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Theoretical analysis to predict the crack propagation of Al 2024 is required and validated by experiment. This theoretical analysis was developed through a mathematical model that is based on the development of the Paris equation. The Paris equation is used to analyze crack propagation against a constant amplitude load. In this paper, a mathematical model based on the Paris equation is developed for the load spectrum, where the effective results are obtained at stage 2 when conditions are stable. The results of the development of this mathematical model are quite promising to be used as a reference for further experiments with the same material [ABSTRACT FROM AUTHOR]

In order to minimize the anthropogenic load, humanity is increasingly thinking about the need to further advance civilization along the path of sustainable development. This research paper studies effectiveness of the activities carried out within the framework of legal regulation of the sustainable development of civilization. The analysis of the results of following the provisions of the Kyoto Protocol showed that they brought positive results. By far, the Kyoto Protocol has ended its operation and the world community is guided by the provisions of the climate agreement adopted in 2015 in Paris. But this Agreement is currently not effective enough and we see the main problem in the lack of material incentives for emitters to reduce greenhouse gas emissions. JSC "Russian Railways" is one of the largest emitters, constantly reducing emissions, but shortcomings of environmental legislation do not allow it to participate in the trade of emission reduction units and receive income from these operations today. We see the solution to this problem in return to emission quotas (as envisaged by the Kyoto Protocol) and the development of the mechanism for trading units of their reduction. [ABSTRACT FROM AUTHOR]

In recent years, the vast amount of offered items can overwhelm users in processing the information for decision-making purposes. In this case, recommender systems have become a functional tool to help people make good decisions. Big companies such as Netflix, Spotify, and YouTube have employed recommender systems in their platform. In the tourism industry, the case also exists, especially when travelers visit a tourist city such as Paris or Bali, which offers them many tourist attractions. In this paper, we employ collaborative filtering techniques to model a recommender system for tourist attractions. Singular value decomposition (SVD), SVD++, and non-negative matrix factorization (NMF) algorithms are used in this paper over a dataset which we collected previously from 44 users and 60 tourist attractions. The optimal parameters of the algorithm are searched based on exhaustive searching techniques against a set of parameter combinations. We used 5-fold cross-validation to evaluate the predicted rating in each algorithm in terms of Root Mean Square Error (RMSE) and Mean Average Error (MAE). Results show that using our dataset, the model built in SVD++ had the minimum error but took a longer training time, while NMF gave the worst RMSE but had a faster training time compared to SVD++. [ABSTRACT FROM AUTHOR]

The paper presents the results of determining the characteristics of fatigue crack propagation resistance of a promising pipe steel of the 26KhMFA type. It has been found that at room temperature this type of steel has high values of fracture toughness resistance regardless of the orientation of the crack propagation path relative to the pipe axis. Anomalous stability of the fatigue crack propagation rate in the linear Paris law section with an increase in the effective range of the stress intensity factor in the range of ΔK=15–20 MPa m1/2 is revealed. The obtained experimental data characterize this steel as a material with increased resistance to fatigue crack propagation in the studied range. [ABSTRACT FROM AUTHOR]

The Simbol-X telescope will be constitued by two satellites in formation flight. One will host the mirror module and the other the detector payload. This payload will be built with two main detectors able to measure the position, energy and arrival time of each focused photon, between 0.5 and 80 keV. The high sensitivity required by Simbol-X will necessitate low noise background detectors. To achieve this goal, those detectors will be surrounded by a passive graded shield, aimed to stop the out of field of view photons, and an active anticoïncidence system to tag the passing particles. This anticoïncidence detector, whose conception, optimisation and realization are under responsibility of the APC Laboratory, Paris, is based on plastic scintillator plates associated to multi-anodes photo-multipliers via optical fibers. In this paper, we will present the present status of the anticoïncidence system and its expected performances. [ABSTRACT FROM AUTHOR]