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Abstract

The paper analyzes the costs of production of wood sawdust briquettes, manufactured by the company Brykiet-Pol2, based in Goleszów in southern Poland. In addition, production technology, raw material supply and distribution of the finished product were analyzed. The costs of producing one ton of briquettes for the four assessed variants ranged from PLN 364.8 (option D) to PLN 648.7 (option A). The cost structure was dominated by the purchase of raw material and depreciation of the technological line. The most economically advantageous production variant was option C, currently implemented in the company (production costs: PLN 458.7·t−1), and the proposed option D, using two briquetting presses. The latter option increased production efficiency and reduced unit costs of briquette production in a three-shift system around the clock.

Abstract

The article presents an analysis of the energy, mechanical and chemical properties of pellets made of wood material. According to the manufacturer, wood pellets were made of hard wood shredded to fractions approx. 1 mm thick and up to 3-4 mm long, and of a waste source - sawdust. Measurements of the selected properties were carried out on pellets with a diameter of 6 and 8 mm. Mechanical durability, humidity, crumble rate, ash quantity, calorific value were determined, as well as macronutrient and heavy metals content. The calorific value of pellets, with moisture content from 7.48% to 6.76% and ash content from 0.31% to 0.55%, ranged from 17.71-19.18 MJ·kg−1, which testified to the beneficial energy use of the tested raw material. Based on the conducted research, it was found that the mechanical properties of pellets made of both sawdust and hard wood predispose them for use as boiler fuel. The tested materials met high quality standards for wood pellets used for non-industrial and industrial purposes.

Abstract

Field tests on the quality of shaking off redcurrant fruit Rosetta cultivar with a half-row trailer harvester “Marek” produced by Dom-Wid were carried out. The tests were performed at two average working speeds ῡ1 = 0.47 m·s−1; ῡ2 = 0.60 m·s−1 and two rotational speeds of a tractor n1 = 1500 rpm; n2 = 1900 rpm. The length and diameter of shoots of redcurrant, length of a bunch, number of fruits in a bunch and mass of fruit were measured. Weather conditions were presented: rain fall, air temperature and moisture. Analysis of results showed that the working speed and the rotational speed has a significant impact on the quality and amount of the yield. At the highest rotations, the harvesting quality of fruit by a harvester was the worst and was 77.15%.

Abstract

The research material was prune plums (Prunus domestica L.), subjected to osmotic pre-treatment, with variable process time parameters and osmotic solution concentration. Plums thus fixed were frozen and stored for 6 months. At even (monthly) intervals, the product was defrosted by the vacuum-steam method, using the s-p-p chamber, until the thermocouple indicated a temperature of 4ºC in the sample’s thermal center. In order to study the kinetics of phenomena occurring during the defrosting process, the chamber was equipped with a measuring system to enable measurement and recording of temperature changes in time in the geometric center of the sample, as well as the temperature on the sample surface. The conducted tests proved that the time of vacuum-steam defrosting of fruit depended on the amount of water contained in it. In plums dehydrated in 45-65% sucrose solutions, duration of the defrosting process was shortened already after three months of frozen storage. After 6 months of storage, defrosting of these fruits was twice as fast as that of control samples.

Abstract

Development of innovative technological solutions in animal production should be associated with reduction of greenhouse gases, ammonia emission, and with rational disposal of natural fertilizers. The presented solutions and concepts of biogas acquisition and its disposal as well as a disposal of digestate mass place a need to improve the technological process before the science. The main aim of the presented solutions for the use of methane fermentation of a natural fertiliser in agricultural conditions is their utilization and energy acquisition, in particular for households and farms. When considering the issue of methane fermentation, one should include all favourable fertilization, energy aspects and firstly, the ecological ones. During the methane fermentation, substrates are stabilized due to removal of a large amount of carbon. The only elements that are removed from the system are evolving gases: CH4, CO2 and H2S. During the discussed process, the entire nitrogen is preserved in the organic or ammonia form.

Abstract

A modern model of agriculture is based on three orders - organic, social and economic. An attempt was made in this paper to apply cluster analysis for assessment of economic and organic sustainability of organic farms. Factors that statistically influenced a decision on which farms should be recognised as sustainable were indicated. Analyses allow the following conclusion: 1) in organic farming, animal production including cattle breeding and rearing must be based on a high acreage of permanent grasslands; 2) neither the performed production processes nor the level of their automation rate or the level of organic balance do not decide on the production effectiveness, but factors of the surrounding including social factors.

Abstract

The aim of the experiment was to determine the impact of UV-C stimulation of tubers, immersion of potato sticks in water, and a frying fat type on the content of fat in dry mass of French fries. Tests were carried out on Innovator tubers which is one of the most often used cultivator in production of French fries by the European and Polish companies. Radiation of potato tubers with ultraviolet in band C were performed with the use of the original stand for stimulation of biological material with electro-magnetic radiation. A statistical analysis of the obtained results of tests indicates that stimulation of tubers and a type of frying fat had a statistically significant impact on the fat content in dry mass of French fries.

Abstract

The paper presents the impact of the initial processing, cultivar, and storage time on the physical and chemical quality of freeze-dried sweet pepper crisps. Sweet pepper after initial washing and crushing was subjected to further four combinations of the initial processing. The first combination included freezing, the second one blanching in 98°C and 2-minutes time, the third one -dehydration in 2% solution of ascorbic acid and the fourth one - dehydration in the 2% solution of sodium chlo-ride. Both types of dehydration were carried out in 70°C for 20 minutes with a 1:4 participation of raw material to osmotic solution. Blanched and dehydrated raw materials were subjected to freezing in -18°C for 24 hours. After the completed process of freezing, the samples were moved to a freezer-drier and were dried by sublimation in -18°C and the reduced pressure of 63 Pa. The research that was carried out proved that the microbiological quality of the obtained sweet pepper lyophilizes was significantly affected by the cultivar, treatment type and storage time. These factors significantly diversified the number of micro-organisms in sweet pepper crisps. No initial processing before sublimation drying caused a considerably average increase of the number of psychrophile and mesophilic bacteria in crisps from both sweet pepper cultivars. A considerable reduction of their total number took place during blanching and dehydration in the ascorbic acid solution and sodium chloride solution. Additionally, along with the storage time, reduction of the total number of psychrophilic, mesophilic bacteria, fungi and yeasts was reported.

Abstract

The paper presents the impact of the initial processing, cultivar, and storage time on the physico-chemical quality of freeze-dried crisps. Sweet pepper after initial washing and crushing was subjected to further four combinations of the initial processing. The first combination included freezing, the second one blanching in 98°C and 2-minutes time, the third one -dehydration in 2% solution of ascorbic acid and the fourth one -dehydration in 2% solution of sodium chloride. Both types of dehydration were carried out in 70°C for 20 minutes with a 1:4 participation of raw material to osmotic solution. Blanched and dehydrated raw materials were subjected to freezing in -18°C for 24 hours. After the completed process of freezing, the samples were moved to a freezer-drier and were dried by sublimation in -18°C and the reduced pressure of 63 Pa. Based on the research analyses a significant variability of physico-chemical properties of the obtained freeze-dried sweet pepper with regard to a cultivar, processing type and storage time were reported. Freeze-dried yellow sweet pepper was the most similar to the fresh raw material. It was dehydrated in the ascorbic acid solution. The storage time considerably influenced the reduction of the quality properties of sweet pepper crisps.

Abstract

The paper analyzes the efficiency of material and energy expenditure in 679 farms with agricultural production as the main source of income for the years 2013-2015. Six groups of farms were identified according to usable agricultural area (UAA). The aim of the work was to determine the impact of UAA of farms on their material and energy expenditure efficiency. It was found that the area of UAA determines the farms’ material and energy expenditure efficiency. It was observed that small farms with UAA of 5 to 10 ha are characterized by the highest material and energy expenditure efficiency. It was proven that the material and energy expenditure efficiency in “Small” farms with UAA (<= 5ha) and “Very large”, with UAA (> 50ha) differs significantly from the efficiency determined for other farm groups. Material and energy expenditures were used the least efficiently in the farms with the smallest UAA.