The emotional valence hypothesis suggests an increased left-brain hemisphere activation during positive situations and vice versa during negative situations. Since facial thermal asymmetries may reflect lateralised brain activity, we investigated this in dairy calves subjected to hot-iron disbudding (Disbudded; n = 12) as a model of negative affective states. As affective responses can vary due to previous experiences, we examined whether calves that had (ExpObs; n = 12) and had not (InexObs; n = 12) experienced disbudding differed in their thermal response to a conspecific being disbudded, and whether calf response to the researcher (approaching, moving away, not moving) was associated with thermal asymmetries. We made thermographic recordings of each calf on three days: Day before disbudding (D1); Disbudding day (D2); and Day after disbudding (D3), and at two different times: Disbudding time/1400(T1) and Afternoon/1700(T2). Data were analysed using multilevel models. Calves had warmer left ears on D2 compared to higher temperatures on the right ear on D1, suggesting higher right-hemisphere activity on D2. ExpObs calves had higher left-eye temperatures when observing a conspecific being disbudded (D2×T1) than InexObs calves that had warmer right eyes, but this reversed on the following day (D3×T1). Calves avoiding the researcher had warmer left eyes whereas those approaching him had warmer right eyes, suggesting greater activation of the right hemisphere in the former. This study provides initial evidence of temperature asymmetries when observing or experiencing a negative event. Further work is required to confirm and build upon these early findings. The study highlights the potential for future development of methods using infrared thermography as a proxy measure of affective valence.

The present paper describes the results of an experimental wind tunnel test campaign aimed at investigating the aerodynamic performance and flow physics related to a wing section equipped with two propellers mounted on a boom. The configuration investigated is meant to be representative of a full-scale eVTOL aircraft in cruise flight condition. The use of full-scale components of an eVTOL aircraft made this setup a quite advanced experiment in the recent literature. Pressure measurements and an infrared thermography technique were used during the test campaign, respectively, to evaluate localised effects induced by the propeller blowing on the wing and to provide a quantitative evaluation of the amount of laminar flow on the wing surface with and without the influence of the propeller at different thrust conditions.

Growing public concern regarding animal welfare and consumer demand for humanely produced products have placed pressure on the meat, wool and dairy industries to improve and confirm the welfare status of their animals. This has increased the need for reliable methods of assessing animal welfare during commercial farm practices. The measurement of the stress caused by commercial farm practices is a major component of animal welfare assessment. However, a major issue for animal welfare science is that many of the techniques used to measure stress involve invasive procedures, such as blood sampling, which may themselves cause a stress response and therefore affect the measurement of interest. To reduce this problem, a number of non-invasive or minimally invasive methods and devices have been developed to measure stress. These include the measurement of cortisol concentrations in saliva and faeces, and remote devices for recording body temperature, heart rate and the collection of blood samples. This review describes the benefits and limitations of some of these methods for measuring stress. In particular, the review focuses on recent advances and current research in the use of infrared thermography (IRT) for measuring stress. Specific applications for IRT in the dairy and beef industries are also described including an automated, non-invasive system for early diagnosis of infection in cattle. It is essential that non-invasive measures of acute and chronic stress are developed for reliable assessment of animal welfare during standard farm management practices and IRT may be a useful tool for this purpose. IRT may offer advantages over many other non-invasive systems as it appears to be capable of measuring different components of the stress axis, including acute sympathetic and hypothalamic-pituitary-adrenocortical responses.

Two experiments were conducted to determine whether maximum eye temperature, measured using infrared thermography (IRT), could be a non-invasive technique for detecting responses of cattle to handling procedures. Experiment one used six crossbred heifers randomly assigned to two groups in a crossover design and subjected to i) being hit with a plastic tube on the rump and ii) being startled by the sudden waving of a plastic bag. Experiment two used 32 crossbred bulls randomly assigned to three treatments: i) control, restraint only; ii) electric prod, two brief applications of an electric prod or, iii) startled, as in experiment one, accompanied by shouting. Exit speed (m s−1) was recorded on release from the restraint. Maximum eye temperature was recorded continuously pre- and post-treatment. In experiment one, eye temperature dropped rapidly between 20 and 40 s following both treatments and returned to baseline between 60 and 80 s following hitting and between 100 and 120 s following startling. In experiment two, eye temperature dropped between 0 and 20 s, following both treatments, and returned to baseline by 180 s, following startling plus shouting, but did not return to baseline for five minutes following electric prod. Exit speed tended to be faster following the electric prod. In conclusion, IRT detected responses that were due possibly to fear and/or pain associated with the procedures and may therefore be a useful, non-invasive method for assessing aversiveness of handling practices to cattle.

The mechanics underlying ice–skate friction remain uncertain despite over a century of study. In the 1930s, the theory of self-lubrication from frictional heat supplanted an earlier hypothesis that pressure melting governed skate friction. More recently, researchers have suggested that a layer of abraded wear particles or the presence of quasi-liquid molecular layers on the surface of ice could account for its slipperiness. Here, we assess the dominant hypotheses proposed to govern ice–skate friction and describe experiments conducted in an indoor skating rink aimed to provide observations to test these hypotheses. Our results indicate that the brittle failure of ice under rapid compression plays a strong role. Our observations did not confirm the presence of full-contact water films and are more consistent with the presence of lubricating ice-rich slurries at discontinuous high-pressure zones (HPZs). The presence of ice-rich slurries supporting skates through HPZs merges pressure-melting, abrasion and lubricating films as a unified hypothesis for why skates are so slippery across broad ranges of speeds, temperatures and normal loads. We suggest tribometer experiments to overcome the difficulties of investigating these processes during actual skating trials.

An automated, non-invasive system for monitoring of thermoregulation has the potential to mitigate swine diseases through earlier detection. Measurement of radiated temperature of groups of animals by infrared thermography (IRT) is an essential component of such a system. This study reports on the feasibility of monitoring the radiated temperature of groups of animals as a biomarker of immune response using vaccination as a model for febrile disease. In Study A, weaned pigs were either treated with an intramuscular vaccine (FarrowSure Gold), a sham injection of 0.9% saline or left as untreated controls. An infrared thermal camera (FLIR A320) was fixed to the ceiling directly above the pen of animals, and recorded infrared images of the treatment groups at 5 min intervals. The effect on temperature of the spatial distribution of pigs within the pen was significant, with higher temperatures recorded when pigs were grouped together into a single cluster. A higher frequency of clustering behaviour was observed in vaccinated animals compared with controls during a period of the afternoon ~4 to 7 h post-vaccination. The daily mean of the maximum image temperature was significantly higher in vaccinated animals compared with control and sham-treated animals. In the vaccination treated group, the 24 h mean of the maximum temperature was significantly higher during the post-vaccination period compared with the 24 h period before vaccination. Increased temperature in the vaccinated animals occurred from ~3 h, peaked at ~10 h, and remained elevated for up to 20 h post-vaccination. In Study B, the effect of prevalence was tested in terms of the difference in maximum temperature between control and vaccination days. A thermal response to vaccination was detected in a pen of 24 to 26 animals when <10% of the animals were vaccinated. The results support the concept of radiated temperature measurements of groups of animals by IRT as a screening tool for febrile diseases in pig barns.

This study presents a NDT method using infrared thermography associated with a microwave excitation. The advantages of such stimulation lie in the volumic absorption of incoming waves which lead to a greater sounded depth. This method is applied to two types of samples. The first is a concrete slab reinforced with CFRP on which a bonding failure is inserted and the second is a wooden plate on which a metallic insert is placed on the back face. The device generating the microwaves is made of a commercial magnetron associated with a pyramidal horn antenna. An infrared camera is placed on the same side as the stimulated surface and thermograms are recorded at regular intervals. The whole assembly is placed in a protective room against high frequencies. The incident power density leads to heating of less than 1 °C of the surface of the samples. The thermograms show a higher temperature rise in front of the defect area. The non-uniformity of the beam, leads us to treat the thermograms with an algorithm of contrast. These first results show the interest of the microwave excitation to detect defects deeper than in the case of surface excitation.

In this work, we approach the possibilities of infrared thermography for non-destructive testing of metallic materials. We show that the passive alternative of the method makes it possible to improve detection of surface defects existing in deep-drawn parts and visible to the naked eye. We then show that active infrared thermography, in particular coupled with induction excitation, can replace in certain cases the magnetic particle inspection, allowing the detection of very fine defects in forged parts. Finally, the study of a stepped block confirms the possibilities of active infrared thermography to detect defects not open to the surface and underlying defects.

Despite the proven ability of infrared thermography (IRT) technology for early detection of subclinical mastitis in dairy cows/sheep/goats, studies on its diagnostic feasibility in dairy camels are lacking. Sixty-five lactating camels in mid lactation, machine milked twice-daily and managed under intensive conditions were screened to evaluate the feasibility of utilising IRT compared with other routine indicators in detecting subclinical mastitis. Immediately before the morning milking, a portable infrared camera was used to obtain thermograms in duplicate for the front and rear left quarters to determine the udder surface temperature (UST). Thereafter, milk samples from quarters were collected, and processed for California mastitis test (CMT) score and somatic cell count (SCC). In the present study, CMT score was used to define subclinical mastitis and the feasibility of IRT to detect subclinical mastitis was compared with CMT and SCC. According to CMT score, subclinical mastitic udders had an average UST of 1·42 °C greater (P<0·0001) than healthy udders. The relationship between UST and CMT was found to be highly correlated (r=0·77; P<0·001), and UST was linearly increased as the CMT increased [UST (°C)=34·86+0·66×CMT score; R2=0·65; P<0·001]. Additionally, high correlations were obtained between UST and SCC score (r=0·75; P<0·001) and the relationship between UST and SCC was fitted best to a logarithmic equation [UST, °C=33·39+0·88×Log (SCC, ×103 cells/ml), R2=0·61, P<0·001]. The cut-off value, sensitivity, specificity and area under the receiver operating characteristics (ROC) curve for UST were 35·15 °C, 0·90, 0·98, and 0·95, respectively, when subclinical mastitis was defined according to CMT score, and were 35·70 °C, 0·89, 0·96 and 0·94, respectively, when categorised according to the obtained SCC threshold (SCC=432 000 cells/ml). In conclusion, IRT, as an indirect non-invasive screening method, was highly feasible for distinguishing subclinical mastitic udders in dairy camels, which is crucial to treat mastitis early and efficiently.

The aims of this study were, first, to evaluate eye temperature (ET) with infrared thermography and heart rate (HR) to measure stress in horses during show jumping competitions and their relationship with competition results, and second, to evaluate the influence of different extrinsic and intrinsic factors of the horse on the stress measurements analysed. One hundred and seventy-three Spanish Sport Horses were analysed for ET and HR, and these measurements were taken 3 h before the competition, just after and 3 h after it. Two interval measurements were also assessed for each parameter. Positive significant correlations were found between ET and HR, measured before (r=0.23), just after competition (r=0.28) and for the later interval (r=0.26), whereas negative correlations with competition results were found only for ET when measured just after competing (r=−0.25). Two intrinsic factors (genetic line and age) and no extrinsic factors showed significant differences for ET, whereas one intrinsic factor (age) and two extrinsic factors (journey duration and number of training hours) showed significant differences for HR. The marginal means showed significantly higher ET values for the Anglo-Arab genetic line and for 5-year-old animals. HR values were significantly higher for 4-year-old animals, for horses which had travelled 4 to 6 h and for horses that had 3 to 6 h of daily training. This study suggests that, although ET and HR seemed to share a similar physiological basis, the factors that most influenced each parameter were different. Finally, ET seems to be a suitable tool for assessing stress during show jumping competitions in horses.

Introduction. Optimising agricultural water use implies thecombination of physiological, technological and engineering techniques, especially thosefor continuously monitoring the water status of plants subjected to deficit irrigation. Amethodology to estimate water stress of young almond trees from thermal images wasdeveloped based on assessing the physiological status of almond crops under limitedwater-supply conditions. Materials and methods. Two irrigation treatmentswere tested during the maximum evapotranspirative demand period (214th to the 243rd day ofthe year) in an experimental almond [Prunus dulcis (Mill) D.A. Webb, cv.Guara] orchard: a low-frequency deficit irrigation (LFDI) treatment, irrigated accordingto the plant-water status, and a fully irrigated treatment (C100) at 100% of cropevapotranspiration. Daily canopy temperature at midday (TC) was measured with an infraredcamera, together with standard measurements of stem-water potential (ΨStem) and stomatalconductance (gS). The time course of these parameters and their relationships wereanalysed. Results and discussion. The time course of the parameters studiedshowed highly significant correlations among the differentials of canopy-air temperature(ΔT), ΨStem and gS. The methodological protocol for analysing thermal images allowed atime saving in processing information and additionally offered the possibility ofestimating the ΨStem and gS values. Conclusion. Our results confirm thatinfrared thermography is a suitable technique for assessing the crop-water status and canbe used as an important step towards automated plant-water stress management in almondorchards.

This paper is based on additional treatments of the experimental results obtained by L. Bodelot, L. Sabatier, E. Charkaluk, P. Dufrénoy [Experimental setup for fully coupled kinematic and thermal measurements at the microstructure scale of an AISI 316l steel, Mater. Sci. Eng. A 501 (2009) 52–60]. In order to perform inter- and intragranular thermomechanical analyses in a metallic polycrystal at the grain scale, a crystallography-based projection technique of the thermal and displacement fields on a polynomial basis is proposed. It enables intragranular coupled analysis of strain and temperature full-field data consistent with the plastic slip activation observed on specimen surface after the test.

The present paper is concerned with the thermoelectric behaviour of CFRP compositesamples subjected to DC currents in view of developing experimental and modelling toolsfor the characterisation of the thermo-electro-mechanical behaviour of composite materialsfor aircraft applications. DC currents up to 8 A are injected through the specimens endsides by employing several different electrode techniques whose performances are assessedand compared. Sample and electrode contact resistances are measured for different valuesof the injected current. The transient and permanent temperatures fields promoted by theinjected currents are experimentally measured by infrared thermography. The temperaturefields are simulated numerically by a thermoelectric coupled model employing theABAQUS®FE commercial code; temperatures can be also approximately calculated by a simple lumpedparameter model discarding thermal conduction. The comparison between simulations by themodels and measurements allows employing the simplified model as a tool to designthermo-electro-mechanical tests.

The present study deals with the thermal behavior of an electric motor used in navalpropulsion. A permanent three-dimensional model based on a nodal approach was developed topredict the thermal behavior of the machine in permanent state. The various heat transfermodes playing a role (mainly the conduction, the convection and the mass transfer) aretaken into account. The three dimensional developed model provides information (in termsof heat fluxes or temperatures) for the whole machine. A parametric study using this modelis carried out aiming at two objectives. The first one consists in an evaluation of theinfluence of several factors on the temperature distribution. The second one aims atobtaining the inception of the thermal optimization and evaluating the more efficientcooling techniques or solutions.