Construction and demolition (C&D) waste management should be accordance with the waste management hierarchy. In practice, C&D waste are often downcycling. It is the result of many factors, including lack of awareness about the value inherent in waste. The paper presents analysis of the adaptability of non-destructive testing (NDT) methods for technical assessment of waste properties. As part of the work, non-destructive testing methods were described and classified in accordance with material and the features they enable testing. The publication presents examples of the use of NDT in the recovery of building materials during construction projects, in the field of influence of technical information of waste on the way it is managed. Finally, a scheme of waste management process during the renovation of an object with the application of NDT methods was presented.
Mihai-Octavian Popp, Mihaela Oleksik, Sever-Gabriel Racz and Gabriela-Petruța Rusu
Incremental forming process is a relatively new process among researchers, which is yet to be implemented in automotive and aerospace industries. The researchers are studying various process strategies and methods to improve the geometrical accuracy of the parts obtained by incremental forming, because the geometry of the parts is one of the key factors holding back the process industrialization. One good method to investigate the benefits of a process strategy is by means of numerical analysis, from which the results obtained can confirm or disprove the gains of the researched strategy. The aim of this paper is to present the advantages of using a fluid under pressure as a supporting die instead of using a conventional fixed backing plate for the single point incremental forming process.
As the dynamic behavior of the concrete is different from that under static load, this research focuses on the study of dynamic responses of concrete by simulating the split Hopkinson pressure bar (SHPB) test. Finite element code LS-DYNA is used for modeling the dynamic behaviors of concrete. Three continuous models are reviewed and the Holmquist-Johnson-Cook model (HJC) is introduced in detail. The HJC model which has been implemented in LS-DYNA is used to represent the concrete properties. The SHPB test model is established and a few stress waves are applied to the incident bar to simulate the dynamic concrete behaviors. The stress-strain curves are obtained. The stress distributions are analyzed. The crack initiation and propagation process are described. It is concluded that: the HJC model can modeling the entire process of the fracture initiation and fragmentation; the compressive of the concrete is significantly influenced by the strain rates.
Salah Guerbaai, Mouna Touiker, Kamel Meftah and Abdeslam Omara
A numerical study is performed to analyze steady state forced convection fluid flow through a confined porous square cylinder. The Darcy-Brinkman-Forchheimer model is adopted for the porous region. The finite volume method and the iterative SIMPLE algorithm are used to solve the governing equations. The results obtained are presented for the streamlines, variation of Nusselt number and drag coefficient for the range of conditions as 5 ≤ Re ≤ 40 and 10−2 ≤ Da ≤ 10−6.
The permanent tendency to invest huge budgets of money in research and development in order to create military capabilities that will allow hitting a large number of targets in a short time and in an extended battlespace continues to be the main direction for neutralizing a possible opponent in the military conflicts. Due to current scientific and technological advances, the focus nowadays is on using artificial intelligence (AI) with the purpose of dominating the operational environment in the theatres of operation (TO). The present paper aims to identify how AI will shape the operational environment of future military conflicts.
Windows and shading devices play a significant role in designing building facades to control the rate of the received daylight and improve visual comfort. This study is aimed to provide an optimization basis for building’s façade considering two variables of Annual Sun Exposure (ASE (1000/250h)) and the view to outside of an office. In this research, the effect of various parameters of shading louvers to the south was investigated in Tehran, Iran. The parameters were number, depth, angle as well as thickness. In this review, Rhino/Grasshopper plug was employed for simulations; moreover, Galapagos evolutionary solver component was used to run the optimization process. This study’s findings showed that it was possible to reach a view of nearly 90% of the interior spaces while the value of ASE (1000/250h) still remained in the reasonable range.
In this paper we will analyze the extent to which the organizational commitment of the teaching staff is influenced by a number of factors in the category of job characteristics, namely: professional satisfaction, trust in the higher education system, global evaluation of the quality of the faculty and perception on the availability of resources learning. Following the regression model realized, the hypothesis was confirmed, according to which job satisfaction fuels attachment to the organization more than other factors.
The paper presents the method of simplified parametric analysis of the sensitivity of a pre-tensioned concrete beam. The presented approach is based on the DOE (design of experiments) data collection which is simulation technique allowing for identification of variables deciding about the effectiveness and costs of designed structures. Additionally, application of the hyper-surface of the construction response allows designers to the development of multi-dimensional trade-off graphs to facilitate, the assessment of the scope of changes in random state variables permitted due to the adequate criteria and selection of their values close to optimum. Design basics, procedures and results of the presented considerations of sensitivity assessment and reliability of the structure has been shown on the example of a pre-stressed concrete beam designed in accordance with the requirements and procedures of Eurocode 2
In the field of communication on land and in the air, there are already functioning fully or partially autonomous devices. However, it is difficult to point to similar solutions regarding autonomous systems, especially in military applications.
The article formulates development perspectives for marine autonomous systems in military applications, taking into account achieved benefits, requirements and development restrictions. Many interesting places devoted to the security of autonomous systems, on the clear improvement of the security situation with the above-mentioned systems, equipment and machines for maintenance, management devices, autonomous systems, controls and controls, devices for carrying out operations.
The recommendations indicate the need to implement joint projects in the field of the development of autonomous marine technologies and are critical in the previous activities undertaken in this field of research.
The paper presents results of research based on analysis of marine icing nomograms, models and charts using in the sea navigation. The problem of ships icing occurs in specific weather and geographical conditions. Every year numbers of vessels navigate in these areas meet a phenomenon of icing. Ice on decks of ships can be formed from fresh water or sea (salt) water. Ships operating in waters where the phenomime of icing is occurred use for safety navigation icing nomograms and icing charts. Icing charts are created based on icing models.
The main aim of the article is to perform a review of currently used in the sea navigation icing nomograms and icing maps, based on icing models, used in navigation to depict the phenomenon of icing.