Bitumen aggregate adhesion and bitumen rheology of hard modified binders

The waterproofing of hydraulic structure is done traiditionally like laying road on dam surface but with specific modified binders. An italian firm recently patented a new method that is re-adaptation of typical surface treatment of roads. The purpose of this study is to find out best aggregate-bitumen mixture that can perform well under service conditions of a large hydraulic structure such as dams. So, 4 different hard modified bitumen were tested with 2 aggregate types i.e. limestone and basalt. The experimental program contained the testing of bitumen aggregate adhesion, using the rolling bottle test and rheology of hard modified binders using multiple stress creep and recovery test and dynamic viscosity test. The results and discussion are presented in detail in this work.

Comparison of radiobiological effects induced by ultra-high and standard dose rate of x-rays on a radio-resistant cell line

Radiotherapy (RT) has recently evolved with the emergence of heavy ion radiations or new fractionation schemes of photon therapy, which modify the dose rate of treatment delivery. The aim of the present study was then to evaluate the in vitro influence of a ultra-high dose rate comparing them with standard dose rate. In this regard, a radioresistant SK-MEL-28 cell line were irradiated with x-ray in order to have a total dose of 2 and 4 Gy, at two different dose rate. The ultra-high dose rate is a specific property of the dense plasma focus (DPF) device, which has pulsed operation and thus gives short and highly energetic pulses of multiple types of rays and particles, in this case, we focused our study on the influence of X-rays. While a low dose rate is obtained with conventional X-ray tube. In this study it results that a ultra-high dose rate enhances radiosensitivity of melanoma cells while reducing the adhesion, proliferation and migration ability of cells.