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An ITS (Intelligent Tutoring System) is a complex, integrated software system that applies the principles and methods of artificial intelligence (AI) to the problems and needs of teaching and learning. They allow searching the student level of knowledge and learning strategies used to increase or correct the students' knowledge. They are intended to support and improve the teaching and learning process in a selected area of knowledge while respecting the individuality of the learner. In the paper a review of intelligent tutoring systems (ITS) is given from the aspect of their application and usability in modern learning concepts.

Application of fracture mechanics at design of RC buildings will provide significant benefit. It will contribute that different size of premises to have the same security. In this way, the security and the cost of construction will be enhanced. There will exist a greater possibility of applying new designs and materials. Especially in large RC buildings, as well as in high-strength premises, the premises made of concrete with the steel fibers, prestressed concrete, large concrete dams, nuclear power plants, the facilities that require high safety, whose damage can cause a disaster, the application of fracture mechanics is of great significance. The impact of size, which relies on mechanical fracture can be defined as the theory of fracture which for the design of RC elements take into account resistance and energy of fracture.

In order to research the influence of the dimensions there have been used the samples of slotted beams on two supports and loaded by force capacity of P = 200 kN and the sensitivity of 100 N fractured (load cell), in the middle, deformations were measured at the point of load and the top of each slot of 50 mm with the sensitivity instrument of 100x10-6 mm LVDT (Tokyo Sokki Kenkyujo Co.SDP-50C). During load all deformations are directly stored with the data logger (30 channels Bucem) that is constantly connected to the computer. The thickness of all samples is constant t = 4 cm and the other two dimensions of height h and length L are changed proportionally. For testing are used three different sizes of the beams and from each sizes are used the three samples. To a mixture of concrete were used two aggregate fractions. A large fraction is 4.76 to 10 mm, smaller fraction is 3 to 4,76 mm. First, sand is put into a mixer, followed by gravel and cement in the dry state and this is going to be mixed for about 2 minutes, after that, the water is added and mixing is going to be carried out for about 2 minutes. From the same samples were set aside the 3 samples in the molds of cylindrical forms with a diameter of 150 mm and a height of 300 mm to determine the brand of concrete. There was used the portland cement (350).

One of the oldest scientific disciplines in the field of technical sciences is the study of building materials. Building and knowledge of materials are closely linked, and due to technical progress, it has become possible to influence the individual properties of materials. The technology range enables high processing and material properties, as well as the formation of completely new materials with predefined properties. Building materials constitute the entire complex of material components that can be both materials and raw materials for the obtaining of other building materials. Based on the application in the construction industry, they can be divided into materials of universal type (construction materials) and materials for special purposes (hydro insulation, thermal insulation, sound insulation, anticorrosive, adhesives, paints, varnishes and other). [ABSTRACT FROM AUTHOR]

An ITS (Intelligent Tutoring System) is a complex, integrated software system that applies the principles and methods of artificial intelligence (AI) to the problems and needs of teaching and learning. They allow searching the student level of knowledge and learning strategies used to increase or correct the students' knowledge. They are intended to support and improve the teaching and learning process in a selected area of knowledge while respecting the individuality of the learner. In the paper a review of intelligent tutoring systems (ITS) is given from the aspect of their application and usability in modern learning concepts. [ABSTRACT FROM AUTHOR]

This paper presents concept, aim and significance of innovative training on teachers for implementation of information and communications technologies in environmental education in the processing of significant environmental dates. Special attention has been given to identification of local needs and potentials in terms of selection of significant environmental dates, as well as promotion of these activities on international level through appropriate information and communications technologies. [ABSTRACT FROM AUTHOR]

The optimized methods for N-alkyl and N,N-dialkyl substituted thioureas synthesis starting from ammonium thiocyanates, waste water constituent from the production of tetramethylthiuram monosulfide (TMTS), and alkyl amine, are presented in this work., Thioureas synthesis was developed in two ways: Method I - reaction of the thiocyanate and alkylamine in the presence of hydrochloric acid; Method II - reaction of the thiocyanate with benzoyl chloride following by amine addition in the first step, and base hydrolysis in the second step. The structure of the synthesized compounds was confirmed by IR, ¹Hand 13C-NMR and MS instrumental methods, and purity was determined by high-performance liquid chromatography method. It is shown that the proposed methods offer a high degree of conversion and purity of product, absence of by-products and technological applicability at industrial scale. Considering the importance of the tetramethylthiuram disulfide (TMTD) and TMTS as vulcanization accelerators as well as thiourea as the pharmacologically active compounds, it can be said that application of the optimized methods of thiourea synthesis will provide significant improvement in sustainable development and implementation of eco-friendly production technology. The described environmentally benign process of thioureas synthesis represents a suitable option to existing methods. [ABSTRACT FROM AUTHOR]