High Relative Humidity Conditions Research Articles

Ionic thermoelectricity of salt-free PVA-hydrogel

As polyvinyl alcohol (PVA) hydrogels have shown a high potential as an ionic thermoelectric generator, this paper aims to study the thermoelectric (TE) power of salt-free PVA hydrogel. Ionic thermoelectric performance, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) are measured at different relative humidities. Findings show that salt-free PVA hydrogels can achieve a relatively high Seebeck (9.26 mV K−1) using only surrounding moisture. Hydrogels with low PVA content have a more stable TE output than hydrogels with high PVA content in high relative humidity conditions. Embedded Ni-foam-CNT electrodes stabilize performance, reduce noise, and provide superior capacitance, resistance, and thermoelectric performance over direct drop-casting of CNT on hydrogels. Recommended operating relative humidity (RH) ranges between 40 % and 60 %, while recommended PVA content ranges from 10 % to 15 % mass ratio of PVA in water. The results pave the way for using PVA hydrogels as thermoelectric devices in biocompatible applications.

Enhancing radon detection accuracy with charcoal canister: A simple method for measuring radon

Charcoal canisters are widely used devices for measuring radon concentration in the atmosphere, but they are sensitive to humidity. A newly designed super absorbent polymer (SAP) filter was applied to charcoal canisters to enhance their resistance to ambient humidity, thereby improving the accuracy of radon concentration measurements. The charcoal canister with the SAP filter had an error of approximately 1.3–2.6% compared to the reference value (measured by RAD7), whereas the charcoal canister without the SAP filter exhibited an error of 12–18% compared to the reference value. Additionally, the charcoal canister with the SAP filter demonstrated over 90% of response value even under very high relative humidity conditions of 90%, indicating strong resistance to ambient humidity.

The effect of relative humidity and the use of algae-based biostimulants on fruit set, yield and fruit size of arctic bramble (Rubus arcticus) arcticus)

Arctic bramble is a niche berry crop with highly variable yield and fruit quality, often limited by low fruit set and incomplete fruit development. In this study, we investigated the effects of relative humidity (RH) and algae-based biostimulants on fruit set, yield, fruit weight and the number of drupelets per fruit. In Experiment 1, arctic bramble cvs. ‘Alli’ and ‘Mesma’ were grown in a greenhouse in 40, 60 or 80% RH and pollinated by bumblebees. In Experiments 2 and 3, commercial biostimulant products Kelpak, Cremalga, Kriss and Alginamin were tested on cv. ‘Alli’ in a greenhouse, and an open high tunnel. Fruit set and yield were strongly affected by RH, being highest in either 40% RH for cv. ‘Mesma’ or 60% RH for cv. ‘Alli’, reduced by nearly 50% in 80% RH. Kriss and Alginamin increased fruit weight by as much as 18% but there was no effect on total yield. We conclude that control of relative humidity in greenhouse cultivation, especially to avoid very high RH conditions, can be highly beneficial for arctic bramble, and that algae-based biostimulants show potential to improve fruit weight.

Acclimation of Agave potatorum Zucc. micropropagated plants

Objective: Agave potatorum Zucc. is an intensively exploited wild plant species. We intend to evaluate how the concentration of mineral salts (MS), indole-butyric acid (IBA), and the incubation conditions affect in vitro-rooted A. potatorum during acclimation. Design/Methodology/Approach: We conducted 18 treatments that resulted from combining three factors: 1) MS concentrations (50%, 75%, and 100%); 2) IBA concentrations (without auxin, 0.5 mg L-1, and 1 mg L-1); and 3) incubation environments (fluorescent lighting in a laboratory or exposure to solar radiation in a greenhouse). Thirteen plants from each treatment were transplanted into individual pots containing a 1:1 mixture of peat moss and perlite. These were placed in the acclimation greenhouse for 150 days, exposed to changes in solar radiation, starting from 600 µmol m-2 s-1 and conditions of high relative humidity (80-90%), and reaching outdoor conditions with full solar radiation,1400 ±200 µmol m-2 s-1. All in vitro culture plants, both in greenhouse and laboratory, underwent the same environmental and management conditions. Results: After 150 days of acclimation, plants micropropagated in a culture medium with 0.5 to 1 mg L-1 of IBA, 100% MS, and incubated in a greenhouse showed better growth. Study limitations/Implications: The in vitro culture protocol was (successfully) modified by providing solar radiation in a greenhouse during the rooting of A. potatorum sprouts. Findings/Conclusions: Solar radiation during in vitro incubation of A. potatorum favors its acclimation.

ErFeO3/α-Fe2O3 nanocomposites derived from MIL-100(Fe) for acetone sensing

Acetone, a flammable and volatile liquid, is toxic and can affect human well-being. Additionally, its presence in exhaled air can indicate the state of human respiratory health. Therefore, the investigation of an acetone gas sensor holds significant urgency in the realm of scientific research. Metal-organic frameworks (MOFs) exhibit significant promise in the field of gas detection due to their extensive surface areas, remarkable porosity, and the inclusion of unsaturated metallic sites. The study conducted the preparation of ErFeO3/α-Fe2O3 nanocomposites through impregnation and oxidation roasting methods. EF21 (MEr(NO3)3∙6H2O:MMIL-100(Fe) = 2:1) exhibited a large surface area of 43.7 m2/g and a high abundant oxygen vacancy of 12.5 %. Gas sensing experiments revealed that the EF21-based gas sensor exhibited a strong response of 55 towards 100 ppm acetone, with a low detection limit of 2 ppm (S = 3.3). Notably, the sensor demonstrated excellent selectivity towards acetone over other volatile organic compounds (e.g., ethanol, methanol, ammonia, ether, and toluene) in gas selectivity tests. Moreover, the EF21-based gas sensor maintained its responsiveness to acetone even under high relative humidity conditions (RH:90 %, S = 27) and demonstrated stability over a 15-day long-term test. The study provided a comprehensive explanation of the gas sensing mechanism responsible for the enhanced performance observed in ErFeO3/α-Fe2O3 through detailed analyses.

Prediction model of asphalt emulsion evaporation rate based on CFD simulation and genetic programming-based symbolic regression

The evaporation rate of asphalt emulsion is critical to the strength development of asphalt emulsion materials. Its value is dependent on environmental factors, i.e. relative humidity, temperature, and wind speed. However, the quantitative relation of evaporation rate with these environmental factors are unclear. To quantificationally study the effect of environmental factors on the water evaporation rate of asphalt emulsion, a computational fluid dynamics (CFD) simulation model of water evaporation is firstly proposed and validated by experiment. Then, wide range of environmental factors are studied in the CFD simulation model, and genetic programming-based symbolic regression is used to train the simulation results of CFD samples. Finally, a relatively accurate prediction equation of the evaporation rate of asphalt emulsion versus environmental factor is proposed, and the sensitivity of the water evaporation rate under the three environmental factors is analyzed. Results show that the evaporation rate can be accurately simulated by CFD. All the three environmental factors can greatly affect the evaporation rate of asphalt emulsion, while their effect on the sensitivity of the water evaporation rate is ranked as: temperature > relative humidity > wind speed. To ensure an acceptable curing period, asphalt emulsion-based materials should be avoided to be paved in the conditions of low temperature and high relative humidity.

Green Anisole as Antisolvent in Planar Triple-Cation Perovskite Solar Cells with Varying Cesium Concentrations.

The feasibility of replacing toxic chlorobenzene antisolvents with environmentally friendly anisole in the fabrication of planar triple-cation perovskite solar cells was explored here. The successful integration of anisole not only ensures comparable device performance but also contributes to the development of more sustainable and green fabrication processes for next-generation photovoltaic technologies. Nevertheless, to ensure the possibility of achieving well-functioning unencapsulated devices whose working operation depends on outdoor atmospheric conditions, we found that adjusting the cesium concentrations in the perovskite layers enabled the electrical characterization of efficient devices even under high relative humidity conditions (more than 40%). We found that 10% of CsI in the precursor solution will make devices with low hysteresis indexes and sustained performance stability over a 90-day period both with cholorobenzene and anisole antisolvent. These results further confirm that green anisole can replace chlorobenzene as an antisolvent.

New Insights into Pore Structure and Hydraulic Conductivity of Sodium Hydroxide Alkali-Activated Slag through Advanced Modelling.

The study of alkali-activated slag (AAS) is motivated by the need for more sustainable alternatives to Portland cement (PC) within the construction industry. Specifically, AAS offers good mechanical and chemical properties. However, the influence of the activator on its pore structure and hydraulic conductivity remains unclear. Both pore structure and hydraulic conductivity are key parameters in understanding the drying process and could potentially explain the high drying shrinkage observed so far. The present study aims to investigate the pore size distribution and hydraulic conductivity of six distinct AAS/sodium hydroxide mortar compositions, with a particular emphasis on the effect of varying the activator's molarity and the solution-to-binder ratio (s/b). This research uses the mass variation in different relative humidity (RH) conditions from experimental tests to model the pore surface area, the pore size distribution, and the hydraulic conductivity. From the results, it emerges that increasing the molarity from 0.5 to 8 M reduces the open porosity and refines the pore structure, while increasing the s/b from 0.5 to 0.8 increases the open porosity while refining the pore structure. In addition, high molarity compositions are not suitable for testing in high RH and natural carbonation conditions due to the occurrence of deliquescence. Moreover, the main drying mechanism in AAS is water vapour transport even at high relative humidity, contrary to what was observed in the literature for PC. Finally, the hydraulic conductivity of alkali-activated slag presents a minimum of around 85% RH against the 60-70% RH for PC, causing AAS to dry faster when the relative humidity decreases from 85 to 50%.

3-Thiophenemalonic Acid Additive Enhanced Performance in Perovskite Solar Cells.

The development of ambient-air-processable organic-inorganic halide perovskite solar cells (OIHPSCs) is a challenge necessary for the transfer of laboratory-scale technology to large-scale and low-cost manufacturing of such devices. Different approaches like additives, antisolvents, composition engineering, and different deposition techniques have been employed to improve the morphology of the perovskite films. Additives that can form Lewis acid-base adducts are known to minimize extrinsic impacts that trigger defects in ambient air. In this work, we used the 3-thiophenemalonic acid (3-TMA) additive, which possesses thiol and carboxyl functional groups, to convert PbI2, PbCl2, and CH3NH3I to CH3NH3PbI3 completely. This strategy is effective in regulating the kinetics of crystallization and improving the crystallinity of the light-absorbing layer under high relative humidity (RH) conditions (30-50%). As a result, the 3-TMA additive increases the yield of the power conversion efficiency (PCE) from 14.9 to 16.5% and its stability under the maximum power point. Finally, we found that the results of this work are highly relevant and provide additional inputs to the ongoing research progress related to additive engineering as one of the efficient strategies to reduce parasitic recombination and enhance the stability of inverted OIHPSCs in ambient environment processing.

Thermo-Mechanical Stability of Hydrocarbon-Based Pemion® Proton Exchange Membranes

Considering the environmental concerns about the disposal of perfluorosulfonic acid (PFSA) membranes as well as the growing interest in higher temperature operability of polymer electrolyte membrane fuel cells (PEMFCs), non-fluorinated hydrocarbon-based proton exchange membranes (PEMs) with aromatic backbones have become an increasingly active area of research. Low reactant cross-over, tunable electrochemical properties, and differentiated chemistries and potentially safer and cost-reducing synthesis procedures, are additional favourable features of hydrocarbon-based PEMs for prospective use in PEMFCs [1]. Vulnerable linking units, however, are known to be the main disadvantages of these polymers in the oxidative environment of fuel cells. During PEMFC operation, destructive radical species such as hydroxyl (HO•) are produced, causing polymer degradation and thinning in the membrane [2]. Recently, sulfo-phenylated polyphenylenes (sPPPs) have shown outstanding oxidative stability due to a polymer backbone comprising only aryl-aryl bonds, with mitigated chemical degradation in ex-situ and in-situ durability studies [3, 4]. Another concern is regarding the thermo-mechanical stability of PEMs. Thus, a systematic thermo-mechanical stability study is required to confirm the potential of sPPP-based PEMs to replace conventional PFSAs, especially for high temperature PEMFC, i.e., 110-120 °C.The present research objective is to assess the thermo-mechanical stability of a commercial reinforced hydrocarbon-based PEM, Pemion® (PF1-HLF8-15-X, 15 µm thick, reinforced), as well as a mechanically-reinforced PFSA-based reference membrane, across a wide range of temperature (30-120 °C) and relative humidity (RH) (10-90%) conditions that includes the crucial high temperature window of interest for future PEMFCs [6]. To this end, a comprehensive design of experiment yielded 19 tensile tests at various hygrothermal conditions with dynamic mechanical analyzer (DMA 850; TA Instruments) equipped with an external environmental chamber accessory (TA Instruments, RH Accessory). Important mechanical properties such as Young’s modulus, ultimate tensile stress, yield stress, maximum elongation at break, strain hardening, and modulus of resilience were extracted and discussed as well. Datapoints were fitted for empirical model development and mechanical properties were estimated for high temperature and RH conditions beyond the capability of the instrument. This method can be employed to assess if the mechanical properties of membrane materials can be retained at higher temperatures, regardless of polymer chemistry and type. Storage modulus and loss modulus were separately measured in a dynamic mode to observe the impact of temperature on the mechanical response of the hydrophobic backbone and hydrophilic ionic clusters, respectively.Overall, Pemion® demonstrates tough tensile properties in the stress-strain tests due to its sterically encumbered polyphenylene backbone (Figure 1a), whereas the reference PFSA (Figure 1b) shows elastomer-like behavior with much lower Young’s modulus, yield stress, and strain hardening (slope of the curve in the plastic deformation region). Figure 1c-f show the main viscoelastic properties extracted from the tensile tests at room (30 °C, 50% RH) and high temperature fuel cell conditions (110 °C, 50% RH). The modulus of elasticity and strain hardening of Pemion® membrane are almost temperature-independent, whereas these properties for the reinforced PFSA material undergo a significant decay at high-temperature ambience. Pemion® maintains good yielding strength even at high temperature and RH conditions (110-120 °C and 80% RH). Nevertheless, small mechanical stress values as low as 1 MPa can cause spontaneous yielding in the PFSA reference material above 110 °C. The modulus of resilience for the reinforced PFSA is also predicted to be zero at elevated hygrothermal conditions (i.e., 90 °C and 70% RH). This is interpreted as an approach to the material’s glass transition condition, where it loses its mechanical integrity and therefore, is potentially unsuitable for higher temperature PEMFC operation. Moreover, the dynamic mechanical thermal analysis revealed that Pemion® retains its robustness at hygrothermal ambience close to high-temperature PEMFCs, i.e., 110-120 °C and 40-50% RH, whereas the backbone of the PFSA material gradually loses its strength. Acknowledgements This project was financially supported by Natural Sciences and Engineering Research Council of Canada (NSERC), Ionomr Innovations Inc, Canada Foundation for Innovation (CFI), British Columbia Knowledge Development Fund (BCKDF), Western Economic Diversification Canada (WD), and Canada Research Chairs (CRC).

Comparison of hermetic and conventional bags for maize seed preservation in Azad Kashmir, Pakistan

Maize (Zea mays L.) is a major cereal crop used as a staple food worldwide for decades. Farmers store their produce in porous polypropylene bags under humid conditions which negatively affects their quality. In this study, maize seeds were stored in hermetic and conventional bags with an initial seed moisture content of 13.5% (wet basis) and 96.3% germination for 8 months at four major maize growing districts (Athmuqam, Hattian Bala, Muzaffarabad and Rawlakot) of Azad Jammu and Kashmir, Pakistan. Due to high ambient relative humidity conditions (>80%), an increase in moisture was observed in seeds stored in porous conventional bags (14. 7%). This increase was because of high initial relative humidity conditions (79–85%) in conventional bags. Seed moisture content remained unchanged in hermetic bags and internal humidity was 59–60%. As a result of hermetic conditions, germination and seed integrity were maintained in hermetic bags compared to conventional woven bags. Germination drastically decreased in conventional bags and fell to 9 % (Athmuqam), 13 % (Hattian Bala), 11 % (Muzaffarabad) and 12 % (Rawlakot). Higher physical quality losses of maize in conventional bags were because of infestation activity of live insect pest populations (S. zeamais, R. dominica and T. castaneum) that initiated 21.7–23.7 % weight loss in polypropylene bags. Hermetic bags protected seeds from insect pest attack and maintained seed quality. Higher contamination of aflatoxin B1, G1, B2 and G2 (ppb) was recorded in seeds stored in conventional bags as compared to hermetic bags. Aflatoxin B1 was maximum in conventional bag at Hattian Bala (8.93 ppb) followed by Muzaffarabad (6.68 ppb), Athmuqam (5.02 ppb) and Rawlakot (0.71 ppb). In conclusion, the use of hermetic dry chain storage preserves maize seed quality and thus can have a significant impact on the livelihoods of smallholder farmers of humid areas.

The application study of the revised IMPROVE atmospheric extinction algorithm in atmospheric chemistry model focusing on improving low visibility prediction in eastern China

Low visibility event, as a disastrous weather, has great impacts on traffic and transportation, aircraft, and people's daily life, etc. Timely and accurate forecasts of low visibility events are urgently needed and meaningful. The reasonable algorithm of atmospheric extinction in atmospheric chemistry models is the basis for quantitatively predicting low visibility. The revised IMPROVE algorithm (RIMP) of atmospheric extinction is incorporated into the chemistry-weather interacted model GRAPES_Meso5.1/CUACE CW V1 to improve the prediction of low visibility events (LVEs) in the urban agglomerations in eastern China, which is compared with the original IMPROVE algorithm (OIMP) used in this model. The study results show that the RIMP effectively reduces the overestimation of low visibility prediction by OIMP in general, leading to a decrease of root-mean-square errors (RMSEs) and an increase of Threat Score (TS) of visibility <3 km, 5 km, and 10 km overall both at regional and city scales in varying degrees due to its more detailed processing of aerosols' size, optical feature and hygroscopic growth; The improvements of visibility prediction of LVEs by RIMP depends on the combined contribution of high relative humidity (RH) and PM2.5 instead of single high RH or PM2.5. The relative contributions of RH and PM2.5 concentration on different levels of low visibility are different in Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) regions due to their different RH and PM2.5, which leads to the different improvement of RIMP in the two regions. The larger improvements by RIMP occur for visibility <5 km in BTH, while in YRD, the larger improvements by RIMP occur for visibility <10 km and >5 km. Moreover, the improvements by RIMP were more evident with higher RH conditions in both regions. The uncertainty created by the extinction algorithm is one important factor of the multiple factors affecting LVEs prediction; accurate modeling of high RH near saturation is also very important for LVEs prediction.

Observational insights into the environmental effect for secondary inorganic aerosol formation in the Northeast China: Influence of biomass burning

Secondary inorganic aerosols (SIA), as one of the main ubiquitous components of PM2.5, still have unclear impacts on their formation in the ambient environment, especially under extremely cold weather conditions. To explore the effects of open biomass burning (OBB) source emissions and meteorological factors on SIA formation, biomass burning tracer, i.e., levoglucosan (LG), was observed along with SIA were analyzed during the heating season at the Longfengshan (LFS) background of Northeast China. Based on the LG/OC ratio and fire hotspots, the entire sampling campaign was divided into OBB and non-open biomass burning (NBB) periods.It was found that OBB emissions had little effect on sulfate formation but a significant impact on nitrate formation. High relative humidity (RH) conditions played a crucial role in SIA formation, with both SO42−/EC and NO3−/EC increasing as RH elevated at temperatures below −10 °C. Furthermore, the temperature dependence of SO42−/EC and NO3−/EC indicated that temperature could enhance the activity of either aqueous-phase production or gas-phase reactions, subsequently promoting the formation of SO42− and NO3− in the ambient environment. Additionally, positive matrix factorization (PMF) analysis was used to scientifically separate the sources of ambient aerosols during OBB and NBB periods.

Improved selectivity of borophene sensor towards NO2 gas with PEI-ZIF-8 overlayer

Stable and selective gas sensing is essential to detect toxic gases and avoid gas leak accidents. Two-dimensional (2D) materials are potential sensing materials for making gas sensors because of their high surface-to-volume ratios, broad surface activity, and defect sites. In this work, a recent 2D material, borophene, is used as the NO2 gas-sensing material. Polyetherimide (PEI) incorporated with the Zeolitic imidazole framework (ZIF-8) with different loading (mixed matrix membrane, MMM) is used as a selective gas separation membrane for its solubility (imide, isopropylidene and ether groups on PEI) and diffusion (porosity) properties. The MMM was selective to NO2 gas as ZIF-8 is selective towards NO2 gas, and PEI is resistant to substances like hydrocarbons, alcohols, and halogenated solvents. A slight variation in borophene's gas sensing response (0.6%) was observed for 25 ppm NO2 at 25 °C and 35% relative humidity (RH) with and without the PEI-ZIF-8 filter, showing the MMM filter is not affecting the sensing response highly. As ZIF-8 is hydrophobic, the borophene sensor showed higher stability at higher RH conditions. These findings suggest that fabricated sensors can detect NO2 gas at varying concentrations for environmental and human safety.

HIGHLY STABLE PEROVSKITE FILM WITH IONIC LIQUID ADDITIVES FOR AMBIENT AIR DEPOSITION

Perovskite solar cells (PSCs) technology has emerged as a highly promising photovoltaic (PV) option due to remarkable advancements in power conversion efficiency (PCE). Nevertheless, the stability of PSCs continues to pose a challenge for commercialization, as factors such as moisture, oxygen, light, and temperature can lead to degradation during fabrication and actual use stage. The stability of the perovskite film is crucial for extending the device’s lifetime and performance. This research seeks to explore the degradation mechanism and improve the perovskite film’s stability by incorporating 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) and 1,3-dimethyl-3-imidazolium hexafluorophosphate (DMIMPF6) ionic liquids into a perovskite precursor using the two-step deposition technique in ambient air. The perovskite film’s degradation and PSCs’ stability were evaluated under high relative humidity conditions, averaging 73%RH without encapsulation. UV-visible spectroscopy results indicate that the most stable perovskite film, containing the BMIMBF4 ionic liquid additive, maintains its α phase perovskite structure for 144 hours without alterations in absorbance and persisted for over 336 hours before degrading into an undesirable δ phase perovskite. Furthermore, PSCs retained 74.1% of their initial PCE after 28 days of exposure to ambient conditions. This research offers promising findings for the large-scale fabrication of stable PSCs.

Standardized agronomic practices for mechanical harvesting of the single-harvest garden pea in India

The field investigations were conducted at Vegetable Research Farm, Department of vegetable Science, Punjab Agricultural University, Ludhiana with the objective to standarize the agronomic practices for mechical harvesting of garden pea. Therefore, effect of different agronomic traits including time of sowing, spacing and sowing method on yield and its attributing traits were studied on single-harvest garden pea. The experiment was laid out in split-plot design with 30 treatments comprising five dates of sowing in main plots and 2 different planting methods (flat and bed) sown at three different spacing in subplots and replicated three times. The bed size was standardized according to front-loading width of the pea combine. Significant interactions were observed between the date of sowing and spacing for a number of pods per plant, green seeds per pod, green pod yield per plant, green pod yield per plot; date of sowing and sowing method for pod length; spacing and sowing method for plant height. However, for all the traits, there was non-significant 3-way interaction. The late sown (20th December) crop resulted in the least number of pods per plant, green seeds per pod, green pod yield per plant and green pod yield per plot which was due to high temperature and low relative humidity conditions at pod development and filling stage. It is concluded that the garden pea cultivar Punjab-89 sown on 5th November at the spacing of 20 × 7.5 cm on beds (bed width of 1.0 m) resulted in significantly highest green pod yield of 12.75 kg/9 m2 in the single harvest. Therefore, the 3 beds of 1 m width can be harvested together with pea combine (because combine has working front width of 3.1 m) results into maximum yield when pea crops is sown on 5th November @ 20 × 7.5 cm spacing.

Microcracking of strawberry fruit cuticles: mechanism and factors

Microscopic cracks in the cuticle (microcracks) are the first symptom of the strawberry fruit disorder ‘water soaking’ in which the fruit surface appears watery, translucent, and pale. Water soaking severely impacts fruit quality. The objective was to investigate the factors and mechanisms of cuticular microcracking in strawberry. Fluorescence microscopy revealed numerous microcracks in the achene depressions, on the rims between depressions and at the bases of trichomes. Microcracks in the achene depressions and on the rims were either parallel or transversely oriented relative to a radius drawn from the rim to the point of attachment of the achene. In the achene depression, the frequency of microcracks with parallel orientation decreased from the calyx end of the fruit, towards the fruit tip, while the frequency of those with transverse orientation remained constant. Most microcracks occurred above the periclinal cell walls of the epidermal cells. The long axes of the epidermal cells were primarily parallel-oriented. Microcracking increased during fruit development. Cuticle mass per fruit remained constant as fruit surface area increased but cuticle thickness decreased. When fruit developed under high relative humidity (RH) conditions, the cuticle had more microcracks than under low RH conditions. Exposing the fruit surface to increasing RHs, increased microcracking, especially above 75% RH. Liquid-phase water on the fruit surface was markedly more effective in inducing microcracking than high vapor-phase water (high RH). The results demonstrate that a combination of surface area growth strain and water exposure is causal in inducing microcracking of the strawberry cuticle.

High radon levels and adverse environmental conditions in using RAD7.

Good response was observed in simultaneously using six RAD7 detectors at high radon concentrations, temperatures and relative humidity conditions. RAD7 detectors were tested in laboratory using radon chambers from 13 up to 59.8kBqm-3, statistical analysis allows to distinct between counting errors and radon variation. RAD7 detectors were exposure to extreme environmental conditions at uranium flat mine. High radon concentration in soil from a confined uranium mineral was 274.3kBqm-3 at 44°C temperature and 20% relative humidity. Inside uranium mine radon increased from 1.0 up to 88.5kBqm-3.

Nontrivial Impact of Relative Humidity on Organic New Particle Formation from Ozonolysis of cis-3-Hexenyl Acetate

The impact of relative humidity (RH) on organic new particle formation (NPF) from the ozonolysis of biogenic volatile organic compounds (BVOCs) remains an area of active debate. Previous reports provide contradictory results, indicating both the depression and enhancement of NPF under conditions of high RH. Herein, we report on the impact of RH on NPF from the dark ozonolysis of cis-3-hexenyl acetate (CHA), a green-leaf volatile (GLV) emitted by vegetation. We show that RH inhibits NPF by this BVOC, essentially shutting it down at RH levels &gt; 1%. While the mechanism for the inhibition of NPF remains unclear, we demonstrate that it is likely not due to increased losses of CHA to the humid chamber walls. New oxidation products dominant under humid conditions are proposed that, based on estimated vapor pressures (VPs), should enhance NPF; however, it is possible that the vapor phase concentration of these low-volatility products is not sufficient to initiate NPF. Furthermore, the reaction of C3-excited state Criegee intermediates (CIs) with water may lead to the formation of small carboxylic acids that do not contribute to NPF. This hypothesis is supported by experiments with quaternary O3 + CHA + α-pinene + RH systems, which showed decreases in total α-pinene-derived NPF at ~0% RH and subsequent recovery at elevated RH.

Development and Evaluation of Corrosion Resistance and Hydrophobic Properties of Thermal Sprayed Coatings over Carbon Steel

Various industrial parts and equipment made of steel need to withstand demanding conditions. In order to increase performance and lifetime, surface processing and functional coatings can be applied. In this study we report on the evaluation of coated carbon steel with commercial corrosion-resistant powders Diamalloy 4276 and Woka 7502 by Oerlikon Metco, using thermal spraying. Further functionalization is performed by rendering thermal sprayed surfaces syperhydrophobic via gas phase deposition of trichloro-1H,1H,2H,2H-perfluorooctyl silane, (PFOTS). Electrochemical impedance spectroscopy, contact angle and water condensation studies reveal the protective properties of coatings prepared by both materials as well as the superiority of Diamalloy 4276 based coatings. Corrosion was evaluated under a harsh 20% w/w H2SO4 environment. Rendering the coating superhydrophobic improves water condensation under the tested conditions of high (80%) relative humidity.