Evaluation of the soft tissue thermal index and the maximum temperature increase for homogeneous and layered tissues

2003 ◽  
Author(s):  
D.S. Ellis ◽  
W.D. O'Brien
Keyword(s):  
Soft Tissue ◽  
Temperature Increase ◽  
Maximum Temperature ◽  
Thermal Index

scholarly journals Assessment of Effects of Laser Light Combining Three Wavelengths (450, 520 and 640 nm) on Temperature Increase and Depth of Tissue Lesions in an Ex Vivo Study

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5340
Author(s):  
Kamil Jurczyszyn ◽  
Witold Trzeciakowski ◽  
Zdzisław Woźniak ◽  
Piotr Ziółkowski ◽  
Mateusz Trafalski
Keyword(s):  
Duty Cycle ◽  
Temperature Increase ◽  
Ex Vivo ◽  
Visible Spectrum ◽  
Maximum Temperature ◽  
Lesion Depth ◽  
Single Beam ◽  
Duty Cycles ◽  
Rate Of Increase

Background: Lasers are widely used in medicine in soft and hard tissue surgeries and biostimulation. Studies found in literature typically compare the effects of single-wavelength lasers on tissues or cell cultures. In our study, we used a diode laser capable of emitting three components of visible light (640 nm, red; 520 nm, green; 450 nm, blue) and combining them in a single beam. The aim of the study was to assess the effects of laser radiation in the visible spectrum on tissue in vitro, depending on the wavelength and pulse width. Methods: All irradiations were performed using the same output power (1.5 W). We used various duty cycles: 10, 50, 80 and 100% with 100 Hz frequency. Maximum superficial temperature, rate of temperature increase and lesion depth were investigated. Results: Maximum superficial temperature was observed for 450 + 520 nm irradiation (100% duty cycle). The highest rate of increase of temperature was noted for 450 + 520 nm (100% duty cycle). Maximum lesion depth was observed in case of three-wavelength irradiation (450 + 520 + 640 nm) for 100, 80 and 50% duty cycles. Conclusions: The synergistic effect of two-wavelength (450 + 520 nm) irradiation was observed in case of maximum temperature measurement. The deepest depth of lesion was noted after three-wavelength irradiation (450 + 520 + 640 nm).

In vitro characterisation of ultrasound-induced heating effects in the mother and fetus: A clinical perspective

Ultrasound ◽  
2020 ◽  
pp. 1742271X2095319
Author(s):  
Stephanie F Smith ◽  
Piero Miloro ◽  
Richard Axell ◽  
Gail ter Haar ◽  
Christoph Lees
Keyword(s):  
Temperature Increase ◽  
Skin Surface ◽  
Maximum Temperature ◽  
Factors Affecting ◽  
Bone Interface ◽  
Heating Effects ◽  
Power Setting ◽  
Lower Temperature

Introduction The quantification of heating effects during exposure to ultrasound is usually based on laboratory experiments in water and is assessed using extrapolated parameters such as the thermal index. In our study, we have measured the temperature increase directly in a simulator of the maternal–fetal environment, the ‘ISUOG Phantom’, using clinically relevant ultrasound scanners, transducers and exposure conditions. Methods The study was carried out using an instrumented phantom designed to represent the pregnant maternal abdomen and which enabled temperature recordings at positions in tissue mimics which represented the skin surface, sub-surface, amniotic fluid and fetal bone interface. We tested four different transducers on a commercial diagnostic scanner. The effects of scan duration, presence of a circulating fluid, pre-set and power were recorded. Results The highest temperature increase was always at the transducer–skin interface, where temperature increases between 1.4°C and 9.5°C were observed; lower temperature rises, between 0.1°C and 1.0°C, were observed deeper in tissue and at the bone interface. Doppler modes generated the highest temperature increases. Most of the heating occurred in the first 3 minutes of exposure, with the presence of a circulating fluid having a limited effect. The power setting affected the maximum temperature increase proportionally, with peak temperature increasing from 4.3°C to 6.7°C when power was increased from 63% to 100%. Conclusions Although this phantom provides a crude mimic of the in vivo conditions, the overall results showed good repeatability and agreement with previously published experiments. All studies showed that the temperature rises observed fell within the recommendations of international regulatory bodies. However, it is important that the operator should be aware of factors affecting the temperature increase.

scholarly journals Effects of diurnal warming on soil respiration are not equal to the summed effects of day and night warming in a temperate steppe

2009 ◽  
Vol 6 (8) ◽  
pp. 1361-1370 ◽  
Author(s):  
J. Xia ◽  
Y. Han ◽  
Z. Zhang ◽  
Z. Zhang ◽  
S. Wan
Keyword(s):  
Soil Respiration ◽  
Temperature Increase ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Temperate Steppe ◽  
Positive Effects ◽  
Diurnal Warming ◽  
Night Warming

Abstract. The magnitude of daily minimum temperature increase is greater than that of daily maximum temperature increase under climate warming. This study was conducted to examine whether changes in soil respiration under diurnal warming are equal to the summed changes under day and night warming in a temperate steppe in northern China. A full factorial design with day and night warming was used in this study, including control, day (06:00 a.m.–06:00 p.m., local time) warming, night (06:00 p.m.–06:00 a.m.) warming, and diurnal warming. Day warming showed no effect on soil respiration, whereas night warming significantly increased soil respiration by 7.1% over the 3 growing seasons in 2006–2008. The insignificant effect of day warming on soil respiration could be attributable to the offset of the direct positive effects of increased temperature by the indirect negative effects via aggravating water limitation and suppressing ecosystem C assimilation. The positive effects of night warming on soil respiration were largely due to the stimulation of ecosystem C uptake and substrate supply via overcompensation of plant photosynthesis. Changes in both soil respiration (+20.7 g C m−2 y−1) and GEP (−2.8 g C m−2 y−1) under diurnal warming are smaller than their summed changes (+40.0 and +24.6 g C m−2 y−1, respectively) under day and night warming. Our findings that the effects of diurnal warming on soil respiration and gross ecosystem productivity are not equal to the summed effects of day and night warming are critical for model simulation and projection of climate-carbon feedback.

Heat generation associated with pressure-induced infiltration in a nanoporous silica gel

2008 ◽  
Vol 23 (7) ◽  
pp. 1902-1906 ◽  
Author(s):  
Aijie Han ◽  
Venkata K. Punyamurtula ◽  
Yu Qiao
Keyword(s):  
Energy Dissipation ◽  
Temperature Variation ◽  
Temperature Change ◽  
Silica Gel ◽  
Heat Generation ◽  
Temperature Increase ◽  
Maximum Temperature ◽  
Nanoporous Silica ◽  
Sorption Behavior ◽  
Multiple Loading

As a liquid moves in the nanopores of a silica gel, because of the hysteresis of sorption behavior, significant energy dissipation can take place. Through a calometric measurement, the characteristics of associated heat generation are investigated. The temperature variation increases with the mass of silica gel, which consists of a reversible part and an irreversible part. The residual temperature change is about 30% to 60% of the maximum temperature increase and can be accumulated as multiple loading cycles are applied.

Effect of Tree Shading on the Thermal Load of a House in a Warm Climate Zone in Mexico

2012 ◽  
Author(s):  
M. A. Chagolla ◽  
G. Alvarez ◽  
E. Simá ◽  
R. Tovar ◽  
G. Huelsz
Keyword(s):  
Temperature Increase ◽  
Energy Savings ◽  
Maximum Temperature ◽  
Warm Climate ◽  
Indoor Temperature ◽  
Maximum Temperature Difference ◽  
Energy Plus ◽  
Test House ◽  
Simulation Results ◽  
North Latitude

This paper presents the effect of the shade of a tree on the indoor temperature and thermal loads of a house (test house) located in the State of Morelos, Mexico, 18° 50′ 43″ north latitude and 99° 10′ 44″ west longitude. Energy Plus was used to simulate different geometries of the shadow of a tree and the simulation results were compared with experimental measurements of the house without air-conditioning, for one warm and one cold week of the year 2011. The results showed that the maximum temperature difference between the measured and simulated temperatures with both geometry models of tree-shading was 1.7°C. When the effect of tree shading is not considered, it was found that there is a maximum temperature increase of 4°C in the warm week compared with the measured results. In the cold week, the temperature increase was 1.3°C compared with the measured results. Simulation results for an air-conditioned tree-shaded test house show that total annual energy consumption for cooling and heating to achieve thermal comfort represents a substantial energy savings of 76.6% when compared with an unshaded house.

Extreme temperatures analysis: A study for Campinas, Brazil

2021 ◽  
Author(s):  
Guilherme Correia ◽  
Ana Maria Ávila
Keyword(s):  
Minimum Temperature ◽  
Temperature Increase ◽  
Heat Waves ◽  
Vulnerable Groups ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
P Value ◽  
Significance Level ◽  
Historical Series ◽  
Maximum Temperatures

<p>Extreme events such as heat waves have adverse effects on human health, especially on vulnerable groups, which can lead to deaths, thus they must be faced as a huge threat. Many studies show general mean temperature increase, notably, minimum temperatures. The scope of this work was to assess daily data of a historical series (1890-2018) available on the Instituto Agronômico de Campinas (IAC), in Campinas, using a suite of indices derived from daily temperature and formulated by the Expert Team on Climate Change Detection and Indices (ETCCDI) and evaluate trends. To compute the extreme indices RClimDex 1.1 was used. The significance test is based on a t  test, with a significance level of 95% (p-value<0,05). Temperature increase is undoubtedly through many indices, especially from 1980, as there is a continuous rise of the temperature. Annual mean maximum temperature rose from 26°C to 29°C, whereas many years consistently have more than 50 days with maximum temperatures as high as 31°C and more than 20% of the days within a year are beyond the 90th percentile of the daily maximum temperatures. Annual mean minimum temperature rose from 14°C to 18°C, whereas many years consistently have more than 150 days with minimum temperatures as high as 18°C and more than 30% of the days within a year are beyond the 90th percentile of the daily minimum temperatures. Therefore, results indicate the increase of minimum temperature is greater than the increase of maximum temperatures.</p>

The relevance of threaded external skeletal fixation pin insertion speed in canine bone with and without predrilling

2014 ◽  
Vol 27 (04) ◽  
pp. 249-256 ◽  
Author(s):  
M. C. Rochat ◽  
T. A. Snider ◽  
M. E. Payton ◽  
J. T. Walker
Keyword(s):  
Temperature Increase ◽  
Null Hypothesis ◽  
Thermal Damage ◽  
Insertion Site ◽  
Maximum Temperature ◽  
Minimal Effect ◽  
Thermal Necrosis ◽  
Pilot Hole ◽  
Damage Data ◽  
Insertion Sites

SummaryObjectives: The effects of insertion speed in revolutions per minute (RPM) and pilot hole predrilling for placement of threaded external skeletal fixation pins on temperature and morphological damage in cortical bone were evaluated. The null hypothesis states that insertion speed and predrilling will have no significant effect on temperature and morphological damage.Methods: Fixation pins were inserted into cadaveric canine femurs at speeds of 700 RPM and 150 RPM, with and without predrilling. Temperature was measured at each cortex 0.5 mm and 3.0 mm from each insertion site. Samples were examined grossly and by scanning electron microscopy for evidence of morphological damage. Data were analysed for maximum temperature, temperature increase, sites above thermal necrosis thresholds, microcracks, thread quality and gross damage.Results: Predrilling had a significant effect on maximum temperature, temperature increase, sites exceeding necrosis thresholds, microcracks, thread quality and gross damage. Speed of insertion had no significant effect on any of the measured parameters following predrilling, but had a significant effect on thread quality without predrilling.Clinical significance: Our results fail to reject the null hypothesis concerning insertion speed, which had no significant effect on thermal damage, and minimal effect on morphological damage, which was negated by predrilling. Our results reject the null hypothesis concerning predrilling and support the practice of predrilling fixation pin insertion sites.

An experiment to test the potential for glass fragments to ignite wildland fuels

2009 ◽  
Vol 18 (7) ◽  
pp. 885 ◽  
Author(s):  
Klaus-Peter Wittich ◽  
Tanja Müller
Keyword(s):  
Forest Fires ◽  
Temperature Increase ◽  
Ignition Source ◽  
Maximum Temperature ◽  
Glass Fragment ◽  
Glass Bottle ◽  
Northern Germany ◽  
Current Opinion ◽  
Spruce Needles ◽  
Realistic Experiment

It is current opinion that glass fragments can serve as an ignition source for grassland, bush and forest fires by focussing sunlight. In order to check the validity of this assumption, ignition experiments were conducted in the open over six litter samples taken from forests in northern Germany. Of several glass fragments, the five bottle bottoms best focussing sunlight were installed 15–50 cm above the litter materials. We found that one bottle bottom was able to slightly char spruce needles, beech leaves and blades of grass. Although this particular bottle bottom let the temperature increase up to 327°C, flame formation did not occur. A secondary (but more realistic) experiment with a glass-bottle bottom lying on the litter led to a maximum temperature of 82°C in the space between the litter and the glass fragment.

Sign in / Sign up

Export Citation Format

Share Document