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This study aims to examine the permeability and acid and sulfate attack of waste rubber-substituted concrete containing recycled rubber in three different grain size classes (chips, crumb and powder) with two different water/cement (w/c) ratios (0.4 and 0.5). Waste rubber at different ratios (0%, 4%, 8%, 12%, 16%, 20%, and 24%) was used in concrete by replacing fine and coarse aggregates. Sorptivity, electrical resistivity, and acid and sulfate attack tests were conducted on concrete cured for 90 days. Although the capillarity coefficient values increased with the waste rubber replacement ratio increase, a decrease occurred after the 20% waste rubber replacement ratio. In 12% waste rubber-substituted concrete (0.4WR12) with a water/cement ratio of 0.4, the electrical resistivity value (8.3 kΩ.cm) was the highest, and concretes with low permeability could be produced. As a result of the use of 16% waste rubber in the concrete, 75% less compressive strength loss was observed after the acid attack compared to the control concrete. In concrete with a water/cement ratio of 0.5, when the waste rubber ratio increased by up to 16%, the compressive strength losses caused by the sulfate attack decreased dramatically (95.76% less) compared to the control concrete. The rubberized concrete with a water/cement ratio of 0.5 showed high resistance to acid and sulfate attacks. The experiment results showed that 12% to 16% waste rubbers are ideal ratios. In this study, the water/cement ratio was a valuable parameter for the waste rubber ratio in rubberized concrete. [ABSTRACT FROM AUTHOR]

This study was performed in order to examine the behavior of natural perlite aggregate composites against durability problems caused by alkali silica reaction (ASR). Mortars containing 5%, 10%, 25%, 50%, 75% and 100% natural perlite were subjected to the ASR test. Mechanical tests were also performed on mortar samples. In addition, scanning electron microscope (SEM) analyzes were also applied. The expansion value of the 25% natural perlite substituted mortar with the highest ASR expansion increased by 145% as compared with the control mortar. When the natural perlite ratio increased from 25% to 100%, the expansion values decreased dramatically. 5% natural perlite substituted mortar had the highest compressive and flexural strengths. The SEM analysis results were obtained to be consistent with the ASR expansion results. Experimental results proved that mortars produced from 100% natural perlite can be used effectively to reduce the durability problems caused by ASR. [ABSTRACT FROM AUTHOR]

Daphnia cucullata is one of the most abundant zooplankton species, found in 85 percent of freshwater and as a model aquatic organism it was chosen from this study. That is why this zooplankton species was chosen. The plankton samples were collected from Keban Reservoir from 2020-2023 with a standard plankton net (55-µm mesh size) at the designated station, Plankton samples were stored in 4% formaldehyde solution. Some water quality parameters were determined by making instant physical measurements with a YSI (EXO 2) model device. Water temperature, pH, electrical conductivity, dissolved oxygen, turbidity (Secchi Disk Depth) and Chlorophyll a were measured. In this study, the fouryear body changes of D. cucullata in August from 2020 to 2023 were monitored. During four years of progressive eutrophication in Keban Reservoir, we found that among the five morphological parameters analyzed in D. cucullata length of head, carapace length, length of tail spine, body length, width of carapace had a tendency to decrease. [ABSTRACT FROM AUTHOR]

This study investigates the alkali-silica reaction (ASR) and mechanical properties of mortars containing crumb and powder rubber instead of river sand. In this regard, mortars were produced using waste rubber whose ratios in the mixture are 0%, 3%, 6%, 9%, 12%, 15%, 18%, and 21%. ASR expansion, compressive and flexural strength tests were conducted on the samples. ASR measurements were performed on days 3, 7, 14, 21, and 28. Besides, at the end of the ASR experiment, the microstructures of the mortars were examined using scanning electron microscope (SEM) images. Examining the results of this study reveals that the use of waste rubber in rising portions in the mortars led to an increase in the ASR expansions of the mortars. The study shows that the ASR expansions of the mortar samples that have 9% and 15% waste rubber replacement are comparatively higher than the other mortar samples. Furthermore, the results of the SEM analysis verified this finding. The study demonstrates that 3% of waste rubber mortar samples have the highest compressive and flexural strengths. On the other side, the ASR expansion of the mortars with 3% substituted waste rubber was considerably low compared to other mortars containing waste rubber. These findings (ASR, compressive and flexural strength tests results) show that using 3% waste rubber is ideal for producing mortars and supports a sustainable production approach in the sector. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We aimed to evaluate the maternal and fetal serum M-30, M-65 and IL6 levels in preeclampsia and gestational diabetes mellitus (GDM) in both maternal and cord blood. PATIENTS AND METHODS: Women with preeclampsia (n=30), GDM (n=30), and uncomplicated pregnancy (n=28) were evaluated in a cross-sectional study. After clamping during delivery, the serum M-30, M-65, and IL-6 levels were measured in both maternal venous blood and cord blood. RESULTS: The serum M-30, M-65, and IL-6 levels were significantly higher in preeclampsia and GDM patients’ maternal blood and cord blood samples compared to the control group. In the preeclampsia group, M-65 was significantly higher in cord blood compared with the level in maternal serum, but there was no significant difference between the GDM and control groups. The control group’s IL-6 level in cord blood was statistically significantly lower than the other groups. Although the M-30 value in both maternal and cord blood was statistically lower in the control group than in the GDM group, there was no significant difference between the two groups when compared to the preeclampsia group. CONCLUSIONS: M-30 and M-65 molecules appear to have the potential to serve as biochemical markers in placental diseases, particularly preeclampsia and gestational diabetes. Due to the insufficient sample sizes, more research is needed. [ABSTRACT FROM AUTHOR]