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Abstract

Air is supplied to a milking machine installation most usually in a constant manner by supply of a small amount of air to a milking chamber of a claw or periodically to a connection pipe of a liner, which enables milk outflow to a milking pipe and improves stabilization of vacuum and limits its fluctuations. On the market of milking machines there is a new solution in the form of mouthpiece vented liners - impulseair®, where air is supplied constantly by a calibrated nozzle in the head of a liner. The objective of the paper was to analyse and assess the selected parameters of milking determined in a milking machine with a claw with fixed volume of a milking chamber (250 cm3) with mouthpiece vented liners in comparison to other solutions used for air supply in milking machines. Measurements were carried out in laboratory conditions with milking to the upper milk pipeline, at variable mass intensities of liquid flow (within 0-8 kg·min−1), for three penetrations of artificial teats (46, 48, 62 mm), at three values of the system vacuum (46, 48 and 50 kPa). A significant impact of the manner of air supply to a milking machine and remaining independent variables of an experiment on the selected milking parameters was proved with the use of a statistical analysis. It was found that a milking unit with mouthpiece vented liners, although it reduces average vacuum of suction [pss], at the same time it limits fluctuations of underpressure in the dp cycle.

Abstract

Combustion and co-combustion of biomass from different sources is one of the most popular technologies applied in Poland. It allows management of numerous industrial, communal and agricultural waste. Organic waste constitutes one of the richest sources of cheap biomass solid fuels since they are very popular. The paper includes an assessment of practical use of biomass waste: hazelnut shell and pistachio nut shell. The impact of pyrolysis temperature (300, 450 and 550°C) of the investigated biomass on the quality of the obtained biochar was determined and the optimal temperature of this process was defined. The quality of the investigated biomass was analysed on account of its use for energy purposes. Numerous advantageous properties of the obtained materials were found out, for instance: low content of ash and a noticeable increase of the calorific value with an increase of the pyrolysis temperature.

Abstract

The paper presents methodology of measuring the values which characterize the thermal balance in a horticultural facility. Thermal transmittance through a plastic tunnel cover and the ratio of solar radiation energy conversion into heat were analysed in detail. The research was carried out in real time with closed ventilators, where no plants were cultivated during the tests. The utility surface area was 144 m2, the cover was 289 m2 and its volume was 508 m3. Basing on the standard relations, first of all, thermal transmittance through a cover was measured. The ratio was measured with the use of standard criteria equations. Then, a correlation equation, which makes its course dependent on the climate parameters (the wind speed and temperature difference between the interior of the facility and its surroundings), was found. Knowing the course of the ratio in the function of the climate parameters, the value of the ratio of solar radiation conversion into heat stored in the facility was measured. Both parameters (thermal transmittance and solar radiation conversion ratios) were calculated from the thermal balance equaition where the change of the energy stored inside the facility was compared to the heat losses through a cover (for thenual transmittance) and the profit (in case of solar radiation conversion). For the obtained values, using the non-linear estimation procedure (with quasi-Newtom method with maintenance of the correlation coefficient of 0.001) the change of both ratios in the function of easily measured parameters of climate inside and outside the facility was found out. In the investigated conditions, the average value of thermal transmittance through a cover was 5.32 W·m−2·K−1, and the solar radiation conversion into heat was 0.36. The values and their course from the climate parameters inside and outside the facility may be used for controlling the amount of supplied heat and location of ventilators.

Abstract

Design intents for an actuator of the suction pressure control system in an autonomous milking machine were presented. For determination of its dynamic properties step characteristic was taken. The considered object was described with transmittance and thermodynamic models. Models were identified and their parameters were adjusted. Computer simulation was carried out in MATLAB®-Simulink. Analysis of research results proved that the thermodynamic model allows more detailed reflection of dynamic characteristic of the real object. Its degree of imperfections is 0.99%. For the transmittance model a degree of imperfection with the value of 2.02% was obtained.

Abstract

The aim of the study was to determine the effect of reduced pressure on the osmotic dehydration of apples. Tests were performed under vacuum of 8 kPa, 67 kPa, 80 kPa and under the atmospheric pressure (100 kPa). The samples were dehydrated in a sucrose solution with a concentration of 30°Bx, 50°Bx and 70°Bx. It has been shown that the effect of low pressure application depends significantly to the concentration of the osmotic solution. It has been found that the overall weight change significantly depend on the concentration of the solution, and after 3 hours of dehydration at a pressure of 80 kPa at solutions of 30°Bx, 50°Bx and 70°Bx total weight loss increased by 65%, 12% and 25% respectively, when compared to samples dehydrated at atmospheric pressure. From the studied variants of reduced pressure, the pressure of 80 kPa seems to be the optimal one, as evidenced by the lowest values of weight gain to water loss ratios for apples dehydrated in solutions of 50°Bx and 70°Bx.

Abstract

The usefulness of raw material obtained from oak leaves, waste from paper mass and fragments of Miscanthus was verified with regard to pellet production. A batch of pellets produced therefrom was subjected to technological shear tests with the use of prototype equipment. Also pellets produced by well-known Polish producers were tested. The suggested method of technological shear enables obtaining credible results through standardization of tests conditions. Statistical processing of results proved that there are significant differences in the values of shear strength and unit shear work obtained for both group of pellets. An experimental batch of pellets has a lower density and thus lower shear strength which limits the scope of industrial application. The research which was carried out proved that there is a strong correlation between mechanical strength and density.

Abstract

In 2010 the experiment, which aim was to examine the sowing value of tansy phacelia seeds after eight and nine years of storage, was conducted in the laboratory of the Academy of Agrobusiness in Łomża. The experiment clearly demonstrates that the period of storage of tansy phacelia seeds has an essential impact on the changes of basic parameters of the sowing value. Vetrovska variety had the highest seed germinability among the other varieties of tansy phacelia which were stored for 8 years. At the same time this variety had the highest decrease in seed germinability after 9 years of storage. During the 9-year storage Natra variety showed the highest decrease in thousand seeds weight despite the highest value of this parameter among all the tested varieties immediately after yielding. The results; of the experiment allowed for the conclusion that the economic life: cycle of tansy phacelia seeds is 8 years.

Abstract

The paper presents the analysis of use of IT technologies by farmers. Data from a research survey carried out in 100 randomly selected farms in 2015 constituted research material. The research area covered farms located in Podlaskie Voivodeship on the area of two counties i.e. Wysokie Mazowieckie (50 questionnaires) and Zambrów County (50 questionnaires). The questionnaire is a research instrument. The research was to determine the level of use of specialist computer programs by farmers and their needs concerning acqui sition of information on innovations in agriculture. Due to the obtained results one may find out that a low number of farmers uses specialist computer programs in their farms. In Wysokie Mazowieckie County it is only 8% of respondents and in Zambrów County 14%. The main source of infonnation on innovations in agriculture is the Internet, professional agricultural press and television.

Abstract

The paper describes basic methodology assumptions related to construction of Bayesian networks. The paper aims at preparation of data for modeling to obtain fresh knowledge on economic and agricultural database and will constitute the first stage of research. Variables (economic and agricultural indicators) with discreet values were used for analysis with the use of two step grouping technique and previous non-typical data were explored. The research was carried out on the group of three hundred individual fanns from Malopolskie and Swiçtokrzyskie Voiovedship. The knowledge obtained from analyses will be used in practice in agricultural engineering in order to support agricultural activity.

Abstract

In order to accelerate the process of drying of grass mowed for hay and haylage there are numerous technological treatments: multiple tedding, raking in rolls and turning rolls, mechanical impact on green forage in the process of mowing by the use of presses and windrow scarifiers. Presently mechanical maceration of green forage with mowing is popular. Papilionaceous feed plants are subjected to windrow presses and graminacenous plants to beating working systems. Analysis of various devices for acceleration of the drying process of green forage proves that they are quite complex and expensive on account of considerable material consumption. In order to eliminate the faults in the Russian Scientific and Research Fodder Institute of Wiliams a completely different windrow scarifier for the rotary mower KR-2.4 M was developed. It has a simple structure and it serves for acceleration of field drying of mowed grass in loose rolls. The paper presents the results of the research on a mower with an experimental windrow scarifier