There is a growing interest of using canopy temperature (Tc) based methods, including crop water stress index (CWSI), for irrigation management. However, different approaches exist to normalize Tc to ...microclimatic conditions, which can influence the accuracy and suitability of CWSI for irrigation scheduling. This study evaluated the performance of CWSI computation approaches and their sensitivity to changes in soil water depletion under different water stress levels. There were six different approaches – two empirical methods using developed lower baseline (i.e., CWSI-EB1, CWSI-EB2), two empirical methods using either artificial (CWSI-EA) or actual/natural (CWSI-EN) canopy reference surfaces, and two theoretical approaches which differ by how aerodynamic and canopy resistances are determined (CWSI-Th1, CWSI-Th2). Stationary infrared thermometers (IRTs) provided continuous Tc to calculate CWSI-EB, CWSI-Th, and CWSI-EN; whereas mobile IRTs and a thermal camera provided one-point-in-time Tc and temperatures of artificial canopy reference surfaces to calculate CWSI-EA. These measurements were all collected from full and deficit irrigated and rainfed maize plots in West Central Nebraska. Day-to-day variations within and across CWSI approaches were evident and their sensitivity to soil water depletion varied. Greater sensitivity and correlation strength to depletion (Dr,i) were observed with CWSI-Th and CWSI-EB under severe stress (i.e., Dr,i > 80%) at deeper soil depths of 1.8 and 2.1 m, producing r2 which ranged from 0.61 to 0.80 (slope: 0.03–0.05) and 0.69–0.79 (slope: 0.03–0.04), respectively. Observed differences in stress magnitudes among approaches and treatments, warrants a specific irrigation triggering threshold for each approach. Additionally, developing a robust index coupling both CWSI and soil water depletion is desirable to improve irrigation water management by accounting for both soil and plant water status.
•Theoretical and empirical CWSI methods were evaluated under different stress levels.•CWSI sensitivity to soil water depletion was assessed at different soil depths.•CWSI was more sensitive to soil water depletion when depletion exceeded 80%.•CWSI approaches varied differently to water stress in irrigated and rainfed settings.•Different irrigation scheduling thresholds are recommended for CWSI methods.
•Thermal stress thresholds automate variable rate irrigation management.•Irrigation scheduling with soil water and canopy temperature sensors optimize grain yield.•Time domain reflectometer sensors ...prevent over- and under-irrigation of sorghum.
Automated irrigation scheduling of grain crops using a combination of plant and soil water sensing feedback has not been widely investigated. A three-year study was conducted at Bushland, Texas to investigate irrigation management of grain sorghum (Sorghum bicolor, L.), in 2012 using plant feedback with a single thermal stress threshold, and in 2018 and 2019 using multiple thermal stress thresholds and a combination of plant and soil water sensing (Hybrid) feedback. The goals of the studies were to optimize grain yield, crop water productivity (CWP) and irrigation water productivity (IWP) using sensor feedback at irrigation levels similar to 80 %, 50 % and 30 % (designated I80, I50 and I30) replenishment of soil water depletion to field capacity as determined with weekly neutron probe readings (the “manual” method). Results in 2012 indicated that irrigation scheduling using plant feedback alone with a single thermal stress threshold produced grain yields that were significantly less (0.49 and 0.38 kg m−2) compared with the manual method (0.63 and 0.51 kg m−2) at the I80 and I50 treatment levels, respectively. However, in 2018, the Hybrid feedback method produced mean grain yields (0.87 kg m−2) that were significantly greater compared with the plant feedback (0.76 kg m−2) and manual (0.74 kg m−2) irrigation scheduling methods at the I80 treatment level. In 2019, mean grain yields (0.86, 0.83 and 0.88 kg m−2), CWP (1.25, 1.29 and 1.20 kg m-3) and IWP (2.11, 2.19 and 1.88 kg m-3) for the Hybrid, plant feedback and manual methods, respectively, were similar at the I80 level. These results suggest that plant and soil water sensing feedback using multiple thermal stress thresholds and watering levels have the potential to produce optimal crop response for grain sorghum. More research is required to test the efficacy of soil water sensing in combination with plant sensing for other crops.
Irrigation has a great impact on global food security as it contributes to the majority of the world’s agricultural food supply. It is essential to judiciously utilize water resources through ...efficient irrigation management since the majority of U.S. groundwater aquifers are rapidly depleting. Thus, quantification of the relationships between water depletion and environmental factors is important for understanding crop response to varying levels of water stresses that depletion can cause. The objectives of this research were to: 1) investigate the relationship between root zone water depletion (Drw) and canopy temperature differential (ΔT) at different ranges of Drw; and 2) develop upper (water stressed) and lower (non-water stressed) baselines for quantification of crop water stress index (CWSI) in a sub-humid climate. The research was conducted over maize and soybean during 2018, 2019, and 2020 growing seasons. Sensor node stations comprising of an infrared thermometer and three soil water sensors were installed at various sites over maize and soybean fields. ΔT tends to increase with the increase in Drw when the range of Drw includes values greater than 170 mm for maize and values greater than 160 mm for soybean. The results indicate that ΔT and Drw are unrelated until a soil-water depletion threshold is attained, and these Drw threshold values could be considered as indicators to trigger irrigation for efficient agricultural water management. To the best of the authors’ knowledge, the research is the first to develop upper and lower CWSI baselines for east-central Nebraska. The baselines developed in this study could facilitate the quantification of CWSI for irrigation scheduling of maize and soybean in east-Central Nebraska. Future work should aim to investigate the potential in using Drw and/or ΔT to determine efficient water allocation and if a threshold CWSI could be used for timing of irrigation to prevent yield loss.
•Inter-relationship between water depletion and temperature differential was studied.•Water-stressed and non-water-stressed baselines were developed for sub-humid regime.•The research was carried on maize and soybean over three growing seasons.•Temperature differential increases with increasing water depletion beyond threshold.•The threshold value could be considered as indicator to prescribe irrigation regime.
Coronavirus disease 19 (COVID-19) is a virus that spreads through contact with the respiratory droplets of infected persons, so quarantine is mandatory to break the infection chain. This paper ...proposes a wearable device with the Internet of Things (IoT) integration for real-time monitoring of body temperature the indoor condition via an alert system to the person in quarantine. The alert is transferred when the body thermal exceeds the allowed threshold temperature. Moreover, an algorithm Repetition Spikes Counter (RSC) based on an accelerometer is employed in the role of human activity recognition to realize whether the quarantined person is doing physical exercise or not, for auto-adjustment of threshold temperature. The real-time warning and stored data analysis support the family members/doctors in following and updating the quarantined people's body temperature behavior in the tele-distance. The experiment includes an M5stickC wearable device, a Microelectromechanical system (MEMS) accelerometer, an infrared thermometer, and a digital temperature sensor equipped with the user's wrist. The indoor temperature and humidity are measured to restrict the virus spread and supervise the room condition of the person in quarantine. The information is transferred to the cloud via Wi-Fi with Message Queue Telemetry Transport (MQTT) broker. The Bluetooth is integrated as an option for the data transfer from the self-isolated person to the electronic device of a family member in the case of Wi-Fi failed connection. The tested result was obtained from a student in quarantine for 14 days. The designed system successfully monitored the body temperature, exercise activity, and indoor condition of the quarantined person that handy during the Covid-19 pandemic.
•Three NDT with different principles, to the detection of damage in paving.•The union of the different data implies integral knowledge of the paving materials.•Fault identification by the combined ...interpretation of inner and superficial data.•Results validate the application of each technique for damage detection.•Individual techniques are reinforced, the combination does not nullify single use.
In order to preserve the condition of infrastructure and guarantee its usability, the availability of inspection techniques is essential, provided these are able to determine the condition of the infrastructure causing minimum disturbance and post-inspection consequences. Non-destructive techniques present characteristics to reach all these requisites, especially regarding time minimization. With the objective of reaching maximum data extent and accuracy, this paper proposes the joint use and interpretation of three techniques: ground-penetrating radar (GPR) for the detection of inner pathologies, infrared thermography (IRT) for the evaluation of the state of the subsurface of the structure, and terrestrial laser scanning (TLS) for the accurate measurement of geometry and detection of external defects. Each technique acquires data of different nature and different parts of the infrastructure, in such way that their interpretation in an integrated way allows for the accurate detection of superficial and inner pathologies, as well as their location and measurement of dimensions. The joint application of the techniques mentioned has been tested in a road next to the sea, composed by different fill materials placed in order to increase the extent of land towards the water, and deteriorated by the use and the erosion provoked by seawater.
Mobile infrared thermometers (IRTs) mounted on moving platforms provide one-time-of-day radiometric measurements (Tr), which can be used to calculate instantaneous actual evapotranspiration (ETa) ...using the two-source energy balance (TSEB) model. However, irrigation scheduling decisions utilize daily ETa estimates, hence the need for time scaling. This study evaluated different upscaling methods to calculate daily maize ETa using one-time-of day Tr under varying water stress conditions. Mobile IRTs were mounted on a high clearance mobile sensing platform and collected Tr in remote locations under full, deficit and rainfed conditions. Seven scaling methods via two pathways were employed to obtain daily ETa. First pathway was scaling one-time-of-day Tr (SC) whereas the second pathway involved use of six upscaling methods of instantaneous ETa including: original and modified evaporative factor ((EF)o, (EF)m) as well as crop coefficient ((Kc)o, (Kc)m), direct canopy resistance (Direct- rc), and solar radiation ratio (Rn/Rs); and all were compared to a neutron-based soil water balance (SWB) determined ETa. From the results, SC outperformed other methods in comparison to SWB ETa across all the selected treatments with smaller discrepancies and lower RMSE (0.9–1.7 mm d−1 vs. 0.7–4.3 mm d−1 for other methods). Furthermore, methods including SC, (EF)o, (EF)m, and Rn/Rs had their daily average ETa values in close agreement to SWB ETa with mean ETa differences ranging between 0.2 and 1.6 mm d−1. Overall, SC method performed better in fully irrigated maize (r2 = 0.52, RMSE = 0.9 mm d−1) than in deficit irrigated maize ( r2 = 0.48, RMSE = 1.4 mm d−1) but worst in rainfed maize (r2 = 0.16, RMSE = 1.7 mm d−1). This implies that SC is more suited for irrigated rather than rainfed settings. Importantly, the choice of any method depends on data requirements, irrigation water management strategy, and ETa estimation accuracy.
•Infrared thermometers (IRTs) mounted on a mobile platform provide one-time-of-day radiometric temperatures (Tr).•Two source energy balance (TSEB) with Tr measurements provide estimates of actual evapotranspiration (ETa).•Different scaling approaches provide daily ETa via two pathways (scaling Tr vs. instantaneous ETa); and all were compared to daily soil water balance ETa.•Water stress impacts the accuracy of daily ETa estimation and better results achieved in irrigated treatments more so with Tr time scaling method.•Preference of scaling method entirely depend on data requirements and accuracy.
Dengue is endemic in over 100 countries and is an important public health problem worldwide. Dengue fever is not endemic in Taiwan; the importation of dengue viruses from neighboring countries via ...close commercial links and air travel is considered to be the cause of local outbreaks. Therefore, efforts toward disease control have focused on preventing the importation of dengue into Taiwan. In this study, we investigated the relationships between the numbers of imported and indigenous dengue cases to test the validity of this strategy.
Data on cases of dengue fever that occurred between 2013 and 2018 were obtained from the surveillance systems of the Taiwan Center for Disease Control and Kaohsiung City Health Department. Standard epidemiological data, including the monthly numbers of indigenous and imported cases of dengue, were calculated. Potential associations between the numbers of indigenous and imported cases were investigated using correlation analyses.
We identified a possible relationship between the period of disease concealment and the number of imported dengue cases, which resulted in epidemics of indigenous dengue fever within local communities. Further analysis of confirmed cases during previous epidemics in Kaohsiung City found that the risk of indigenous dengue fever may be related to the likelihood that patients with imported dengue fever will stay within local communities.
Given the correlations found between imported and indigenous cases of dengue fever, as well as the relationship between the disease concealment period and the risk of indigenous dengue fever, prevention of disease importation and efficient identification of dengue cases within high-risk communities remain the major priorities for disease control.
Purpose
The main objective of this work was to evaluate, in laboratory, the reliability of temperature measurements performed by forehead infrared radiation thermometers (FIRTs), widely employed for ...body temperature measurements as a policy for preventing the spread of Covid-19. Additionally, the suitability of commercial infrared thermometer calibrators for the characterization of those FIRTs was assessed.
Methods
Eighteen FIRTs of ten different models available in the Brazilian market were calibrated employing a commercial flat-plate infrared thermometer calibrator and a custom-designed blackbody cavity as reference thermal radiation sources. The thermometers were assessed with respect to their accuracy and reproducibility, under laboratory conditions, according to the ISO/IEC 8061–2-56:2017 standard. The FIRTs were calibrated both in
direct
(uncorrected) and
adjusted
(corrected for estimating the temperature in a specific body site) modes.
Results
The results showed that only 50% of the FIRTs evaluated were approved in the laboratory accuracy tests, performed in direct mode. In adjusted mode, the agreement of the measurements performed by different models was very poor when compared with each other. The results also showed good agreement between the calibration results performed by the blackbody cavity and the commercial infrared calibrator, despite the high uncertainties obtained with the latter.
Conclusion
The results found show that the FIRTs available in the market are not, in general, reliable instruments for detecting febrile individuals. This conclusion is based on the poor agreement of the measurement results obtained with different FIRT models in adjusted mode, even though some models have shown good performance when assessed in direct mode, under laboratory conditions. In the absence of a skin temperature standard, clinical tests with real people are necessary to confirm the results found in this study. The results also show that even though there is good agreement between the measurements performed with the calibrator and the blackbody cavity, the uncertainties of the measurements performed with the calibrator are still too high to support the use of these devices for testing FIRTs with sufficient accuracy.
Body Temperature is one of the most common and an important sign of health and disease. Considering the need of keeping physical distance, newer methods have evolved such as; thermal imaging systems ...which have been used by several countries during epidemics. Therefore, the present study was conducted to compare body temperatures obtained with thermo graphic camera and commercially available thermal gun with reference to standard digital clinical thermometer.
The study was comparative analytical in nature and quantitative method was used to collect data. Temperatures in degrees Fahrenheit were taken simultaneously using the three different thermometers in 101 patients at the outpatient fever screening clinic at Tribhuvan University Teaching Hospital, Kathmandu. The Bland Altman statistical test was used to assess the concordance by the 95% limits of agreement.
The thermo-graphic camera gave concordance (limits of agreement-0.0360 to 0.0440 °F) with standard digital clinical thermometer. Similarly, commercially available thermal gun gave the concordance (limits of agreement 0.0042 to 0.1293 °F) with standard digital clinical thermometer.
The results of the present study show that both thermo-graphic camera and thermal gun were found to be concordant compared to digital clinical thermometer. Therefore, it could be a preferable option for the screening of fever in mass number of individuals as part of an initial check at entry points.
Between August 31st and September 4th 2020 in a tertiary care hospital in Seoul, the fever detection rate by infrared thermoscanning camera at the gates was 0.002% (95% confidence interval CI, ...0.001%-0.006%) and that by manual fever check at the outpatient clinics was 0.02% (95% CI, 0.01%-0.03%) (
< 0.001). The difference strongly suggests that sensitivity of the thermoscanning camera in the market must be upgraded.
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