A current worldwide economy problem includes both the responsible management of the planet's non-renewable resources and the waste management. The benefits of using recyclable materials and recycling technologies with asphalt mixtures consist mainly of reducing fuel consumption and greenhouse gas emissions. It is well known that oil (from which bitumen is obtained) is a non-renewable resource, hence the its price increase. Therefore, at present, the world is looking for solutions that will lead to a better use of natural resources and to an economic integration of sub-products from various industries. This paper intends to raise awareness of the possibilities for asphalt mixtures recycling and of the recyclable materials that can be used as additives with benefits of each.
Ghindea Cristian Lucian, Răcănel Ionuţ Radu and Cruciat Radu Iuliu
Dynamic testing of bridges has as target to establish their response on pulse forces between the wheels and unevenness of road surface. Generally, during the tests, real time accelerations or deformations are to be measured and which through successive processing methods lead to other data as velocities, displacements, dynamic impact factor, but also the damping ratio. In order to validate the bridge response following testing, the measured data are compared both with allowable limits existing in standards and with the results obtained using analytical or numerical models.
In Romania, the dynamic testing of bridges is recommended by the current standards, only for important bridges, erected in complex or special solutions and also for large span bridges.
The aim of this paper is to outline the results obtained from the on-site measurements during dynamic testing of a viaduct placed on the motorway A1, sector Orăştie-Sibiu. The bridge superstructure is a composite one, continuous girder on 12 spans: 40+10×60+40 m, the substructure consisting in 11 piers with lamellar elevations and variable height in the range 8.50-24m.
In the paper a finite element model is also presented which was used for time-history analyses using an impulse type load. Finally, the results obtained on the site and using the numerical model are compared and discussed.
Edyta Bauer, Justyna Żychlińska-Buczek, Anna Karbowniczak and Hubert Latała
Dairy cows production plays a significant role in development of Podkarpackie Voivodeship. Progress in this production branch may depend on the dairy production support which is given after relevant types of actions are undertaken. The objective of the research was to determine changes in the level of welfare of production animals, evaluation of practice in dairy cows breeding in the province of Ropczyce and Sędziszów. Breeding documentation and control protocols of the Coordinated Veterinary Inspection Program were applied pursuant to the resolution (1) of the Minister of Agriculture and Rural Development of 28 June 2010 on minimal conditions of maintaining farm animal species. 10 production herds of dairy cows (n-240) and heifers (n=101) which produce ≥ 10200 kilo of milk per lactation were used to achieve this objective. Dairy production was observed during individual visits in farms. Surveys were carried out with farm employees with the use of properly prepared veterinary control protocols of the Coordinated Veterinary Inspection Program. Control results were obtained based on the respondents' opinion from controlling institutions, such as: The Agency for Restructuring and Modernization of Agriculture, Regional Veterinary Office and similar certified bodies.
The judicious pavement design is the key factor in achieving the longest service life and the lowest maintenance and rehabilitation costs. It is based on the consideration of the phenomena in which the pavement structures are subjected to exploitation and the limitation of their destructive effects.
The aim of this study is to verify the possibility of implementing in the flexible pavement structures design practice of another design criterion based on limiting the bituminous mixtures creep phenomenon and that to be called: The criterion of admissible octahedral shear stresses in the bituminous layers.
Estimation of octahedral shear stresses is done with a calculation model based on finite element method, and hereafter referred to as 2D ASFEM (2D Axi-Symmetric Finite Element Model). The paper presents the results obtained by modeling several specific calculation assumptions for the behaviour of flexible pavement structures in service.
The study underlines the fact that the Octahedral Shear Stresses Ratio (OSSR) can be an additional design criterion to be taken into account when designing flexible pavement structures alongside other established criteria.
A proposal of a mathematical method of modelling of the lemon shape with Bézier's curves was presented. Lisbon, Verna, Genoa lemon cultivars were selected for verification of the modelling method. The lemon contour, which is its meridian, was described with three smoothly combined Bézier's curves. Pictures taken in 10 locations changing every 36o were the basis for description of lemon contours. Bézier's curves, which approximate meridians located on the surface of lemons, are their 3D models. The presented method may be applied for mathematical modelling of the lemon shape.
Dariusz Błażejczak, Rafał Nowowiejski and Jan B. Dawidowski
The objective of the research was to determine the impact of the friction force between the cylinder wall and soil on the soil compaction resistance in relation to the sample height and diameter of the compaction plate. Samples with the diameter of (D) 100 mm and heights (H) of 30, 50 or 100 mm made of of soil material collected from subsoil of the selected plastic soils were used. The soil material wasidentified by the following properties: the granulation type, density of the solid phase, humus and calcium carbonate content, reaction, plastic and liquid limit. Properties of the samples were described with moisture, dry density of solid particles, porosity of aeration, plastic degree and saturation. The samples were loaded with plates of varied diameters (dA: 20; 30; 50; 70; 80; 90 and 98 mm) measuring at the same time forces on the main plate (FA) and the bottom one (FB) with the fixed diameter (dB=98 mm). The registered relationships between the forces FA and FB and plate sinkage (samples deformation) were used for determination of the impact of external friction forces (between the cylinder wall and soil) on the compression resistance of soils. It was found out that the participation of the friction force in relation to the height of samples and plate diameter varied from 0 to ca. 70%. It was proved that one may avoid the impact of the plate diameter dA on the measurement of force FA, when the relation dA/D, for samples with the heights of H30 and H50, is respectively within 0.5 ≤ dA/D < 0.8 and 0.5 ≤ dA/D < 0.7.
Jerzy Bieniek, Marek Mielnicki, Leszek Romański and Piotr Komarnicki
The paper presents analysis of the impact of irrigation dose on the winter wheat Bystra yield, which is recommended for cultivation in Poland. It is a low-growing high-yield wheat cultivar. A reel sprinkler equipped with a computer for control of parameters of its operation, which was supplied with pond water was used for irrigation. Test were carried out on five fields, where four irrigation doses were used: 15, 20, 25, 30 mm. A change of weather during research in May and June caused the need to irrigate a field four times. During research, the size of the irrigation dose was measured with rain gauges on each of the investigated fields in five measurement points. One of the fields was a control field, which was not irrigated. The investigated wheat was characterized during harvesting. Research proved that the size of the irrigation dose influences the wheat yield. The grain yield between a control field and a field with the highest irrigation dose increased by twofold. Moreover, analysis of costs incurred during sprinkling were analysed.
A comparative analysis of milk production in Poland and Belarus was carried out. The basic tendencies of modern development of the dairy industry and offered upcoming trends of innovative modernization of milk production processes were analyzed. On the basis of the analysis of trends in the global production of milk and new scientific knowledge on the biosynthesis of milk, a conceptual approach to the design of equipment for machine milking, is provided, considered the relationship of technical and physiological parameters.
Photovoltaic systems are very efficient concerning proper utilization of solar radiation. However, the nanotechnology solution can replace the photovoltaic by the use of new production technology to lower the price of solar cells to one tenth. Sun provides nearly unlimited energy resource, but existing solar energy harvesting technologies are quite expensive and cannot compete with fossil fuels. The central part of Poland, which represents about 50 percent of the area, gives solar radiation at the level of 1000 kWh·m−2/year. Other new developments, which can help improve existing efficiency of solar systems are: diatoms utilization, artificial photosynthesis, nanoleaves and rotation solar towers.
Silviu Alexandru Constantinescu and Ionuț Radu Răcănel
This paper presents a new type of seismic isolator that uses the principle of electromagnetic attraction and repulsion, to control the friction force between two electromagnets during earthquakes. The two electromagnets are used in conjunction with a secondary high friction dissipating and damping mechanism composed from a 10mm thick neoprene ring layer and two steel surfaces coated with Si3N4 that are used to dissipate the kinetic energy in the bridge deck at some maximum ground accelerations. The isolator utilizes tri-axial accelerometers embedded in the abutments, high current rechargeable batteries and an automated controlling unit. The presented isolator was developed specifically for a concrete bridge deck with a span of 36 meters and simple supported on two abutments, using time history electromagnetic and structural analyses. The paper presents the advantages of using this active seismic isolation system, compared to classical passive devices and the important results obtained in terms of decreasing internal forces on the substructure elements cross sections together with the reduction of relative displacements between the two electromagnets.