Krzysztof Jarosza, Piotr Niesłonya and Piotr Löschnera
In this article, a novel approach to computer optimization of CNC toolpaths by adjustment of cutting speed vcand depth of cut apis presented. Available software works by the principle of adjusting feed rate on the basis of calculations and numerical simulation of the machining process. The authors wish to expand upon this approach by proposing toolpath optimization by altering two other basic process parameters. Intricacies and problems related totheadjustment of apand vcwere explained in the introductory part. Simulation of different variant of the same turning process with different parameter values were conducted to evaluate the effect of changes in depth of cut and cutting speed on process performance. Obtained results were investigated on the account of cutting force and tool life. The authors have found that depth of cut substantially affects cutting force, while the effect of cutting speed on it is minimal. An increase in both depth of cut and cutting speed affects tool life negatively, although the impact of cutting speed is much more severe. An increase in depth of cut allows for a more significant reduction of machining time, while affecting tool life less negatively. On the other hand, the adjustment of cutting speed helpsto reduce machining time without increasing cutting force component values and spindle load.
B.V. Shalyuta and E.V. Kostitskaya
The article presents the results of two-year studies on the influence of the method of sowing and the level of nitrogen application on the yield of seeds of Silphium perfoliatum L. − a new fodder crop for the conditions of Belarus. Silphium is precious for the nutritive value of green mass. According to the literature sources, dry matter contains 16-28% of protein, more than 60% of nitrogen-free extractives, 13-23% of sugars, high content of mineral substances, a small amount of fiber, adequate calcium and phosphorus, carotene, vitamin C. Mineral composition of Silphium contains 17.6% of dry matter, including 152.3 mg·kg−1 of ash. Macro elements: calcium – 18.1, phosphorus − 2.55, manganese – 4.48, potassium – 24.03, sodium – 0.40, sulphur – 0.40 mg· kg−1 of mg· kg−1 of dry matter. The mass of 1000 seeds was from 23.7 to 25.5 g. The seed germination was good and varied from 75% to 84%. It has been established that the best way to sow the Silphium is planting seedlings according to the 70x30 scheme. This option ensured the yield of seeds of 3.6 and 3.7 c/ha. The applying of increased doses of nitrogen fertilizers N90 and N120 and sowing seeds ensured the yield of seeds ranging from 3,6 to 3,9 c·ha−1.
Krzysztof Lejman, Zygmunt Owsiak, Krzysztof Pieczarka and Tomasz Sekutowski
The objective of the paper was to determine the impact of the shearing speed and cultivator tines flexibility on the vertical forces value. The study was carried out in field conditions in sandy clay soil and the average moisture of 11.2%. The vertical forces acting on four “s” tines with flexibility of 0.0061; 0.0711; 0.0953 and 0.1406 m∙kN−1 were measured. Tines were ended with a cultivator point with the curvature radius of 0.17 m. Measurements were made for four shearing speeds (1.0; 1.7; 2.4 and 3.0 m·s−1) and the shearing depth of 11 cm. A stand for measurement of forces acting on soil shearing farm tools in field conditions was used. It was concluded that the shearing speed caused a linear increase of the vertical force but the growth gradient does not depend on the tines flexibility. It was also concluded that the increase in flexibility causes an initial increase and then decrease of the vertical force, which was described with the second degree parabola equation. Flexibilities, at which extremes of courses occur, grow along with the reduction of the shearing speed.
Marcin Niemiec and Monika Komorowska
The aim of this study was to assess the possibility of using slow-release fertilizers under intensive vegetable cultivation. To achieve the set research objective, a field experiment was set up in 2017, where slow-release fertilizer (NPK (%) 20-10-10+4MgO) was applied. The experiment comprised three levels of fertilization with the use of slow-release fertilizers, the control without fertilization, and the control fertilized with conventional fertilizers. The slow-release fertilizer was applied directly under each plant and in rows – approximately 8 cm below the root level. The designed systems were evaluated based on the size of commercial yield, productivity index, agronomic efficiency index, removal efficiency index, and physiological efficiency index. The results obtained in the field experiment indicate that the highest plant yield (54.22 Mg of commercial yield∙ha−1) was obtained at the highest dose of slow-release fertilizers (600 kg∙ha−1 applied in rows approximately 8 cm below the root level). In the case of direct fertilization, in the treatment with the highest dose of slow-release fertilizer, a reduction in yield was observed. The best results, in terms of equalizing the mass of individual roots, were obtained under conventional fertilization. The most favorable value of the productivity index was obtained in the variant where 400 kg∙ha−1 slow-release fertilizer was applied directly, while in the case of row application the best results were obtained at the dose of 600 kg∙ha−1. Celeriac fertilization with slow-release fertilizers under root may result in producing a yield of bigger differences in root mass, compared to conventional fertilization system.
Arkadiusz Matysiak, Agnieszka Wójtowicz and Tomasz Oniszczuk
The aim of the research was to determine the effect of extrusion conditions (various moisture content of raw materials and screw rotation speed), as well as the effect of recipe composition on the process efficiency and the energy consumption during treatment of potato and multigrain products. The efficiency of the extrusion process (Q) was determined by the mass of the product obtained at a given time for all prepared raw material mixtures and the process parameters used, while the specific mechanical energy demand was determined using the SME index. The obtained results allow to conclude that the level of raw materials moisture content had a greater impact on the efficiency and energy consumption of the extrusion process than the variable screw speed during the treatment. The efficiency of the process increased with the increasing moisture of the tested compositions, while a decrease in the requirements of SME was observed. The use of differentiated raw material compositions also influenced the Q and SME values determined during the tests.
Elijah Oladimeji Aina, Alex Folami Adisa, Tajudeen Mukaila Adeniyi Olayanju and Salami Olasunkanmi ismaila
The thick vesicant oil liquid contained in the shell of cashew nut, called cashew nut shell liquid (CNSL), has been known for its innumerable applications in chemical industries. Performance evaluation of a newly developed CNSL expeller was carried out to determine the effect of moisture content and pressing duration on extraction parameters. The nut shells were grouped as A: 14.00-16.99%, B: 17.00-19.99% and C: 20.00-22.99% (w.b.) moisture content at 2, 4, 6, 8 and 10 minutes pressing time and combination of 1, 2, 3, 4 and 5 kg of cashew nut shells. Analysis of variance (ANOVA) was used for the stastical analysis. The best mass of liquid extracted, best extraction efficiency and best percentage oil recovery occured at pressing duration of 10 minutes and moisture content of 14.00-16.99% (w.b.), while the best machine capacity was at pressing duration of 2 minutes and moisture content of 14.00-16.99% (w.b.). Results showed that the effects of the pressing duration and moisture content on mass of liquid extracted, machine capacity, extraction efficiency and percentage liquid recovery were significant at 0.05. Meanwhile, the effects of the pressing duration and moisture contents were not significant for the feed rate. Increase in the pressing duration at decreasingthe moisture content resulted in the increase in the mass of liquid extracted, extraction efficiency and percentage liquid recovery while increase in pressing duration and moisture content resulted in decrease in machine capacity of the expeller.
Zygmunt Owsiak, Krzysztof Lejman, Krzysztof Pieczarka and Tomasz Sekutowski
The paper presents the outcomes of the research on the impact of shearing depth and flexibility of cultivator tines with cultivator points on the value of vertical forces acting thereon. The object of the research consisted in “S” tines with the flexibility coefficient of 0.0061; 0.0711; 0.0953 and 0.1406 m∙kN−1. The investigations were carried out in field conditions in sandy clay soil with moisture of 11.2%. The forces were measured for the assumed shearing depths which were 5, 9 and 13 cm at the shearing speed of 3 m∙s−1. A stand for measurement of forces acting on soil shearing tools in the field conditions was used. It was found out that the increase of the shearing depth causes a linear increase of the vertical force, but the force gradient decreases with the growth of the tine flexibility. Moreover, it was found out that the increase of the tine flexibility at the beginning causes the increase and then the decrease of the vertical force regardless the shearing depth. The impact of flexibility on the vertical force value was described with the parabola equation. The tines flexibility, at which the highest value of vertical force may be expected, grows with the reduction of the shearing depth.
The paper presents the results of analysis concerning the impact of temperature on sedimentation in the caustic soda solution that constitute a contamination after the process of cleaning utensils and pipes for hopped wort transport in the brewery. The solution was collected from the production plant after the process of cleaning and subjected to 12-hour sedimentation and changes of the solid particles participation, their size and percentage share in the solution was determined. The study was carried out with the Shadow Sizing method. The results were subjected to statistical analysis and the surface area of the response of the relation between the time and temperature of sedimentation and the number of particles which stay in the solution was calculated. The research results proved that the temperature significantly affects the cleaning degree of solutions by sedimentation and its duration. After sedimentation in solutions, particles with the surface area from 0.001-0.003 mm2 remain. Those particles are not subject to sedimentation and constitute a coloidal suspension in the solution.