The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Christian Phalippou - One of the best experts on this subject based on the ideXlab platform.
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Energy-based wear law for oblique impacts in Dry Environment
Tribology International, 2017Co-Authors: Thibaut Souilliart, Emmanuel Rigaud, Alain Le Bot, Christian PhalippouAbstract:Abstract Wear generated by repetitive impacts between an Inconel tube sample and a stainless steel flat bar target is studied through experiments in Dry Environment. Incident energy and angle of impacts are controlled, normal and tangential loads during impact are measured as well as rebound energy and angle of impacts. Impacts characteristics are analyzed and the influence of the energy loss during impacts and the incidence angle on generated wear is analyzed. Wear volume is found to be proportional to the energy loss, for which a maximum is observed at an incidence angle close to 25° from horizontal. An impact wear energy coefficient is introduced and an impact wear law with a strong mechanical meaning is proposed. This energy-based law well predicts the observed experimental wear.
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Energy-based wear law for oblique impacts in Dry Environment
Tribology International, 2017Co-Authors: Thibaut Souilliart, Emmanuel Rigaud, Alain Le Bot, Christian PhalippouAbstract:Wear generated by repetitive impacts between an Inconel tube sample and a stainless steel flat bar target is studied through experiments in Dry Environment. Incident energy and angle of impacts are controlled, normal and tangential loads during impact are measured as well as rebound energy and angle of impacts. Impacts characteristics are analyzed and the influence of the energy loss during impacts and the incidence angle on generated wear is analyzed. Wear volume is found to be proportional to the energy loss, for which a maximum is observed at an incidence angle close to 25° from horizontal. An impact wear energy coefficient is introduced and an impact wear law with a strong mechanical meaning is proposed. This energy-based law well predicts the observed experimental wear. Highlights Impact wear between an Inconel tube and a stainless steel bar is studied. Wear is observed to be proportional to the energy loss during impacts. The energy loss during impacts strongly depends on incidence angle. An energy-based impact wear law is proposed.
Ricardo Mora-rodriguez - One of the best experts on this subject based on the ideXlab platform.
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Relevance of individual characteristics for thermoregulation during exercise in a hot-Dry Environment
European Journal of Applied Physiology, 2011Co-Authors: Juan Del Coso, Nassim Hamouti, Juan F. Ortega, Valetín E. Fernández-elías, Ricardo Mora-rodriguezAbstract:The aim of this study was to investigate the relevance of individual characteristics for thermoregulation during prolonged cycling in the heat. For this purpose, 28 subjects cycled for 60 min at 60% V O_2peak in a hot-Dry Environment (36 ± 1°C; 25 ± 2% relative humidity, airflow 2.5 m/s). Subjects had a wide range of body mass (99–43 kg), body surface area (2.2–1.4 m^2), body fatness (28–5%) and aerobic fitness level ( V O_2peak = 5.0–2.1 L/min). At rest and during exercise, rectal and mean skin temperatures were measured to calculate the increase in body temperature (Δ T _body) during the trial. Net metabolic heat production ( M _NET) and potential heat loss (by means of evaporation, radiation and convection) were calculated. Although subjects exercised at the same relative intensity, Δ T _body presented high between-subjects variability (range from 0.44 to 1.65°C). Δ T _body correlated negatively with body mass ( r = −0.49; P
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Relevance of individual characteristics for thermoregulation during exercise in a hot-Dry Environment
European journal of applied physiology, 2011Co-Authors: Juan Del Coso, Nassim Hamouti, Juan F. Ortega, Valetín E. Fernández-elías, Ricardo Mora-rodriguezAbstract:The aim of this study was to investigate the relevance of individual characteristics for thermoregulation during prolonged cycling in the heat. For this purpose, 28 subjects cycled for 60 min at 60% VO2peak in a hot-Dry Environment (36 ± 1°C; 25 ± 2% relative humidity, airflow 2.5 m/s). Subjects had a wide range of body mass (99–43 kg), body surface area (2.2–1.4 m2), body fatness (28–5%) and aerobic fitness level (VO2peak = 5.0–2.1 L/min). At rest and during exercise, rectal and mean skin temperatures were measured to calculate the increase in body temperature (ΔTbody) during the trial. Net metabolic heat production (MNET) and potential heat loss (by means of evaporation, radiation and convection) were calculated. Although subjects exercised at the same relative intensity, ΔTbody presented high between-subjects variability (range from 0.44 to 1.65°C). ΔTbody correlated negatively with body mass (r = −0.49; P 0.05). ΔTbody positively correlated with the body surface area/mass ratio (r = 0.46; P < 0.01) and the difference between MNET and potential heat loss (r = 0.56; P < 0.01). In conclusion, a large body size (mass and body surface area) is beneficial to reduce ΔTbody during cycling exercise in the heat. However, subjects with higher absolute heat production (more aerobically fit) accumulate more heat because heat production may exceed potential heat loss (uncompensability).
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In a hot–Dry Environment racewalking increases the risk of hyperthermia in comparison to when running at a similar velocity
European journal of applied physiology, 2010Co-Authors: Ricardo Mora-rodriguez, Juan F. Ortega, Nassim HamoutiAbstract:The purpose of this study was to determine if in a hot–Dry Environment, racewalking increases intestinal temperature (Tint) above the levels observed when running either at the same velocity or at a similar rate of heat production. Nine trained racewalkers exercised for 60 min in a hot–Dry Environment (30.0 ± 1.4°C; 33 ± 8% relative humidity; 2.4 m s−1 air speed) on three separate occasions: (1) racewalking at 10.9 ± 1.0 km h−1 (Walk), (2) running at the same velocity (RunVel) and (3) running at 13 ± 1.8 km h−1 to obtain a similar \( \dot{V}{\text{O}}_{2} \) than during Walk (Run\( \dot{V}{\text{O}}_{2} \)). As designed, energy expenditure rate was similar during Walk and Run\( \dot{V}{\text{O}}_{2} \), but lower during RunVel (842 ± 78 and 827 ± 75 vs. 713 ± 55 W; p < 0.01). Final Tint was lower during RunVel than during both Walk and Run\( \dot{V}{\text{O}}_{2} \) (38.4 ± 0.3 vs. 39.2 ± 0.4 and 39.0 ± 0.4°C; p < 0.01). Heart rate and sweat rate were also lower during RunVel than during Walk and Run\( \dot{V}{\text{O}}_{2} \) (i.e. heart rate 159 ± 13 vs. 179 ± 11 and 181 ± 11 beats min−1 and sweat rate 0.8 ± 0.3 vs. 1.1 ± 0.3 and 1.1 ± 0.3 L h−1; p < 0.01). However, we could not detect differences in skin temperature among trials. In conclusion, our data indicate that in a hot–Dry Environment racewalking increases the risk of hyperthermia in comparison with when running at a similar velocity. However, exercise mode (walking vs. running) had no measurable impact on TINT or heat dissipation when matched for energy expenditure.
Thibaut Souilliart - One of the best experts on this subject based on the ideXlab platform.
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Energy-based wear law for oblique impacts in Dry Environment
Tribology International, 2017Co-Authors: Thibaut Souilliart, Emmanuel Rigaud, Alain Le Bot, Christian PhalippouAbstract:Abstract Wear generated by repetitive impacts between an Inconel tube sample and a stainless steel flat bar target is studied through experiments in Dry Environment. Incident energy and angle of impacts are controlled, normal and tangential loads during impact are measured as well as rebound energy and angle of impacts. Impacts characteristics are analyzed and the influence of the energy loss during impacts and the incidence angle on generated wear is analyzed. Wear volume is found to be proportional to the energy loss, for which a maximum is observed at an incidence angle close to 25° from horizontal. An impact wear energy coefficient is introduced and an impact wear law with a strong mechanical meaning is proposed. This energy-based law well predicts the observed experimental wear.
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Energy-based wear law for oblique impacts in Dry Environment
Tribology International, 2017Co-Authors: Thibaut Souilliart, Emmanuel Rigaud, Alain Le Bot, Christian PhalippouAbstract:Wear generated by repetitive impacts between an Inconel tube sample and a stainless steel flat bar target is studied through experiments in Dry Environment. Incident energy and angle of impacts are controlled, normal and tangential loads during impact are measured as well as rebound energy and angle of impacts. Impacts characteristics are analyzed and the influence of the energy loss during impacts and the incidence angle on generated wear is analyzed. Wear volume is found to be proportional to the energy loss, for which a maximum is observed at an incidence angle close to 25° from horizontal. An impact wear energy coefficient is introduced and an impact wear law with a strong mechanical meaning is proposed. This energy-based law well predicts the observed experimental wear. Highlights Impact wear between an Inconel tube and a stainless steel bar is studied. Wear is observed to be proportional to the energy loss during impacts. The energy loss during impacts strongly depends on incidence angle. An energy-based impact wear law is proposed.
Xiaolei Yang - One of the best experts on this subject based on the ideXlab platform.
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solvent controlled growth of inorganic perovskite films in Dry Environment for efficient and stable solar cells
Nature Communications, 2018Co-Authors: Pengyang Wang, Xingwang Zhang, Yuqin Zhou, Qi Jiang, Zema Chu, Xiaolei Yang, Zhigang Yin, Jingbi YouAbstract:Inorganic halide perovskites such as cesium lead halide are promising due to their excellent thermal stability. Cesium lead iodide (CsPbI3) has a bandgap of 1.73 eV and is very suitable for making efficient tandem solar cells, either with low-bandgap perovskite or silicon. However, the phase instability of CsPbI3 is hindering the further optimization of device performance. Here, we show that high quality and stable α-phase CsPbI3 film is obtained via solvent-controlled growth of the precursor film in a Dry Environment. A 15.7% power conversion efficiency of CsPbI3 solar cells is achieved, which is the highest efficiency reported for inorganic perovskite solar cells up to now. And more importantly, the devices can tolerate continuous light soaking for more than 500 h without efficiency drop.
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solvent controlled growth of inorganic perovskite films in Dry Environment for efficient and stable solar cells
Nature Communications, 2018Co-Authors: Pengyang Wang, Xingwang Zhang, Yuqin Zhou, Qi Jiang, Qiufeng Ye, Xingxing Li, Xiaolei YangAbstract:Inorganic halide perovskites such as cesium lead halide are promising due to their excellent thermal stability. Cesium lead iodide (CsPbI3) has a bandgap of 1.73 eV and is very suitable for making efficient tandem solar cells, either with low-bandgap perovskite or silicon. However, the phase instability of CsPbI3 is hindering the further optimization of device performance. Here, we show that high quality and stable α-phase CsPbI3 film is obtained via solvent-controlled growth of the precursor film in a Dry Environment. A 15.7% power conversion efficiency of CsPbI3 solar cells is achieved, which is the highest efficiency reported for inorganic perovskite solar cells up to now. And more importantly, the devices can tolerate continuous light soaking for more than 500 h without efficiency drop. Cesium lead iodide inorganic perovskite solar cells have great potential but the phase instability hinders their development. Here Wang et al. show a controlled Drying process to make phase stable and highly efficient solar cells with power conversion efficiency of 15.7%.
Tíscar Espigares - One of the best experts on this subject based on the ideXlab platform.
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Vegetation succession in reclaimed coal-mining slopes in a Mediterranean-Dry Environment
Ecological Engineering, 2008Co-Authors: Mariano Moreno-de Las Heras, J. M. Nicolau, Tíscar EspigaresAbstract:Abstract Mining reclamation results obtained in the Teruel coalfield (Mediterranean-Dry Spain) during the last 30 years have been quite limited. In order to improve restoration operations we conducted a study to analyse the trajectories of ecological succession and identify the main driving forces that control vegetation dynamic in reclaimed artificial slopes. A total of 87 slopes of different ages and restoration treatments were classified and characterized after recording different variables related to topography, restoration techniques, vegetation, local disturbances and soil erosion. Successional trends were inferred from gradient analysis as well as the factors, mechanisms and processes implied. We found a wide variety of plant communities and successional trajectories. Initial conditions (soil quality and revegetation treatments) as well as the Environmental scenario (climatic conditions and vicinity of preserved propagule sources) were the main driving forces directing vegetation succession. Soil erosion triggered by external run-on coming from surrounding structures was also identified as a key factor determining the evolution of vegetation in these Dry Environments. Other local disturbances (grazing and fungal pests) can favour vegetation transition in communities dominated by highly competitive non-native sown species to more diverse shrub communities. Some practical considerations for future reclamation projects are suggested.
