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PubMed | Kiev National University of Construction and Architecture, EC and Hasselt University
Type: | Journal: Journal of environmental radioactivity | Year: 2016

Bauxite residue, also known as red mud, can be used as an aggregate in concrete products. The study involves the radiological characterization of different types of concretes containing bauxite residue from Ukraine. The activity concentrations of radionuclides from the


Heuss-Assbichler S.,Ludwig Maximilians University of Munich | John M.,Ludwig Maximilians University of Munich | Klapper D.,Ludwig Maximilians University of Munich | Blass U.W.,Friedrich - Schiller University of Jena | Kochetov G.,Kiev National University of Construction and Architecture
Journal of Environmental Management | Year: 2016

Recently the focus of interest changed from merely purification of the waste water to recover heavy metals. With the slightly modified ferritization process presented here it is possible to decrease initial Cu2+ concentrations up to 10 g/l to values <0.3 mg/l. The recovery rates of copper of all experiments are in the rage of 99.98 to almost 100%. Copper can be precipitated as oxide or zero valent metal (almost) free of hydroxide. All precipitates are exclusively of nanoparticle size. The phase assemblage depends strongly on experimental conditions as e.g. reaction temperature, pH-value, initial concentration and ageing time and condition. Three different options were developed depending on the reaction conditions. Option 1.) copper incorporation into the ferrite structure ((Cu,Fe)Fe2O4) and/or precipitation as cuprite (Cu2O) and zero-valent copper, option 2.) copper incorporation into the ferrite structure and/or precipitation as cuprite and/or tenorite (CuO) and option 3.) copper precipitation as tenorite. Ferrite is formed by the oxidation of GR in alkaline solution without additional oxygen supply. The chemistry reaches from pure magnetite up to 45% copper ferrite component. First experiments with wastewater from electroplating industry confirm the results obtained from synthetic solutions. In all cases the volume of the precipitates is extremely low compared to typical wastewater treatment by hydroxide precipitation. Therefore, pollution and further dissipation of copper can be avoided using this simple and economic process. © 2016 Elsevier Ltd.


PubMed | Ludwig Maximilians University of Munich, Kiev National University of Construction and Architecture and Friedrich - Schiller University of Jena
Type: | Journal: Journal of environmental management | Year: 2016

Recently the focus of interest changed from merely purification of the waste water to recover heavy metals. With the slightly modified ferritization process presented here it is possible to decrease initial Cu(2+) concentrations up to 10g/l to values <0.3mg/l. The recovery rates of copper of all experiments are in the rage of 99.98 to almost 100%. Copper can be precipitated as oxide or zero valent metal (almost) free of hydroxide. All precipitates are exclusively of nanoparticle size. The phase assemblage depends strongly on experimental conditions as e.g. reaction temperature, pH-value, initial concentration and ageing time and condition. Three different options were developed depending on the reaction conditions. Option 1.) copper incorporation into the ferrite structure ((Cu,Fe)Fe2O4) and/or precipitation as cuprite (Cu2O) and zero-valent copper, option 2.) copper incorporation into the ferrite structure and/or precipitation as cuprite and/or tenorite (CuO) and option 3.) copper precipitation as tenorite. Ferrite is formed by the oxidation of GR in alkaline solution without additional oxygen supply. The chemistry reaches from pure magnetite up to 45% copper ferrite component. First experiments with wastewater from electroplating industry confirm the results obtained from synthetic solutions. In all cases the volume of the precipitates is extremely low compared to typical wastewater treatment by hydroxide precipitation. Therefore, pollution and further dissipation of copper can be avoided using this simple and economic process.


Krivenko P.V.,Kiev National University of Construction and Architecture | Guzii S.G.,Kiev National University of Construction and Architecture | Bodnarova L.,Brno University of Technology | Valek J.,Brno University of Technology | And 2 more authors.
Journal of Building Engineering | Year: 2016

The paper presents the results of investigations to determine the optimum thickness of intumescent aluminosilicate coating providing protection of concrete and reinforced concrete structures, in particular tunnels, in case of fire. It is shown that the developed intumescent aluminosilicate coating prevents heating of the surface structures of concrete and metal reinforcement of concrete to the limiting condition, i.e., to temperatures of 653 K and 773 K. The protective coating on the concrete surface, in thicknesses of 6 mm, can prevent concrete and reinforced concrete from brittle fracture and reinforcement from occurrence of plastic deformation for at least 2 h. The developed coatings were studied by heating the coated concrete surface using a spot fire (point source fire) for a period of 3 h, and temperatures beneath the coating and at a distance of 20 mm from the surface (embedded reinforcement) were measured. Measurements of pull-off adhesion of the coating were taken using an adhesion testing equipment before and after exposure of fire. Increasing the thickness of the protective coating reduces heating of the concrete in depth; the average temperature of the heating of the concrete at the depth of the metal reinforcement (20 mm) is 414.4 K, which is 1.9 times less than the limit of heating temperature of the metal fittings. The increase in thickness of the coating and time of fire exposure will result in even better heat insulating and fireproofing properties. Test results of the developed coating 6 mm in thickness suggested concluding that before exposure of fire type, its type of fracture – was А/В (concrete substrate/coating adhesion fracture) and its pull-off strength was 2.15 MPa. A mean value of adhesion (pull-off strength) of the developed coatings 12 and 18 mm in thickness was 1.55 MPa, type of fracture – В (cohesion fracture within the coating). After exposure of fire, not depending upon thickness of the coating, a mean value of adhesion (pull-off strength) was 0.85 MPa, type of fracture – В (cohesion fracture within the swollen porous coating). © 2016 Elsevier Ltd


Sergeychuk O.,Kiev national University of construction and architecture | Radomtsev D.,Kiev national University of construction and architecture
International Journal of Smart Home | Year: 2016

New standard CIE S 011/E:2003 "CIE standard general sky" was accepted in Ukraine in 2010. With its adoption the question of its appropriate usage with national documents became an important event. Feasible way of standard's utilization with Ukrainian daylighting standards and effects of its implementation are given in the paper. © 2016 SERSC.


On the basis of a semi-analytical finite element method, an effective approach has been developed for studying transient processes of dynamic deformation of three-dimensional heterogeneous bodies of revolution and prismatic bodies of complex shape and structure by the action of time-and space-varying pulsed stressing with allowance for the plastic properties of the material and time-varying contact interaction conditions. New types of finite elements have been created, on the basis of which computational relationships of the semi-analytical finite element method (SAFEM) for problems of dynamics have been constructed. Modified relationships of the Newmark method have been obtained, which have been formulated for the amplitude subsystems of SAFEM. Effective block iteration algorithms for the solution of large systems of nonlinear equations of SAFEM have been developed and realized. © 2013 Springer Science+Business Media New York.


Bazhenov V.A.,Kiev National University of Construction and Architecture | Pogorelova O.S.,Kiev National University of Construction and Architecture | Postnikova T.G.,Kiev National University of Construction and Architecture
Strength of Materials | Year: 2011

The relationship between the dynamic behavior of the nonlinear impact-vibratory system and variation of some parameters: damping factor, elastic modulus, surface of one of the colliding bodies, is analyzed. The double-impact subharmonic vibration mode of the system was revealed. © 2011 Springer Science+Business Media, Inc.


Bazhenov V.A.,Kiev National University of Construction and Architecture | Gulyar A.I.,Kiev National University of Construction and Architecture | Solodei I.I.,Kiev National University of Construction and Architecture
Strength of Materials | Year: 2014

Possibilities of the semi-analytical finite element method in the investigation of transient processes of the three-dimensional deformation of heterogeneous bodies of revolution and complex-shaped prismatic bodies by the action of pulsed stressing with allowance for contact interaction zones and nonlinear work of material are shown by calculations of real structures. © 2014 Springer Science+Business Media New York.


Bazhenov V.A.,Kiev National University of Construction and Architecture | Pogorelova O.S.,Kiev National University of Construction and Architecture | Postnikova T.G.,Kiev National University of Construction and Architecture
Strength of Materials | Year: 2014

The modification of the one-parameter numerical continuation method for studying the dynamics of vibroimpact systems subject to periodic external loads is proposed. The behavior of a vibroimpact double spring mass system with two degrees of freedom is analyzed in relation to the load intensity. Specific applications of the method are compared with the two impact simulation procedures: contact force on the basis of the Hertz quasistatic theory and boundary conditions using the coefficient of restitution based on the stereomechanical theory of impact. Numerical analysis results for dynamic system states with the two impact simulation procedures are presented. © 2014, Springer Science+Business Media New York.


Radomtsev D.,Kiev National University of Construction and Architecture | Sergeychuk O.,Kiev National University of Construction and Architecture
Proceedings - 9th International Conference on Future Generation Communication and Networking, FGCN 2015 | Year: 2015

With the acceptance of new standard CIE S 011/E:2003 "CIE standard general sky" in Ukraine the question of it's adoption to the national documents became an important event. Feasible way of implementation standard into Ukrainian daylighting calculations standards and methods of designing systems of room daylight is giving in the paper. © 2015 IEEE.

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