Performance of the bentonite barrier at temperatures beyond 100 °C: A critical review

Core Ideas High doses of biochar increased water retention of sandy soil in both dry and wet conditions. Larger sized biochar decreased water retention at field capacity (FC). High‐pyrolysis biochar could increase water retention at FC and in dry conditions. We investigated the impact of biochar application on the evaporation rate of sandy soil. Knowledge of soil hydraulic properties under dry (below permanent wilting point) and wet (from saturation to permanent wilting point) conditions is helpful for evaluating soil physical quality and modeling the movement of the substances (water and nutrients) in biochar‐amended soils. To investigate the effect of biochar application on hydraulic properties of sandy soil under dry and wet conditions, water retention in wet conditions and soil drying curves from wet to dry conditions were measured under different application rates (1, 3, and 5%, w/w), particle sizes (<0.25, 0.25–0.5, 0.5–1, and 1–2 mm), and pyrolysis temperatures (300, 450, and 600°C) of wheat ( Triticum aestivum L.) straw‐derived biochar. Results showed that when higher rate biochar (3 and 5%) was applied into the sandy soil, water retention became higher under dry and wet conditions. Biochar application with a larger particle size (0.5–1 and 1–2 mm) increased water retention under saturation and dry conditions but decreased water retention at field capacity. Sandy soil amended with biochar at the higher pyrolysis temperatures (450 and 600°C) had higher water retention under field capacity or dry conditions. Increasing biochar application rate, particle size, and pyrolysis temperature decreased the evaporation rate of sandy soil under dry conditions. Our findings suggested that hydraulic properties of the sand–biochar mixture were mainly determined by biochar properties under dry conditions and were highly related to the interpores between particles under wet condition.

Invasive species have disrupted thousands of acres of natural areas in Florida and appear to have a physiological competitive advantage over native species. The influence of light and temperature on germination was determined for the invasive Mexican petunia (Ruellia tweediana Griseb.) and native wild petunia (Ruellia caroliniensis Steud.). Seeds were collected and germinated in incubators with light or darkness at 15, 24, 33, and 30/20 °C. Light increased germination for each species, except at 15 °C (R. caroliniensis). For R. caroliniensis, highest germination (86% to 94%) occurred at 33 °C and 30/20 °C. Highest germination of R. tweediana (98% to 100%) occurred at 30/20 °C. Studies also were initiated to determine if R. tweediana has a competitive advantage over the native species when grown under wet and dry substrate conditions. Growth and development measurements after 8 weeks under controlled conditions revealed that R. tweediana grown in wet conditions had the greatest dry weight increase as compared to other treatments. Ruellia caroliniensis had higher specific leaf area when grown in wet or dry conditions, as compared to R. tweediana. Throughout the experiment, net CO2 assimilation of R. caroliniensis grown under dry or wet conditions was consistently lower than that of R. tweediana. Shoot nitrogen and phosphorus use efficiencies were generally greatest for R. tweediana plants grown in wet conditions. For shoot nutrient content, significant species × moisture interactions occurred for measured phosphorus (P) and calcium (Ca). When grown in wet conditions, R. tweediana had less shoot P and Ca as compared to dry conditions. For root nutrient content, species × moisture interactions were insignificant for each measured nutrient, with the exception of potassium (K). Potassium use efficiency of R. tweediana roots grown in wet conditions was higher than that of R. tweediana grown in dry conditions and R. caroliniensis grown in wet conditions.

Braking behaviours of C/C–SiC mated with iron/copper-based PM in dry, wet and salt fog conditions

The general objective of this study was to evaluate the stability of patterns of apparent soil electrical conductivity (ECa) in dry versus wet soil conditions in a shallow soil typically used for pastures in Mediterranean conditions of the southern region of Portugal. A 6 ha experimental field of permanent bio-diverse pasture was divided into 76 squares of 28 × 28 m. The soil electrical conductivity was measured using a Dualem 1S sensor under dry conditions (June 2007) and under wet conditions during the rainy season (March 2010). Soil samples, geo-referenced with GPS, were collected in a depth range of 0–0.30 m. The soil was characterized in terms of bedrock depth, moisture content, texture, pH, organic matter content, and macronutrients (nitrogen, phosphorus, and potassium). Pasture samples, also geo-referenced with GPS, were collected to measure the pasture dry matter yield. The statistical analysis of apparent electrical conductivity between dry and wet soil conditions resulted in a linear significant correlation coefficient (R = 0.88). The results also showed a significant correlation between apparent electrical conductivity and the relative field elevation (R = −0.64 and R = −0.66), the pasture dry matter yield (R = 0.42 and R = 0.48), the bedrock depth (R = 0.40 and R = 0.27), the pH (R = 0.50 and R = 0.49), the silt (R = 0.27 and R = 0.38) and soil moisture content (R = 0.48 and R = 0.45), in dry and wet conditions, respectively. A multi-variate regression was carried out using the following soil parameters that showed significant correlation with ECa and that did not present multi-collinearity: pH, bedrock depth, silt and moisture content. The results showed, in dry and wet conditions, that the analysis was significant (R = 0.75 and R = 0.84, respectively). Overall, these results indicate the temporal stability of ECa patterns under different soil moisture contents, which is relevant with respect to the time when a field should be surveyed and is important for using the electrical conductivity sensor, as a decision support tool for management zones in precision agriculture.

ABSTRACTThis work investigates the start-up phase of anaerobic digestion in wet, semi-dry and dry conditions of rice straw analysing the role of volatile fatty acid (VFA) production on process kinetics. Methane production yields and biodegradation kinetics in reactors operated under wet semi-dry and dry conditions were investigated. The experimental results showed a reduction in the specific final methane production yield of 57% and 63% in, respectively, semi-dry (TS = 14.8%) and dry (TS = 23.4%) conditions compared to wet (TS = 4.8%) conditions. The total VFA concentration and speciation are proposed as indicators of process development at different total solids content. High VFA concentrations were found in dry conditions, with a maximum total VFA concentration of 2110 mg/kg in dry conditions, 930 mg/kg in semi-dry conditions and 180 mg/kg in wet conditions.

In recent decades, human-induced climate change has caused a worldwide increase in the frequency/intensity/duration of extreme events, resulting in enormous disruptions to life and property. Hence, a comprehensive understanding of global-scale spatiotemporal trends and variability of extreme events at different intensity levels (e.g., moderate/severe/extreme) and durations (e.g., short-term/long-term) of normal, dry and wet conditions is essential in predicting/forecasting/mitigating future extreme events. This article analyses these aspects using estimates of a non-stationary standardized precipitation evapotranspiration index corresponding to different accumulation periods for 0.5° resolution CRU grids at globe-scale. Results are analyzed with respect to changes in land-use/landcover and geographic/location indicators (latitude, longitude, elevation) at different time scales (decadal/annual/seasonal/monthly) for each continent. The analysis showed an (i) increasing trend in the frequency/count of both dry and wet conditions and variability of dry conditions, and (ii) contrasting (decreasing) trend in the variability of wet conditions, possibly due to climate change-induced variations in atmospheric circulations. Globally, the highest variability in the wet and dry conditions is found during the Northern hemisphere's winter season. The decadal-scale analysis showed that change in variability in dry and wet conditions has been predominant since the 1930s and 1950s, respectively and is found to be increasing in recent decades.

Dimensional accuracy and surface detail reproduction of two hydrophilic vinyl polysiloxane impression materials tested under dry, moist, and wet conditions

Previous reports showed that cosmetic cleansing oil for removing makeup, which contains mineral oil and surfactant, can deform some silicone hydrogel contact lenses (SHCLs) when applied directly to the lenses, although plasma-coated SHCLs (lotrafilcon A and B) were not affected. In the present study, we investigated hydrogel lenses and SHCLs in both wet and dry conditions. Several brands of hydrogel and SHCLs were immersed in a cleansing oil solution containing Sudan Black B for 5 min under wet and dry conditions. The lenses under the wet condition were simply picked up from the saline, whereas those under the dry condition were blotted with paper wipes. After immersing, the excess solution remaining on the lenses was removed by finger rubbing with a multipurpose solution. The lenses were then examined using a stereomicroscope, and their mean brightness was measured and compared. The cosmetic cleansing oil was not absorbed by the hydrogel lenses under wet or dry conditions. However, four of seven brands of SHCLs absorbed the cosmetic cleansing oil under both conditions (dry and wet), whereas asmofilcon A absorbed it only under the dry condition. Lotrafilcon B and delefilcon A did not absorb cleansing oil even under the dry condition. Hydrogel lenses resist cosmetic cleansing oil. However, SHCLs have different degrees of resistance depending on the lens material. Some SHCLs absorbed cosmetic cleansing oil more under dry conditions than under wet conditions.

Generation of airborne wear particles from the wheel–rail contact under wet conditions using a twin-disk rig

Smart laser technologies are desired that can accurately cut and characterize tissues, such as bone and muscle, with minimal thermal damage and fast healing. Using a long-pulsed laser with a 0.5–10 ms pulse width at a wavelength of 1.07 µm, we investigated the optimum laser parameters for producing craters with minimal thermal damage under both wet and dry conditions. In different tissues (bone and muscle), we analyzed craters of various morphologies, depths, and volumes. We used a two-way Analysis of Variance (ANOVA) test to investigate whether there are significant differences in the ablation efficiency in wet versus dry conditions at each level of the pulse energy. We found that bone and muscle tissue ablated under wet conditions produced fewer cracks and less thermal damage around the craters than under dry conditions. In contrast to muscle, the ablation efficiency of bone under wet conditions was not higher than under dry conditions. Tissue differentiation was carried out based on measured acoustic waves. A Principal Component Analysis of the measured acoustic waves and Mahalanobis distances were used to differentiate bone and muscle under wet conditions. Bone and muscle ablated in wet conditions demonstrated a classification error of less than 6.66% and 3.33%, when measured by a microphone and a fiber Bragg grating, respectively.

<p>In recent decades, the uncertainty associated with characteristics (i.e., frequency, intensity, severity, and duration) of extreme events (e.g., droughts, floods) has increased considerably due to the changing global climatic condition and intensification of anthropogenic activities. Effective in-situ monitoring of the hydrometeorological drivers (e.g., precipitation, temperature) is crucial for precise prediction/forecasting and early warnings to initiate measures for mitigating the adverse effects of these extreme events.  However, due to the increased availability of satellite-based data products and economic constraints, the density of in-situ gauges has reduced drastically over the past few decades. Against this backdrop, this study proposes a multivariate hydrometeorological gauge network design methodology to facilitate integrated monitoring of dry and wet conditions. It harnesses the advantages of multi-objective optimization and fuzzy concepts and involves multi-level clustering and the use of multiple ground- and satellite-based hydrometeorological products.  The multi-level clustering is based on (i) a newly proposed multi-objective Non-dominated Sorting Genetic Algorithm III (NSGA-III) based fuzzy optimization clustering and (ii) fuzzy ensemble clustering. The key stations in the designed network were selected based on the Drought/Wetness Gauge Demand Index (DWGDI), which accounts for the region's drought/wetness characteristics and crop yield.  It also offers scope to consider additional attributes based on the specific purpose of the network design. The potential of the proposed methodology is illustrated through Monte Carlo simulations on a hypothetical region and a case study on Karnataka state (~191,791 km<sup>2</sup>) in India to arrive at gauge network monitoring three hydrometeorological variables (precipitation, maximum and minimum temperature, and soil moisture). A random forest-based merging procedure is considered to obtain hydrometeorological time-series at ungauged locations using ground-based measurements and multiple gridded/satellite-based products (CRU, CPC, IMD, CHIRPS and IMERG). Overall, the proposed network design methodology appears promising for application to small as well as large data-sparse areas. To the best of our knowledge, this is the first study of its kind, which proposes a multivariate gauge network design procedure for integrated monitoring of dry and wet conditions. The proposed methodology yielded wet/dry condition-specific monitoring networks for the Karnataka state. Additionally, the key stations crucial for monitoring both wet and dry conditions are identified. The counts of precipitation, temperature and soil moisture stations in the network designed for monitoring (i) dry conditions are 1059, 1059, and 552, respectively, (ii) wet conditions are 1144, 1144, and 664, respectively. Stations in the two networks were prioritized by assigning ranks based on DWGDI. The information could be helpful to decision-makers in identifying potential locations for the installation of new gauges accounting for budgetary constraints. The real-time observations from the designed gauge network could be helpful for various purposes, such as better water management to meet irrigation demands, monitoring droughts and floods, and forecasting natural hazards like wildfires, soil erosion, and landslides. </p>

Background: The dimensional accuracy and surface detail reproduction of impression materials play a major role in determining the extent to which indirectly produced prostheses and restorations have an acceptable fit. The purpose of the present study was to compare the dimensional accuracy and surface detail reproduction of hydrophilic polyvinylsiloxane (PVS) impression material tested under dry and moist salivary conditions. Methods: The study samples were assigned two groups based on the condition in which they were made. One group consisted of casts obtained from impressions made in dry condition (n = 12), while the other group consisted of casts obtained from impressions made in moist salivary conditions (n = 12). Impressions of the master model were made using hydrophilic PVS impression material by two-step putty-wash technique and working casts were obtained. Dimensional accuracy was measured by comparing the inter-abutment distance in each cast to the master model using a profile projector with an accuracy of 0.001 mm, while surface detail reproduction was evaluated using the American Dental Association specification No. 19 criteria of continuous replication of at least two of the three horizontal lines. Descriptive statistics such as mean and standard deviation were calculated for both the groups. Differences from the master model were analyzed by paired t–test, while one-way analysis of variance (ANOVA) was used for intergroup comparisons. P ≤ 0.05 was considered statistically significant. Results: One-way ANOVA revealed a highly significant difference in the dimensional accuracy of impressions made under moist conditions as against those which were made under dry condition (P < 0.001). The percentage change in dimension of 0.6% in Group A casts and 0.3% in Group B casts, also, showed a high clinical significance. Under dry condition, the impression material satisfactorily replicated the surface details in 100% of the cases, while under moist conditions, only 58% of the impressions were found to be satisfactory. Conclusion: The presence of moisture caused a significant adverse impact on the dimensional accuracy and surface detail reproduction of hydrophilic PVS impression material underlying the clinical significance of moisture control for successful impressions.

Munirathna Padmanaban, Andrew Romano, Gu anyang Lin, Simon Chiu, Allen Timko, Frank Houlihan, Dalil Rahman, S. Chakrapani, T. K udo, Ralph R. Dammel, Karen Turnquest*, Georgia Rich*, Scott D. Schuetter**, Timot hy A. Shedd**, Gregory F. Nellis** AZ Electronic Materials, 70 Meis ter Avenue, Somerville, NJ 08807 *International SEMATECH, 2706 Montopolis Dr., Austin, Texas 78741 **Computational mechanics center, Uni versity of Wisconsin-Madison, WI 53706 Abstract 193 nm immersion lithography is rapidly moving towa rds industrial application, and an increasing number of tools are being installed worldwide, all of which will require immersion-capable photoresists to be availa ble. At the same time, existing 193 nm processes are being ramped up using dry lithography. In this situ ation, it would be highly a dvantageous to have a si ngle 193 nm resist that can be used under both dry and wet conditions, at least in the initial stages of 45nm node process development. It has been shown by a number of studi es that the dominant (meth)acrylate platform of 193 nm dry lithography is in principle capable of being ported to immersion lithography, however, it has been an open question whether a single resist formulation can be optimized for dry and wet exposures simultaneously. For such a dry/wet crossover resist to be successful, it will need to make very few compromises in terms of performance. In particular, the resist should have similar LER/LWR, acceptable process window and controlled defects under wet and dry exposure conditions. Additionally, leaching should be at or below specifica tions, preferably without but at very least with the use of a top protective coat. In this paper, we will present th e performance of resists under wet and dry conditions and report on the feasibility of such crossover resists. Available results so far indicate that it is possible to design such resists at least for L/S applications. Detailed data on lithographic performance under wet and dry conditions will be presented for a prototype dry/wet crossover L/S resist.

To study the effects of addition of a redox metal, copper, antioxidants and metal chelators on the formation of free radicals in natural white Caucasian hair subsequently exposed to UV light. Three different methods, electron paramagnetic resonance (EPR), a fluorescent probe for hydroxyl radical formation (terephthalate) and free radical photoyellowing, were used. These methods utilized different UV sources and reaction conditions, and so can give insights into the different mechanisms of action occurring during UV oxidation of hair. In addition, this study demonstrates how antioxidants and chelators can be screened to determine whether they can protect hair from UV damage. The three methods gave somewhat different results, illustrating the importance of reaction conditions and wavelength on the photochemical mechanisms, and the efficacy of additives to influence these reactions. EPR results showed that N-acetylcysteine (NAC) pre-treatment eliminated the intensity of the signal because of sulphur and carbon free radicals in white hair both before and after exposure to UVB radiation. Doping the hair with copper ions had no effect on the intensity of the EPR signal under dry conditions. Terephthalate fluorescent probe data showed that under wet conditions, irradiation of white hair with UVA produced significant amounts of hydroxyl radicals. Pre-treatment of hair with NAC reduced the number of •OH radicals produced by natural white hair compared to an untreated control. In contrast to the EPR result, white hair doped with copper ions produced significantly higher levels of •OH radicals under wet conditions. It appears that the ability of copper ions to catalyse the photogeneration free radicals in hair is highly dependent on water content. Photoyellowing data showed a benefit for oxalic acid but no difference for NAC and an increase in yellowing for EDTA. The micro-EPR and terephthalate fluorescent probe methods are both effective techniques to study production of free radicals by hair exposed to UV light under wet and dry conditions, respectively. Both assays are simple methods for determining the effectiveness of potential protective hair treatments against UV damage, but because they assess free radical damage under dry vs wet conditions, the chemistry created on UV exposure is different. This gives insights into mechanism of action, but results may not be consistent between the two methods for actives added for reduction of UV damage. NAC pre-treatment did reduce free radical generation in UV-exposed hair under both wet and dry conditions. Photoyellowing data are more complicated as it is a less direct measure of UV damage and is highly dependent on irradiation source. Using UVB irradiation is experimentally convenient but may not be appropriate, because UVB wavelengths comprise only 0.3% of terrestrial sunlight. The photochemistry of hair exposed to sunlight involves concurrent photobleaching and photoyellowing processes and is far more complex. Under UVB irradiation conditions, oxalic acid showed a yellowing benefit.

Every growing season, paddy fields are kept both flooded and drained for a significant period of time. As a consequence, these soils develop distinct physico-chemical characteristics. For practical reasons, these soils are mostly sampled under dry conditions, but the question arises how representative the results are for the wet growing conditions. Therefore, the apparent electrical conductivity (ECa) of a 1.4 ha alluvial paddy field located in the Brahmaputra floodplain of Bangladesh was measured in both dry and wet conditions by a sensing system using the electromagnetic induction sensor EM38, which does not require physical contact with the soil, and compared both surveys. Due to the smooth water surface under wet conditions which ensured increased stability of the sensing platform, the results of the survey showed considerably reduced micro-scale variability of ECa. Furthermore, the wet survey results more reliably furnished soil-related information mainly due to the absence of soil moisture dynamics. The differences between ECa under wet and dry conditions were attributed to differences in soil texture, mainly the sand content variation having considerable effect on soil moisture differences when flooded following drainage. Accordingly, the largest differences between ECa under wet and dry conditions were found in those parts of the field with a large sand content. Hence, the conclusion was that an ECa survey on flooded fields has an added value to precision soil management.