The Experts below are selected from a list of 5607 Experts worldwide ranked by ideXlab platform
Shane K Maloney - One of the best experts on this subject based on the ideXlab platform.
-
homeothermy and primate bipedalism is water shortage or solar radiation the main threat to baboon papio hamadryas homeothermy
Journal of Human Evolution, 2009Co-Authors: Duncan Mitchell, Andrea Fuller, Shane K MaloneyAbstract:Abstract Other than the hominin lineage, baboons are the diurnally active primates that have colonized the arid plains of Africa most successfully. While the hominin lineage adopted bipedalism before colonizing the open, dry plains, baboons retained a quadrupedal mode of locomotion. Because bipedalism has been considered to reduce the thermoregulatory stress of inhabiting open dry plains, we investigated how baboons cope with thermal loads and water restriction. Using implanted data loggers, we measured abdominal temperature every 5 min in six unrestrained baboons while they were exposed to simulated desert conditions (15 °C at night rising to 35 °C during the day, with and without extra Radiant Heating), or an ambient temperature of 22 °C. At 22 °C, core temperature averaged 37.9 °C and cycled nychthemerally by 1.7 °C. Mean, minimum, and maximum daily core temperatures in euhydrated baboons in the simulated desert environments did not differ from the temperatures displayed in the 22 °C environment, even when Radiant Heating was applied. At 22 °C, restricting water intake did not affect core temperature. During the desert simulations, maximum core temperature increased significantly on each day of water deprivation, with the highest temperatures (>40 °C) on the third day in the simulation that included Radiant heat. When drinking water heated to 38 °C was returned, core temperature decreased rapidly to a level lower than normal for that time of day. We conclude that baboons with access to water can maintain homeothermy in the face of high air temperatures and Radiant heat loads, but that a lack of access to drinking water poses a major threat to baboon homeothermy. We speculate that any competitive thermoregulatory advantage of bipedalism in early hominins was related to coping with water shortage in hot environments, and that their freed hands might have enabled them to transport enough water to avoid dangerous hyperthermia.
-
homeothermy and primate bipedalism is water shortage or solar radiation the main threat to baboon papio hamadryas homeothermy
Journal of Human Evolution, 2009Co-Authors: Duncan Mitchell, Andrea Fuller, Shane K MaloneyAbstract:Other than the hominin lineage, baboons are the diurnally active primates that have colonized the arid plains of Africa most successfully. While the hominin lineage adopted bipedalism before colonizing the open, dry plains, baboons retained a quadrupedal mode of locomotion. Because bipedalism has been considered to reduce the thermoregulatory stress of inhabiting open dry plains, we investigated how baboons cope with thermal loads and water restriction. Using implanted data loggers, we measured abdominal temperature every 5 min in six unrestrained baboons while they were exposed to simulated desert conditions (15 degrees C at night rising to 35 degrees C during the day, with and without extra Radiant Heating), or an ambient temperature of 22 degrees C. At 22 degrees C, core temperature averaged 37.9 degrees C and cycled nychthemerally by 1.7 degrees C. Mean, minimum, and maximum daily core temperatures in euhydrated baboons in the simulated desert environments did not differ from the temperatures displayed in the 22 degrees C environment, even when Radiant Heating was applied. At 22 degrees C, restricting water intake did not affect core temperature. During the desert simulations, maximum core temperature increased significantly on each day of water deprivation, with the highest temperatures (>40 degrees C) on the third day in the simulation that included Radiant heat. When drinking water heated to 38 degrees C was returned, core temperature decreased rapidly to a level lower than normal for that time of day. We conclude that baboons with access to water can maintain homeothermy in the face of high air temperatures and Radiant heat loads, but that a lack of access to drinking water poses a major threat to baboon homeothermy. We speculate that any competitive thermoregulatory advantage of bipedalism in early hominins was related to coping with water shortage in hot environments, and that their freed hands might have enabled them to transport enough water to avoid dangerous hyperthermia.
Everson Kandare - One of the best experts on this subject based on the ideXlab platform.
-
compressive softening and failure of basalt fibre composites in fire modelling and experimentation
Composite Structures, 2017Co-Authors: T Bhat, P Di Modica, A G Gibson, Everson Kandare, Adrian P. MouritzAbstract:In this study, the fire structural properties of a basalt fibre reinforced polymer laminate under compressive loading were investigated analytically and experimentally, and compared against an E-glass fibre composite with the same fibre content, ply orientation and polymer matrix. A thermal-mechanical model was used to compute the softening rate and failure stress of basalt fibre laminates which collapse, when loaded in compression, by either global buckling or material failure when exposed to fire. Fire structural measurements involving one-sided Radiant Heating with axial compressive loading were also performed. The measurements revealed that the softening behaviour and failure stress of the basalt fibre laminate were inferior to those of the glass fibre composite. Furthermore, the fire reaction properties, such as heat release rate and smoke density, were also less favourable for the basalt laminate. This appears to be mainly due to the thermal absorptivity of the basalt fibre laminate being higher, which causes it to heat up at a faster rate and reach higher temperatures when exposed to a Radiant heat flux.
-
compressive softening and failure of basalt fibre composites in fire modelling and experimentation
Composite Structures, 2017Co-Authors: T Bhat, P Di Modica, A G Gibson, Everson Kandare, Adrian P. MouritzAbstract:In this study, the fire structural properties of a basalt fibre reinforced polymer laminate under compressive loading were investigated analytically and experimentally, and compared against an E-glass fibre composite with the same fibre content, ply orientation and polymer matrix. A thermal-mechanical model was used to compute the softening rate and failure stress of basalt fibre laminates which collapse, when loaded in compression, by either global buckling or material failure when exposed to fire. Fire structural measurements involving one-sided Radiant Heating with axial compressive loading were also performed. The measurements revealed that the softening behaviour and failure stress of the basalt fibre laminate were inferior to those of the glass fibre composite. Furthermore, the fire reaction properties, such as heat release rate and smoke density, were also less favourable for the basalt laminate. This appears to be mainly due to the thermal absorptivity of the basalt fibre laminate being higher, which causes it to heat up at a faster rate and reach higher temperatures when exposed to a Radiant heat flux.
-
modelling flaming combustion in glass fibre reinforced composite laminates
Journal of Composite Materials, 2013Co-Authors: Edward D Mccarthy, Peter Myler, Gerard Edwards, Everson Kandare, Jifeng Yuan, Baljinder K KandolaAbstract:A heat transfer model based on the well-known Henderson equation has been modified to allow for self-sustained ignition and the flaming combustion phenomena of E-glass fibre-reinforced epoxy composites to be predicted from first principles using known thermal-physical and thermodynamic data for their constituents. The modifications consider: (1) the assignment of thermodynamic conditions (e.g. ignition temperature and mass flux of volatiles) necessary and sufficient to trigger self-sustained ignition, and (2) the inclusion of an integrated loop allowing the heat energy generated from the flaming combustion process to be fed back into the burning laminate. The model compares moderately well with experimental results obtained from cone calorimetric measurements. The additional modelling capabilities considered in this study provide the basis for an analytical model that can more accurately predict the thermal response and flaming combustion of glass fibre-reinforced polymer composites exposed to a one-sided Radiant Heating environment in the presence of an ignition source.
-
a comparative study on the efficacy of varied surface coatings in fireproofing glass epoxy composites
Polymer Degradation and Stability, 2012Co-Authors: Baljinder K Kandola, Everson Kandare, Waqas BhattiAbstract:Abstract This paper investigates the efficacy of varied (non-intumescent and intumescent) polymer-based surface coatings in providing fire protection to glass fibre-reinforced (GFR) epoxy composites exposed to one-sided Radiant Heating. In addition to an intumescent surface coating, two other non-intumescent surface coatings are considered – one that is active in the condensed phase and promotes surface char formation and another that is active in the gaseous phase and inhibits flaming combustion. The fire resistance of surface-coated GFR epoxy composite laminates is evaluated using the cone calorimeter at incident heat fluxes of 25, 50 and 65 kW/m 2 . For all tests conditions considered, there is a significant improvement in the fire performance of surface-protected GFR epoxy laminates relative to their unprotected counterparts. The intumescent surface-coated laminate showed the most significant variations in fire reaction properties with changes in irradiance.
Adrian P. Mouritz - One of the best experts on this subject based on the ideXlab platform.
-
compressive softening and failure of basalt fibre composites in fire modelling and experimentation
Composite Structures, 2017Co-Authors: T Bhat, P Di Modica, A G Gibson, Everson Kandare, Adrian P. MouritzAbstract:In this study, the fire structural properties of a basalt fibre reinforced polymer laminate under compressive loading were investigated analytically and experimentally, and compared against an E-glass fibre composite with the same fibre content, ply orientation and polymer matrix. A thermal-mechanical model was used to compute the softening rate and failure stress of basalt fibre laminates which collapse, when loaded in compression, by either global buckling or material failure when exposed to fire. Fire structural measurements involving one-sided Radiant Heating with axial compressive loading were also performed. The measurements revealed that the softening behaviour and failure stress of the basalt fibre laminate were inferior to those of the glass fibre composite. Furthermore, the fire reaction properties, such as heat release rate and smoke density, were also less favourable for the basalt laminate. This appears to be mainly due to the thermal absorptivity of the basalt fibre laminate being higher, which causes it to heat up at a faster rate and reach higher temperatures when exposed to a Radiant heat flux.
-
compressive softening and failure of basalt fibre composites in fire modelling and experimentation
Composite Structures, 2017Co-Authors: T Bhat, P Di Modica, A G Gibson, Everson Kandare, Adrian P. MouritzAbstract:In this study, the fire structural properties of a basalt fibre reinforced polymer laminate under compressive loading were investigated analytically and experimentally, and compared against an E-glass fibre composite with the same fibre content, ply orientation and polymer matrix. A thermal-mechanical model was used to compute the softening rate and failure stress of basalt fibre laminates which collapse, when loaded in compression, by either global buckling or material failure when exposed to fire. Fire structural measurements involving one-sided Radiant Heating with axial compressive loading were also performed. The measurements revealed that the softening behaviour and failure stress of the basalt fibre laminate were inferior to those of the glass fibre composite. Furthermore, the fire reaction properties, such as heat release rate and smoke density, were also less favourable for the basalt laminate. This appears to be mainly due to the thermal absorptivity of the basalt fibre laminate being higher, which causes it to heat up at a faster rate and reach higher temperatures when exposed to a Radiant heat flux.
Duncan Mitchell - One of the best experts on this subject based on the ideXlab platform.
-
homeothermy and primate bipedalism is water shortage or solar radiation the main threat to baboon papio hamadryas homeothermy
Journal of Human Evolution, 2009Co-Authors: Duncan Mitchell, Andrea Fuller, Shane K MaloneyAbstract:Abstract Other than the hominin lineage, baboons are the diurnally active primates that have colonized the arid plains of Africa most successfully. While the hominin lineage adopted bipedalism before colonizing the open, dry plains, baboons retained a quadrupedal mode of locomotion. Because bipedalism has been considered to reduce the thermoregulatory stress of inhabiting open dry plains, we investigated how baboons cope with thermal loads and water restriction. Using implanted data loggers, we measured abdominal temperature every 5 min in six unrestrained baboons while they were exposed to simulated desert conditions (15 °C at night rising to 35 °C during the day, with and without extra Radiant Heating), or an ambient temperature of 22 °C. At 22 °C, core temperature averaged 37.9 °C and cycled nychthemerally by 1.7 °C. Mean, minimum, and maximum daily core temperatures in euhydrated baboons in the simulated desert environments did not differ from the temperatures displayed in the 22 °C environment, even when Radiant Heating was applied. At 22 °C, restricting water intake did not affect core temperature. During the desert simulations, maximum core temperature increased significantly on each day of water deprivation, with the highest temperatures (>40 °C) on the third day in the simulation that included Radiant heat. When drinking water heated to 38 °C was returned, core temperature decreased rapidly to a level lower than normal for that time of day. We conclude that baboons with access to water can maintain homeothermy in the face of high air temperatures and Radiant heat loads, but that a lack of access to drinking water poses a major threat to baboon homeothermy. We speculate that any competitive thermoregulatory advantage of bipedalism in early hominins was related to coping with water shortage in hot environments, and that their freed hands might have enabled them to transport enough water to avoid dangerous hyperthermia.
-
homeothermy and primate bipedalism is water shortage or solar radiation the main threat to baboon papio hamadryas homeothermy
Journal of Human Evolution, 2009Co-Authors: Duncan Mitchell, Andrea Fuller, Shane K MaloneyAbstract:Other than the hominin lineage, baboons are the diurnally active primates that have colonized the arid plains of Africa most successfully. While the hominin lineage adopted bipedalism before colonizing the open, dry plains, baboons retained a quadrupedal mode of locomotion. Because bipedalism has been considered to reduce the thermoregulatory stress of inhabiting open dry plains, we investigated how baboons cope with thermal loads and water restriction. Using implanted data loggers, we measured abdominal temperature every 5 min in six unrestrained baboons while they were exposed to simulated desert conditions (15 degrees C at night rising to 35 degrees C during the day, with and without extra Radiant Heating), or an ambient temperature of 22 degrees C. At 22 degrees C, core temperature averaged 37.9 degrees C and cycled nychthemerally by 1.7 degrees C. Mean, minimum, and maximum daily core temperatures in euhydrated baboons in the simulated desert environments did not differ from the temperatures displayed in the 22 degrees C environment, even when Radiant Heating was applied. At 22 degrees C, restricting water intake did not affect core temperature. During the desert simulations, maximum core temperature increased significantly on each day of water deprivation, with the highest temperatures (>40 degrees C) on the third day in the simulation that included Radiant heat. When drinking water heated to 38 degrees C was returned, core temperature decreased rapidly to a level lower than normal for that time of day. We conclude that baboons with access to water can maintain homeothermy in the face of high air temperatures and Radiant heat loads, but that a lack of access to drinking water poses a major threat to baboon homeothermy. We speculate that any competitive thermoregulatory advantage of bipedalism in early hominins was related to coping with water shortage in hot environments, and that their freed hands might have enabled them to transport enough water to avoid dangerous hyperthermia.
Yiping Wang - One of the best experts on this subject based on the ideXlab platform.
-
building space Heating with a solar assisted heat pump using roof integrated solar collectors
Energies, 2011Co-Authors: Zhiyong Yang, Yiping WangAbstract:A solar assisted heat pump (SAHP) system was designed by using a roof-integrated solar collector as the evaporator, and then it was demonstrated to provide space Heating for a villa in Tianjin, China. A building energy simulation tool was used to predict the space Heating load and a three dimensional theoretical model was established to analyze the heat collection performance of the solar roof collector. A floor Radiant Heating unit was used to decrease the energy demand. The measurement results during the winter test period show that the system can provide a comfortable living space in winter, when the room temperature averaged 18.9 °C. The average COP of the heat pump system is 2.97 and with a maximum around 4.16.
-
very low temperature Radiant Heating cooling indoor end system for efficient use of renewable energies
Solar Energy, 2010Co-Authors: Yiping Wang, Congrong Wang, Weicheng XiongAbstract:Abstract Solar or solar-assisted space Heating systems are becoming more and more popular. The solar energy utilization efficiency is high when the collector is coupled with indoor Radiant Heating suppliers, since in principle, lower supply temperature means lower demand temperature and then the system heat loss is less. A new type Radiant end system is put forward for even lower supply temperature compared to the conventional Radiant floor Heating systems. A three dimensional model was established to investigate its energy supply capacities. Simulation results show that 50 W per meter length tube can be achieved with the medium temperature of 30 °C for Heating and 15 °C for cooling. The predicted results agree well with the actual data from a demonstration building. Furthermore, it is demonstrated that a supply temperature of 22 °C in winter and of 17 °C in summer already met the indoor requirements. The new end system has good prospects for effective use of local renewable resources.
