A sensor for vector electric field measurements through a nonlinear anisotropic optical crystal

Electrical applications require the development of electric field sensors that can reproduce vector electric field waveforms with a very large spectral width ranging from 50 Hz to at least 70 MHz. This makes it possible to measure both the normal operation modes of electrical components and abnormal behaviors such as the corona emission and partial discharges. In this work, we aim to develop a fully dielectric sensor capable of measuring two components of the electric field using a wide class of optical crystals including anisotropic ones, whereas most of the efforts in this field have been devoted to isotropic crystals. We report the results of the measurements performed at 50 Hz and with a lightning impulse, to validate the sensor

Comparison between XRF, TXRF and PXRF analyses for provenance classification of archaeological bricks

Ceramics provenance studies based on minor and trace elements are widely used to help in gathering knowledge of local furnace presence and commercial trades. Most of the times, destructive analyses are allowed because of the high amount of material, but sometimes (integer vessels, architectural decorations, etc.), a nondestructive examination is required. In both cases, X-ray fluorescence (XRF) analysis can be a useful tool. In this work, we compare the classification results obtained on a set of bricks from the medieval Chartusian monastery Certosa di Pavia in the Po valley, northern Italy, exploiting XRF, portable XRF, and total reflection XRF (TXRF) spectrometers. The XRF nondestructive analyses were performed both in situ before sampling and in the laboratory without preparing the shards. Grounded samples were instead used to obtain semi-quantitative TXRF analysis without dissolving the samples but using a suspension in high-purified water. The project aimed at verifying if a correct classification was possible even if a quantitative determination of minor and trace elements is abandoned, allowing a faster response when a large amount of data is concerned. For this reason, weight concentration was determined from laboratory XRF measurements only, whereas semiquantitative results and entire spectra were considered for TXRF and the in situ campaign, respectively. Data were then submitted to different statistical data treatments to obtain provenance classification

Heat dissipation evaluation in exercise by infrared thermography

INTRODUCTION Heat dissipation during sport exercise is very important to improve athlete performance. An help to physiological mechanism of generation and transport of heat in the muscle under stress and in surrounding districts, is given by IR thermography to evaluate the surface heat dissipation locally. Thermography is useful because of its high sensitivity (0.05\ub0C) and global representation of thermal process. Its use is recommended for the athletic evaluation because it is a non-invasive technique that doesn\u2019t need any contact with the skin, avoiding physic and psychologic conditioning (Merla et al., 2010). METHODS We tested two groups of female subjects: 9 athletes and 9 sedentaries (mean age 19.39\ub13.26 y, weight 53.82\ub15.36 kg, height 1.64\ub10.06 m). They performed an exercise (standing calf raise with both feet) that limits the work to one group of muscle (gastrocnemius and soleus) and allows a perfect visibility for a correct thermographic shoot. It consists to raise and lower heels (rate 1 s) without over load (N.S.C.A., 2010). Thermal images was recorded (1 Hz frame-rate) during 14 minutes (2 min. of pre-exercise to determinate basal temperature, 2 min. of exercise, 10 min. of recover). Two Regions of Interest (ROI) were selected following anatomical and functional correspondence with the muscles involved in exercise, one on each calf (Zaidi et al., 2007). The data were analyzed with a dedicated software for thermal images. The considered parameter was the mean temperature over an area of 2mmq of the hottest spot in the calf. RESULTS Both groups show a minimum in temperature after few seconds of the exercise. The calves temperatures increase with linear trend during the whole exercise and in the first minutes of recover, but with a different slope. Temperature variation in 2min. recovery-time of the athletes is 1.07\ub0C, while for the group of sedentaries is 0.76\ub0C. DISCUSSION From these preliminary results is clear that IR thermography is a valid diagnostic method in evaluation of heat dissipation during and after physical exercise. The different slopes of the temperature trends during exercise and the two minutes post exercise indicate that calves of athletes dissipate more heat than calves of sedentaries. It can be explained with a better muscular efficiency in trained subjects, used to do exercise, and probably due to a less fat mass in the calves of athletes than in calves of sedentaries (Merla et al., 2010). REFERENCES Merla, A., Mattei Peter A., Di Donato L., Romani G. (2010). Ann. Biomed. Eng. 38:158\u2013163. N.S.C.A. (2010). Esercizi per l\u2019allenamento in palestra. Calzetti-Mariucci. Zaidi H., Taiar R., Fohanno S., Polidori G. (2007). Acta Bioeng. Biomech. 9:47-51

Heat dissipation evaluation in exercise by infrared thermography

INTRODUCTION Heat dissipation during sport exercise is very important to improve athlete performance. An help to physiological mechanism of generation and transport of heat in the muscle under stress and in surrounding districts, is given by IR thermography to evaluate the surface heat dissipation locally. Thermography is useful because of its high sensitivity (0.05\ub0C) and global representation of thermal process. Its use is recommended for the athletic evaluation because it is a non-invasive technique that doesn\u2019t need any contact with the skin, avoiding physic and psychologic conditioning (Merla et al., 2010). METHODS We tested two groups of female subjects: 9 athletes and 9 sedentaries (mean age 19.39\ub13.26 y, weight 53.82\ub15.36 kg, height 1.64\ub10.06 m). They performed an exercise (standing calf raise with both feet) that limits the work to one group of muscle (gastrocnemius and soleus) and allows a perfect visibility for a correct thermographic shoot. It consists to raise and lower heels (rate 1 s) without over load (N.S.C.A., 2010). Thermal images was recorded (1 Hz frame-rate) during 14 minutes (2 min. of pre-exercise to determinate basal temperature, 2 min. of exercise, 10 min. of recover). Two Regions of Interest (ROI) were selected following anatomical and functional correspondence with the muscles involved in exercise, one on each calf (Zaidi et al., 2007). The data were analyzed with a dedicated software for thermal images. The considered parameter was the mean temperature over an area of 2mmq of the hottest spot in the calf. RESULTS Both groups show a minimum in temperature after few seconds of the exercise. The calves temperatures increase with linear trend during the whole exercise and in the first minutes of recover, but with a different slope. Temperature variation in 2min. recovery-time of the athletes is 1.07\ub0C, while for the group of sedentaries is 0.76\ub0C. DISCUSSION From these preliminary results is clear that IR thermography is a valid diagnostic method in evaluation of heat dissipation during and after physical exercise. The different slopes of the temperature trends during exercise and the two minutes post exercise indicate that calves of athletes dissipate more heat than calves of sedentaries. It can be explained with a better muscular efficiency in trained subjects, used to do exercise, and probably due to a less fat mass in the calves of athletes than in calves of sedentaries (Merla et al., 2010). REFERENCES Merla, A., Mattei Peter A., Di Donato L., Romani G. (2010). Ann. Biomed. Eng. 38:158\u2013163. N.S.C.A. (2010). Esercizi per l\u2019allenamento in palestra. Calzetti-Mariucci. Zaidi H., Taiar R., Fohanno S., Polidori G. (2007). Acta Bioeng. Biomech. 9:47-51

Thermal imaging of exercise-associated skin temperature changes in trained and untrained female subjects

Heat dissipation during sport exercise is an important physiological mechanism that may influence athletic performance. Our aim was to test the hypothesis that differences exist in the dynamics of exercise-associated skin temperature changes between trained and untrained subjects. We investigated thermoregulation of a local muscle area (muscle-tendon unit) involved in a localized steady-load exercise (standing heels raise) using infrared thermography. Seven trained female subjects and seven untrained female controls were studied. Each subject performed standing heels raise exercise for 2 minutes. Thermal images were recorded prior to exercise (1 minute), during exercise (2 minutes), and after exercise (7 minutes). The analysis of thermal images provided the skin temperature time course, which was characterized by a set of descriptive parameters. Two-way ANOVA for repeated measures detected a significant interaction (p=0.03) between group and time, thus indicating that athletic subjects increased their skin temperature differently with respect to untrained subjects. This was confirmed by comparing the parameters describing the speed of rise of skin temperature. It was found that trained subjects responded to exercise more quickly than untrained controls (p<0.05). In conclusion, physical training improves the ability to rapidly elevate skin temperature in response to a localized exercise in female subjects

Mood, mileage and the menstrual cycle

Forty women took part in a study to determine the effects of high-intensity training and the menstrual cycle on mood states. Half of the sample were competitive distance runners following a training load of between 50 km and 130 km running per week. Seven athletes were amenorrhoeic and 13 either eumenorrhoeic or oligomenorrhoeic. The remaining 20 subjects were inactive women who menstruated regularly. The mean age of all 40 subjects was 29 years. Each subject completed two identical Profile of Mood States (POMS) questionnaires. The 33 menstruating subjects completed both a premenstrual and a midcycle form and the amenorrhoeic athletes completed the questionnaires at a 3-week interval, which acted as a control for the potential effects of premenstrual syndrome (PMS) among the menstruating females. Results showed highly significant differences in mood profiles among amenorrhoeic athletes, non-amenorrhoeic athletes and inactive women. The greatest difference was between premenstrual and midcycle measures for the inactive group. PMS appears to cause marked negative mood swings among menstruating women which the POMS inventory is sensitive in detecting. While the lowerintensity- training runners appeared to benefit psychologically from a training distance of approximately 50km week-', high-intensity training had an adverse effect on mood