scholarly journals Změna teplot sněhu při běhu na lyžích v obraze sekvenční termografie

2010 ◽  
Vol 4 (2) ◽  
pp. 109-118
Author(s):  
Jan Novotný ◽  
Jan Ondráček ◽  
Jan Novotný sr.
Keyword(s):  
Infrared Thermography ◽  
Paired Comparison ◽  
Wilcoxon Test ◽  
Graphic System ◽  
Temperature Changes ◽  
Change Of State ◽  
Rapid Changes ◽  
Baseline Temperature ◽  
Rapid Temperature ◽  
Dynamic Thermography

Twenty years ago it was shown that friction increases the temperature of snow skis. Change of state permits for water skis glide. Th e aim of this pilot study was to determine whether dynamic infrared thermography is able to capture rapid changes in temperature of snow some areas (not just at one point), the ski tracks before and aft er passing. We monitored the snow on the track aft er 60 races two runners in various weights (86 and 73 kg) on two types of skis and lubrication (for classic and skating cross) and three diff erent speeds (3,04±0,180, 3,81±0,273 a 5,30±0,314 m.s-1). Measurements of infrared radiation and the calculation of snow surface temperature immediately before and aft er passing skier was carried out thermo-graphic system FLIR SC620 with 30 Mhz. Nonparametric Wilcoxon test for paired comparison of values was found signifi cant increases in temperature aft er the snow cleared the skies: runner A from -3,71 to -3,50 °C (p=0,000000) and runner B from -3,75 na -3,50 °C (p=0,000000). To return to the baseline temperature is within 5 seconds aft er passing. Diff erences were demonstrated in the heat of snow between runners with diff erent masses and for the use of diff erent types of skis. Th e study confi rmed the ability of dynamic infrared thermography to register a very rapid temperature changes of snow in an area immediately before and aft er crossing the cross-country skiers. Dimensional dynamic thermography would seem to contribute to the choice of the correct strategy and lubrication in ski racing. However, it is necessary to make a series of validation studies.

scholarly journals Assessing the Risks of Vessel Icing and Aviation Hazards during Downslope Windstorms in the Russian Arctic

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 760
Author(s):  
Anna A. Shestakova
Keyword(s):  
Cold Season ◽  
Load Factor ◽  
Russian Arctic ◽  
Temperature Changes ◽  
Novaya Zemlya ◽  
Rapid Changes ◽  
Aviation Hazards ◽  
Rapid Temperature ◽  
Downslope Windstorms ◽  
Great Danger

Downslope windstorms are known sources of hazardous weather, such as severe gusty winds, rapid temperature changes, ship icing, strong turbulence and others, posing a great danger to people and infrastructure. This paper investigates the risks of ship icing and aviation hazards (rapid changes in the angle of attack and gust load factor) during downslope windstorms in five regions in the Russian Arctic based on observational data, reanalysis, and mesoscale numerical modeling. The highest frequency of ship icing was found during downslope windstorms downstream from Svalbard and Novaya Zemlya. Icing is rare during Tiksi and Wrangel Island downslope windstorms due to almost permanent sea ice cover during the cold season, while icing is absent during very warm Pevek downslope windstorm even in the ice-free conditions. Conditions for heavy icing are rather frequent (up to 5% of cases in winter) during Novaya Zemlya downslope windstorms and less frequent (up to 0.5% in spring) during Svalbard windstorm. The presence of downslope windstorms in those regions causes an increase in the maximum icing rate by about 2 times. Strong aviation turbulence hazardous for light aircraft is typical for all considered regions with downslope windstorms; it is observed mainly at an altitude of 1 to 4 km above the surface. Hazardous turbulence for jet aircraft like Boeing 737 on its cruising flight levels was found on Svalbard and in Tiksi region in 10–15% of cases during strong downslope windstorms.

Measuring Facial Skin Temperature Changes Caused by Mental Work-Load with Infrared Thermography

2016 ◽  
Vol 136 (11) ◽  
pp. 1581-1585 ◽  
Author(s):  
Tota Mizuno ◽  
Takeru Sakai ◽  
Shunsuke Kawazura ◽  
Hirotoshi Asano ◽  
Kota Akehi ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Infrared Thermography ◽  
Work Load ◽  
Facial Skin ◽  
Mental Work ◽  
Temperature Changes ◽  
Mental Work Load

A global perspective on tropical montane rivers

Science ◽  
2019 ◽  
Vol 365 (6458) ◽  
pp. 1124-1129 ◽  
Author(s):  
Andrea C. Encalada ◽  
Alexander S. Flecker ◽  
N. LeRoy Poff ◽  
Esteban Suárez ◽  
Guido A. Herrera-R ◽  
...  
Keyword(s):  
Biological Diversity ◽  
Ecosystem Processes ◽  
High Elevation ◽  
Global Perspective ◽  
Model Systems ◽  
Flow Disturbance ◽  
Tropical Mountains ◽  
Rapid Changes ◽  
Rapid Temperature ◽  
Biodiversity And Ecosystem Function

Tropical montane rivers (TMR) are born in tropical mountains, descend through montane forests, and feed major rivers, floodplains, and oceans. They are characterized by rapid temperature clines and varied flow disturbance regimes, both of which promote habitat heterogeneity, high biological diversity and endemism, and distinct organisms’ life-history adaptations. Production, transport, and processing of sediments, nutrients, and carbon are key ecosystem processes connecting high-elevation streams with lowland floodplains, in turn influencing soil fertility and biotic productivity downstream. TMR provide key ecosystem services to hundreds of millions of people in tropical nations. In light of existing human-induced disturbances, including climate change, TMR can be used as natural model systems to examine the effects of rapid changes in abiotic drivers and their influence on biodiversity and ecosystem function.

Infrared thermography reveals surface body temperature changes during proestrus and estrus reproductive phases in Gyr heifers (Bos taurus indicus)

2020 ◽  
Vol 92 ◽  
pp. 102662
Author(s):  
Rogério R. Vicentini ◽  
Yuri R. Montanholi ◽  
Renata Veroneze ◽  
André P. Oliveira ◽  
Maria L.P. Lima ◽  
...  
Keyword(s):  
Body Temperature ◽  
Infrared Thermography ◽  
Bos Taurus ◽  
Temperature Changes ◽  
Bos Taurus Indicus ◽  
Reproductive Phases

Neonatal Thermoregulation: Bed Surface Transfers

1999 ◽  
Vol 18 (4) ◽  
pp. 35-38 ◽  
Author(s):  
Leslie Altimier ◽  
Barbara Warner ◽  
Stephanie Amlung ◽  
Carole Kenner
Keyword(s):  
Birth Weight ◽  
Preterm Infants ◽  
Temperature Stability ◽  
Outcome Variable ◽  
Convenience Sample ◽  
Temperature Changes ◽  
Baseline Temperature ◽  
Main Outcome Variable ◽  
Radiant Warmer

Purpose: To describe temperature changes that occur in preterm infants following bed surface transfers.Design: The design was descriptive.Sample: The convenience sample was comprised of 20 preterm infants (<1,500 gm birth weight).Main outcome variable: Temperature stability after a bed transfer (i.e., radiant warmer to incubator) was the main outcome variable.Results: There were no significant differences in temperatures after bed surface transfer. However, the temperatures one hour after bed surface transfer were lower than baseline temperature before bed surface transfer.

scholarly journals Amplitude of sound waves in pipes

1926 ◽  
Vol 112 (762) ◽  
pp. 522-541 ◽  
Keyword(s):  
Optical Method ◽  
Sound Waves ◽  
Temperature Changes ◽  
Rapid Changes ◽  
Periodic Pressure ◽  
Air Motion ◽  
Organ Pipe ◽  
Pressure Changes ◽  
Considerable Doubt

There has always existed considerable doubt as to the magnitude of the periodic pressure changes, and the concomitant velocity and temperature changes which the air in a sounding organ pipe undergoes. The difficulty of following these rapid changes has prevented the success of many attempts, and results obtained by a few successful experimenters have not been in agreement. Kundt, and, later, Dvorak, using a manometer provided with a valve, which opened and shut with the frequency of the air oscillations in the pipe, measured the cumulative pressure of the condensations. Töpler and Boltzmann used an optical method. That part of a stopped pipe close to the node was fitted with glass windows and placed between the plates of a Jamin interferometer, so that part of the light which produced the interference bands in the instrument passed through and part outside the pipe. The interference bands appeared to be broadened when the pipe was sounded; from the extent of the broadening, the change of density or of pressure at the node due to the vibration was calculated. Raps obtained actual photographs of the oscillating bands, which the optical fatigue of the eye made to appear widened in the earlier experiments. A summary of their results is given in Table I. Of course, the oscillatory change of pressure will depend on the form of the pipe and the pressure at which it is blown, but with the average stopped diapason, blown at a few inches of water, the discrepancy between the results by different methods is still too great. Against the valve-manometer the criticism may be levelled that the motion of the air in the pipe is seriously affected by the motion of the valve pallet, which will cause additional variations of pressure in the pipe. Kundt's values are the highest (his maximum recorded amplitude was 1/16 atmosphere); Töpler and Boltzmann recorded 1/60, Raps 1/22. Interference methods have the advantage of leaving the air entirely undisturbed, but are troublesome both int their adaptation to existing pipes and in their interpretation, while slight vibration of the walls under the action of the sound waves or the blast produces shifts of the bands of the same order as those sought for in the air motion.

Sign in / Sign up

Export Citation Format

Share Document