Peculiarities of stress corrosion fracture of sensitized and neutron irradiated chromium-nickel austenitic steel

The results of SEM studies of fracture surfaces for the 12Cr18Ni9 austenitic steel ruptured under a fixedtensile load in FeCl3 water solutionand in air are presented. The samples of austenized, sensitized at 650° and irradiated with neutrons (to 1020n/cm2) steel were examined. It was shown thatirradiation hardening and sensitizing annealing increased the susceptibility of steel to intergranular cracking in corrosive solution. Structural features of formation of the strain-induced α’-martensite and its reinforcing effect on fracture in various environments are discussed.

Intercultural Dialogue as a Tool for Maintaining Sustainable Partnerships in Tourism

International partnerships have a reinforcing effect and lasting benefits for modern economy and social life. The principles of intercultural partnerships in tourism can be compared to other principles of sustainable development. This chapter recognises the ultimate role of sustainable development in the sphere of tourism, while applying the theory of intercultural dialogue as an approach to the SDG 17 and tracing back partnerships to the bridge where different cultures meet. Such meetings very often need a bridge to cross over cultural gaps. In view of the proposed research, one such bridge is presented by the International Tourism Fair Holiday and SPA EXPO 2020, and it is against the background of this event that the established partnerships mediated by intercultural dialogue are classified.

Study of Ballast Track Dynamic Behavior Evaluation Comparative Analysis According to the On-Site Laying of Rectangular-Parallelepiped Fiber Reinforcement Sack

The roadbed reinforcement method using cuboidal fiber reinforcement is an eco-friendly method that compensates for the shortcomings of various existing roadbed reinforcement technologies. A rectangular parallelepiped fiber reinforcement was installed in section oo of the existing line where fine-grained gravel, floating sleepers, and sleeper cracks occurred. The basic physical property test of the upper subgrade was conducted, and the vertical displacement and acceleration of rails and sleepers were compared and analyzed according to the train operation of the reinforced and non-reinforced sections. A comparative analysis of the vertical displacement and acceleration according to train operation after laying the rectangular parallelepiped fiber reinforcement demonstrated that the vertical displacement and acceleration were reduced by up to 84% and 80%, respectively. The dynamic movement of the rail was reduced owing to the reinforcing effect of the rectangular parallelepiped reinforcement, thereby improving the roadbed bearing capacity and stability.

Studies on reinforcing effect of industrial nano silica in chloroprene vulcanizates containing carboxy-terminated liquid natural rubber

Maleic anhydride was chemically attached to depolymerized natural rubber, and the product was named as carboxy-terminated liquid natural rubber (CTNR). The CTNR can act as a potential plasticizer in chloroprene (CR) vulcanizates. This paper describes the use of commercial nano silica (NS) as a promising cost-effective filler, which can enhance the tensile properties and ageing resistance of the CR vulcanizates incorporated with CTNR (CR-CTNR). The enhancement in properties may be attributed to the increased bound-rubber content owing to the large surface area of the nano-sized filler. The characteristics of the NS-filled CR vulcanizates containing CTNR (NS CR-CTNR) were compared with those containing amorphous silica. The NS CR-CTNR vulcanizates showed superior ageing and oil resistance due to the finer rubber filler interaction modified by ionic cross linking.

Strain Transfer of Fiber Bragg Grating Sensor Externally Bonded to FRP Strip for Structural Monitoring after Reinforcement

To date, a method of attaching a FRP (fiber-reinforced polymer) to concrete members with epoxy has been widely applied to increase the strength of the member. However, there are cases in which the adhesion of the epoxy deteriorates over time and the reinforcing effect of the FRP is gradually lost. Therefore, monitoring whether or not the reinforcing effect is properly maintained is needed in order to prevent a decrease in the structural performance of the member improved by FRP reinforcement. In this regard, this study examines FRP with OF (optical fiber) sensors to monitor the reinforcing effect of FRP in concrete structural members. In particular, this paper seeks to determine an appropriate adhesion length when FBG (fiber Bragg grating) based OF sensors are externally bonded to FRP strips with epoxy resin. To this end, a tensile test was carried out to evaluate the sensing performance according to the adhesion length. In addition, an analytical approach was performed and the result were compared with test result. The results of the experimental and analytical studies showed that the strain generated in the FRP is sufficiently transferred to the OF if the total adhesion length of it is 40 mm or more in consideration of the error in the epoxy thickness.