The characteristics of plumes during continuous wave laser irradiation of laminated carbon fiber reinforced plastics (CFRP) under tangential air flow or nitrogen gas flow are investigated. The ...temperature of the plume is measured by the infrared thermal imager. The change in relative mass concentration of the plume is studied by the laser extinction method. The front surface emissivity-corrected temperature maps of CFRP are measured by the infrared thermal imager to estimate the influences of plumes. The highest temperature in the plume is closely related to the absorption of the laser by the plume rather than the combustion effects of the plume. The differences of the plumes, temperature, the material surface temperature and the heat affect zone, under the two different kinds of gas flows, are all due to the effect of the burning of the plume under air flow. As the mass concentration of plumes decreases, these differences gradually disappear or no longer increase. The results of this work can be referenced for the application of the laser processing and the laser damage.
During the coronavirus 2019 (COVID-19) pandemic, the implementation of non-contact infrared thermometry (NCIT) became an increasingly popular method of screening body temperature. However, data on ...the accuracy of these devices and the standardisation of their use are limited. In the current study, the body temperature of non-febrile volunteers was measured using infrared (IR) thermography, IR tympanic thermometry and IR gun thermometry at different facial feature locations and distances and compared with SpotOn core-body temperature. Poor agreement was found between all IR devices and SpotOn measurements (intra-class correlation coefficient <0.8). Bland–Alman analysis showed the narrowest limits of agreement with the IR gun at 3 cm from the forehead (bias = 0.19°C, limits of agreement (LOA): −0.58°C to 0.97°C) and widest with the IR gun at the nose (bias = 1.40°C, LOA: −1.15°C to 3.94°C). Thus, our findings challenge the established use of IR thermometry devices within hospital settings without adequate standard operating procedures to reduce operator error.
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GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
ABSTRACTSepsis continues to be a major challenge for modern medicine. Several preclinical models were developed to study sepsis and each has strengths and weaknesses. The cecal slurry (CS) method is ...a practical alternative because it does not require surgery, and the infection can be dosed. However, one disadvantage is that the dosage must be determined for each CS preparation using survival studies. Our aim was to refine a survival protocol for the CS model by determining a premonitory humane endpoint that would reduce animal suffering. Mice become hypothermic in sepsis; therefore, we tested whether reductions in surface temperature (Ts), measured by noninvasive infrared thermometry, could predict eventual death. We injected 154 C57BL/6J mice with CS (0.9–1.8 mg/g) and periodically monitored Ts at the xiphoid process over 5 days. We used, as predictors, combinations of temperature thresholds (29°C –31°C) and times, postinjection (18–36 h). A receiver-operator curve, sensitivity, and specificity were determined. A Distress Index value was calculated for the threshold conditions. The optimum detection threshold (highest Youden index) was found at Ts ≤ 30.5°C at 24 h (90% specific, 84% sensitive). This threshold condition reduced animal suffering by 41% while providing an accurate survival rate estimate. Using this threshold, only 13 of 154 mice would have died from sepsis; 67 would have been euthanized at 24 h, and only 7 of 154 would have been euthanized unnecessarily. In conclusion, using a humane endpoint of Ts ≤ 30.5°C at 24 h accurately predicts mortality and can effectively reduce animal suffering during CS survival protocols.
To evaluate the effectiveness of a foot self-management strategy that utilized a commercially-available infrared thermometer (CAIT) for prevention of diabetic foot ulcers.
In this six-month pilot ...randomized controlled trial, Phase 2 of a three-phase mixed methods research study, 62 participants were randomized to a thermometer and education group (n = 34) and an education-only group (n = 26). Both groups received foot care education and were assessed by a certified orthotist. All participants recorded their number of steps and recorded a foot assessment in a logbook daily. The thermometer and education group also recorded their daily temperature assessment. A temperature difference of >4° Fahrenheit (F) between the two feet prompted participants to rest their feet. Participants were directed to see their healthcare provider if the temperature difference did not decrease to below 4° F in two days. Phase 3 of the study explored the Phase 2 results to understand the findings further.
The strategy improved foot assessment and action: the thermometer and education group had significantly more days with any assessment completed than the education-only group (150.98/180 vs. 119.84/180, p = 0.02). Phase 3 findings showed that the thermometer engaged participants, prompted action, and offered reassurance regarding foot health.
A CAIT is a tool that could support foot self-management and may offer several benefits, such as promoting and providing structure for a foot assessment and direction for action.
NCT0306776 clinicaltrials.gov.
•Monitoring of foot temperature with a medical-grade thermometer is a strategy to help patients identify inflammation that could lead to an ulcer.•We wanted to ask whether daily temperature monitoring with a low-cost commercially available infrared thermometer supports self-management.•We found that the strategy engaged patients, improved foot assessment, and prompted action to address foot concerns.•The low-cost commercially available thermometer is a tool that could support foot self-management and prevent foot ulcers.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
•Direct experimental measurement of wall heat flux partitioning was performed.•Bubble area of influence factor significantly affected the wall heat flux partitioning.•Optimum value of bubble area of ...influence factor was found to be 0.5.•Correction for overlapping area of influence of merging bubbles was proposed.
Heat transfer models in liquid-vapor two-phase flow with wall boiling rely on the wall heat flux partitioning to quantify heat transfer to liquid and vapor separately. Several wall heat flux partitioning models have been proposed over the years based on variety of heat transfer mechanisms, but the three basic mechanisms that form the core of these models are liquid convection, surface quenching and evaporation heat transfer. A key parameter commonly used to determine the relative contribution made by each mechanism is area fraction of influence of bubble which is determined by multiplying maximum bubble projected area fraction with bubble area of influence factor (K). In classic wall heat flux partitioning models, K accounts for the area within which heat is transferred to liquid that moves in towards the heated wall as bubbles lift-off. The value of K has been a subject of controversy over the years with no unanimous conclusion among researchers. Therefore, in this paper, advanced diagnostic approach involving the combination of infrared thermometry and total reflection principle was employed to experimentally study nucleate flow boiling. Rigorous data analyses was performed to partition the wall heat flux into the aforementioned three basic heat transfer mechanisms using different values of K. All three heat transfer mechanisms were significantly sensitive to varying values of K, but setting K = 0.5 with percentage uncertainties of −60%/+50% closely predicted the experimental measurements. In addition, overlapping area of influence due to merging bubbles was observed to be significant in the model at high heat flux condition and must be discounted to get the true bubble area of influence. A correction method for the overlapping area of influence was therefore proposed to enhance accuracy of the predictive model.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Temperature measurements based on spectral radiation are often limited by prior knowledge of target surface properties and detector sensitivity. Here the present work describes a multispectral ...pyrometry method for temperature estimation that does not require information on surface emissivity or calibration. Digital camera simulations considering a silicon-based sensor and five bandpass filters are used to create synthetic images of targets. The detector sensitivity is compensated via high dynamic range imaging technique. The effect of natural and detector noise on temperature estimates is assessed via Monte Carlo simulations. Results from a wavelength-independent model (Gray) are compared with those from the Band model (with emissivity varying between constant spectral bands). The effect of detector dynamic range and spectral position of bandpass filters is discussed. Temperatures as low as 520 K are obtained, with an overall uncertainty of the order of 10 K. The proposed method is applicable to temperature measurements using commercial-grade CMOS/CCD cameras.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
•Comprehensive Stress Indicator and stem water potential were reasonably correlated.•Comprehensive Stress Indicator is derived from energy balance of a leaf.•Comprehensive Stress Indicator does not ...depend on a lower baseline.
This study evaluated a comprehensive plant water stress indicator that integrates the leaf temperature and the environmental conditions that can provide feedback on the plant response to irrigation scheduling. This quantity—Comprehensive Stress Indicator (CSI)—is based on the reformulation of the leaf energy balance equation. Specifically, CSI is the ratio of the temperature difference between a dry leaf (i.e., a leaf with a broken stem) and a live leaf (on the same tree) i.e., Tdry-Tleaf and the difference between the vapor pressure inside the stomatal cavity at saturation and the vapor pressure of the air at ambient temperature i.e., es(TL)-e(TA). The required measurements to compute CSI include dry leaf temperature, live leaf temperature, relative humidity, and air temperature at the tree being monitored. In this study, all measurements were obtained using a sensor suite called the leaf monitor. Leaf monitors were connected to a wireless mesh network to communicate the data to a website. The leaf monitor included two thermal infrared sensors, one for the dry leaf and one for the live leaf, both of which were housed in the same unit with almost identical environmental conditions due to a diffusing hemispherical dome that enclosed these sensors. The CSI is a dynamic indicator with a value for every data sample collected. For a single indicator representing each day, the CSI was evaluated in two ways. First, the CSI was integrated with respect to time from 10 A.M. to 6 P.M. to obtain the Integrated Comprehensive Stress Indicator (ICSI). Second, the CSI was averaged from 1 P.M. to 3 P.M. to obtain the Average Comprehensive Stress Indicator (ACSI). Both ICSI and ACSI were compared to other stress indicators, including the existing Crop Water Stress Index (CWSI) and Integrated Degrees Above Non-Stressed (IDANS). Results show that ICSI and ACSI are satisfactorily correlated with midday stem water potential (SWP). The ICSI and ACSI indicators may be more convenient than other stress indicators because they require measurements only at the tree being monitored.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Efficiency in power lines operation is becoming more crucial as the electrification increases and more renewable energies are connected into the grid. New methods and sensors are being added to ...create smart grids to face these challenges and conductor temperature sensors are one of them. Contact temperature sensors have several problems regarding safety and electronic damage due to the electromagnetic fields induced on the conductors. The goal of this paper is to describe an infrared temperature measurement sensor and to compare contact and non-contact temperature measurements to estimate the temperature of power lines. Measurements were done for almost a year, storing around 150,000 measures of contact and infrared thermometers for many different weather and load conditions. The results conclude that the infrared system can be successfully used to control the temperature of the overhead conductor within a range of less than 4 ∘C difference with respect to contact temperature methods for the 88% of the samples and less than 6 ∘C for the 99%.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This study was conducted to develop the relationship between canopy–air temperature difference and vapour pressure deficit for no stress condition of wheat crop (baseline equations), which was used ...to quantify crop water stress index (CWSI) to schedule irrigation in winter wheat crop (
Triticum aestivum L.). The randomized block design (RBD) was used to design the experimental layout with five levels of irrigation treatments based on the percentage depletion of available soil water (ASW) in the root zone. The maximum allowable depletion (MAD) of the available soil water (ASW) of 10, 40 and 60 per cent, fully wetted (no stress) and no irrigation (fully stressed) were maintained in the crop experiments. The lower (non-stressed) and upper (fully stressed) baselines were determined empirically from the canopy and ambient air temperature data obtained using infrared thermometry and vapour pressure deficit (VPD) under fully watered and maximum water stress crop, respectively. The canopy–air temperature difference and VPD resulted linear relationships and the slope (
m) and intercept (
c) for lower baseline of pre-heading and post-heading stages of wheat crop were found
m
=
−1.7466,
c
=
−1.2646 and
m
=
−1.1141,
c
=
−2.0827, respectively. The CWSI was determined by using the developed empirical equations for three irrigation schedules of different MAD of ASW. The established CWSI values can be used for monitoring plant water status and planning irrigation scheduling for wheat crop.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Heat transfer plays a key role in polymer extrusion based additive manufacturing (AM) processes. Measurement and modeling of how temperature distribution on the platform bed changes with time during ...the dispensing of a polymer filament is of particular interest, as it determines the effectiveness of merging with neighboring filaments, and therefore, the properties of the built part. This paper reports infrared thermography based measurement of temperature field on the platform bed as a function of time during filament dispense and comparison with an analytical model based on moving heat source theory. Measurements identify two key heat transfer processes that influence temperature distribution on the bed. Data show that diffusion of thermal energy deposited on the bed with the filament and heat transfer from the hot nozzle tip both influence the temperature distribution on the bed. The relative contributions of these two sources of temperature rise on the bed are measured for different values of key process parameters. Measurement of temperature rise due to diffusion of thermal energy deposited on the bed is found to be in excellent agreement with an analytical model based on moving heat source theory. Evolution of the temperature field after completion of rastering of a line is measured. These data play a critical role in determining how effectively a filament merges with neighboring filaments. By identifying the key heat transfer processes that determine the temperature field on the platform bed, this work contributes towards thermal optimization of polymer-based additive manufacturing.
•Presents temperature field measurement in polymer AM using infrared thermometry.•Identifies two key processes that influence temperature field on platform bed.•Results may help optimize heat transfer processes during polymer AM.•Results may be used for designing process for parts with desired properties.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
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