Large inconsistencies still exist in nuclear data libraries regarding the kinetic parameters of delayed neutron (DN) precursors. As an example, there is a 17% gap between ENDF-B/VIII.0 and JEFF-3.3 on the average lifetime T1/2 of DN precursors from thermal fission of 235U. This parameter is of major importance for reactivity predictions of nuclear reactors in nominal or accidental configurations. In this context, CEA is actively participating to the ALDEN project (Average number and Lifetime of DElayed Neutrons) which aims at providing the nuclear data community with new data sets of DN from thermal and fast neutron induced fission of various actinides. A dedicated experimental setup was designed and optimized for that purpose and is presented in this paper. It consists of a “long counter” detector containing 16 proportional counters filled with 3He, embedded in a high density polyethylene matrix. The detector surrounds a fissile target prepared in the form of a miniature fission chamber, containing a few hundreds of micro-grams of fissile material. This set-up is connected to fast and efficient neutron shutters that can produce step-irradiations of variable durations. The equations driving the DN counting following step-irradiations of the fissile target are established and discussed in the perspective of DN yield or group parameter measurement. A comprehensive analysis of the different steps of data reduction is detailed: dead time characterization, Region of Interest (ROI) determination, absolute and relative efficiency calibration, fission rate estimation, irradiation time and background determination, DN decay curve production and physical parameter fitting. Following a prototype experiment performed in 2018 at the PF1b cold neutron beam line of Institute Laue Langevin (ILL, Grenoble, France), we discuss here the analysis of two campaigns occurring in 2019 and 2021 in which significant improvements were achieved in terms of background minimization, counting statistics and fission rate determination. The achievements of this work are the measurement of the delayed neutron emission per fission for the thermal neutron induced fission of 235U, estimated at (1.625 ± 0.010) % and the group parameters leading to an estimated lifetime of T1/2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${T}_{1/2}$$\\end{document} = (8.87 ± 0.10) s. Those results are consistent with the values recommended by the IAEA/CRP work and they come with reduced uncertainties compared with previously published results.

Tunable annealing temperature for the structural, magnetic, optical, and dielectric characteristics of Mn0.5Zn0.5Ni0.5Fe1.5O4 nano-ferrite

The as-prepared Mn0.5Zn0.5Ni0.5Fe1.5O4 ferrite was prepared by the co-precipitation process and annealed at 300, 500, 900, and 1100 °C. The single-phase cubic spinel structure was confirmed by XRD patterns, Rietveld fitting, TEM imaging and several structural parameters, including crystalline size and lattice constant have been examined. The FTIR spectrum confirmed the main two absorption bands of tetrahedral and octahedral sites in ferrite, where the elastic parameters such as force constants and Debye temperature have been investigated. The saturation magnetization increases with the annealing temperature, while the energy band gap decreases with the annealing temperature, and also the ac conductivity decreases with annealing temperature.

High-intensity interval training vs. yoga in improving binge eating and physical fitness in inactive young females

Yoga is effective in binge eating disorder (BED) treatment, but it does not seem effective enough to improve low physical fitness. In contrast, high-intensity interval training (HIIT) is effective in improving physical fitness but has never been studied in the context of BED. In the study, 47 young inactive females with mild to moderate BED were recruited and randomly assigned to a HIIT group (HIIT), a Yoga group (YG), or a control group (CG; age, 19.47 ± 0.74, 19.69 ± 0.874, and 19.44 ± 0.63 years; BMI, 21.07 ± 1.66, 21.95 ± 2.67, and 20.68 ± 2.61 kg/m2, respectively). The intervention groups participated in 8-week specific exercises, while the CG maintained their usual daily activity. Before and after the training, participants were evaluated for BED using the binge eating scale (BES) and for physical fitness. The obtained data were compared within groups and between groups, and a correlation analysis between BES and physical fitness parameters was performed. After the training, the YG presented significant improvements in BES (− 20.25%, p = 0.006, ηp2 = 0.408), fat mass (FM, − 3.13%, p = 0.033, ηp2 = 0.269), and maximal oxygen consumption (VO2max, 11.51%, p = 0.000, ηp2 = 0.601), whereas the HIIT showed significant improvements in body weight (BW, − 1.78%, p = 0.006, ηp2 = 0.433), FM (− 3.94%, p = 0.033, ηp2 = 0.285), and BMI (− 1.80%, p = 0.006, ηp2 = 0.428), but not in BES. Comparisons between groups revealed that both HIIT and YG had significantly higher VO2max levels than CG (HIIT 12.82%, p = 0.006, ηp2 = 0.088; YG: 11.90%, p = 0.009, ηp2 = 0.088) with no difference between HIIT and YG. Additionally, YG presented significantly lower BES than both HIIT (15.45%, p = 0.02, ηp2 = 0.03) and CG (11.91%, p = 0.022, ηp2 = 0.03). In conclusion, Yoga is an effective treatment for BED, but HIIT is not, despite its high efficacy in improving physical fitness.

Binary Adsorption Equilibria of Three CO2+CH4 Mixtures on NIST Reference Zeolite Y (RM 8850) at Temperatures from 298 to 353 K and Pressures up to 3 MPa.

Adsorption equilibria of CO2, CH4, and their mixtures were measured on binderless pellets of NIST reference zeolite NaY (RM 8850) using a static gravimetric setup. The unary adsorption isotherms are reported at temperatures from 298 to 393 K up to a pressure of 3 MPa and compare favorably with independent results on RM 8850 powder. The competitive adsorption measurements were performed at temperatures from 298 to 353 K and up to 3 MPa for three premixed gas mixtures with CO2 molar feed compositions of 0.25, 0.50, and 0.75. The results constitute the first competitive adsorption dataset reported for any of the NIST reference materials. RM 8850 shows a strong selectivity for CO2 adsorption toward CH4. The experimental unary and binary adsorption isotherms are accurately modeled using the simplified statistical isotherm model (SSI). Notably, the agreement with the model improves only slightly (and within experimental uncertainties) when the whole dataset is used for parameter fitting as opposed to only using the unary data.

Spectral Properties of Suprathermal Protons Associated with Interplanetary Shocks from WIND/STICS Data

Here are analyzed 3D velocity distribution functions (VDFs) of protons in the suprathermal energy-per-charge (E/Q) domain of 6.2 to 223.1 keV/e, as observed by the WIND Suprathermal Ion Composition Spectrometer (WIND/STICS) between 1995 and 2019, upon passage of interplanetary (IP) shocks. “Suprathermal” designates energies above the bulk, “thermal” solar wind, including inner-source pickup ions, cometary ions, solar energetic particles, and suprathermal tail particles. Within the WIND/STICS measurements, here treated as a standalone data set, only 3D VDFs within 9 hr prior to and following the shock passage are selected, as identified by the Center for Astrophysics (CfA) Harvard Interplanetary Shock Database. These are subsequently averaged, first over the STICS field of view, then over 3 hr intervals in the 9 hr about the shock. The averages, with errors assuming Poisson statistics, are then fitted using the Levenburg–Marquardt nonlinear least squares technique to two simple, observationally suggested functions arising from diffusive shock acceleration (DSA) formalism: a power law in E/Q with spectral index (model I), and a power-law with exponential rollover having a cutoff in E/Q (model II). The first result is a comparison of upstream spectral indices, e-folding energies, and normalization constants with corresponding downstream values. The second is a comparison of fitted spectral indices against those given by measured CfA shock compression ratios and a comparison of fitted e-folding energies with those given by measured ratios and shock normal angles, per DSA-derived predictions. There is additionally a comparison between fitted parameters given by the two functional forms. Little agreement is found with values given by DSA.

Concentration calculation model for calibration of non-dispersive infrared gas detection system

Non-dispersive infrared (NDIR) gas detection systems have been extensively used for gas monitoring because they are considered the simplest approach with moderate sensitivity and fast response. Concentration calculation models for calibration are particularly important in NDIR gas detection systems because of the nonlinear relationship between the output voltage ratio and concentration. We propose a concentration calculation model with two fitting parameters for non-dispersive infrared gas detection systems, accounting for the fact that not all IR radiation that impinges upon the detector is absorbed by the gas and for the saturation effects in absorption peaks leading to the nonlinear relationship. Despite the small number of fitting parameters of the proposed concentration calculation model, it presents high quality curve fitting to experimental data. The performance of the proposed model is compared to that of other concentration calculation models.

Assessment of aluminium alloys’ formability by elevated temperature testing

Abstract This work presents an investigation of the warm formability of AA7075-T6 aluminium alloy sheets using both experimental and numerical methods. Forming limit diagrams (FLDs) can be created by plotting the failure criteria on a graph with two axes representing major and minor strains. Sheets with a grid can be used to quantify both large and minor strains. General techniques available for the grid involve regular patterns of circles in this experiment. Experiments were conducted at various temperature levels, including room temperature, 100, 120, 140, 160, and 180 °C, as well as different strain rates. The investigation has revealed a significant impact of temperature on formability, while the effect of forming speed is quite insignificant across the whole range studied. At an ageing temperature of 140 °C, the distribution of precipitates is evenly balanced, resulting in improved mechanical strength. To offer accurate numerical models for warm-forming processes, a proposed constitutive model is introduced for aluminium alloy sheets. The present model incorporates plastic anisotropy and the effects of temperature and strain rate dependence. An investigation was conducted on the stress-strain behaviour of thin sheets composed of AA7075-T6 aluminium alloy under elevated temperatures and different strain rates. The objective was to ascertain the appropriate fitting parameters. It was associated with ABAQUS finite element modelling. The recommended material model was utilized to build finite element models, which were subsequently compared to the experimental data. The findings obtained from simulated isothermal uniaxial tensile tests were compared to the empirical measurements. The models used in the tensile test accurately predicted the material’s mechanical response. The predicted failure location, punch forces, and strain distributions for all three forming processes were found to be in close agreement with the experimental results. During deep draw operation, the warm forming limit curves were utilized to precisely predict both the pierce depth at which failure occurs and the precise location where the failure initiates.

Superphot+: Real-time Fitting and Classification of Supernova Light Curves

Photometric classifications of supernova (SN) light curves have become necessary to utilize the full potential of large samples of observations obtained from wide-field photometric surveys, such as the Zwicky Transient Facility (ZTF) and the Vera C. Rubin Observatory. Here, we present a photometric classifier for SN light curves that does not rely on redshift information and still maintains comparable accuracy to redshift-dependent classifiers. Our new package, Superphot+, uses a parametric model to extract meaningful features from multiband SN light curves. We train a gradient-boosted machine with fit parameters from 6061 ZTF SNe that pass data quality cuts and are spectroscopically classified as one of five classes: SN Ia, SN II, SN Ib/c, SN IIn, and SLSN-I. Without redshift information, our classifier yields a class-averaged F 1-score of 0.61 ± 0.02 and a total accuracy of 0.83 ± 0.01. Including redshift information improves these metrics to 0.71 ± 0.02 and 0.88 ± 0.01, respectively. We assign new class probabilities to 3558 ZTF transients that show SN-like characteristics (based on the ALeRCE Broker light-curve and stamp classifiers) but lack spectroscopic classifications. Finally, we compare our predicted SN labels with those generated by the ALeRCE light-curve classifier, finding that the two classifiers agree on photometric labels for 82% ± 2% of light curves with spectroscopic labels and 72% ± 0% of light curves without spectroscopic labels. Superphot+ is currently classifying ZTF SNe in real time via the ANTARES Broker, and is designed for simple adaptation to six-band Rubin light curves in the future.