INFLUENCE OF DEFORMATION CONDITIONS ON THE RHEOLOGICAL PROPERTIES OF 6xxx SERIES Al ALLOY

Knowledge of the characteristics describing the technological properties of the material is the basis for correct numerical simulation and the design of new technological processes or the modernization of existing ones. For each technological process of plastic forming, a set of features should be defined that correctly describe the susceptibility of the material to its shaping in a given process.The paper presents the results of rheological tests of 6xxx series Al alloy, obtained for deformation parameters corresponding to the process of the extrusion of large-size profiles. The effect of deformation conditions on changes in yield stress was determined. Next, the true values of the mathematical model coefficients describing the rheological properties of the tested material were determined using the inverse method, which is the basis for conducting numerical tests

The influence of herb addition to broilers` diet on production results and meat chemical composition

Celem doświadczenia była ocena wprowadzenia do mieszanki paszowej dla kurcząt brojlerów dodatku ziół, w celu poprawy wyników produkcyjnych osiąganych przez ptaki oraz składu chemicznego mięsa. Badaniem objęto 144 dwutygodniowe kurczęta brojlery, podzielone na 2 grupy (po 72 osobniki w każdej)- 1.- żywiona standardową mieszanką pełnoporcjową oraz 2.- otrzymująca tę samą mieszankę wzbogaconą w 2.5% dodatek ziół. W czasie eksperymentu kontrolowano ilość paszy spożytej przez ptaki oraz określono masę ciała kurcząt na początku i na końcu doświadczenia. Uzyskane dane posłużyły do określenia stopnia wykorzystania paszy (FCR) i Europejskiego Wskaźnika Wydajności (EWW). Ostatniego dnia eksperymentu z każdej grupy wybrano po 30 ptaków, pozbawiono je dostępu do paszy, ubito i wypatroszono. Po schłodzeniu tuszek pobrano próby mięśnia piersiowego i oznaczono skład chemiczny mięsa. Otrzymane rezultaty poddano analizie statystycznej przy użyciu programu SAS. Odnotowano wpływ dodatku ziół do mieszanki pełnoporcjowej na FCR, który był mniejszy o 12.5% u ptaków żywionych dawką wzbogaconą w zioła, w porównaniu z kurczętami otrzymującymi mieszankę bez dodatku ziół. Nie wykazano natomiast wpływu dodatku ziół na skład chemiczny mięsa.The evaluation of herbs introduction to broiler chickens diet was this experiment`s purpose, to improve production effects gained by the poultry and the chemical composition of the final product. The investigation took on 144 twoweek-old broiler chicks, divided into 2 groups, 72 in each. First group was fed full portioned commercial feed without the herbal mix (the control group) and the second (the experimental group) received feed mix enriched by 2.5% dried herb mix. During the experiment the amount of feed consumed by the birds was registered and the body mass of the chickens was determined at the beginning and at the end of the experiment. Thus, obtained information served to determine FCR and EEI. On the last day of the study from each of the groups, were selected 30 birds, they were not fed for 12 hours, then slaughtered and gutted. Obtained carcasses were sectioned. On the sampled breast muscle portions, a chemical composition of the meat has been performed. The results were statistically analyzed. The effect of the herb’s addition on the FCR was noted. The FCR was 12.5% lower in birds fed the herb enriched diet in comparing with the birds fed without the herbs added. The influence of the differentiated diet on the chemical composition of the meat was not noted however

Ground vibrations caused by wind power plant work as environmental pollution - case study

The paper presents issues related to the impact of wind farms on the environment. Emphasis was placed on vibrations that are transferred to the ground through the foundations. As research has shown - a case study - vibrations are felt up to about 1000 m from wind farms. According to other literature sources, this may affect living organisms in the ground

Mathematical Model for Determining the Time of Preventive Replacements in the Agricultural Machinery Service System with Minimal Repair

In this paper, a semi-Markov model for determining the optimal time for preventive replacements according to the age of technical objects is presented. In the analyzed system of transportation, due to its specific characteristics, the basic type of renewal process carried out is minimal repair. Minimal repairs of technical objects in semi-Markov models have been analyzed in the literature to date. In the system studied, the technical objects (sets of agricultural tractors with trailers), due to the continuous operation of combine harvesters, should carry out the assigned tasks of transporting agricultural crops without interruption. The damage to agricultural tractors that arises during the implementation of transport tasks should be repaired in the shortest possible time. The repairs to damaged tractors are carried out primarily by the Technical Emergency Service and, due to their purpose and scope, may be considered minimal repairs. The effectiveness of the function of the tested technical objects is analyzed by two criteria functions, which are very important for the system managers. These are profit per unit of time and availability. In the analyzed case, it is the availability to carry out the assigned transport tasks. The conditions for the existence of a maximum of criterion functions have been written for the assumptions. The analyzes carried out, which are presented in the work, are illustrated with sample calculations. It has been proven that, under general assumptions, the criterion functions considered in the paper have exactly one maximum. On the basis of the conducted analysis, sufficient conditions for the existence of a maximum of these functions were formulated. In the analyzed transport system, it is possible to increase the efficiency of the function of the technical facilities in use as a result of planning additional preventive replacements (increasing the frequency of these replacements). This is especially important for a system where transport units must have high availability

How to Harvest Haylage Bales in Sustainable Agriculture

Storing silage in round bales (balage) is a commonly used method for preserving forage for use as stock fodder that has a higher nutritional content than hay. Baling at the optimum density is important for ensuring ideal fermentation conditions. In the manuscript, we present the research methodology and the results of the experiment. We did experiments over the density of haylage bales. We investigated the effect of the moisture content in the harvested material, the length of the cut material and the pressing pressure in the round baler. We used the Barenbrug BG-5 forage mix at different moisture content levels (69, 63, 56, 49, and 42%), that was either unchopped or chopped by the round baler’s cutter bars (312 and 183 mm length) and baled at three different pressing pressures (0.9, 1.4, and 1.8 MPa). The results showed that forage density in the bales reached the highest value at a moisture content of 56% and a pressing pressure of 1.8 MPa, with the forage chopped by the cutter bars

Methods for diagnosing defects in glued joints - a methods review

The paper presents the applications of glued joints in many industry branches. The advantages and disadvantages of glued joints as well as the methods of detecting weld damage are presented. The methods of damage analysis to the glued joints were divided and explained. The most important detection techniques are the X-ray method, the ultrasonic method, the Laser Ultrasound method, the guided wave method, the electromechanical impedance method and the active thermography method. The advantages and limitations that may allow for the proper selection of the research method depending on the diagnosed material and the conditions accompanying the study were indicated

The method of assessment and formation the availability of the subsystem ensuring fitness for means of transport

In systems of means of transport operation in order to achieve appropriate completion of assigned transportation tasks it is necessary to maintain a required number of means of transport in the state of availability for carrying out of transportation task (roadworthy and stocked). In general, the processes of rendering vehicles roadworthy are connected to supplying them with fuel and operational materials, carrying out services and repairs, condition diagnostics. In the analyzed system of transport means operation, the processes are carried out in serviceability assurance subsystem SAS. In complex operation systems, the processes of rendering technical objects roadworthy are carried out at specifically designed technical infrastructure posts. The possibility of carrying out the assigned service and repair tasks depends on the availability and the number of such posts. The article presents the method of defining the operational availability and the number of technical infrastructure posts required for appropriate functioning of assigned service and repair task. Then typical calculation results are presented in charts prepared on the basis of data obtained from tests at existing transport means operation system

Semi-Markov Model of the System of Repairs and Preventive Replacements by Age of City Buses

The paper presents a mathematical model of the system of repairs and preventive replacements by age of city buses. The mathematical model was developed using the theory of semi-Markov processes. In the model developed, four types of city bus renewal processes are considered and three types of corrective repairs and preventive replacement. Corrective repairs are considered in two types: minimal repairs (repairs carried out by the Technical Service units) and perfect repairs (repairs carried out at the stations of the Service Station). The models of restoration systems that use semi-Markov processes in which minimal repairs, perfect repairs, and preventive replacements by age, have been examined in the literature to a limited extent. The system under consideration is analysed from the point of view of two criteria: profit per time unit and availability of city buses to carry out the assigned transport tasks. Conditions of criterion functions’ extremum (maximum) existence were formulated for the adopted assumptions. The considerations presented in the paper are illustrated by exemplary results of calculations