Detecting Groundwater Temperature Shifts of a Subsurface Urban Heat Island in SE Germany

The subsurface beneath cities commonly shows a temperature anomaly, a so-called Subsurface Urban Heat Island (SUHI), due to anthropogenic heat input. This excess heat has multiple effects on groundwater and energy resources, such as groundwater chemistry or the efficiency of geothermal systems, which makes it necessary to investigate the temporal development of a SUHI. For this purpose, temperature profiles of 38 observation wells in the German city of Nuremberg were evaluated from 2015 to 2020 and the measured temperature changes were linked to the surface sealing. The results show that the groundwater temperatures changed between −0.02 K/a and +0.21 K/a, on average by +0.07 K/a during this period. A dependence between the temperature increase and the degree of sealing of the land surface was also observed. In areas with low surface sealing of up to 30% the warming amounts were 0.03 K/a on average, whereas in areas with high sealing of over 60% significantly higher temperature increases of 0.08 K/a on average were found. The results clearly emphasize that the subsurface urban heat island in its current state does not represent a completed process, but that more heat energy continues to enter the subsoil within the city than is the case with near-natural land surfaces.

Quantification of water erosion and characterization of surface sealing in Ultisols in semiarid areas in Brazil

The lack of cover is one of the main accelerators of soil degradation. Without protection and exposed to rainfall, the soil breaks the particles, causing surface sealing, making infiltration difficult. This study characterizes surface sealing and hydraulic erosion in Ultisols of the Alto Ipanema Basin. Eight erosion plots were established under the treatments: bare soil and soil with Brachiaria decumbens mulch. Three rain events were simulated at 24-hour intervals, with an intensity of 54.63 mmh-1. After each simulation, the surface micromorphology and the amount of soil lost were investigated. The use of mulch reduced runoff by 42% and the loss of soil and the rate of disaggregation was reduced by 70% on average. Infiltration was increased by 242%. Mulch was effective in preserving soil porosity and microstructure for the first simulated rainfall event (0 h), but was not observed in the second (24 h) and third (48 h) rainfall events.

Variation in Atmospheric Precipitation in Poland in the Years 2001–2018

Climate change scenarios are in agreement as to the direction of air temperature changes in global warming, although the magnitude of the warming depends on the scenario adopted. In contrast, projections of changes in precipitation totals in Poland are not clear and obvious. Analysis of long-term observational series reveals no clear significant trends in levels of precipitation, despite periods of fluctuation, as well as an upward trend reported in the annual amount of precipitation, especially in northern Poland. However, the increasing variability of annual rainfall totals is commonly highlighted. In the years 1861–1990, the coefficient of variation of annual precipitation totals increased from about 10% to 16%. In the years 1971–2000, this coefficient for Poland increased to 17%, and in the period of 2001–2018, which is the subject of the present study, to 19%. Despite the lack of clear trends in annual totals, the increase in the coefficient of variation results in an increase in the frequency of both drought and floods. This unfavorable situation is exacerbated by the downward trend observed in the share of summer rainfall in the annual total. In urban areas with increasing surface sealing, the share of surface runoff in the water balance increases, and in this situation short-term rainfall will cause local flooding.

Estimating regional to global fresh-brackish-salt groundwater occurrence to support future projections

<p>Coastal areas, including deltas, are hotspots for population growth and economic development. The rising demand for fresh water that results from these developments has resulted in increased rates of groundwater pumping and an associated enhanced risk of groundwater salinization. Future sea-level rise, climate change and surface sealing due to urbanisation are likely to further increase salinization risk in the near future. In order to correctly project the future fate of fresh groundwater resources in coastal areas under climate and socio-economic change, a correct estimate of the current fresh-brackish-salt groundwater occurrence is imperative. The reason for this is that future salinity projections are very sensitive to initial conditions, due to the large inertia of variable-density groundwater systems. Here, we make a case that estimating the current fresh-brackish-salt groundwater distribution by itself is a major challenge. The presence of conductivity contrasts in coastal areas, the past occurrence of sea-level transgressions and the aforementioned system inertia makes that traditional estimation methods such as interpolations between in-situ salinity observations or equilibrium (steady-state) modelling approaches are incapable of producing sufficiently realistic fresh-brackish-salt groundwater distributions. Using examples from the Rhine-Meuse delta, the Nile delta and the global coast, we show that advancements in airborne geophysics and high-resolution paleo-groundwater modelling may be key to providing distributions that are both realistic and accurate.</p>

Comparative Study of Color Stability of Three Composite Materials, Treated by Finishing and Coated Sealing, After Immersion in Different Wholesale

The present study was conducted to evaluate the effects of common drinks consumed by patients (Coffee, Coca-Cola, Black Tea) on different types of composite restorations, finishing and surface sealing (nanocomposites, nanohybrids, ormocers) regarding color changes. 45 specimens of composite materials (Nanoceramic, Nanocomposite and Nanohybrid) were made and divided into 3 groups G1-control group, G2 - finished in 2 stages, and G3 glaze coated. The LOVIBOND RT 300 portable spectrophotometer was used to determine the color by following the CIELAB scale. The data was analyzed using Mann-Whitney followed by a multiple comparison t test. Significant differences were found between the groups in terms color changes (p[0.001). The results showed that for both groups of composites (G2 and G3), irrespective of the beverage they were immersed in, the DE values were significantly higher at 7 days compared with the 30 day values.

ANALYSIS OF THE CLINICAL EFFICIENCY OF RESTORATIVE FILLING MATERIALS

Aim. To conduct a clinical assessment of short- and long-term surface sealing in patients having a different hygienic status of the oral cavity.Materials and methods. For clinical trials, a group of 250 male and female patients aged 25–45 years old and diagnosed with Black’s class III and V carious lesions was selected. All patients were divided into three groups depending on the state of oral hygiene and the applied methods of aesthetic restoration: control group — defect restoration by Filtek Z-250 microhybrid composite (3M ESPE); comparison group — Filtek Z-250 restoration (3M ESPE) + Easy Glaze (Voco) surface sealing on the day of restoration; and the main group with three subgroups: 2α subgroup — Restavrin restoration + Easy Glaze sealant on the day of treatment; 2β subgroup — Restavrin restoration + Easy Glaze sealant on the day of treatment and re-sealing with a frequency of 1 time per year; 2γ subgroup — Restavrin restoration + Easy Glaze sealant on the day of treatment and re-sealing with a frequency of 1 time per 6 months. The quality of caries cavities was assessed by USPHS criteria, including anatomical shape (AS), marginal pigmentation (MP), marginal adaptation (MA), the presence of secondary caries (SC) and sensitivity (S). The evaluation was conducted on the day of the visit and following 6, 12 and 24 months.Results. A comparison of the clinical evaluation of photocomposite restorations by the Filtek Z-250 (3M ESPE) microhybrid composite in the control group of patients, in comparison group and in the main Restavrin (Technodent) group showed that the Easy Glaze (Voco) surface sealing of the Restavrin composite restorations carried out in the 2α subgroup of the main group onе time on the day of restoration, in the 2β subgroup with re-sealing after 12 months, and in the 2γ subgroup with sealing every 6 months had allowed the maximum number of restorations to be corresponded to the “satisfactory” value according to the AS, MP, MA, SC, S evaluation criteria throughout the entire observation period.Conclusion. The Restavrin (Technodent, Russia) polymeric nanohybrid fi lling material is shown to produce the most effective and durable restorations compared to other materials under study. The applicatiyon of Restavrin followed by the Easy Glaze (Voco) sealing protective system with a frequency dependent on the hygienic status of the oral cavity allows therapeutic methods for dentin caries treatment to be optimized.

Surface sealing and water erosion of soils with mulching in the semi-arid region of Brazil

ABSTRACT Evaluating soil sealing process of the semi-arid region of Brazil is important to describe this process and mitigate its effects. The objective of this work was to evaluate surface sealing and physical properties of the main soils of the Upper Ipanema watershed, in Pesqueira, Pernambuco state, Brazil, with the use of mulch. The experiment was conducted in a completely randomized design with three replications, using a 3 × 3 × 2 factorial arrangement consisted of three soil classes (abruptic Eutrophic Yellow Argissolo - AEYA, typical Eutrophic Fluvic Neossolo - TEFN, and typical Eutrophic Yellow Argissolo - TEYA), three application times of simulated rainfalls (at 0, 24, and 48 h), and two mulching conditions (with and without mulch), totaling 54 tests. Soil erosion rates, surface sealing, and resistance to penetration were evaluated. The use of mulch decreased significantly the soil water losses by 71.9% (AEYA), 62.9% (TEFN), and 41.1% (TEYA) after the first rainfall application (0 h) when compared to treatments without mulch, and promoted a higher water infiltration rate. The lowest soil resistance to penetration were found in soils with mulch. The AEYA and TEFN presented changes in porosity and migration of fine particles in the treatment without mulch. The TENF was the only soil that presented an incipient soil surface sealing layer in the treatment without mulch.