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Quantifying drought tolerance in crops is critical for agriculture management under environmental change, and drought response traits in grape vine have long been the focus of viticultural research. Turgor loss point (πtlp) is gaining attention as an indicator of drought tolerance in plants, though estimating πtlp often requires the construction and analysis of pressure-volume (P-V) curves which are very time consuming. While P-V curves remain a valuable tool for assessing πtlp and related traits, there is considerable interest in developing high-throughput methods for rapidly estimating πtlp, especially in the context of crop screening. We tested the ability of a dewpoint hygrometer to quantify variation in πtlp across and within 12 clones of grape vine (Vitis vinifera subsp. vinifera) and one wild relative (Vitis riparia), and compared these results to those derived from P-V curves. At the leaf-level, methodology explained only 4–5% of the variation in πtlp while clone/species identity accounted for 39% of the variation, indicating that both methods are sensitive to detecting intraspecific πtlp variation in grape vine. Also at the leaf level, πtlp measured using a dewpoint hygrometer approximated πtlp values (r2 = 0.254) and conserved πtlp rankings from P-V curves (Spearman's ρ = 0.459). While the leaf-level datasets differed statistically from one another (paired t-test p = 0.01), average difference in πtlp for a given pair of leaves was small (0.1 ± 0.2 MPa (s.d.)). At the species/clone level, estimates of πtlp measured by the two methods were also statistically correlated (r2 = 0.304), did not deviate statistically from a 1:1 relationship, and conserved πtlp rankings across clones (Spearman's ρ = 0.692). The dewpoint hygrometer (taking ∼ 10–15 min on average per measurement) captures fine-scale intraspecific variation in πtlp, with results that approximate those from P-V curves (taking 2–3 h on average per measurement). The dewpoint hygrometer represents a viable method for rapidly estimating intraspecific variation in πtlp, and potentially greatly increasing replication when estimating this drought tolerance trait in grape vine and other crops. [ABSTRACT FROM AUTHOR]

This essay proposes that the only publication of the Accademia del Cimento, referred to as Saggi,11 Accademia del Cimento, Saggi di naturali esperienze fatte nell’ Accademia del Cimento sotto la protezione del serenissimo principe Leopoldo di Toscana e descritte dal segretario di essa Accademia (Firenze: Per Giuseppe Cocchini, 1667). had as one of its main goals the celebration of the House of Medici’s paternity of cutting-edge experiments and instruments during the reign of Grand Duke Ferdinando II. These included Ferdinando II’s thermometers and hygrometers, Torricelli’s experiment and barometer, and Galileo’s pendulum as a clock-regulator. It seems that this agenda went unnoticed, not at the time of its initial circulation, but rather in modern historiography. Christiaan Huygens’s challenged invention of the pendulum clock provides a case study to explore the agenda of this publication and the problem of defining an invention in seventeenth-century Europe. This paper presents for the first time the document that attests to when the first specimen of Huygens’s clock arrived in Florence, disproving the previously believed date of September 1657. The paper argues that over the last two centuries, this error has made the Medici narratives of this dispute appear inconsistent and marginalized them. In light of this new find, they must be reconsidered.Accademia del Cimento, Saggi di naturali esperienze fatte nell’ Accademia del Cimento sotto la protezione del serenissimo principe Leopoldo di Toscana e descritte dal segretario di essa Accademia (Firenze: Per Giuseppe Cocchini, 1667). [ABSTRACT FROM AUTHOR]

The brief life of the Accademia del Cimento (1657–1667), the first known society with a purely experimental programme,1 is entangled with the most surprising advancements in the history of scientific instruments of that century, from the telescope to the microscope, the thermometer to the barometer, the hygrometer to the pendulum as a time-regulator, and more. The making of instruments at the Florentine court shows the interaction of princely, scholarly and artisanal actors. This paper explores this collaboration and shows how the supposed "invisibility' of artisans depended on their proximity to the academicians and princes, who mainly communicated verbally with them, directly or through middlemen. The visibility of artisans increases proportionally to their physical distance from the Court. In this essay I unveil the identity of the artisans of the Cimento and, finally, attempt to attribute five instruments (some lost and others still extant) to specific makers, shedding light also on relations between the artisan and his patron. [ABSTRACT FROM AUTHOR]

Solar power is a demand of our planet in coming days due to the depletion of non-renewable sources of energy. The renewable sources of energy are responsible for 80 % of world’s power and we all are directly dependent on non-renewable source which will only last in coming decades. Due to increase in power demands new development in renewable sources of energy are going on due to which on commercial level solar cell achieved an efficiency of 15 – 20 % and improving day by day. At a panel inclination of 22 oC, the effect of panel temperature and relative humidity on photovoltaic are studied. A precision digital hygrometer and thermometer, and a digital clamp meter were used in the process. Results obtained show that the effect of relative humidity on current, voltage, power of single and 10 panels combined together. The results also show that voltage and current remain fairly stable between 15 % to 35 % relative humidity. Panel’s temperature also plays a significant role on performance after 55 ºC, the voltage started dropping in both cases. Output from the wind turbine has also been measured on a working condition day, and different readings have been recorded with an interval of 15 mins at different wind speeds. It works by converting the kinetic energy in the wind first into rotational kinetic energy in the turbine and then electrical energy that can be supplied. The output energy comes directly depend on speed of wind and the blades swept area. Renewable Energy Hybrid System (REHS) is a system that utilizes two sources or more of renewable energy. As an advantage, it will produce continuous source of energy and utilizing one source in the absence of other source(s). The aim of this study is to enhance the energy output of renewable energy system which is the wind turbine by incorporating solar panels. [ABSTRACT FROM AUTHOR]

A collection of quaternary, high-MgO (≤13.4 wt%) basanite and minette cinder and lava cones, with an enhanced arc geochemical signature, are located along the northern margin of the N–S Colima rift in western Mexico. The Colima rift overlies the lithospheric suture between the Jalisco block and Guerrero terrane, as well as the tear between the Rivera and Cocos subducting oceanic plates. From the literature, volatile analyses of olivine-hosted melt inclusions in the Colima cone samples document notably high concentrations of dissolved H2O in the melt (≤ 7.0 wt%) as well as degassing-induced phenocryst growth over a range of depths ≤25 km. In this study, it is shown that the high-MgO character of the Colima suite reflects liquid compositions, consistent with evidence for their rapid transit to the surface, without stalling in a crustal magma chamber. The most Mg-rich olivine analyzed in each sample matches the equilibrium composition at the liquidus based on olivine-melt Mn–Mg and Fe2+–Mg exchange coefficients. Application of both a Mg- and Ni-based olivine-melt thermometer, calibrated on the same experimental data set, to the Colima cone suite provides the temperature and dissolved H2O content at the liquidus. Because the Ni thermometer is insensitive to dissolved H2O in the melt, it gives the actual temperature at the onset of olivine phenocryst growth. For the nine Colima samples that range from 13.4–9.2 wt% MgO, resulting temperatures range from 1221°C to 1056°C (± 6–11°C). In contrast, the Mg thermometer is sensitive to dissolved H2O in the melt, and its application (without a correction of H2O) gives the temperature of olivine crystallization under anhydrous conditions. When the Mg- and Ni-based temperatures are paired, the depression of the liquidus (∆T = TMg–TNi) due to dissolved H2O can be obtained. For the high-MgO (>9 wt%) Colima samples, ∆T values range from 188°C to 109°C. Corrections for the effect of pressure (i.e. evidence that phenocryst growth began at ~700 MPa), increase ∆T by ~21°C. An updated model calibration (on experiments from the literature) that relates ∆T with dissolved H2O in the melt shows that the best fit (R2 = 0.95) is linear, wt% H2O = 0.047*∆T, with a standard error of ±0.5 wt%. Although the experimental data set spans a wide range of melt composition (e.g. 47–58 wt% SiO2, 4.4–10.2 wt% MgO, 1.3–4.9 wt% Na2O, 0.1–5.0 wt% K2O, 0.3–5.3 wt% H2O), no dependence on anhydrous melt composition is resolved. Application of this updated model to the Colima suite gives H2O contents of 5.1–8.8 wt% H2O, consistent with those analyzed in olivine-hosted MIs from the literature. When the thermometry and hygrometry results for the Colima cone suite are compared to those for the adjacent calc–alkaline basalts from the Tancítaro Volcanic Field (TVF) in Michoacán, two distinct linear trends in a plot of wt% H2O vs. temperature are found, indicative of different mantle sources. It is proposed that the high-MgO (>11 wt%) Colima cone melts were derived from a phlogopite-bearing harzburgitic mantle at the base of the Jalisco block lithosphere, whereas both TVF and Colima melts with ≤10 wt% MgO were derived from the asthenosphere (i.e. arc mantle wedge). In both mantle sources, slab-derived fluids were an important source of H2O. [ABSTRACT FROM AUTHOR]

Measuring the relative humidity of air is an important challenge for meteorological measurements, food conservation, building design, and evaporation control, among other applications. Relative humidity can be measured with a psychrometer, which is a hygrometer composed of two identical thermometers. The bulb of one thermometer is covered by a wick soaked with water so that evaporative cooling makes it indicate a lower temperature than the dry-bulb thermometer; it is possible to determine the relative humidity from the difference between these readings. We describe both a model and an experimental setup to illustrate the principle of a psychrometer for a pedagogical laboratory. The science of psychrometry could be more broadly taught at the undergraduate level to help introduce students to aspects of measurement techniques, fluid mechanics, heat transfer, and non-equilibrium thermodynamics. [ABSTRACT FROM AUTHOR]

This study aimed to obtain reference dosimetry practices for flattened photon and electron beams. A questionnaire survey on these practices was sent to 37 facilities that performed radiotherapy using these beams in Fukui, Ishikawa, Niigata and Toyama, Japan. The survey comprised equipment (dosemeters, water phantoms, thermometers, barometers and hygrometers) and procedures for reference dosimetry (water used as the phantoms, verification of chamber placement, periodic checks of ion recombination- and polarity-corrections, pre-irradiation and relative humidity monitoring). Responses were received from 19 institutions. In the 19 institutions, a reference-class dosemeter was used for the reference dosimetry. In 6 of the 19 institutions, a 10-year-old or older dosemeter was used. Any barometers, thermometers and hygrometers were not recalibrated. Dosimetry equipment necessitates regular maintenance. Moreover, it is necessary to have a backup dosimetry system in clinics to account for potential malfunctions or instances when the primary system is sent for calibration. [ABSTRACT FROM AUTHOR]

The article sheds light on the invention of early modern precision instruments and their application in medicine, by analysing a neglected work by one of the Italian pupils of the physician Santorio Santori (1561–1636). This source provides vital information on Santorio's experimental sample, and on the practical use and dimensions of instruments such as thermometers, hygrometers, pulsimeters and precision scales, showing that they also had a normative purpose: regulating the environmental factors affecting human health. The article first establishes the derivative nature of the source from Santorio's teachings, and then contextualises the invention of precision instruments with regard to Santorio's published and unpublished output. In the conclusions, I argue that the new instruments were meant to address the shortcomings of the traditional diagnostic rationale and are best conceptualised as 'intensity meters' meant to assess 'the magnitude' (magnitudo) of a patient's illness in degrees. [ABSTRACT FROM AUTHOR]

The mid-infrared lightweight stratospheric hygrometer, "Pico-Light H2O", the successor of Pico-SDLA H2O, is presented and its performances are evaluated during the AsA 2022 balloon-borne intercomparison campaign conducted at CNES Aire-sur-l'Adour (AsA) balloon launch facility and the Aeroclub d'Aire-sur-l'Adour. The Pico-Light instrument primarily been developed for sounding of the upper troposphere and stratosphere. Though, during the AsA 2022 campaign we expand the range of comparison including the lower troposphere additionally. Three different types of hygrometers and two models of radiosonde were flown, operated by the French Space Agency (CNES) and the NOAA Global Monitoring Laboratory (GML) scientific teams: Pico-Light H2O, the NOAA Frost Point Hygrometer (FPH), the micro hygrometer (in an early phase of development), M20 and iMet-4 sondes. In this frame, we intend to validate measurements of Pico-Light H2O through a first intercomparison with the NOAA FPH instrument. The in situ monitoring of water vapour in the UT-LS keeps being very challenging from an instrumental point of view because of the very small amounts of water vapour to be measured in these regions of the atmosphere. Between the lapse rate tropopause (11 to 12.3 km) and 20 km, the mean relative difference between water vapour mixing ratio measurements by Pico-Light H2O and NOAA FPH was (4.2 ± 7.7) %, mean tropospheric difference is was (3.84 ± 23.64)%, with differences depending on the altitude range considered. In the troposphere, relative humidity over water (RH) comparisons leads to an agreement between both Pico-Light and NOAA FPH of -0.2% on average, with excursions of about 30% RH due to moisture variability. Expanding the comparison to meteorological sondes, the iMet-4 sondes agree well with both Pico-Light and FPH between ground and 7.5 km (within ± 3% RH) and so does for M20 sondes, up to 13 km, which are wet biased by 3% RH and dry biased by 20% in case of saturation. [ABSTRACT FROM AUTHOR]

Satellite data records of stratospheric water vapour have been compared to balloon-borne frost point hygrometer (FP) profiles that are coincident in space and time. The satellite data records of 15 different instruments cover water vapour data available from January 2000 through December 2016. The hygrometer data are from 27 stations all over the world in the same period. For the comparison, real or constructed averaging kernels have been applied to the hygrometer profiles to adjust them to the measurement characteristics of the satellite instruments. For bias evaluation, we have compared satellite profiles averaged over the available temporal coverage to the means of coincident FP profiles for individual stations. For drift determinations, we analysed time series of relative differences between spatiotemporally coincident satellite and hygrometer profiles at individual stations. In a synopsis we have also calculated the mean biases and drifts (and their respective uncertainties) for each satellite record over all applicable hygrometer stations in three altitude ranges (10–30 hPa, 30–100 hPa, and 100 hPa to tropopause). Most of the satellite data have biases <10 % and average drifts <1 % yr -1 in at least one of the respective altitude ranges. Virtually all biases are significant in the sense that their uncertainty range in terms of twice the standard error of the mean does not include zero. Statistically significant drifts (95 % confidence) are detected for 35 % of the ≈ 1200 time series of relative differences between satellites and hygrometers. [ABSTRACT FROM AUTHOR]

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The quantities that are usually measured are time, pressure, temperature, and relative humidity to mention but a few. The word humidity is used when we are dealing with water vapor which is a gas. The instrument used to measure the humidity is the hygrometer that can be based on electronics, optics, mechanics, chemicals, and others. The measurement of humidity shows its importance in applications such as food processing, meteorological, semiconductor, building and construction, medical, and automotive to mention but a few. This paper shows the adaptation of an optical interferometer, the Fabry-Perot (F-P), to measure the relative humidity. The transductors that have been probed are gelatin-thin films that are inserted between the mirrors of the FP. When water molecules are absorbed (desorbed) by the gelatin film, its refractive index and thickness change giving a movement of the rings in the interference pattern. The calibration plot comprises the ring displacement as a function of the relative humidity. [ABSTRACT FROM AUTHOR]

Climate change causes extreme heat and high humidity in some regions. The wet-bulb temperature (Tw) is a heat stress index, and the threshold is 35 °C. It is difficult to measure the value of Tw using a psychrometer, but the Tw value can be calculated using the air temperature and humidity. To provide accuracy for the Tw calculation, an empirical equation is established using regression analysis. This study defines the empirical equation as Tw = − 4.391976 + 0.0198197 RH + 0.526359 Td + 0.00730271 RH · Td + 2.4315 × 10 − 4 RH 2 − 2.58101 × 10 − 5 Td · RH 2 , where Td is the air temperature in °C and RH is the relative humidity in %. This equation applies to a temperature of 20~45 °C and RH of 40~99%. The fit is better than that for the Stull equation in this range. The prediction accuracy is 0.022 °C and there is no fixed pattern for the error distribution for the range of Td and RH. The measurement uncertainty for Tw values for thermometer and humidity sensors that are not calibrated is 1.4~2.2%. If these sensors are calibrated, the measurement uncertainty for Tw values is 0.16~0.28 °C. Therefore, well-calibrated sensors are necessary to enhance the accuracy of the Tw predictive equation. [ABSTRACT FROM AUTHOR]

Nineteen limb-viewing data sets (occultation, passive thermal, and UV scattering) and two nadir upper tropospheric humidity (UTH) data sets are intercompared and also compared to frost-point hygrometer balloon sondes. The upper troposphere considered here covers the pressure range from 300–100 hPa. UTH is a challenging measurement, because concentrations vary between 2–1000 ppmv (parts per million by volume), with sharp changes in vertical gradients near the tropopause. Cloudiness in this region also makes the measurement challenging. The atmospheric temperature is also highly variable ranging from 180–250 K. The assessment of satellite-measured UTH is based on coincident comparisons with balloon frost-point hygrometer sondes , multi-month mapped comparisons, zonal mean time series comparisons, and coincident satellite-to-satellite comparisons. While the satellite fields show similar features in maps and time series, quantitatively they can differ by a factor of 2 in concentration, with strong dependencies on the amount of UTH. Additionally, time-lag response-corrected Vaisala RS92 radiosondes are compared to satellites and the frost-point hygrometer measurements. In summary, most satellite data sets reviewed here show on average ∼30 % agreement amongst themselves and frost-point data but with an additional ∼30 % variability about the mean bias. The Vaisala RS92 sonde, even with a time-lag correction, shows poor behavior for pressures less than 200 hPa. [ABSTRACT FROM AUTHOR]

As the near-surface atmosphere over the Antarctic Plateau is cold and pristine, its physico-chemical conditions resemble to a certain extent those of the high-troposphere where cirrus clouds form. In this paper, we carry out an observational analysis of two shallow fog clouds forming at cirrus-temperatures - that is, temperatures lower than 235 K - at Dome C, inner Antarctic Plateau. The combination of lidar profiles with temperature and humidity measurements from advanced thermo-hygrometers along a 45-m mast makes it possible to characterise the formation and development of the fog. High supersaturations with respect to ice are observed before the initiation of fog and the values attained suggest that the nucleation process at play is the homogeneous freezing of solution aerosol droplets. To our knowledge, this is the first time that in situ observations show that this nucleation pathway can be at the origin of an ice fog. Once nucleation occurs, the relative humidity gradually decreases down to subsaturated values with respect to ice in a few hours, likely owing to vapour deposition onto ice crystals and turbulent mixing. The development of fog is tightly coupled with the dynamics of the boundary-layer which, in the first study case, experiences a weak diurnal cycle while in the second case, transits from a very stable to a weakly stable dynamical regime. Overall, this paper highlights the potential of the site of Dome C for carrying out observational studies of cloud microphysical processes in natural conditions and using in-situ ground-based instruments. [ABSTRACT FROM AUTHOR]

Filament production is a demanding process, which we decided to optimize by designing a laminar box in this scientific study. From a number of designs, we decided to choose a purposeful design for the future construction of the laminar box. The production of filaments takes place on a filament maker, which must be placed in a laminar box. The laminar box then provides ideal conditions in the production process, such as the optimum ambient temperature, which according to standards should be in the range of 18 to 19 degrees Celsius. Furthermore, this laminar box is equipped with a thermometer, hygrometer and control unit. All technical specifications are written in this scientific study. The study contains a number of illustrations for a better idea. The laminar box represents a significant contribution to the production and optimization of the conditions for the production of biomedical filaments. His design is unique and follows from the scientific research of the authors of the scientific study. [ABSTRACT FROM AUTHOR]

Dry eye disease (DED) is one of the conditions that most commonly leads patients to visit an ophthalmologist. Fast and accurate diagnosis relieves patient discomfort and spares them from long-term effects on the ocular surface. Many tests used in the diagnosis of DED may be considered subjective as they rely on an experienced observer for image interpretation, resulting in variations in diagnosis. On one hand, the non-contact nature of the anterior segment optical coherence tomography (AS-OCT) device and its rapid image acquisition enable the measurement of the tear meniscus parameter without reflex tearing. On the other hand, an ocular hygrometer allows a rapid, safe, but also efficient, analysis and is associated with low costs and the repeatability of the procedure. [ABSTRACT FROM AUTHOR]

The pressure chamber, the most popular method used to measure xylem water potential, is a discontinuous and destructive technique and is therefore not suitable for automated monitoring. Continuous non-destructive monitoring could until very recently be achieved only by use of the thermocouple psychrometer (TP). Here we present the high-capacity tensiometer (HCT) as an alternative method for continuous non-destructive monitoring. This provided us with a unique chance to cross-validate the two instruments by installing them simultaneously on the same sapling stem. The HCT and the TP showed excellent agreement for xylem water potential less than –0.5 MPa. Response to day/night cycles and watering was remarkably in phase, indicating excellent response time of both instruments despite substantially different working principles. For xylem water potential greater than –0.5 MPa, the discrepancies sometimes observed between the HCT and TP were mainly attributed to the kaolin paste used to establish contact between the xylem and the HCT, which becomes hydraulically poorly conductive in this range of water potential once dried beyond its air-entry value and subsequently re-wetted. Notwithstanding this limitation, which can be overcome by selecting a clay paste with higher air-entry value, the HCT has been shown to represent a valid alternative to the TP. [ABSTRACT FROM AUTHOR]

Wearable sweat sensors have received significant research interest and have become popular as sweat contains considerable health information about physiological and psychological states. However, measured biomarker concentrations vary with sweat rates, which has a significant effect on the accuracy and reliability of sweat biosensors. Wearable sweat loss measuring devices (SLMDs) have recently been proposed to overcome the limitations of biomarker tracking and reduce inter‐ and intraindividual variability. In addition, they offer substantial potential for monitoring human body homeostasis, because sweat loss plays an indispensable role in thermoregulation and skin hydration. Previous studies have not carried out a comprehensive and systematic review of the principles, importance, and development of wearable SLMDs. This paper reviews wearable SLMDs with a new health perspective from the role of sweat loss to advanced mechanisms and designs. Two types of sweat and their measurement significance for practical applications are highlighted. Then, a comprehensive review of advances in different wearable SLMDs based on hygrometers, absorbent materials, and microfluidics is presented by describing their respective device architectures, present situations, and future directions. Finally, concluding remarks on opportunities for future application fields and challenges for future sweat sensing are presented. [ABSTRACT FROM AUTHOR]

Nineteen limb viewing (occultation and passive thermal) and two nadir humidity data sets are intercompared and also compared to frostpoint hygrometer balloon sondes. The upper troposphere considered here covers the pressure range from 300-100 hPa. Water vapor in this region is a challenging measurement because concentrations vary between 2-1000 parts per million volume with sharp changes in vertical gradients near the tropopause. The atmospheric temperature is also highly variable ranging from 180-250 K. The assessment of satellite measured humidity is based on coincident comparisons with frostpoint hygrometer sondes, multi month mapped comparisons, zonal mean time series comparisons and coincident satellite to satellite comparisons. While the satellite fields show similar features in maps and time series, quantitatively, they can differ by a factor of two in concentration, with strong dependencies on the amount of H2O. Additionally, time-lag response corrected Vaisala-RS92 radiosondes are compared to satellites and the frostpoint hygrometer measurements. In summary, most satellite data sets reviewed here show on average ~30 % agreement amongst themselves and frostpoint data but with an additional ~30 % variability about the mean. The Vaisala-RS92 sonde even with a time-lag correction shows poor behavior for pressure less than 200 hPa. [ABSTRACT FROM AUTHOR]

Water vapor fluxes play a key role in the energy budget of the atmosphere, and better flux measurements are needed to improve our understanding of the formation of clouds and storms. Large-scale measurements of these fluxes are possible by employing the eddy correlation (EC) method from an aircraft. A hygrometer used for such measurements needs to deliver a temporal resolution of at least 10 Hz while reliably operating in the harsh conditions on the exterior of an aircraft. Here, we present a design concept for a calibration-free, first-principles, open-path dTDLAS hygrometer with a planar, circular and rotationally symmetric multipass cell with new, angled coupling optics. From our measurements, the uncertainty of the instrument is estimated to be below 4.5% (coverage factor k = 1). A static intercomparison between a dTDLAS prototype of the new optics setup and a traceable dew point mirror hygrometer was conducted and showed a systematic relative deviation of 2.6% with a maximal relative error of 2.2%. Combined with a precision of around 1 ppm H 2 O at tropospheric conditions, the newly designed setup fulfills the static precision and accuracy requirements of the proposed airborne EC hygrometer. [ABSTRACT FROM AUTHOR]

Why this research Matters: The inner bark plays important roles in tree stems, including radial exchange of water with the xylem and translocation of carbohydrates. Both processes affect the water content and the thickness of the inner bark on a diurnal basis. For the first time, we simultaneously measured the diurnal variations in the inner bark thickness of hinoki cypress (Chamaecyparis obtusa) by using point dendrometers and those of local xylem potential by using stem psychrometers located next to the dendrometers to determine how these variations were related to each other, to phloem turgor and carbohydrate transport. We also estimated the axial hydrostatic pressure gradient by measuring the osmolality of the sap extracted from the inner bark. The inner bark shrunk during the day and swelled during the night with an amplitude related to day‐to‐day and seasonal variations in climate. The relationship between changes in xylem water potential and inner bark thickness exhibited a hysteresis loop during the day with a median lag of 2 h. A phloem turgor‐related signal can be retrieved from the diurnal variations in the inner bark thickness, which was higher at the upper than at the lower position along the trunk. However, a downward hydrostatic pressure gradient was only observed at dawn, suggesting diurnal variations in the phloem sap flow velocity. [ABSTRACT FROM AUTHOR]

This work describes the latest design, calibration and application of a near-infrared laser diode-based photoacoustic (PA) hygrometer developed for total water content measurement in simulated atmospheric freezing precipitation and high ice water content conditions with relevance in fundamental icing research, aviation testing, and certification. The single-wavelength and single-pass PA absorption cell is calibrated for molar water vapor fractions with a two-pressure humidity generator integrated into the instrument. Laboratory calibration showed an estimated measurement accuracy better than 3.3 % in the water vapor mole fraction range of 510–12 360 ppm (5 % from 250–21 200 ppm) with a theoretical limit of detection (3 σ) of 3.2 ppm. The hygrometer is examined in combination with a basic isokinetic evaporator probe (IKP) and sampling system designed for icing wind tunnel applications, for which a general description of total condensed water content (CWC) measurements and uncertainties are presented. Despite the current limitation of the IKP to a hydrometeor mass flux below 90 gm-2s-1 , a CWC measurement accuracy better than 20 % is achieved by the instrument above a CWC of 0.14 gm-3 in cold air (-30 ∘ C) with suitable background humidity measurement. Results of a comparison to the Cranfield University IKP instrument in freezing drizzle and rain show a CWC agreement of the two instruments within 20 %, which demonstrates the potential of PA hygrometers for water content measurement in atmospheric icing conditions. [ABSTRACT FROM AUTHOR]

Balloon-borne water vapour measurements in the upper troposphere and lower stratosphere (UTLS) by means of frost point hygrometers provide important information on air chemistry and climate. However, the risk of contamination from sublimating hydrometeors collected by the intake tube may render these measurements unusable, particularly after crossing low clouds containing supercooled droplets. A large set of (sub)tropical measurements during the 2016–2017 StratoClim balloon campaigns at the southern slopes of the Himalayas allows us to perform an in-depth analysis of this type of contamination. We investigate the efficiency of wall contact and freezing of supercooled droplets in the intake tube and the subsequent sublimation in the UTLS using computational fluid dynamics (CFD). We find that the airflow can enter the intake tube with impact angles up to 60 ∘ , owing to the pendulum motion of the payload. Supercooled droplets with radii > 70 µ m, as they frequently occur in mid-tropospheric clouds, typically undergo contact freezing when entering the intake tube, whereas only about 50 % of droplets with 10 µ m radius freeze, and droplets < 5 µ m radius mostly avoid contact. According to CFD, sublimation of water from an icy intake can account for the occasionally observed unrealistically high water vapour mixing ratios (χH2O > 100 ppmv) in the stratosphere. Furthermore, we use CFD to differentiate between stratospheric water vapour contamination by an icy intake tube and contamination caused by outgassing from the balloon and payload, revealing that the latter starts playing a role only during ascent at high altitudes (p < 20 hPa). [ABSTRACT FROM AUTHOR]

Cocoa is grown under production systems such as agroforestry and full sunlight exposition, its use depends on the agroecological regions where it is cultivated. The management of the shade canopy affects the microclimatic conditions that mainly benefit the hydric behaviour (sap flow Vs and water potential Ѱ) in the cocoa plant. It was evaluated how the modification of the shade canopy (full sunlight exposition systems SLE and agroforestry with MPAR medium and low BPAR transmitted radiation) affects the water status of cocoa trees in contrasting periods of precipitation. For the measurement of Vs and Ѱ heat sensors and stem psychrometers were installed in cocoa type CCN51 trees. An effect of the production system and monitoring season on Vs and Ѱ was found in cocoa plants. The Ѱ was higher in SLE in both seasons, but it was more accentuated in the period of minimum precipitation. A contrary behavior was found in Vs, since in minimum precipitation this variable was greater in BPAR. According to the results obtained, the management of shade canopies in cocoa crops under suboptimal climates positively affects water status. [ABSTRACT FROM AUTHOR]

Objective: Humidity and temperature are fundamental for the balance in the life cycle of living beings and, consequently, for maintaining the well-being of the human population and reducing the prevalence of infectious diseases. Thus, in order to mitigate the impact of climate change, especially in the period when humidity is not the ideal, it is necessary to adopt some assistance measures. The present experimental study aims to elucidate what would be the recommended option to improve the quality of life of the human being and to clarify which resources (air humidifier, bucket of water or wet towel) will be effective to improve the humidity of the air in times of drought and low moisture. Methods: The experimental study was carried out with INKBIRD hygrometers allowing the analysis of the variation of air humidity throughout the day. Three forms of treatment were established: humidifier, wet towel and bucket of water. In each room, two hygrometers were placed equidistant from the occupant of the room and their respective treatment that varied between 1m and 2m away from the headboard indoor each room. In addition, two environments were used as controls, one being an external environment and the other an internal closed environment, totaling five rooms for the study. The rooms were monitored between the end of July and the end of August 2019 in Goiania (GO). Results: Although assistance measures are used to significantly improve air pollution in times of extreme drought, there was a significant difference between them. The humidifier and a wet towel had 7.50% and 5.71% more humidity in the external relation (external control), respectively, more efficient. The volume of water, however, did not show significant difference (p>0.05) and, therefore, there was no variation. Conclusion: The humidifier and the towel are treatments considered more efficient, and that there was a significant effect of distance on humidity. Therefore, 1m of distance is more efficient in increasing and/or maintaining air humidity, inducing improvements in the populations’ health. [ABSTRACT FROM AUTHOR]

This is a review of high-frequency methods for measuring and controlling the humidity of various materials. The moisture of cotton seeds is a major factor affecting their qualitative and quantitative characteristics in technologies for their storage, transport, and processing. Thus, direct humidity measurements of cotton seeds during processing is an important problem. A mathematical model of a high-frequency hygrometer for cotton seeds is constructed in which the test material is represented as a complicated dielectric in an electric field. A substitution circuit containing a capacitance between electrodes is proposed, along with capacitances and resistances corresponding to different forms of polarization. Four variants of the substitution circuit are examined which approximately describe the dependence of the tangent of the dielectric loss angle on the frequency of the electromagnetic field. It is shown that the simplest parallel two-component RC substitution circuit corresponds most closely to the actual object of measurement at frequencies of 105–108 Hz. [ABSTRACT FROM AUTHOR]

In situ observations of reduced stratospheric water vapor combined with those of ice particle formation are rarely conducted. On the one hand, they are essential to broaden our knowledge about the formation of polar stratospheric clouds (PSCs). On the other hand, the observed profiles allow the comparison with global circulation models. Here we report about a balloon‐borne observation above Sodankylä, Finland on 26 January 2005. The frostpoint hygrometer detected layers of reduced water vapor by up to 2 ppmv from 18.5 to 23 km. Beneath, a 1‐km‐deep layer of increased water vapor was identified. An aerosol backscatter sonde measured the presence of stratospheric ice clouds. According to meteorological analysis the PSCs were formed upstream above the east coast of Greenland due to mountain wave‐induced cooling. The inertia‐gravity waves generated a large and persistent stratospheric wake far downstream of Greenland and led to the observed dehydration. Comparing the most recent ERA5 data with operational analyses from 2005, we find an improved representation of mesoscale internal gravity waves, dehydration and PSC formation for this particular event. Plain Language Summary: This paper investigates unique in situ observations of stratospheric water vapor and combines them with nearly simultaneous optical property measurements of ice particles. The presented results reveal Antarctic‐like stratospheric dehydration and rehydration inside the Arctic polar vortex. Balloon‐borne observations of this kind are extremely rare and constitute a valuable data set for extending our knowledge about both the cloud formation processes and the representation of water vapor in global circulation models. Here, we make use of state‐of‐the art numerical weather prediction models with high spatial resolution. They allow to resolve dynamically processes that were not accessible when the observations were conducted in 2005. Besides the large‐scale cooling inside the Arctic polar vortex, it is the far‐ranging impact of the numerically resolved stratospheric mountain waves that was responsible for maintaining the thermodynamic conditions leading to the unique observations over Sodankylä, Finland. Key Points: We present unique balloon‐borne observations of stratospheric water vapor and aerosol backscatter above northern ScandinaviaThe balloon‐borne measurements reveal Antarctic‐like dehydration and rehydration and the existence of solid ice particlesThe far‐ranging impact of Greenland's mountain wave‐induced temperature fluctuations is a key process [ABSTRACT FROM AUTHOR]

This work describes the latest design, calibration and application of a near-infrared laser diode-based photoacoustic (PA) hygrometer, developed for total water content measurement in simulated atmospheric freezing precipitation and high ice water content conditions with relevance in fundamental icing research, as well as aviation testing and certification. The single-wavelength and single-pass PA absorption cell is calibrated for molar water vapor fractions with a two-pressure humidity generator integrated into the instrument. Laboratory calibration showed an estimated measurement accuracy better than 3.3 % in the water vapor mole fraction range of 510-12,360 ppm (5 % from 250-21,200 ppm) with a theoretical limit of detection (3 sigma) of 3.2 ppm. The hygrometer is examined in combination with a basic isokinetic evaporator probe (IKP) and sampling system designed for icing wind tunnel application, for which a general description of total condensed water content (CWC) measurement and uncertainties are presented. Despite the current limitation of the IKP to a hydrometeor mass flux below 90 g m-2 s-1, a CWC measurement accuracy better than 20 % is achieved by the instrument above a CWC of 0.14 g m-3 in cold air (-30 °C) with suitable background humidity measurement. Results of a comparison to the Cranfield University IKP instrument in freezing drizzle and rain show a CWC agreement of the two instruments within 20 %, which demonstrates the potential of PA hygrometers for water content measurement in atmospheric icing conditions. [ABSTRACT FROM AUTHOR]

Balloon-borne water vapour measurements in the (sub)tropical upper troposphere and lower stratosphere (UTLS) by means of frost point hygrometers provide important information on air chemistry and climate. However, the risk of contamination from sublimating hydrometeors collected by the intake tube may render these measurements difficult, particularly after crossing low clouds containing supercooled droplets. A large set of measurements during the 2016-2017 StratoClim balloon campaigns at the southern slopes of the Himalayas allows us to perform an in-depth analysis of this type of contamination. We investigate the efficiency of wall-contact and freezing of supercooled droplets in the intake tube and the subsequent sublimation in the UTLS using Computational Fluid Dynamics (CFD). We find that the airflow can enter the intake tube with impingement angles up to 60°, owing to the pendulum motion of the payload. Supercooled droplets with radii >70μm, as they frequently occur in mid-tropospheric clouds, typically undergo contact freezing when entering the intake tube, whereas only about 50% of droplets with 10μm radius freeze, and droplets <5μm radius mostly avoid contact. According to CFD, sublimation of water from an icy intake can account for the occasionally observed high water vapour mixing ratios (χ(H2O)>100ppmv) in the stratosphere. Furthermore, we use CFD to differentiate between stratospheric water vapour contamination by an icy intake tube and contamination caused by outgassing from the balloon and payload, revealing that the latter starts playing a role only at high altitudes (p<20hPa). [ABSTRACT FROM AUTHOR]

In Romania the climate is temperate continental, but climate change from recent times fragmenting this climate into one with nuances of excess. This is due to large temperature variations between the hot and cold seasons, but also of large temperature differences between day and night. In addition to these aspects, the uneven distribution of precipitation as well as extremely large variations in their total quantity registered from one year to another negatively influences the growth and fruiting of grapevine plants. This paper presents methods and systems for detecting water stress in viticulture. Among the most commonly used instruments are tensiometers and soil psychrometers to measure directly the capillary tension or energy with which water is withheld by the soil. [ABSTRACT FROM AUTHOR]

• We report a new method for humidity measurements by using human hairs. • A short segment of a single strand of hair mounted on a machined jig simply constitutes a mechanical resonator. • The hair resonator offers high spatial and temporal resolutions with the aid of its miniaturized dimension. • Historical hair hygrometers are successfully revisited with improved performance. Hairs have long been used for humidity sensing with the aid of their unique property, elongation upon the increase of ambient humidity. However, relatively long strands of hairs are required to induce measurable length change. While such long strands of hairs amplify the readout signal, they, in turn, compromise the spatiotemporal resolution. Here, we revisit the hair hygrometer, firstly demonstrated by a Swiss physicist and geologist, Horace Bénédict de Saussure in 1783, by making suspended string resonators with a short segment of human hairs. A short segment of human hair is placed onto a substrate with a through-hole and then firmly fixed under tension to make a taut suspended string. As a final step, a thin gold layer is locally deposited onto the suspended hair through a shadow mask. While the prepared hair resonator is driven by a piezo actuator, its resonance frequency is optically measured. Measurements confirm that the resonance frequency of the hair resonator decreases as the relative humidity increases. The water absorption decreases both the tension and the stiffness of the hair resonator and increases the inertial mass of the hair resonator, all of which contribute to the reduction of the resonance frequency. [ABSTRACT FROM AUTHOR]

The article presents the results of researches of influence of working conditions of mechanics-drivers, who carry out defoliation of cotton by new import substituting low-toxic defoliants on the functional state of different systems of organism. It is revealed that working conditions and character of working processes at defoliation cause unfavorable shifts of physiological reactions of different systems of organism at mechanics-drivers, and noise and intense character of working process cause probability of risk of development of professionally caused diseases that specifies necessity of introduction of measures on improvement of working conditions. [ABSTRACT FROM AUTHOR]

Abstract The moisture storage curve is an important hygric property of porous building materials. It describes the moisture storage characteristic of a material via the relation between the moisture content and the moisture potential. Current experimental protocols for measuring moisture storage curves are not satisfactory, as they often require extensive facilities while still lacking the capability to handle the adsorption process in most of the over-hygroscopic range. This paper proposes two novel and simple methods – the semi-permeable membrane method and the psychrometer method – to solve these issues. Measurements on calcium silicate, autoclaved aerated concrete and ceramic brick are performed and validated by comparing the experimental outcomes obtained from these two novel methods and from other existing protocols. It is proven that the semi-permeable membrane method and the psychrometer method are applicable for both adsorption and desorption processes, the latter both from saturated and capillary moisture content. Limited by the accuracy of the psychrometer and the condensation caused by temperature fluctuations, these two methods show their best applicable range for capillary pressures below −1·105 Pa. The semi-permeable membrane method and the psychrometer method also feature in low cost, simple handling and application efficiency. Highlights • Two novel methods for measuring the moisture storage curves are proposed. • They feature in wide applicable range, low cost, simple handling and efficiency. • Both adsorption and desorption in the over-hygroscopic range can be measured. • Tests on 3 representative porous building materials are performed and validated. [ABSTRACT FROM AUTHOR]

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• Development of a low-cost sensor for measuring soil pH and moisture content. • Using soil resistivity as measured parameter, regression models were developed. • Calibration successful in accounting for soil temperature and sensor depth. • Common tropical soils were evaluated – clay, thionic, and fine sandy loam. • Prediction model was accurate up to 98%. Soil moisture content and soil pH values, especially in the surface layers of the soil play a significant role in agriculture production in hydrological processes, meteorology observation and horticulture study. This paper proposes an analytical model of estimating the moisture content, acidity and alkalinity in soil through measurement of soil resistivity by an on-site, real-time method. In this study, a low-cost soil resistivity sensor YL-69 was used to characterize the dynamics of soil moisture content and its pH value. Laboratory calibrated regression models were developed for three types of soils, i.e., clay, thionic, and fine sandy loamy to evaluate the effect of soil temperature and the depths of sensor on the apparent soil moisture content and pH value with a single resistive sensor. The prediction models were found to be accurate with the accuracy of 98%. The findings obtained from this study could provide inexpensive and accurate simultaneous soil moisture content and pH value measurement. [ABSTRACT FROM AUTHOR]

Highlights • Combined action of pressure regulator and balance reduces the pressure oscillations. • Dew point realization uncertainties are improved by using the pressure balance. • Pressure balance reduces the oscillations of the chilled mirror hygrometer readings. Abstract This paper describes two methods for measurement of air pressure inside the saturation chambers of two primary dew/frost point generators, used as national humidity standards at Laboratory for process measurement (HMI/FSB-LPM) in Croatia. Together, the generators cover the dew/frost point temperature range from −70 °C to + 65 °C. Low range generator operates at air temperatures between −70 °C and 5 °C, while high range covers the range between 1 °C and 65 °C. The saturation pressures considered are in the range between atmospheric and 1060 hPa, at the air flow rates between 1.0 L min−1 and 2.5 L min−1. The dew/frost point of the saturated air depends strongly on the saturation pressure, making improvement in this kind of measurements of great importance for humidity realizations. In the old method, the precise digital barometer is used for determination of saturated air pressure inside the saturation chamber. The barometer is traceable to the pressure balance, which is used as a national standard for pressure in Croatia. In the new method, the pressure was maintained directly by the primary pressure balance, achieving this way the significant improvement of related measurement uncertainties for both, pressure measurement and the dew/frost point realization. The paper will give a detailed description of both measurement setups as well as corresponding measurement uncertainty analyses. During the experiments it was also observed that in the second setup, balance stabilized the pressure oscillations as well as oscillations of the dew-point temperature measured by the chilled mirror hygrometer under calibration, making indirect improvement of related measurement uncertainties. [ABSTRACT FROM AUTHOR]

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Abstract In this work, we experimentally demonstrated a microfiber knot resonator (MKR) for ambient relative humidity (RH) measurement. The microfiber device was manufactured by forming a ring from a low-loss microfiber, fabricated from a single-mode fiber (SMF) by using flame-heating technique. The resonator was successfully formed when a periodic output resonance spectrum was achieved. Without employing any coating hygroscopic material, the MKR was observed to highly sensitive to the variation of ambient RH ranging from of 30% RH to 94% RH. The proposed device is an extremely compact and fast response sensor, useful for a wide spectrum of industrial applications. Highlights • A humidity sensor based on a bare MKR without hygroscopic material coating is proposed. • The RH sensitivity reaches 5.95 pm/% RH in the linear range from 30% RH to 94% RH. • The sensor has a fast response time with good repeatability. [ABSTRACT FROM AUTHOR]

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)