Influence of training status on cardiac and vascular functioning in young recreational and competitive male rowers.

Introduction: The aim of the study was to investigate the influence of training status on cardiovascular function in young male recreational and competitive rowers. Methods: Ejection duration in percentage to the heart rate period (ED%), subendocardial viability ratio (SEVR), augmentation index at 75 bpm (AIx75) and carotid to femoral pulse wave velocity (cf-PWV) of competitive rowers (CR) (age 17.6 ± 4.1 years), recreational rowers (RR) (age 16.7 ± 2.70 years) and athletes practicing other recreational sports (ORS) (age 15.3 ± 1.4 years) were assessed. Results: ED% was lower in CR compared to ORS (31.9 ± 3.9% vs. 38.4 ± 4.8%; p = 0.026) and cf-PWV was higher in CR compared to ORS (5.5 ± 1.0 m/s vs. 4.7 ± 0.5 m/s; p = 0.032). SEVR was higher in CR compared to RR and ORS (165.8 ± 33.7% vs. 127.4 ± 30.4% and 128.3 ± 27.8%; p = 0.022) and AIx75 was lower in CR compared to RR and ORS (-15.7 ± 8.6% vs. 1.2 ± 9.9% and 1.5 ± 9.1; p = 0.001). Discussion: Healthy, young competitive male rowers reported higher myocardial performance and better cardiovascular health than recreational athletes. Interpretations of cf-PWV in competitive rowers should be performed alongside other cardiovascular indicators.

Strong Noise Rejection in VLC Links under Realistic Conditions through a Real-Time SDR Front-End.

One of the main challenges in the deployment of visible light communication (VLC) in realistic application fields, such as intelligent transportation systems (ITSs), is represented by the presence of large background noise levels on top of the optical signal carrying the digital information. A versatile and effective digital filtering technique is, hence, crucial to face such an issue in an effective way. In this paper, we present an extensive experimental evaluation of a complete VLC system, embedding a software-defined-radio (SDR)-based digital signal processing (DSP) filter stage, which is tested either indoors, in the presence of strong artificial 100-Hz stray illumination, and outdoors, under direct sunlight. The system employs low-power automotive LED lamps, and it is tested for baud rates up to 1 Mbaud. We experimentally demonstrate that the use of the DSP technique improves 10× the performance of the VLC receiver over the original system without the filtering stage, reporting a very effective rejection of both 100-Hz and solar noise background. Indoors, the noise margin in the presence of strong 100-Hz noise is increased by up to 40 dB, whilst in the outdoor configuration, the system is capable of maintaining error-free communication in direct sunlight conditions, up to 7.5 m, improving the distance by a factor of 1.6 compared to the case without filtering. We believe that the proposed system is a very effective solution for the suppression of various types of noise effects in a large set of VLC applications.

Characterization of noise regimes in mid-IR free-space optical communication based on quantum cascade lasers.

The recent development of Quantum Cascade Lasers (QCLs) represents one of the biggest opportunities for the deployment of a new class of Free Space Optical (FSO) communication systems working in the mid-infrared (mid-IR) wavelength range. As compared to more common FSO systems exploiting the telecom range, the larger wavelength employed in mid-IR systems delivers exceptional benefits in case of adverse atmospheric conditions, as the reduced scattering rate strongly suppresses detrimental effects on the FSO link length given by the presence of rain, dust, fog, and haze. In this work, we use a novel FSO testbed operating at 4.7 µm, to provide a detailed experimental analysis of noise regimes that could occur in realistic FSO mid-IR systems based on QCLs. Our analysis reveals the existence of two distinct noise regions, corresponding to different realistic channel attenuation conditions, which are precisely controlled in our setup. To relate our results with real outdoor configurations, we combine experimental data with predictions of an atmospheric channel loss model, finding that error-free communication could be attained for effective distances up to 8 km in low visibility conditions of 1 km. Our analysis of noise regimes may have a key relevance for the development of novel, long-range FSO communication systems based on mid-IR QCL sources.

The Role of Bidirectional VLC Systems in Low-Latency 6G Vehicular Networks and Comparison with IEEE802.11p and LTE/5G C-V2X.

In this paper, we present very recent results regarding the latency characterization of a novel bidirectional visible light communication (VLC) system for vehicular applications, which could be relevant in intelligent transportation system (ITS) safety applications, such as the assisted and automated braking of cars and motorbikes in critical situations. The VLC system has been implemented using real motorbike head- and tail-lights with distances up to 27 m in a realistic outdoor scenario. We performed a detailed statistical analysis of the observed error distribution in the communication process, assessing the most probable statistical values of expected latency depending on the observed packet error rate (PER). A minimum attainable observed round-trip latency of 2.5 ms was measured. Using our dataset, we have also estimated the probability to receive correctly a message with a specific average latency for a target PER, and we compare it to the ultra-reliable low-latency (URLL) 5G communications service. In addition, a mobility model is implemented to compare the VLC and radio frequency (RF) technologies (IEEE802.11p, LTE, 5G) to support an automated braking systems for vehicles in urban platooning.

Oxygen uptake efficiency slope in healthy normal weight young males: an applicable framework for calculation and interpretation.

Background: The oxygen uptake efficiency slope (OUES) is considered a reliable indicator of cardiorespiratory fitness in young and clinical populations who cannot achieve maximal effort during a graded exercise test. However, OUES accuracy depends on the data points used for its calculation and it is still not clear if the submaximal OUES can accurately assess CRF in healthy young males. Objective: We investigated the association between peak oxygen uptake and peak and submaximal OUES, and the agreement between submaximal OUES and peak OUES in male adolescents and young adults. Methods: In this cross-sectional, observational study, fifty normal weight healthy participants (age 14-22 years, peak oxygen uptake 43.8 ± 7.3 mL·min-1·kg-1) performed a graded exercise test on a cycle ergometer and pulmonary gas exchange was assessed using breath-by-breath analysis. Peak oxygen uptake, and oxygen consumption at the aerobic and at the anaerobic threshold were determined as the 30-s average of the oxygen consumption values. Peak OUES (up to peak) and submaximal OUES (up to the aerobic and anaerobic thresholds) were calculated from the logarithmic relation between oxygen consumption and pulmonary ventilation. Results: Very strong correlations were observed between peak oxygen uptake and peak OUES (r = 0.80-0.88) while fair-to-very strong correlations were observed between the peak oxygen uptake and the two submaximal OUES (r = 0.32-0.81). The level of agreement between peak OUES and OUES up to the anaerobic threshold (r = 0.89-0.93; Typical percentage error 6%; Intraclass correlation coefficient = 0.89-0.93) was greater than the one between the peak oxygen uptake with OUES up to the aerobic threshold (r = 0.39-0.56; Typical percentage error 15%; Intraclass correlation coefficient = 0.38-0.56). Conclusions: . The peak OUES is a better indicator of aerobic fitness than the OUES up to the anaerobic threshold in healthy, young males. The OUES up to the anaerobic threshold is a valid alternative to peak OUES.

Central arterial stiffness, wave reflection, and heart rate variability following 4-week high-intensity resistance training intervention in young active women.

PURPOSE: Arterial stiffness, expedited wave reflection, and autonomic dysfunction are risk factors for cardiovascular disease, which is the leading cause of death in women in the United States. Evaluation of the effects of resistance training on these factors has been inconclusive, and even less is known about the effects of high-intensity resistance training (HIRT). This study evaluated the effects of a 4-week HIRT intervention on central arterial stiffness, wave reflection, and heart rate variability in young healthy and active women. METHODS: 9 women were recruited and underwent a 4-week control period followed by the intervention. Measurements were recorded pre-control, post-control/pre-intervention, and post-intervention. RESULTS: There were no significant changes to central arterial stiffness, wave reflection, or heart rate variability. There was a significant increase in resting heart rate (bpm: 62 ± 7, 66 ± 10; p = 0.003) and a significant decrease in baroreceptor sensitivity (30 ± 7, 21 ± 7; p = 0.018) pre- to post-intervention. There was a significant decrease in total peripheral resistance pre- to post-intervention (1.076 ± 0.281, 0.916 ± 0.250; p = 0.002). Squat, bench press, and deadlift increased pre- to post-intervention (kg: 62 ± 11, 71 ± 9, p = 0.000; 37 ± 7, 40 ± 7, p = 0.002; 76 ± 19, 84 ± 19, p = 0.000). CONCLUSION: 4 weeks of HIRT can supplement a healthy lifestyle in women by increasing strength while decreasing peripheral resistance and preserving arterial pressures. Further evaluation is necessary to investigate the observed increase in resting heart rate and decrease in baroreceptor sensitivity and to determine long-term effects of this training.

A Systematic Review and Meta-Analysis on the Association and Differences between Aerobic Threshold and Point of Optimal Fat Oxidation.

Over the past two decades, scientists have attempted to evaluate whether the point of maximal fat oxidation (FATmax) and the aerobic threshold (AerT) are connected. The existence of such a relationship would allow a more tailored training approach for athletes while improving the efficacy of individualized exercise prescriptions when treating numerous health-related issues. However, studies have reported conflicting results, and this issue remains unresolved. This systematic review and meta-analysis aimed: (i) to examine the strength of the association between FATmax and AerT by using the effect size (ES) of correlation coefficient (r) and standardized mean difference (SMD); (ii) to identify potential moderators and their influence on ES variability. This study was registered with PROSPERO (CRD42021239351) and ClinicalTrials (NCT03789045). PubMed and Google Scholar were searched and fourteen articles, consisting of overall 35 ES for r and 26 ES for SMD were included. Obtained ESs were analyzed using a multilevel random-effects meta-analysis. Our results support the presence of a significant association between FATmax and AerT exercise intensities. In conclusion, due to the large ES variance caused by clinical and methodological differences among the studies, we recommend that future studies follow strict standardization of data collection and analysis of FATmax and AerT-related outcomes.

Factors Determining the Agreement between Aerobic Threshold and Point of Maximal Fat Oxidation: Follow-Up on a Systematic Review and Meta-Analysis on Association.

Regular exercise at the intensity matching maximal fat oxidation (FATmax) has been proposed as a key element in both athletes and clinical populations when aiming to enhance the body's ability to oxidize fat. In order to allow a more standardized and tailored training approach, the connection between FATmax and the individual aerobic thresholds (AerT) has been examined. Although recent findings strongly suggest that a relationship exists between these two intensities, correlation alone is not sufficient to confirm that the intensities necessarily coincide and that the error between the two measures is small. Thus, this systematic review and meta-analysis aim to examine the agreement levels between the exercise intensities matching FATmax and AerT by pooling limits of agreement in a function of three parameters: (i) the average difference, (ii) the average within-study variation, and (iii) the variation in bias across studies, and to examine the influence of clinical and methodological inter- and intra-study differences on agreement levels. This study was registered with PROSPERO (CRD42021239351) and ClinicalTrials (NCT03789045). PubMed and Google Scholar were searched for studies examining FATmax and AerT connection. Overall, 12 studies with forty-five effect sizes and a total of 774 subjects fulfilled the inclusion criteria. The ROBIS tool for risk of bias assessment was used to determine the quality of included studies. In conclusion, the overall 95% limits of agreement of the differences between FATmax and AerT exercise intensities were larger than the a priori determined acceptable agreement due to the large variance caused by clinical and methodological differences among the studies. Therefore, we recommend that future studies follow a strict standardization of data collection and analysis of FATmax- and AerT-related outcomes.

Correlation Between Heart Rate at Maximal Fat Oxidation and Aerobic Threshold in Healthy Adolescent Boys and Girls.

PURPOSE: To investigate the association between the heart rate (HR) at maximal fat oxidation (MFO) and the HR at the aerobic threshold (AerT) in adolescent boys and girls, and to identify sex differences in the intensity that elicits MFO (Fatmax) as a percentage of HR peak (HRpeak). METHODS: Fifty-eight healthy adolescents participated in this study (29 boys and 29 girls). Participants performed a cardiopulmonary exercise test on a cycle ergometer. MFO was calculated using a stoichiometric equation, and the AerT was identified using gas exchange parameters. RESULTS: A strong correlation between HR at Fatmax and HR at AerT was found in both boys and girls (r = .96 and .94, respectively). Fatmax as a percentage of HRpeak occurred at 61.0% (4.9%) of HRpeak and 66.8% (6.9%) of HRpeak in adolescent boys and girls (P = .001, F = 13.6), respectively. MFO was higher in boys compared with girls (324 [150] and 240 [95] mg/min, respectively), and no sex differences were observed in the relative contribution of fat to energy expenditure at Fatmax. CONCLUSIONS: HR at Fatmax and HR at AerT were highly correlated in adolescent boys and girls. Girls obtained Fatmax at a higher percentage of HRpeak than boys.

Measures of ejection duration and subendocardial viability ratio in normal weight and overweight adolescent children.

The aim of our study was to determine how being overweight (OW) affects measures of ejection duration (ED), subendocardial viability ratio (SEVR), and central arterial health in a sample of adolescent children. Thirty-four sex and age-matched adolescent children (n = 34, 17 OW, age = 14 ± 2 years) participated in one laboratory visit. Anthropometric measures, body composition, and cardiovascular measures including resting heart rate, aortic systolic blood pressure (ASBP), carotid-femoral pulse wave velocity (cf-PWV), ED (EDms absolute vs. relative ED%), and the SEVR were ascertained. Transfer functions were applied to obtain ASBP. ED was measured as the time from the beginning of the upstroke of the pulse wave and the dicrotic notch, SEVR as the quotient of the diastolic pressure-time area to the systolic pressure-time area, and cf-PWV as the quotient of distance between carotid-femoral measurement sites and the transit time of the pulse wave. cf-PWV was significantly higher in OW compared to normal weight participants (5.13 ± 0.85 vs. 4.53 ± 0.46 m/s respectively; p = 0.015, d = 0.51). OW adolescents also reported significantly higher values for ASBP (103.1 ± 11.8 vs. 95.7 ± 8.2 mmHg respectively; p = 0.043, d = 0.72) and significantly lower values of SEVR (114.4 ± 25.9% vs. 132.2 ± 22.0% respectively; p = 0.038; d = 0.33). Overweight adolescents demonstrated higher cf-PWV, ASBP, and SEVR then normal weight peers.

Validity, reliability and minimum detectable change of COSMED K5 portable gas exchange system in breath-by-breath mode.

PURPOSE: This study aimed to examine the validity, reliability and minimum detectable change (MDC) of the Cosmed K5 in breath by breath (BxB) mode, against VacuMed metabolic simulator. Intra and inter-units reliability was also assessed. METHODS: Fourteen metabolic rates (from 0.9 to 4 L.min-1) were reproduced by a VacuMed system and pulmonary ventilation (VE), oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured by two different K5 units. Validity was assessed by ordinary least products (OLP) regression analysis, Bland-Altman plots, intraclass correlation coefficients (ICC), mean percentage differences, technical errors (TE) and MDC for VE, VO2, and VCO2. Intra- and inter-K5 reliability was evaluated by absolute percentage differences between measurements (MAPE), ICCs, TE, and MDC. RESULTS: Validity analysis from OLP regression data and Bland- Altman plots indicated high agreement between K5 and simulator. ICC values were excellent for all variables (>0.99). Mean percentage differences in VE (-0.50%, p = 0.11), VO2 (-0.04%, p = 0.80), and VCO2 (-1.03%, p = 0.09) showed no significant bias. The technical error (TE) ranged from 0.73% to 1.34% (VE and VCO2 respectively). MDC were lower than 4% (VE = 2.0%, VO2 = 3.8%, VCO2 = 3.7%). The intra and inter K5 reliability assessment reveled excellent ICCs (>0.99), MAPE <2% (no significant differences between trials), TE < or around 1%, MDC

Does the aerobic threshold correlate with the maximal fat oxidation rate in short stage treadmill tests?

BACKGROUND: The aim of this study was to identify the exercise intensity that elicited the highest rate of fat utilization (FATmax) and to assess its relationship with the aerobic threshold (AeT) in male athletes. We hypothesized existence of high correlation of these two parameters when a short-staged graded treadmill test with AeT identified through breath-by-breath gas exchange analysis was used. METHODS: Fifty-six trained male athletes (age 25.6±3.4 y, height 197.8±5.6 cm, body mass 98.5±6.6 kg) participated in the study. Pearson correlation coefficient (r) and effect size (R2) were used to evaluate the existence of connection between VO2 at AeT and at FATmax. Maximal oxygen consumption (VO2max) and substrate oxidation were determined using breath-by-breath indirect calorimetry during a short-staged graded treadmill test to exhaustion. RESULTS: Mean VO2max was 52.12±9.02 mL·kg-1·min-1. FATmax and AeT occurred at 47.47±10.59% of VO2max and 45.95±10.21% of VO2max, respectively. Fat utilization at FATmax was 0.59±0.24 g·min-1. A high correlation was found between VO2 at FATmax and at AeT (r=0.88, P<0.01, 95% CI: 0.80 to 0.93). The effect size was 77.44%. CONCLUSIONS: Our results confirm the hypothesis of an existence of a high correlation between AeT and FATmax allowing implementation of more accurate training approach.

Lanthanum hexaboride for solar energy applications.

We investigate the optical properties of LaB6 - based materials, as possible candidates for solid absorbers in Concentrating Solar Power (CSP) systems. Bulk LaB6 materials were thermally consolidated by hot pressing starting from commercial powders. To assess the solar absorbance and spectral selectivity properties, room-temperature hemispherical reflectance spectra were measured from the ultraviolet to the mid-infrared, considering different compositions, porosities and surface roughnesses. Thermal emittance at around 1100 K has been measured. Experimental results showed that LaB6 can have a solar absorbance comparable to that of the most advanced solar absorber material in actual plants such as Silicon Carbide, with a higher spectral selectivity. Moreover, LaB6 has also the appealing characteristics to be a thermionic material, so that it could act at the same time both as direct high-temperature solar absorber and as electron source, significantly reducing system complexity in future concentrating solar thermionic systems and bringing a real innovation in this field.

Metabolomic Shifts Following Play-Based Activity in Overweight Preadolescents.

BACKGROUND: Play-based activities can be a positive intervention to increase participation of overweight children. Metabolomics can reveal elemental shifts in the metabolome, lending to potential mechanistic explanations behind improvements in physiological systems. OBJECTIVE: To elucidate dose-response urinary metabolomic signature shifts in overweight preadolescents following four or eight weeks of supervised play-based activity versus a typical summer break control group. We hypothesized that eight weeks of activity would cause the greatest shift in the metabolites. STUDY DESIGN: Twenty-two recreationally active preadolescents (12 males, 10 females) were randomly assigned to a four-week (4w) or eight-week (8w) activity group or to a control group (C). Participants reported to the laboratory on two separate occasions during which descriptive characteristics were recorded and urine samples were obtained. Children in the 4w and 8w cohort were tested at the beginning and end of the four and eight weeks of a supervised play-based physical activity program where they were active for 6 hours a day, 5 days a week. Children in the C group were tested before and after eight weeks of an unsupervised summer break. RESULTS: A valid supervised partial least squares discriminant analysis model was obtained between post-exercise subjects in 8w and C (3 components, R2X = 0.332, R2Y = 0.976, Q2 = 0.091). The eight week intervention yielded significant metabolomic changes in several identified compounds. CONCLUSION: When compared to a typical unsupervised summer break, a supervised play-based intervention provides enough of a stimulus for a shift in the metabolome.

Fat Utilization During High-Intensity Exercise: When Does It End?

BACKGROUND: This study examined substrate oxidation at high-intensity exercise and aimed to determine when fat oxidation ends (FATmin). We hypothesized the existence of a connection between the anaerobic threshold (AnT) and FATmin point. METHODS: Breath-by-breath data obtained from indirect calorimetry during a graded treadmill test were used to measure substrate oxidation and maximal oxygen uptake (VO2max) on 47 males (30 athletes (ATL) and 17 non-athletes (NATL)). Pearson correlation coefficient (r) and effect size (R 2) were used to test correlations between VO2 at AnT and at FATmin. RESULTS: Maximal oxygen uptake (VO2max) was 56.17 ± 4.95 and 46.04 ± 3.25 ml kg-1 min-1 in ATL and NATL, respectively. In ATL, AnT was observed at 87.57 ± 1.30 % of VO2max and FATmin was observed at 87.60 ± 1.60 % of VO2max. In NATL, AnT and FATmin were at 84.64 ± 1.10 % of VO2max and 85.25 ± 1.10 % of VO2max, respectively. Our data show large correlations between VO2 at AnT and VO2 at FATmin for ATL (r = 0.99, p < 0.01, 95 % CI 0.99 to 1.00) and NATL (r = 0.97, p < 0.01, 95 % CI 0.91 to 0.98). The effect size of correlations for ATL and NATL were 0.98 and 0.94, respectively. CONCLUSIONS: Our results show high correlation between AnT and FATmin in both ATL and NATL with equal substrate oxidation rates at AnT.

Effects of combined physical education and nutritional programs on schoolchildren's healthy habits.

Background. A multidisciplinary approach seems to be effective in creating healthy habits in children. The aim of this study was to evaluate the efficacy of three 5-month combined physical education (PE) and nutritional interventions on body composition, physical activity (PA) level, sedentary time and eating habits of schoolchildren. Methods. Anthropometric data, weekly PA level, sedentary time and eating habits of 230 healthy students were analysed using a repeated-measures ANOVA with Group (experimental group 1 vs experimental group 2 vs control group), Adiposity Status (under fat vs normal fat vs obese), and Time (pre vs post) as factors. Results. Body fat mass percentage increased after intervention (18.92 ± 8.61% vs 19.40 ± 8.51%) in all groups. The weekly PA level significantly increased after intervention in both experimental groups. Sedentary time significantly decreased after the intervention period (565.70 ± 252.93 vs 492.10 ± 230.97 min/week, p < 0.0001). Moreover, obese children were more sedentary than under fat and normal fat children. Children significantly changed the consumption of some specific foods after intervention. Discussion. This study revealed the effectiveness of a combined PE and nutritional intervention to improve children's healthful dietary practices and to encourage an active lifestyle. However, it needs a further appropriate development to establish patterns of healthful dietary practices that encourage an active lifestyle with which to maintain healthy habits through life.

Processing, Mechanical and Optical Properties of Additive-Free ZrC Ceramics Prepared by Spark Plasma Sintering.

In the present study, nearly fully dense monolithic ZrC samples are produced and broadly characterized from microstructural, mechanical and optical points of view. Specifically, 98% dense products are obtained by Spark Plasma Sintering (SPS) after 20 min dwell time at 1850 °C starting from powders preliminarily prepared by Self-propagating High-temperature Synthesis (SHS) followed by 20 min ball milling. A prolonged mechanical treatment up to 2 h of SHS powders does not lead to appreciable benefits. Vickers hardness of the resulting samples (17.5 ± 0.4 GPa) is reasonably good for monolithic ceramics, but the mechanical strength (about 250 MPa up to 1000 °C) could be further improved by suitable optimization of the starting powder characteristics. The very smoothly polished ZrC specimen subjected to optical measurements displays high absorption in the visible-near infrared region and low thermal emittance at longer wavelengths. Moreover, the sample exhibits goodspectral selectivity (2.1-2.4) in the 1000-1400 K temperature range. These preliminary results suggest that ZrC ceramics produced through the two-step SHS/SPS processing route can be considered as attractive reference materials for the development of innovative solar energy absorbers.

Impacts of coordinative training on normal weight and overweight/obese children's attentional performance.

This study investigated the efficacy of a physical activity (PA) program to improve the attention span in normal weight vs. overweight/obese children. The study was designed as a cluster-randomized controlled intervention. One hundred fifty-seven normal weight and overweight/obese primary school children were randomly divided in three cohorts: Traditional PA, Coordinative PA and a Control group (not attending any PA). Before and after 5 months of intervention, children were administered the d2-R test of attention. Results showed that participants' attentional performances were significantly affected by Time (pre vs. post; P < 0.01) and by Time × Group interaction (traditional vs. coordinative vs. control; P < 0.001), revealing significant different effects of intervention/exercise modality on children's attentional performance, independently of their weight status. These data suggest that a 5-month school-based PA intervention can improve the cognitive performance in children. Further, the Coordinative PA intervention resulted in the most significant improvement in children's attention.

Facility for assessing spectral normal emittance of solid materials at high temperature.

Spectral emittance is a key topic in the study of new compositions, depositions, and mechanical machining of materials for solar absorption and for renewable energies in general. The present work reports on the realization and testing of a new experimental facility for the measurement of directional spectral emittance in the range of 2.5-20 µm. Our setup provides emittance spectral information in a completely controlled environment at medium-high temperatures up to 1200 K. We describe the layout and first tests on the device, comparing the results obtained for hafnium carbide and tantalum diboride ultrarefractory ceramic samples to previous quasi-monochromatic measurements carried out in the PROMES-CNRS (PROcedes, Materiaux et Energie Solaire- Centre National de la Recherche Scientifique, France) solar furnace, obtaining a good agreement. Finally, to assess the reliability of the widely used approach of estimating the spectral emittance from room-temperature reflectance spectrum, we compared the calculation in the 2.5-17 µm spectral range to the experimental high-temperature spectral emittance, obtaining that the spectral trend of calculated and measured curves is similar but the calculated emittance underestimates the measured value.