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[en] Recording high quality biosignals by dry textile electrodes is a common challenge in medical health monitoring garments. The aim of this study was to improve skin–electrode interface and enhance the quality of recorded electrocardiography (ECG) signals by modification of textile electrodes embedded in WearItMed smart garment. The garment has been developed for long-term health monitoring in patients suffering from epilepsy and Parkinson’s disease. A skin-friendly electro-conductive elastic paste was formulated to coat and modify the surface of the knitted textile electrodes. The modifications improved the surface characteristics of the electrodes by promoting a more effective contact area between skin and electrode owing to a more even surface, fewer pores, greater surface stability against touch, and introduction of humidity barrier properties. The modifications decreased the skin–electrode contact impedance, and consequently improved the recorded ECG signals obviously when low pressure was applied to the electrodes, therefore contributed to greater patient comfort. The created contact surface allowed the natural humidity of the skin/sweat to ease the signal transfer between the electrode and the body, while introducing a shorter settling time and retaining moisture over a longer time. Microscopic images, ECG signal measurements, electrode–skin contact impedance at different pressures and times, and water absorbency were measured and reported.
[en] A common coldrex, paracetamol, was used as humidity sensing material. The capacitance-type humidity sensor was fabricated by aerosol deposition method. The humidity sensitive properties were investigated through dielectric measurements. Our results reveal that the sensor has exciting performances in high relative humidity. Both −OH and −NH groups have contributions to water absorption. The −OH groups lead to a water-containing surface layer giving rise to pronounced Maxwell-Wagner response, which in turn, yields the humidity response that can be easily adjusted by an external electric field. This work indicates that the paracetamol is a promising humidity sensing material. (paper)
[en] Recently, the humidity sensors have captivated huge attention for making human life more comfortable and to diagnose several diseases. Here, we reported the excellent humidity responsiveness of V0.5Sn0.5Se2 ternary alloy for human breath monitoring and touchless positioning interface. The resistive sensor based on direct vapour transport grown bulk crystal of V0.5Sn0.5Se2 ternary alloy is fabricated and explored for its static response in different humidity levels ranging from 20 to 90%. The sensor showed excellent dynamic switching characteristics between relative humidity of 20% and 90% with responsivity of 6.78%, response time of 3.2 s and recovery time of 2.3 s. Subsequently, the sensor is exploited for giant responsiveness for human breath monitoring and words recognitions. The sensor exhibited quite distinct response towards different words namely, “Pratik”, “Chetan” and “Mohit”. Besides, novel touch-less positioning interface is explained with respect to humidity variation. Overall, the results advocate development of resistive sensors for intended humidity, biomedical as well as for intelligent touch-less sensing applications.
[en] Here, we report the preparation of PEDOT:PSS-MoS2 nanocomposite thin films and their electrical resistance response under humidity conditions revealing their promising properties as humidity sensor materials. One of the most interesting features of our samples is the transition from positive to a negative electrical resistance response to humidity conditions with increasing MoS2 additions. Our confocal Raman imaging studies revealed that the presence of MoS2 yields a local charge rearrangement in the thiophenyl rings of PEDOT:PSS, in relation to the enhancement of the electrical resistance negative response as observed by impedance spectroscopy analysis. The enhancement on the negative response with increasing MoS2 additions could be explained through the increment of hole carriers in MoS2 nanosheets under humidity conditions, thus leading to an enhancement in the electrical transport along the PEDOT:PSS chains.
[en] The paper presents the results of an experiment on the adsorption coefficient and heat capacity of cobalt catalysts based on porous granulated aluminum oxide in a humidifying environment. Cobalt catalysts having a cylindrical shape with dimensions of 0.85-1.25 mm are designed to carry out the decomposition processes of single-component liquid hydrazine fuels and nitrous oxide. The study of heat capacity and the adsorption technical important composite materials in the solid phase at room temperature is of great scientific and applied importance. Systematic studies of the heat capacity and the coefficient of adsorption provide useful information about the nature of materials, allow to determine their practical use, and also serve as the basis for the further development of solid-state physics. Knowledge of heat capacity and adsorption characteristics is especially important when designing industrial thermal installations of the most diverse types. (author)
[en] This study compares the interdecadal variations in tropical cyclone (TC) activities over the western North Pacific (WNP) basin during the peak season (July–September) and late season (October–December) of 1955–2014 and explores the possible physical mechanisms behind the variations. Both the peak- and late-season tropical storm (TS) days show distinct interdecadal variations, while the late-season TS days lead the peak-season TS days by approximately 4 years on an interdecadal time scale. The late-season TC activity is related to the east-west sea surface temperature (SST) gradient across the equatorial Pacific. The westerly winds induced by the SST gradient can reduce the vertical wind shear and increase the low-level vorticity, which favors TC genesis over the TC genesis region. The peak-season TC activity appears to relate to the SST gradient between the Indian Ocean and the Central Pacific. The westerly wind induced by the SST gradient can reduce the vertical wind shear and increase the mid-level relative humidity, thereby enhancing the TC activity. The full picture of the interdecadal variation in the WNP TC activity during the peak and late seasons revealed in this study provides a new perspective on the seasonal TC forecasts and future projections.
[en] The paper presents the variability of meteorological conditions: air temperature, wind speed and relative air humidity; and biometeorological indices: wind chill temperature, predicted clothing insulation and accepted level of physical activity on Franz Josef Land (in Teplitz Bay and Calm Bay) in the years 1899–1931. It employs meteorological measurements taken during four scientific expeditions to the study area. The analysis mainly covered the period October–April, for which the most complete data set is available. For that period of the year, which includes the part of the year with the Franz Josef Land’s coldest air temperatures, the range and nature of changes in meteorological and biometeorological conditions between historical periods and the modern period (1981–2010) were studied. The data analysis revealed that during the three oldest expeditions (which took place in the years 1899–1914), the biometeorological conditions in the study area were more harsh to humans than in the modern period (1981–2010) or similarly harsh. In contrast, during the 1930/1931 expedition, which represents the Early Twentieth Century Warming (ETCW), conditions were clearly more favourable (including predicted clothing insulation being 0.3 clo lower and 4.0 °C higher wind chill temperature than conditions observed nowadays).
[en] Crop evapotranspiration (ET) is one of the main components in calculating the water balance in agricultural, hydrological, environmental, and climatological studies. Solar radiation (Rs) supplies the available energy for ET, and therefore, precise measurement of Rs is required for accurate ET estimation. However, measured Rs and ET and are not available in many areas and they should be estimated indirectly by the empirical methods. The Angström-Prescott (AP) is the most popular method for estimating Rs in areas where there are no measured data. In addition, the locally calibrated coefficients of AP are not yet available in many locations, and instead, the default coefficients are used. In this study, we investigated different approaches for Rs and ET calculations. The daily measured Rs values in 14 stations across arid and semi-arid areas of Fars province in south of Iran were used for calibrating the coefficients of the AP model. Results revealed that the calibrated AP coefficients were very different and higher than the default values. In addition, the reference ET (ETo) was estimated by the FAO56 Penman–Monteith (FAO56 PM) and FAO24-radiation methods by using the measured Rs and were then compared with the measured pan evaporation as an indication of the potential atmospheric demand. Interestingly and unlike many previous studies, which have suggested the FAO56 PM as the standard method in calculation of ETo, the FAO24-radiation with the measured Rs showed better agreement with the mean pan evaporation. Therefore, the FAO24-radiation with the measured Rs was used as the reference method for the study area, which was also confirmed by the previous studies based on the lysimeter data. Moreover, the accuracy of calibrated Rs in the estimation of ETo by the FAO56 PM and FAO24-radiation was investigated. Results showed that the calibrated Rs improved the accuracy of the estimated ETo by the FAO24-radiation compared with the FAO24-radiation using the measured Rs as the reference method, whereas there was no improvement in the estimation of ETo by the FAO56 PM method compared with the FAO24-radiation using the measured Rs. Moreover, the empirical coefficient (α) of the Priestley and Taylor (PT) ETo estimation method was calibrated against the reference method and results indicated ca. 2 or higher α values than the recommended α = 1.26 in all stations. An empirical equation was suggested based on yearly mean relative humidity for estimation of α in the study area. Overall, this study showed that (1) the FAO24-radiation method with the either measured or calibrated Rs is more accurate than the FAO56 PM, (2) the spatially calibrated AP coefficients are very different from each other over an arid and semi-arid area and are higher than those proposed by the FAO56, (3) the original PT model is not applicable in arid and semi-arid area and substantially underestimates the ETo, and (4) the coefficient of the PT should be locally calibrated for each station over an arid and semi-arid area.
[en] This study examined the sensitivity of reference crop evapotranspiration (ET0) to climatic variables in a humid region in Iran. ET0 was estimated using the FAO-56 Penman–Monteith (PMF-56), Blaney–Criddle (BC), and Hargreaves–Samani (HG) methods. Sensitivity analysis was performed by two distinct methods which were (i) changing the value of a certain climatic parameter in a range between ± 20% of its long-term mean with an increment of 5%, and calculating the percentage of change in ET0, while the other parameter values were kept constant; and (ii) calculating the sensitivity coefficients (SCs) for each of the climatic variables. For each of the climatic parameters, the Iso-SC maps were plotted using the Arc-GIS software. Results indicated that the most sensitive parameter for ET0 was the maximum air temperature (Tmax) by PMF-56 and HG methods. Increasing Tmax up to 20% led to an increase in ET0 between 8.5 and 15%, at the selected stations by PMF-56. In contrast, the less sensitive parameter for ET0 was the minimum air temperature (Tmin) for PMF-56 and Tmean for HG. For PMF-56, increasing the minimum relative humidity (RHmin) to 20% led to a decrease in ET0 in the range between 0.5 and 5%. The highest values of SC in the cases of Tmax and Tmin were found to be equal to 0.8 and 0.53, respectively. Similarly, the SC in the case of RHmin varied between − 0.29 and − 0.0038. This range for wind speed was between 0.06 and 0.22 and in the case of sunshine hours it was between 0.272 and 0.385. These findings would be useful in the scientific management of water resources in the region.
[en] Based on 1.5 °C and 2.0 °C warming experiments of Community Earth System Model, this study documents future changes in the East Asian summer monsoon (EASM) and associated monsoon precipitation. The model reproduces reasonably well the climatology of East Asian summer rainfall. All ensemble means show an increase in EASM intensity and associated precipitation over most parts of the East Asian region in 1.5 °C “never-exceed” (1.5degNE), 1.5 °C “overshoot” (1.5degOS), and 2.0 °C (2.0degNE) experiments. There is no significant difference in the future changes in EASM intensity, EASM precipitation, and its location among the three scenarios. A moisture budget analysis demonstrates that the increased precipitation over East Asia in three scenarios should be ascribed to the changes in evaporation, vertical motion, and humidity. The contributions of these three dominant terms increase sequentially under 1.5degNE, 1.5degOS, and 2degNE scenarios. However, the differences among the three scenarios are quite small in three dominant terms. Over East Asia, the contributions of evaporation and vertical motion are generally larger than that of humidity to the domain-averaged EASM rainfall in each scenario.