Using Twist-off Method for Measuring CFRP/Concrete Adhesion when Exposed to Cyclic Temperature Changes, Wet-Dry and Freeze-Thaw

One of the main applications of salt in civil engineering is its use as a de-icing agent on roads in cold areas. The purpose of this research is to find out the mechanical behaviour of an asphalt concrete when it is subjected to temperature changes and freeze–thaw cycles. These temperature interactions have been carried out for dry specimens, specimens submerged in distilled water and specimens submerged in salt water (5% of sodium chloride, NaCl). An AC16 Surf D bituminous mixture was evaluated under three types of temperature interaction: three reference series remained at a controlled temperature of 20 °C, another three series were subjected to five freeze–thaw cycles and the last three series have been subjected to one year outside in Santander (Spain). The mechanical behaviour of the mixture was determined by Indirect Tensile Strength Test (ITS), Water Sensitivity Test (ITSR) and Wheel Tracking Test, Dynamic Modulus Test and Fatigue Tests. The results of the tests show that, although the temperature changes have a negative effect on the mechanical properties, salt water protects the aggregate-binder adhesive, maintains the mechanical strength, increases the number of load cycles for any strain range and reduces the time that the mixture is in contact with frozen water.

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Membrane Homeoviscous Adaptation in Sinorhizobium Submitted to a Stressful Thermal Cycle Contributes to the Maintenance of the Symbiotic Plant–Bacteria Interaction

Frontiers in Microbiology ◽

10.3389/fmicb.2021.652477 ◽

2021 ◽

Vol 12 ◽

Author(s):

Natalia Soledad Paulucci ◽

Adriana Belén Cesari ◽

María Alicia Biasutti ◽

Marta Susana Dardanelli ◽

María Angélica Perillo

Keyword(s):

Lipid Bilayers ◽

Sinorhizobium Meliloti ◽

Symbiotic Interaction ◽

Homeoviscous Adaptation ◽

Temperature Changes ◽

Thermal Changes ◽

Cyclic Temperature ◽

The One ◽

Term Response

Here, we estimate fast changes in the fluidity of Sinorhizobium meliloti membranes submitted to cyclic temperature changes (10°C–40°C–10°C) by monitoring the fluorescence polarization (P) of DPH and TMA-DPH of the whole cell (WC) as well as in its outer (OM) and inner (IM) membranes. Additionally, the long-term response to thermal changes is demonstrated through the dynamics of the phospholipid and fatty acid composition in each membrane. This allowed membrane homeoviscous adaptation by the return to optimal fluidity levels as measured by the PDPH/TMA-DPH in WC, OM, IM, and multilamellar vesicles of lipids extracted from OM and IM. Due to probe-partitioning preferences and membranes’ compositional characteristics, DPH and TMA-DPH exhibit different behaviors in IM and OM. The rapid effect of cyclic temperature changes on the P was the opposite in both membranes with the IM being the one that exhibited the thermal behavior expected for lipid bilayers. Interestingly, only after the incubation at 40°C, cells were unable to recover the membrane preheating P levels when cooled up to 10°C. Solely in this condition, the formation of threads and nodular structures in Medicago sativa infected with S. meliloti were delayed, indicating that the symbiotic interaction was partially altered but not halted.

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Research of engine and transmission oils for thermo-oxidative stability with cyclic temperature changes

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/537/6/062074 ◽

2019 ◽

Vol 537 ◽

pp. 062074

Author(s):

B I Kovalsky ◽

Yu N Bezborodov ◽

N N Lysyannikova ◽

E G Kravtsova ◽

A V Lysyannikov ◽

...

Keyword(s):

Oxidative Stability ◽

Temperature Changes ◽

Cyclic Temperature

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X-ray studies of thermal cycles in the transformation of potassium cyanide

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1959.0165 ◽

1959 ◽

Vol 252 (1271) ◽

pp. 445-456 ◽

Cited By ~ 43

Keyword(s):

Solid Solution ◽

Single Crystals ◽

Potassium Cyanide ◽

Crystal Form ◽

Sodium Cyanide ◽

Normal Cycle ◽

Temperature Changes ◽

X Ray ◽

Cyclic Temperature ◽

Thermodynamic Transformations

Single crystals of pure potassium cyanide, and of potassium cyanide containing various amounts of sodium cyanide in solid solution, have been subjected to cyclic temperature changes traversing the thermaltransformation at around — 110 °C. By means of Laue and Bragg photographs, persistence of the crystal axes has been observed in a ‘normal cycle’ high → low → high, but a metastable crystal form was also produced by a particular sequence of changes. There was considerable hysteresis in the transformation of single crystals. Introducing lattice disturbances by incorporating sodium cyanide in solid solution broadened the transformation. Co-existence was observed of various domains of the low-temperature form in ‘hybrid’ single crystals; there was also evidence for the co-existence of domains of the low- and high-tem perature forms over a range of temperatures. These results are discussed in relation to theories of continuous thermodynamic transformations in solids.

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