Evaporation Measurements Research Articles

Measuring and Validating the Actual Evaporation and Soil Moisture Dynamic in Arid Regions under Unirrigated Land Using Smart Field Lysimeters and Numerical Modeling

Though forming a fundamental component of the water budget, soil evaporation is challenging to quantify in practice. Most water balance and soil moisture studies rely on pan evaporation or empirical relations to calculate evaporation, which is later used for water budget estimation. This study is based on the in situ measurement of soil evaporation in arid regions using smart field lysimeters. These lysimeters calculate the actual evaporation and downward leakage within the soil column using changes in weight, in addition to measuring temperature, soil moisture, soil matric potential, and other ancillary parameters in real time. The study analyses 17 months of data collected from two smart-field lysimeters installed in loamy soil within unirrigated land in Qatar. Lysimeter data were validated using a 1D numerical unsaturated flow model using Hydrus, and utilized laboratory testing results of the water retention. The Hydrus model output shows a good match between numerical and lysimeter results. The volumetric soil moisture of the topsoil in the lysimeters varies between 6% and 36%, with a rapid response to rainfall events. The actual recharge based on data analysis amounts to 5% of the annual rainfall. An analysis of the results reveals a substantial difference between the potential evaporation and the actual evaporation. While the potential values can be adequate for wet countries where rainfall is high, it is irrelevant in arid countries, due to the lack of moisture available for evaporation throughout most of the year. Results also show that while the topsoil responds quickly to rainfall events, it takes a considerable amount of time until such effects are propagated to below the soil’s lower boundary. The findings of this study may help decision makers, researchers, and irrigation engineers plan for the sustainable management and protection of scarce resources.

Ventilation and irrigation management strategy for tomato cultivated in greenhouses

Appropriate ventilation and water management strategy are beneficial to boost crop yield and quality in greenhouses, and their optimization is crucial for improving water use efficiency (WUE). Here, we set up three irrigation levels based on measurements of the cumulative pan evaporation (AEpan) (i.e. 0.9 AEpan, 0.7 AEpan, and 0.5 AEpan), and three ventilation modes through opening the greenhouse vents at different location (VST: open the both roof and south vents; VT: open the roof vents only; VS: open the south vents only) to reveal the effects of ventilation mode and irrigation amount on picking, yield (Y), evapotranspiration (ET), WUE and quality of tomato grown in a solar greenhouse. Nine treatments were split block design with ventilation mode as main treatment and irrigation amount as vice treatment. Each treatment was replicated three times. Results showed that harvesting time of tomato were substantially influenced by ventilation mode as a result of interior temperature differences. The VT treatment was beneficial to early maturity of tomato than the VST and VS treatments. The proportion of VT in the first three harvesting was ~36.8 % and ~26.3 % higher than of VST and VS, respectively. Irrigation amount had a marked effect on ET, Y, WUE, irrigation water use efficient (IWUE), and irrigation water compensation (Irc). Here, ET, Y and Irc of K0.9 were 51.7 % and 69.8 %, 11.0 % and 19.6 %, 7.0 % and 13.5 % higher than those of K0.7 and K0.5 treatments, respectively, while the WUE and IWUE were 13.1 % and 24.8 %, 18.6 % and 28.6 % lower than K0.7 and K0.5, respectively. However, the significant interaction between ventilation and irrigation were only found on Y, WUE and IWUE. Both ventilation and irrigation treatments had considerable effect on soluble solids (TSS), Vc and organic acid. TSS could represent the comprehensive quality of tomato, because TSS was very significantly positively correlated with the comprehensive quality scores. A better combination of ventilation and irrigation was recommended as VST × 0.7 AEpan by using the TOPSIS method based on a compromise of Y, quality and WUE.

Comparing and Quantifying the Efficiency of Cocrystal Screening Methods for Praziquantel.

Pharmaceutical cocrystals are highly interesting due to their effect on physicochemical properties and their role in separation technologies, particularly for chiral molecules. Detection of new cocrystals is a challenge, and robust screening methods are required. As numerous techniques exist that differ in their crystallization mechanisms, their efficiencies depend on the coformers investigated. The most important parameters characterizing the methods are the (a) screenable coformer fraction, (b) coformer success rate, (c) ability to give several cocrystals per successful coformer, (d) identification of new stable phases, and (e) experimental convenience. Based on these parameters, we compare and quantify the performance of three methods: liquid-assisted grinding, solvent evaporation, and saturation temperature measurements of mixtures. These methods were used to screen 30 molecules, predicted by a network-based link prediction algorithm (described in Cryst. Growth Des. 2021,21(6), 3428–3437) as potential coformers for the target molecule praziquantel. The solvent evaporation method presented more drawbacks than advantages, liquid-assisted grinding emerged as the most successful and the quickest, while saturation temperature measurements provided equally good results in a slower route yielding additional solubility information relevant for future screenings, single-crystal growth, and cocrystal production processes. Seventeen cocrystals were found, with 14 showing stability and 12 structures resolved.

Efficiencies of cobalt- and copper-based coatings applied by different deposition processes for applications in intermediate-temperature solid oxide fuel cells

Solid Oxide Fuel Cells (SOFCs) are electrochemical conversion devices that produce electricity directly by oxidising a fuel. The interconnects between the individual cells need to be coated to limit Cr(VI) evaporation from the steel and to preserve electrical conductivity. Physical Vapour Deposition (PVD)-coated samples with Ce/Co, Ce/Cu, and Ce/MnCu, and Thermal Spray (TS)-coated Mn/Co, Cu and Mn/Cu and AISI 441 steel samples were exposed at 650 °C for up to 1000 h. The PVD Ce/Co and Ce/Cu coatings, as well as the TS Mn/Co coating, exhibited the formation of a thin protective Cr2O3 scales underneath the coating. These samples also exhibited the lowest area-specific resistance (ASR) values. The remainder of the samples exhibited much higher mass gains and higher ASR values. Cr(VI) evaporation measurements showed that all the coatings behaved approximately the same despite the PVD coatings being only about one-tenth of the thickness of the TS coatings.

Amorphous silica amendment to improve sandy soils’ hydraulic properties for sustained plant root access under drying conditions

Climate scenarios predict more frequent and longer drought periods, potentially threatening agricultural yield. The water holding capacity of soils is crucial in controlling drought stress intensity for plants. Recently, amorphous silica was suggested to increase soil water holding capacity and availability. The objective of this study was to explore the potential impact of Si application to soils on the retention and flow of water in soils and their consequence on plant access to water under soil drying conditions. Two sandy soils were mixed with varying contents (0, 1 and 5% g/g) of some selected ASi amendments. The soil water retention and soil hydraulic conductivity were determined using evaporation measurement device implemented in a commercial device called HYPROP. For both soils, an application of ASi at rates of 1 or 5% increased the water holding capacity and soils treated with ASi maintained a higher hydraulic conductivity under soil drying conditions than the control soil. Simulation demonstrated that soils treated with ASi could longer sustain the transpirational demand of plants during a soil drying cycle. These first results confirm expected positive crop-growth effect of silica amendments on hydraulic properties of coarse-textured soils mainly by longer keeping up capillary flow during water extraction by plant roots.

Optical Microwave Scintillometer Evaporation Measurements over a Saline Lake in a Heterogeneous Setting in the Atacama Desert

Abstract Estimating lake evaporation is a challenge due to both practical considerations and theoretical assumptions embedded in indirect methods. For the first time, we evaluated measurements from an optical microwave scintillometer (OMS) system over an open-water body under arid conditions. The OMS is a line-of-sight remote sensing technique that can be used to measure the sensible and latent heat fluxes over horizontal areas with pathlengths ranging from 0.5 to 10 km. We installed an OMS at a saline lake surrounded by a wet-salt crust in the Salar del Huasco, a heterogeneous desert landscape in the Atacama Desert. As a reference, we used eddy covariance systems installed over the two main surfaces in the OMS footprint. We performed a footprint analysis to reconstruct the surface contribution to the OMS measured fluxes (80% water and 20% wet salt). Furthermore, we investigated the applicability of the Monin–Obukhov similarity theory (MOST), which was needed to infer fluxes from the OMS-derived structure parameters to the fluxes. The OMS structure parameters and MOST were compromised, which we mitigated by fitting MOST coefficients to the site conditions. We argue that the MOST deviation from values found in the literature is due to the effects of the surface heterogeneity and the nonlocal processes induced by regional circulation. With the available dataset we were not able to rule out instrument issues, such as additional fluctuations to the scintillation signal due to absorption or the effect of vibration in high-wind conditions. The adjusted MOST coefficients lowered by a factor of 1.64 compared to using standard MOST coefficients. For H and LυE, we obtained zero-intercept linear regressions with correlations, R2, of 0.92 and 0.96, respectively. We conclude that advances in MOST are needed to successfully apply the OMS method in landscapes characterized by complex heterogeneity such as the Salar del Huasco.

Evaporation and Molecular Beam Scattering from a Flat Liquid Jet.

An experimental setup for molecular beam scattering from flat liquid sheets has been developed, with the goal of studying reactions at gas-liquid interfaces for volatile liquids. Specifically, a crossed molecular beam instrument that can measure angular and translational energy distributions of scattered products has been adapted for liquid jet scattering. A microfluidic chip is used to create a stable flat liquid sheet inside vacuum from which scattering occurs, and both evaporation and scattering from this sheet are characterized using a rotatable mass spectrometer that can measure product time-of-flight distributions. This article describes the instrument and reports on the first measurements of evaporation of dodecane and Ne from a Ne-doped dodecane flat jet, as well as scattering of Ne from a flat jet of pure dodecane.

Transpiration of a Tropical Dry Deciduous Forest in Yucatan, Mexico

The study of forest hydrology and its relationships with climate requires accurate estimates of water inputs, outputs, and changes in reservoirs. Evapotranspiration is frequently the least studied component when addressing the water cycle; thus, it is important to obtain direct measurements of evaporation and transpiration. This study measured transpiration in a tropical dry deciduous forest in Yucatán (Mexico) using the thermal dissipation method (Granier-type sensors) in representative species of this vegetation type. We estimated stand transpiration and its relationship with allometry, diameter-at-breast-height categories, and previously published equations. We found that transpiration changes over time, being higher in the rainy season. Estimated daily transpiration ranged from 0.562 to 0.690 kg m–2 d–1 in the late dry season (April–May) and from 0.686 to 1.29 kg m–2 d–1 in the late rainy season (September–October), accounting for up to 51% of total evapotranspiration in the rainy season. These daily estimates are consistent with previous reports for tropical dry forests and other vegetation types. We found that transpiration was not species-specific; diameter at breast height (DBH) was a reliable way of estimating transpiration because water use was directly related to allometry. Direct measurement of transpiration would increase our ability to accurately estimate water availability and assess the responses of vegetation to climate change.

Effects of Evaporative Emissions Control Measurements on Ozone Concentrations in Brazil

In this work, the possible benefits obtained due to the implementation of evaporative emissions control measures, originating from vehicle fueling processes, on ozone concentrations are verified. The measures studied are: (1) control at the moment when the tank trucks supply the fuel to the gas stations (Stage 1); (2) control at the moment when the vehicles are refueled at the gas stations, through a device installed in the pumps (Stage 2); (3) same as the previous control, but through a device installed in the vehicles (ORVR). The effects of these procedures were analyzed using numerical modeling with the VEIN and WRF/Chem models for a base case in 2018 and different emission scenarios, both in 2018 and 2031. The results obtained for 2018 show that the implementation of Stages 1 and 2 would reduce HCNM emissions by 47.96%, with a consequent reduction of 19.9% in the average concentrations of tropospheric ozone. For 2031, the greatest reductions in ozone concentrations were obtained with the scenario without ORVR, and with Stage 1 and Stage 2 (64.65% reduction in HCNM emissions and 31.93% in ozone), followed by the scenario with ORVR and with Stage 1 and Stage 2 (64.39% reduction in HCNM emissions and 32.98% in ozone concentrations).

Measurement and Analysis of Evaporation in Indoor Swimming Pools: Comparison with the ASHRAE’s Activity Factor

The evaporation rate from the swimming pool is a main parameter influencing the energy use in swimming facilities. Quantifying this phenomenon is crucial when modelling the facility in Building Performance Simulation. This study investigates the accuracy of ASHRAE equation using field measurements. This equation is widely used and implemented in BPS tools, such as the pool model in IDA ICE. The investigated dataset was based on two different indoor swimming pool facilities in Norway. It includes in total 75 swimming lessons (i.e., occupied pool) and 477 hours of unoccupied operation. While ASHRAE recommend 1.0/0.5 for occupied and unoccupied pools, respectively, the average activity factor was found to be 0.7 and 0.8 for the investigated occupied pools, with a maximum at 1.1. Moreover, the activity factor was between 0.50 and 0.57 for unoccupied pools.

Explosive atmosphere analysis for simulation of acetone source of release using ALOHA software

The analysis of the explosive atmosphere for the simulation of acetone using ALOHA (Arial Location Hazardous Atmosphere) was evaluated against a previous evaporation measurement in the present study. With ALOHA, evaporation from large liquid surfaces can be studied on a global scale. Such fluid surfaces can be formed during high leakage from process units. In third world countries, there are still operating pools that, under normal operating conditions, contain large quantities of flammable and explosive substances that can be a source of highly explosive atmospheres. In the more developed countries of Europe, you are more likely to encounter puddles during overfilling and dumping. Unlike under normal operating conditions, failure may result in the formation of large liquid surface in storage salvage tray or transport tank leaks. The simulation considers several boundary conditions, such as the type and temperature of the solid or porous medium on which the fluid surface is located, as well as different weather factors. An additional advantage of the software is that it can be used to investigate the extent of hazardous areas geographically anywhere, depending on different concentrations.

Atmospheric humidity deficits tell us how soil moisture deficits down-regulate ecosystem evaporation

Knowing how actual evaporation is down-regulated from potential evaporation during periods with soil moisture deficits is one of the greatest challenges towards computing evaporation everywhere on a regular basis. We propose the hypothesis that vegetated landscapes transmit information on soil moisture deficits through its down-regulation of evaporation, which in turn affects the humidification and growth of the planetary boundary layer. To test this hypothesis, we examined how the evaporative fraction, defined as the ratio between actual and potential evaporation, corresponds with the soil moisture stress index, defined as the relative humidity with a power law dependence on vapor pressure deficit times a parameter, β.We tested the parameterized soil moisture stress index with direct eddy covariance measurements of actual evaporation and computations of potential evaporation based on meteorological conditions, averaged on monthly time steps. The analysis was conducted on a dataset obtained from 144 FLUXNET sites. These sites spanned much of the world's climates and biomes and contained over 5900 months of observations.Observations of the evaporative fraction fit the model of the soil moisture stress index best for semi-arid and arid ecosystems, and least for the humid and wet ecosystems. Consequently, a significant relationship between measurements of the evaporative fraction and soil moisture stress index held for about one-half of the population of sites. Under this condition, the median value of the parameter, β, was 1.41.To investigate the mechanism of this empirical soil moisture stress index, we diagnosed it with a coupled evaporation-planetary boundary layer model. The soil moisture stress index is strongly related to surface resistance, as defined by inverting Penman-Monteith equation. Consequently, this index provides an independent estimate of surface resistance based on easy to measure mean monthly weather conditions like relative humidity and temperature. Thereby, this soil moisture stress index has potential to be applied to weather, climate and biogeochemical models and the interpretation of satellite derived evaporation products, like the one provided by the ECOSTRESS mission.

Experimental Measurement of Vacuum Evaporation of Aluminum in Ti-Al, V-Al, Ti6Al4V Alloys by Electron Beam

Titanium alloys have been widely used in aerospace engineering due to their excellent mechanical properties, especially their strength-to-weight ratio. In addition, Ti6Al4V (TC4) alloy is the most widely used among α+β alloys. The main three elements of TC4 alloy are titanium (Ti), aluminum (Al) and vanadium (V). Since the boiling point of aluminum is much lower than the melting point of the other two elements, the consistency of TC4 alloy during smelting, additive manufacturing and surface treatment is difficult to control. Therefore, in order to study the difficult problem of composition control in TC4 alloy production, we measured the vacuum evaporation of Al, Ti and V in Ti-Al, V-Al and TC4 alloys, and tracked the changes of molten pool temperature, heating time and weight. According to the results, the Al started to evaporate near 1300 ± 10 °C in vacuum and totally evaporated after 225 s heating to 1484 °C at 10−2 Pa. However, V and Ti barely evaporated below 2000 °C. The Al in Ti-Al alloy started to evaporate at 1753 ± 10 °C and lost 20.6 wt.% aluminum during 500 s at 1750~1957 °C. The Al in V-Al alloy started to evaporate at 1913 ± 10 °C and lost 26.4 wt.% aluminum during 543s at 1893~2050 °C. The Al in TC4 alloy started to evaporate at 1879 ± 10 °C and lost 79.6 wt. % aluminum after 113 s at 1879~1989 °C. The results indicate that smelting TC4 alloy with Ti-Al and V-Al alloys by EBM below 1900 °C improves the consistency and performance. Additionally, the lowest loss of Al occurred in the additive manufacturing of TC4 alloy below 1900 °C.

Interferometric measurement of co-operative evaporation in 2D droplet arrays

The evaporation dynamics of multiple droplet arrays is important in inkjet printing and spray coating, where co-operative “shielding” effects increase the overall evaporation time. However, current measurement methods provide limited information on how individual droplets contribute to the overall dynamics. In this work, we present a simple interferometric technique for precise measurements of droplet evaporation rates, which is not possible via traditional approaches. We validate the technique on a single droplet. We then extend our analysis to ordered and random 2D arrays of droplets. We demonstrate that the evaporation rate is highly dependent on the position of the droplet within the array and its confinement. The more confined droplets exhibit lower evaporation rates. Our results of ten different configurations and well over 100 droplets are in good quantitative agreement with a recent analytical model of co-operative evaporation rates. Our approach opens up possibilities for studies of collective evaporation effects, including in areas of current importance such as sneezes and exhaled breath.

TEMPERATURE-DRIVEN EVAPORATION ANALYSIS OVER BALLIKAYA CATCHMENT

Hydrometeorological analysis such as terrain characteristics, flood forecasts and water potentials have become possible through computer models today in parallel with rapidly ever-evolving technology. While the surface-runoff during a storm has linearly and highly correlation with effective precipitation, it is inversely proportional to hydrological losses, including interception, infiltration, transpiration and evaporation. However, flood estimation analysis, in especially rural areas in Turkey, is still not widely and accurately usable, due to difficulties in accessing the necessary ground-based data records such as evaporation, which affects much of the rainfall. Although direct measurement of evaporation is not available now, indirect methods such as evaporation pans have been developed to give acceptable results. On the one hand, observation networks are built by Turkish State Meteorological Service for the estimation of evaporation from open water bodies, these measurements, on the other hand, are only obtained at large climatological stations such as city centers and generally for only six months of the year. In this sense, evaporation values, in order to apply rainfall-runoff analysis, were estimated by Kharrufa, Blaney-Criddle, and modified Blaney-Criddle methods to be used in Monthly Average models. While the highest underestimations were obtained in modified Blaney-Criddle method, Kharrufa method outperformed the other Blaney-Criddle products. The results, confirmed by analysis of the temperature-based Kharrufa approach in two urban areas close to the study basin, show to be appliable for estimation of long-term hydrographs. The analyzed method can be applied over rural watersheds lacking in-situ evaporation measurements as well as enables more accurate rainfall-runoff simulations processes with calibrated and verified hydrological models.

Amorphous High‐Entropy Hydroxides of Tunable Wide Solar Absorption for Solar Water Evaporation

AbstractThe high‐entropy materials have raised much attention in recent years due to their extraordinary performances in mechanical, catalysis, energy storage fields. Herein, a new type of high‐entropy hydroxides (e.g., NiFeCoMnAl(OH)x) that are amorphous and capable of broad solar absorption is reported. A facile one‐pot co‐precipitation method is employed to synthesize these amorphous high‐entropy hydroxides (a‐HEHOs) under ambient conditions. The a‐HEHOs thus obtained display widely tunable bandgap (e.g., from 2.6 to 1.1 eV) due to their high‐entropy and amorphous characteristics, enabling efficient light absorbance and photothermal conversion in the solar regime. Further solar water evaporation measurements show that the a‐HEHOs delivered a considerable energy conversion efficiency of 55%, comparable to black titanium oxides that are synthesized using more complex and expensive methods.

Measuring the Chemical Evolution of Levitated Particles: A Study on the Evaporation of Multicomponent Organic Aerosol.

Single-particle levitation methods provide an effective platform for probing the physical properties of atmospheric aerosol via micrometer-sized particles. Until recently, chemical composition measurements on levitated particles were limited to spectroscopy, yielding only basic chemical information. Here, we describe, benchmark, and discuss the applications of an approach for probing the physical properties and chemical composition of single levitated particles using high-resolution mass spectrometry (MS). Using a linear quadrupole electrodynamic balance (LQ-EDB) coupled to paper spray mass spectrometry, we report accurate measurements of the evolving size within 5 nm (using broadband light scattering) and relative composition (using MS) of evaporating multicomponent levitated particles in real time. Measurements of the evaporation dynamics of semivolatile organic particles containing a range of n-ethylene glycols (n = 3, 4, and 6) in various binary and ternary mixtures were made under dry conditions and compared with predictions from a gas-phase diffusion evaporation model. Under assumptions of ideal mixing, excellent agreement for both size and composition evolution between measurements and models were obtained for these mixtures. At increased relative humidity, the presence of water in particles causes the assumption of ideality to break down, and the evaporative mass flux becomes a function of the mole fraction and activity coefficient. Through compositionally resolved evaporation measurements and thermodynamic models, we characterize the activity of organic components in multicomponent particles. Our results demonstrate that the LQ-EDB-MS platform can identify time-dependent size and compositional changes with high precision and reproducibility, yielding an effective methodology for future studies on chemical aging and gas-particle partitioning in suspended particles.

Annual Actual Evapotranspiration Estimation via GIS Models of Three Empirical Methods Employing Remotely Sensed Data for the Peloponnese, Greece, and Comparison with Annual MODIS ET and Pan Evaporation Measurements

Actual evapotranspiration (ETa) has been insufficiently investigated in Greece. This study aimed to estimate annual ETa by empirical methods (Turc, modified Turc, and Coutagne) for the Peloponnese, Greece, a Mediterranean testbed, between 2016–2019, four of the warmest years since the preindustrial era, and compare them to MODIS ET. Furthermore, measurements of annual pan evaporation (Epan) were performed for two Class A pan stations in the Peloponnese with different reliefs and conditions. The empirical methods and statistical formulae (RMSD, MB, and NMB) were developed as models in ArcMap. The outcomes of the Turc method resembled MODIS ET ranges for all years, followed by those of Coutagne. The estimates by the modified Turc method were almost identical to MODIS ET. Therefore, the modified Turc method can be used as an alternative to MODIS ET (and vice versa) for the Peloponnese for 2016–2019. Moreover, the Epan at Patras University station (semiurban, low elevation) exhibited an upward trend resembling the trends of the empirical methods over the study years, whereas the Epan at Ladonas station (higher elevation, lakeside) required investigation on a monthly time scale. Additionally, the gradual decrease of pan-water icing at Ladonas in December (from 20 d in 2016 to 0 d in 2019) could imply an undergoing decrease in snowpack storage retention across the mountains of the Peloponnese.

Repeatability and Reproducibility of Tear Film Evaporation Rate Measurement using a new Closed-Chamber Evaporimeter

Purpose: This study evaluates the repeatability and reproducibility of tear film evaporation rate measurement using a commercially available handheld closed-chamber evaporimeter (VapoMeter, Delfin Technologies, Finland). Study Design: This was a randomized observational study, in which two visits were required. At visit 1, screening tests were performed on the participants. Subsequently, tear evaporation was measured thrice by examiner 1 (E1). The procedure was then repeated by examiner 2 (E2) at visit 2. Methods: 40 healthy participants with no ocular diseases were recruited for this study. A closed chamber evaporimeter was used in this study (VapoMeter, Delfin Technologies, Finland). Primary investigations, including slit-lamp examination, tear production test, and ocular discomfort, were performed during the first visit for the purpose of screening. Results: The mean of the three measurements of tear evaporation obtained by examiner 1 at visit 1 was 19.38 ± 0.79 g/m2/h, and the mean of the three readings obtained by examiner 2 at visit 2 was 20.49 ± 0.48 g/m2/h. The average Intraclass Correlation Coefficient (ICC) among the three readings of tear evaporation was 0.84 and 0.63 with a 95% confidence interval (CI) at visits 1 and 2, respectively. A comparison of the reliability of the measurements from the two examiners revealed an ICC of 0.69 with a 95% CI. Conclusion: The VapoMeter provides repeatable and reproducible measurements of tear film evaporation. This study demonstrates that the VapoMeter could provide clinicians with a readily available method for rapid evaluation of tear film evaporation. By considering the significance of tear evaporation as a diagnostic tool for dry eyes, the VapoMeter may help to diagnose better and manage dry eye syndrome.

Reevaluating the Cr Evaporation Characteristics of Ce/Co Coatings for Interconnect Applications

Cathode poisoning by chromium evaporation from the interconnects is one of the major degradation mechanisms in SOFC. Coatings have proved to be very effective in suppressing chromium evaporation on interconnects. The quantification of chromium evaporation is important for determining the chromium consumption in the interconnect and predicting the lifetime of the interconnect. Chromium evaporation of uncoated and Ce/Co coated Crofer 22 APU is reevaluated at 800°C. The chromium evaporation of Ce/Co coatings on steel sheets and precut steels is studied. Coupons cut from Ce/Co coated sheets have uncoated edges, which influence the chromium evaporation measurements. The true chromium evaporation of the coated interconnects is evaluated. The PVD Ce/Co coatings on Crofer 22 APU reduce the chromium evaporation by at least 60 times compared to the uncoated at 800°C.