scholarly journals Water-Stressed Plants Do Not Cool: Leaf Surface Temperature of Living Wall Plants under Drought Stress

2021 ◽  
Vol 13 (7) ◽  
pp. 3910
Author(s):  
Michael Gräf ◽  
Markus Immitzer ◽  
Peter Hietz ◽  
Rosemarie Stangl
Keyword(s):  
Drought Stress ◽  
Surface Temperature ◽  
Leaf Surface ◽  
Canopy Temperature ◽  
Infrared Camera ◽  
Control Group ◽  
Thermal Cameras ◽  
Living Wall ◽  
Leaf Level ◽  
Vertical Greening

Urban green infrastructures offer thermal regulation to mitigate urban heat island effects. To gain a better understanding of the cooling ability of transpiring plants at the leaf level, we developed a method to measure the time series of thermal data with a miniaturized, uncalibrated thermal infrared camera. We examined the canopy temperature of four characteristic living wall plants (Heuchera x cultorum, Bergenia cordifolia, Geranium sanguineum, and Brunnera macrophylla) under increasing drought stress and compared them with a well-watered control group. The method proved suitable to evaluate differences in canopy temperature between the different treatments. Leaf temperatures of water-stressed plants were 6 to 8 °C higher than those well-watered, with differences among species. In order to cool through transpiration, vegetation in green infrastructures must be sufficiently supplied with water. Thermal cameras were found to be useful to monitor vertical greening because leaf surface temperature is closely related to drought stress. The usage of thermal cameras mounted on unmanned aerial vehicles could be a rapid and easy monitoring system to cover large façades.

Research note: Leaf cooling curves: measuring leaf temperature in sunlight

2006 ◽  
Vol 33 (5) ◽  
pp. 515 ◽  
Author(s):  
Andrea Leigh ◽  
John D. Close ◽  
Marilyn C. Ball ◽  
Katharina Siebke ◽  
Adrienne B. Nicotra
Keyword(s):  
Surface Temperature ◽  
Close Agreement ◽  
Leaf Surface ◽  
Specular Reflection ◽  
Leaf Temperature ◽  
Cooling Curve ◽  
Cooling Curves ◽  
Infrared Studies ◽  
Leaf Level ◽  
The Difference

Despite the obvious benefits of using thermography under field conditions, most infrared studies at the leaf level are generally conducted in the laboratory. One reason for this bias is that accuracy can potentially be compromised in sunlight because reflected radiation from the leaf might affect the calculation of the temperature measurement. We have developed a method for measuring leaf temperature in sunlight by using thermal imagery to generate cooling curves from which the time constant for cooling, τ, can be calculated. The original temperature of the sunlit leaf may be determined by extrapolating backwards in time. In the absence of specular reflection, there is close agreement between the extrapolated sunlit temperature and the sunlit temperature recorded by the camera. However, when reflected radiation is high, the difference between the initial (incorrect) temperature determined from the sunlit image and the temperature extrapolated from the cooling curve can be > 2°C. Notably, our results demonstrate a close agreement between the extrapolated sunlit temperature and the temperature of the leaf approximately 1 s after being shaded, suggesting that this shaded image provides a good estimate of the original sunlit temperature. Thus, our technique provides two means for measuring leaf surface temperature in sunlight.

Characterization of Fouled Flat Sheet Membranes by Infrared Thermography

2014 ◽  
Author(s):  
Kennethrex O. Ndukaife ◽  
George Agbai Nnanna
Keyword(s):  
Surface Temperature ◽  
Infrared Thermography ◽  
Spectral Power ◽  
Membrane Surface ◽  
Infrared Camera ◽  
Feed Solution ◽  
Feed Concentration ◽  
Ir Camera ◽  
Measure Surface Temperature

An Infrared thermography (IRT) technique for characterization of fouling on membrane surface has been developed. The emitted spectral power from the fouled membrane is a function of emissivity and surface morphology. In this work, a FLIR A320 IR camera was used to measure surface temperature and emissivity. The surface temperature and the corresponding emissivity value of various areas on the fouled membrane surface is measured by the infrared camera and recorded alongside its thermogram. Different fouling experiments were performed using different concentrations of aluminum oxide nanoparticle mixed with deionized water as feed solution (333 ppm, 1833 ppm and 3333 ppm) so as to investigate the effect of feed concentration on the degree of fouling and thus its effect on the emissivity values measured on the membrane surfaces. Surface plots in 3D and Line plots are obtained for the measured emissivity values and thickness of the fouling deposit on the membrane surface respectively. The results indicate that the IRT technique is sensitive to changes that occur on the membrane surface due to deposition of contaminants on the membrane surface and that emissivity is a function of temperature, surface roughness and thickness of the specimen under investigation.

Response of Interspecific Hybrid Species of Manchurian Ash to MJ and NO Signals and Preliminary Study on the Formation Mechanism of Drought Resistance Advantage

2021 ◽  
Author(s):  
Yang Cao ◽  
fei song ◽  
Xingtang Zhao ◽  
Liming He ◽  
Yaguang Zhan
Keyword(s):  
Gene Expression ◽  
Drought Stress ◽  
Drought Resistance ◽  
Interspecific Hybrid ◽  
Normal Growth ◽  
Control Group ◽  
Physiological Indicators ◽  
Manchurian Ash ◽  
In The Wild ◽  
Set Up

Abstract Background: In this study, sodium nitrate (SNP, a donor of nitric oxide) and methyl jasmonate (MJ) were used as exogenous hormones. The experiment was conducted with the offspring (interspecific hybrid) D110 of ash and ash, and their respective parents (non-interspecific hybrid) D113 and 4-3 as experimental materials. The experiment set up three experimental groups of drought stress, exogenous hormone SNP and MJ, and a control group under normal growth (non-drought stress), to study the physiological indicators and gene expression of manchurian ash. Result: The results showed that under drought stress and exogenous application of hormone SNP or MJ, there were significant differences between hybrids and parents in plant growth, photosynthesis, defense enzyme activity, hormone content and gene expression.Conclusions: This experiment provides a new theoretical support for the existing hormone breeding methods of manchurian ash, which can improve the drought resistance of manchurian ash and increase its survival rate in the wild. Increasing the growth rate and breeding efficiency of manchurian ash brings new ideas.

scholarly journals In vitro assessment of wheat tolerance to drought

Genetika ◽  
2005 ◽  
Vol 37 (2) ◽  
pp. 165-171 ◽  
Author(s):  
Vladislava Galovic ◽  
Zorana Kotaranin ◽  
Srbislav Dencic
Keyword(s):  
Drought Stress ◽  
Nutrient Medium ◽  
Callus Tissue ◽  
Geographic Origin ◽  
Control Group ◽  
Zygotic Embryos ◽  
Fresh Weight ◽  
Effects Of Drought ◽  
In Vitro Effects

Analyzed in this paper were the in vitro effects of drought stress in 13 genotypes of winter wheat, one genotype of spring wheat, and three Triticale genotypes of different geographic origin. Callus tissue was induced from immature zygotic embryos (10-15 days after pollination) on a modified MS nutrient medium. After two weeks, callus tissue was transplanted onto the same medium enriched with 5% high-molecular polyethylene glycol (PEG 6000), which was used as the stress agent to produce the effect of drought chemically. A control group of calluses was grown on an identical medium but without PEG. After four weeks of growing calluses on these mediums, we assessed callus mass survival ability of the genotypes before the transplantation as well as percentage reduction of callus fresh weight after the transplantation onto the nutrient medium with 5% PEG. Statistically significant differences were found among the genotypes in their response to the induced stress. The best survival ability before the transplantation was found in the genotype Mexicol20 (83%), while the lowest was recorded in Slavija (11.3%). Culture growing under stress conditions significantly reduced callus fresh weight in all of the genotypes. The lowest decrease of the callus mass relative to control was recorded in Rozofskaja (14.4%) and the highest in Miranovska (58.4%), indicating the genotypes' tolerance levels towards drought stress.

scholarly journals Scheduling of irrigation in snap bean (Phaseolus vulgaris var. nanus) using canopy temperature

2005 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Helyes ◽  
Z. Pék ◽  
Gy. Varga ◽  
J. Dimény
Keyword(s):  
Phaseolus Vulgaris ◽  
Water Supply ◽  
Surface Temperature ◽  
Yield Loss ◽  
Canopy Temperature ◽  
Water Turnover ◽  
Snap Bean ◽  
Snap Beans ◽  
Yield Production ◽  
Spring Sowing

The present paper evaluates the result of irrigation experiments carried out on snap beans sown in spring and summer and grown with and without irrigation. The experiments were run over the course of 12 years. In the average of 12 years, the yield was 2.8t ha-I for spring sown and 1.9 t ha-I in summer-sown plants without irrigation. The lowest level of profitable production, the 5.5t ha-I was reached twice in the case of spring sowing and only once in the case of summer sowing. Profitable yield production can be ensured only with regular irrigation and thus the yield may be increased by 4-5 times. In four of the twelve years we determined the canopy surface temperature of snap bean stands with and without irrigation. A Raynger II infrared remote thermometer determined the canopy surface temperature every day at 13.00 hours. The canopy temperature can well characterize the water supply of plant stands. This parameter may be used for describing the degree of drought and the water turnover of plant stands with different water supply. The positive values of foliage-air temperature differences (SDD) numerically express the degree of drought and the water supply of the crops. The results indicated that a 1 °C higher SDD value may cause 90-130 kg/ha yield loss.

Surface Temperature Field Statistics at an Air/Water Interface for Grid-Generated Sub-Surface Turbulence

2002 ◽  
Author(s):  
Karen A. Flack ◽  
Geoffrey B. Smith
Keyword(s):  
Surface Temperature ◽  
Infrared Camera ◽  
Temperature Fields ◽  
Interface Temperature ◽  
Water Interface ◽  
Bulk Fluid ◽  
Air Water Interface ◽  
Evaporative Convection ◽  
The Difference ◽  
Oscillation Frequencies

Surface temperature fields and statistics are presented for the case of sub-surface grid-generated turbulence impacting an air/water interface. Temperature measurements are obtained with an infrared camera, sensitive in the 3–5 micron wavelength range. Results indicate that increased grid oscillation frequencies, and shallower grid depths, lead to increased surface mixing, yielding lower values of RMS temperature. Non-dimensionalization of the RMS temperatures using the difference in the average surface and the bulk fluid temperatures, collapses the data obtained for different grid depths and oscillation frequencies. This scaling is related to the thermal boundary layer thickness. The results are compared to the baseline case of turbulence due to evaporative convection without an oscillating grid.

scholarly journals The Feasibility of Identifying Defects Illustrated on Building Facades by Applying Thermal Infrared Images with Shadow

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 3
Author(s):  
Tsai ◽  
Huang ◽  
Tai
Keyword(s):  
Surface Temperature ◽  
Infrared Thermography ◽  
Infrared Camera ◽  
Thermal Infrared ◽  
Infrared Images ◽  
Building Facades ◽  
Thermal Infrared Images ◽  
Non Destructive

Infrared thermography (IRT) has been widely employed to identify the defects illustrated in building facades. However, the IRT covered with a shadow is hard to be applied to determine the defects shown in the IRT. The study proposed an approach based on the multiplicated model to describe quantitively the shadow effects, and the IRT can be segmented into few classes according to the surface temperature information recorded on the IRT by employing a thermal infrared camera. The segmented results were compared with the non-destructive method (acoustic tracing) to verify the correctness and robustness of the approach. From the processed results, the proposed approach did correctly identify the defects illustrated in building facades through the IRTs were covered with shadow.

Experimental Investigations and Finite-Element Modeling of Thermoplastic Effect during Tensile Tests of Metal Material

2013 ◽  
Vol 634-638 ◽  
pp. 2835-2838
Author(s):  
Wei Qing Wang ◽  
Li Yang ◽  
Shi Gui Lv
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Temperature Field ◽  
Surface Temperature ◽  
Strain Rate ◽  
Numerical Procedure ◽  
Infrared Camera ◽  
Tensile Tests ◽  
Experimental Investigations ◽  
Finite Element Software

During plastic deformation of materials, part of the plastic work is converted into heat, and the temperature field will be changed, this phenomenon is well known as thermoplastic effect. Based on the analysis of thermoplastic effect, the surface temperature of Q235 steel during quasi-static tensile tests was measured by using an infrared camera, and the surface temperature field and it versus time for different strain rate were obtained. A numerical procedure was devised to model the thermoplastic effect during the tensile tests by using ANSYS software. The results showed that, the heat loss during deformation process will be smaller as the strain rate increase, and the temperature increase on the specimen surface generated by the plastic deformation will be higher. The simulation results matched well with the experiment results showed that it was a good way to analyse the thermoplastic effect by the commercial finite element software.

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