Leachate water from sanitary landfills represents one of the most complex global environmental problems. This paper examines the possibility of using aluminosilicate material, pyrophyllite, from the Parsovići deposit, as an adsorbent. It was researched the influence of two granulations of pyrophyllite (0-53 μm and 0-100 μm) on the degree of adsorption of heavy metals (Fe, Ni, Mn) from leachate water from the municipal landfill "Desetine", Tuzla. The adsorption experiment was performed using the Batch method, depending on the contact time between the adsorbent and the adsorbate, the mixing speed, and the mass of the adsorbent, pyrophyllite, through two treatments. The results indicate a higher efficiency of the finer fraction of pyrophyllite, and in the competition of the three examined metals, iron is completely removed in the first treatment with both granulations and then nickel with finer granulation and manganese with coarser. After the first treatment, the unpleasant smell was removed, which is certainly a consequence of the removal of ammonia compounds as the most abundant compounds in leachate water. In these pioneering researches, pyrophyllite proved to be effective, and at the same time, it is a cheap, easily available, and environmentally friendly material for leachate water purification.

The micro-roughness represents the basic structure of the roughness of the treated surfaces and they are mainly a consequence of the machining during the production. The microgeometry of treated surfaces has a significant impact on the contact conditions of surfaces, which is reflected in the quality of gluing, pressing, and surface treatment and assembly, ie the interchangeability of structural details of the product, and thus the product quality. The roughness of treated wood surfaces is almost impossible to reliably determine theoretically using analytical models, and the application of experimental analysis of the investigated influential parameters is essential to improve the treatment regime, while maintaining the cost and quality of treatment at a satisfactory level. The aim of this paper is to examine the significance of the influential parameters of roughness of the treated surface, ie wood density, feed rate and cutting depth when turning solid wood elements, and analysis of experimental data for achieving lower roughness of the treated surface, without compromising the quality and total production costs. The purpose of the experimental plan is to generate a mathematical model that describes the process.

This study aims to investigate the influence of thermal modification (TM) on the physical and mechanical properties of wood. For this purpose, the experimental part focused on selected influential parameters, namely temperature, residence time, and density, while the four-point bending strength is obtained as the output parameter. The obtained experimental data are stochastically modeled and compared with the model created by genetic programming (GP). The classical mathematical analysis obtained treatment parameters in relation to the maximum bending strength (T = 187 °C, t = 125 min = 0.780 g/cm3) and compared with the results obtained by genetic algorithm (GA) (T = 208 °C, t = 122 min, and = 0.728 g/cm3). It is possible to obtain models that describe experimental results well with stochastic modeling and evolutionary algorithms.

The paper presents the results of modeling the bending strength of wood. During the experimental examination and definition of the model, solid wood was taken, where the bending was performed perpendicular to the grain. The experiment was done with thirteen replications and the input values that varied at three levels were wood density and board thickness. The thirteen-repetition experiment also involved four repetitions in the marginal areas, so two more wood densities and two board thicknesses had to be taken. The experimental measurement was performed in the laboratory of the Technical Faculty Bihać. Based on the experimental results, a sufficiently adequate mathematical model of the breaking force of a solid wood panel perpendicular to the grain is obtained.

Paper presents the design of experiment and determining mathematical model to calculate roughness parameter of wood planned surface. For design of experiment three different types of solid wood were taken and processed on the planner with three different displacements and three different cutting speeds. After measuring the roughness parameter Rz, experimental results were obtained on the basis of which the central composite plan of the experiment was made. Based on that, a model of roughness parameter Rz was made, which is adequate and with high accuracy. The significance of the model coefficients was determined using the R software and the results were presented using the Design Expert software.

Abstract The paper presents the development of the mathematical model of joint parameters impact, during solid wood lengthening with a mini tooth, on the joint strength. Impact parameters are wood density (ρ), ratio of wood element width and thickness (b/h) and geometrical size of mini tooth expressed as ratio of length and distance between width of the tooth (l/p). This paper presents an example of how the process of joining solid wood can be optimized prior to the production process to avoid exploitation testing and increased costs of the process. Based on the obtained model (F), force optimization was performed as a function of the maximum tensile force. The results of the conducted research indicate that mathematical modelling and optimization can be successfully used to define the tensile break force and technological parameters of solid wood elements lengthened by finger joint.

Natural sources of energy are constantly renewed by natural means, which means that they simply can't be exhausted. Such sustainable energy sources are often called "alternative energy" because they are considered an alternative to traditional fossil fuels such as petroleum and coal. One of the special renewable energy sources is solar energy, wind energy, biomass, geothermal energy, and potential water energy, the potential energy of tides and tides and sea waves and thermal energy of the sea. When it's to exploitation alternative energy for wood drying, conventional, solar, and airborne energy is imposed here. In this paper, we will present the drying of wood in solar dryers and drying wood to air exposure as one of the alternative sources of energy. At the same time, we will briefly discuss getting acquainted with renewable energy sources, their potential purpose and the reasons for their use.

The development of technology has also been advanced in the wood industry. Private use of traditional carpentry stands as a „regalia” way of processing, industrial companies pay more attention to new technologies and increasingly use CNC machines. The production of machine tools has the task of producing more precisely, more precisely and more economical than manual processing, but it is an important task to replace human labor. Adding programming units that manage machine tools have become even more economical, more precisely with simpler human work. In this paper new CNC technology will be presented. At the same time, the operating principle and configuration of the vertical processing center BHX 055 and the software we need for drilling will be explained. It will also be noted what are the advantages of CNC technology over conventional machines.

ABSTRACT This paper presented the quality of the treated surface, which is most often followed by roughness representing micro-geometric irregularities of the treated surface. The processing influence parameters behaviour of on the roughness of the treated wood surface was considered, where the results of measurements of the average deviation of the roughness profile of the surface of beech and maple wood from the area of Bosnia and Herzegovina after processing with orthogonal cutting on a four-sided shaper was studied, at different feed speed and cutting depth . The mathematical model of the influence parameters on the treated surface roughness of solid wood was also presented. The paper presented a sample example of how a process can be predicted before it goes into production, avoiding exploitation testing and increased costs of the process itself.

In this paper, for the research of the models of genetically programed pressing forces, experimentally given values of pressing forces of axial symmetric stratified wood were used, given by the procedure of bending and simultaneous sticking while being warmed up by high frequency electricity. Namely, during the experiment the pressing forces were measured as output values, with variable parameters which determine the conditions of the experiment that are defined by independent varying input process variables. Those are: contact pressure, tangent voltage and strains determined by the thickness of the workpiece. For research purposes, special tools were made by using necessary measurement devices, and for the production of the models a software package for genetic programing called GPdotNET was used. This program was developed for modeling and optimization by using genetic programing. Based on the results given by the GP model, the coefficient of multiple regression was calculated thus implying that the GP model exquisitely describes the interpretation process.