A High-Resolution Voxel Model for Predicting Local Tissue Temperatures in Humans Subjected to Warm and Hot Environments

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
D. A. Nelson ◽  
S. Charbonnel ◽  
A. R. Curran ◽  
E. A. Marttila ◽  
D. Fiala ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Core Temperature ◽  
Spatial Resolution ◽  
Rectal Temperature ◽  
Environmental Conditions ◽  
Temperature Increase ◽  
High Spatial Resolution ◽  
Compartment Model ◽  
Voxel Model ◽  
Hot Environments

This work describes and presents results from a new three-dimensional whole-body model of human thermoregulation. The model has been implemented using a version of the “Brooks Man” anatomical data set, consisting of 1.3×108 cubic volume elements (voxels) measuring 0.2 cm/side. The model simulates thermoregulation through passive mechanisms (metabolism, blood flow, respiration, and transpiration) and active mechanisms (vasodilatation, vasoconstriction, sweating, and shivering). Compared with lumped or compartment models, a voxel model is capable of high spatial resolution and can capture a level of anatomical detail not achievable otherwise. A high spatial resolution model can predict detailed heating patterns from localized or nonuniform heating patterns, such as from some radio frequency sources. Exposures to warm and hot environments (ambient temperatures of 33–48°C) were simulated with the current voxel model and with a recent compartment model. Results from the two models (core temperature, skin temperature, metabolic rate, and evaporative cooling rate) were compared with published experimental results obtained under similar conditions. Under the most severe environmental conditions considered (47.8°C, 27% RH for 2 h), the voxel model predicted a rectal temperature increase of 0.56°C, compared with a core temperature increase of 0.45°C from the compartment model and an experimental mean rectal temperature increase of 0.6°C. Similar, good agreement was noted for other thermal variables and under other environmental conditions. Results suggest that the voxel model is capable of predicting temperature response (core temperature and skin temperature) to certain warm or hot environments, with accuracy comparable to that of a compartment model. In addition, the voxel model is able to predict internal tissue temperatures and surface temperatures, over time, with a level of specificity and spatial resolution not achievable with compartment models. The development of voxel models and related computational tools may be useful for thermal dosimetry applications involving mild temperature hyperthermia and for the assessment of safe exposure to certain nonionizing radiation sources.

scholarly journals Core Temperature in Triathletes during Swimming with Wetsuit in 10 °C Cold Water

Sports ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 130 ◽  
Author(s):  
Jørgen Melau ◽  
Maria Mathiassen ◽  
Trine Stensrud ◽  
Mike Tipton ◽  
Jonny Hisdal
Keyword(s):  
Water Temperature ◽  
Skin Temperature ◽  
Core Temperature ◽  
Rectal Temperature ◽  
Physiological Response ◽  
Cold Water ◽  
Temperature Response ◽  
Open Water ◽  
Open Water Swimming ◽  
Ironman Distance

Low water temperature (<15 °C) has been faced by many organizers of triathlons and swim-runs in the northern part of Europe during recent years. More knowledge about how cold water affects athletes swimming in wetsuits in cold water is warranted. The aim of the present study was therefore to investigate the physiological response when swimming a full Ironman distance (3800 m) in a wetsuit in 10 °C water. Twenty triathletes, 37.6 ± 9 years (12 males and 8 females) were recruited to perform open water swimming in 10 °C seawater; while rectal temperature (Tre) and skin temperature (Tskin) were recorded. The results showed that for all participants, Tre was maintained for the first 10–15 min of the swim; and no participants dropped more than 2 °C in Tre during the first 30 min of swimming in 10 °C water. However; according to extrapolations of the results, during a swim time above 135 min; 47% (8/17) of the participants in the present study would fall more than 2 °C in Tre during the swim. The results show that the temperature response to swimming in a wetsuit in 10 °C water is highly individual. However, no participant in the present study dropped more than 2 °C in Tre during the first 30 min of the swim in 10 °C water.

scholarly journals Estimating Daily Actual Evapotranspiration at a Landsat-Like Scale Utilizing Simulated and Remote Sensing Surface Temperature

2021 ◽  
Vol 13 (2) ◽  
pp. 225
Author(s):  
Dakang Wang ◽  
Tao Yu ◽  
Yan Liu ◽  
Xingfa Gu ◽  
Xiaofei Mi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Temperature ◽  
Skin Temperature ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Remote Sensing Data ◽  
Model Surface ◽  
Spatiotemporal Resolution ◽  
Sensing Data ◽  
Surface Skin Temperature

Actual evapotranspiration (ET) with high spatiotemporal resolution is very important for the research on agricultural water resource management and the water cycle processes, and it is helpful to realize precision agriculture and smart agriculture, and provides critical references for agricultural layout planning. Due to the impact of the clouds, weather environment, and the orbital period of optical satellite, there are difficulties in providing daily remote sensing data that are not contaminated by clouds for estimating daily ET with high spatial-temporal resolution. By improving the enhanced spatial and temporal adaptive reflectance fusion model (ESTARFM), this manuscript proposes the method to fuse high temporal and low spatial resolution Weather Research and Forecasting (WRF) model surface skin temperature (TSK) with the low temporal and high spatial resolution remote sensing surface temperature for obtaining high spatiotemporal resolution daily surface temperature to be used in the estimation of the high spatial resolution daily ET (ET_WRFHR). The distinction of this study from the previous literatures can be summarized as the novel application of the fusion of WRF-simulated TSK and remote sensing surface temperature, giving full play to the availability of model surface skin temperature data at any time and region, making up for the shortcomings of the remote sensing data, and combining the high spatial resolution of remote sensing data to obtain ET with high spatial (Landsat-like scale) and temporal (daily) resolution. The ET_WRFHR were cross-validated and quantitatively verified with MODIS ET products (MOD16) and observations (ET_Obs) from eddy covariance system. Results showed that ET_WRFHR not only better reflects the difference and dynamic evolution process of ET for different land types but also better identifies the details of various fine geographical objects. It also represented a high correlation with the ET_Obs by the R2 amount reaching 0.9186. Besides, the RMSE and BIAS between ET_WRFHR and the ET_Obs are obtained as 0.77 mm/d and −0.08 mm/d respectively. High R2, as well as the small RMSE and BIAS amounts, indicate that ET_WRFHR has achieved a very good performance.

Evidence against a 40°C core temperature threshold for fatigue in humans

2009 ◽  
Vol 107 (5) ◽  
pp. 1519-1525 ◽  
Author(s):  
Brett R. Ely ◽  
Matthew R. Ely ◽  
Samuel N. Cheuvront ◽  
Robert W. Kenefick ◽  
David W. DeGroot ◽  
...  
Keyword(s):  
Heart Rate ◽  
Field Study ◽  
Skin Temperature ◽  
Core Temperature ◽  
Rectal Temperature ◽  
Temperature Limit ◽  
Temperature Threshold ◽  
Elapsed Time ◽  
Skin Temperatures ◽  
Cardiovascular Strain

Evidence suggests that core temperatures of ∼40°C can induce fatigue, although this may be confounded by coincident elevations in skin temperatures and maximal cardiovascular strain. In an observational field study to examine core temperature threshold for fatigue, we investigated whether running performance is impaired when rectal temperature (Tre) is >40°C and skin temperature remains modest. Seventeen competitive runners (7/10 women/men: 8 km best 1,759 ± 78/1,531 ± 60 s) completed 8-km track time trials in cool (WBGT ∼13°C; n = 6), warm (WBGT ∼27°C; n = 4), or both ( n = 7) conditions. Tre, chest skin temperature, and heart rate were logged continuously; elapsed time was recorded every 200 m. Running velocity for Tre >40°C was compared with that for Tre <40°C for each runner. Changes in running velocity over the last 600 m were compared between runners with Tre >40°C and <40°C. Twelve runners achieved Tre >40.0°C with ≥600 m remaining (range 600–3,400 m). Average running velocity for Tre <40°C (282 ± 27 m/min) was not different from that for Tre >40°C (279 ± 28 m/min; P = 0.82). There were no differences in running velocity during the final 600 m between runners with final Tre >40°C or <40°C ( P = 0.16). Chest skin temperature ranged from 30 to 34°C, and heart rate was >95% of age-predicted maximum. Our observation that runners were able to sustain running velocity despite Tre >40°C is evidence against 40°C representing a “critical” core temperature limit to performance.

Effects of sodium salicylate on physiological responses to work in heat

1964 ◽  
Vol 19 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Eugene D. Jacobson ◽  
David E. Bass
Keyword(s):  
Skin Temperature ◽  
Pulse Rate ◽  
Rectal Temperature ◽  
Temperature Regulation ◽  
Sodium Salicylate ◽  
Sweat Rate ◽  
High Dose ◽  
Desert Environment ◽  
Ambient Conditions ◽  
Hot Environments

The hypothesis was tested that men given sodium salicylate would work in the heat at a lower level of temperature regulation. Healthy young volunteers were exposed to a standardized workload consisting of a 100-min walk at 3.5 mph on a level treadmill. Two ambient conditions were studied: a) simulated desert (120 F D.B., 80 F W.B.) and b) simulated jungle (92 F D.B., 87 F W.B.). Rectal temperature (Tr), skin temperature (Ts), sweat rate ( SR), and pulse rate ( PR) were measured in the subjects during work in the heat under three drug regimens: no drug (control), 0.6 g (low dose), and 7.8 g (high dose). It was found that sodium salicylate had no effect on Ts or PR compared with control; this finding applied to both doses in both hot environments. There was, however, a higher Tr and SR in men who received the high dose of the drug in the tropic environment and an increased SR in the desert climate. There was no decrease in Tr in the desert environment during salicylate administration. The results of this investigation do not confirm the original hypothesis; to the contrary, they suggest that high doses of sodium salicylate potentiates the hyperthermia of unacclimatized men working in the heat. body temperature regulation; exercise; simulated desert environment; simulated jungle environment; hyperthermia; rectal temperature, skin temperature, sweat rate, and pulse rate in hot environments; antipyretics Submitted on August 26, 1963

High spatial resolution AEM observations of yttrium segregation in chromia scales grown on Co-45%Cr

1986 ◽  
Vol 44 ◽  
pp. 518-519
Author(s):  
K. Przybylski ◽  
A. J. Garratt-Reed ◽  
G. J. Yurek
Keyword(s):  
Spatial Resolution ◽  
Outer Surface ◽  
Maximum Concentration ◽  
High Spatial Resolution ◽  
Reactive Elements ◽  
Chromia Scales

The addition of so-called “reactive” elements such as yttrium to alloys is known to enhance the protective nature of Cr2O3 or Al2O3 scales. However, the mechanism by which this enhancement is achieved remains unclear. An A.E.M. study has been performed of scales grown at 1000°C for 25 hr. in pure O2 on Co-45%Cr implanted at 70 keV with 2x1016 atoms/cm2 of yttrium. In the unoxidized alloys it was calculated that the maximum concentration of Y was 13.9 wt% at a depth of about 17 nm. SIMS results showed that in the scale the yttrium remained near the outer surface.

Integration of Core-Edge Spectroscopy Methods for the Study of Polymers

1996 ◽  
Vol 54 ◽  
pp. 154-155
Author(s):  
E. G. Rightor
Keyword(s):  
Excited State ◽  
Polymer Blends ◽  
Gas Phase ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Electronic States ◽  
Core Electron ◽  
Bulk Solids ◽  
Development Application

Core edge spectroscopy methods are versatile tools for investigating a wide variety of materials. They can be used to probe the electronic states of materials in bulk solids, on surfaces, or in the gas phase. This family of methods involves promoting an inner shell (core) electron to an excited state and recording either the primary excitation or secondary decay of the excited state. The techniques are complimentary and have different strengths and limitations for studying challenging aspects of materials. The need to identify components in polymers or polymer blends at high spatial resolution has driven development, application, and integration of results from several of these methods.

Color Hologram Generation Using High Spatial Resolution Camera

2013 ◽  
Vol 67 (3) ◽  
pp. J108-J115
Author(s):  
Kosuke Nomura ◽  
Ryutaro Oi ◽  
Takanori Senoh ◽  
Taiichiro Kurita ◽  
Takayuki Hamamoto
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution
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