The paper aimed to show effect of period, when cows were kept in pens with a free-stall system, on lying time and other form of behaviour, including one circumstance: bedding material (sand) was not delivered during the investigation period. Two technological groups of dairy cows kept in the barn with a free-stall system were investigated. Each group of cows showed decreased lying time in the analysed period. The paper proposed a method of approach to analyse the research data. The results of analysis indicate that relationship between combined periods (doubled days) and lying time can be presented with a linear function with higher value of determination coefficient in comparison with single days. Doubling days in the constant measurement of lying time of cows translated into the possibility of describing a dependent variable (lying time of cows in the considered period) with a linear model which differs a considerably high value of the coefficient of determination in comparison to the option, which includes single days.
The objective of this work was to study the possibility of using existing models for determination of the minimum fluidization velocity during freezing fruits and vegetables by reverse fluidization. The frozen material was formed from French fries, brussels sprouts, broccoli florets, carrot in the form of a cube with sides of 1 cm and slices with dimensions of 3x3x0.5 cm. The values of minimum fluidization velocity were measured by means of anemometer. The results of the calculation from the four models of calculation of the minimum fluidization velocity were compared with the values obtained experimentally. The calculated values were affected by the average errors of 24% in case of a carrot cube to 224% in case of broccoli florets. There was no statistical difference between the results obtained between the tested models.
The objective of the paper was to analyse thermograms of the milk flow from quarters of cows' udders on account of initial separation of disturbing factors which influence the conditions of milk temperature measurement during a machine cow milking. Research was carried out in cowshed conditions with the use of a special milking device, equipped with thermistor temperature sensors mounted in milking cups and microprocessor recorder of measurement signals. Based on the analysis of thermograms obtained during the cowshed tests, the impact of the health conditions of lobes of cows' udders, individual physiology of milking by cows, milking phase, correctness of the sensor operation on the shaping of temperature in a milking cup of a mechanical milking machines were reported.
Critical velocity of transportation, basic dimensions (length, width and thickness) as well as the mass of parsnip seeds was determined. Based on the measurements which were carried out, a geometrical hydraulic diameter, proportion index, spherical index and unit mass were calculated. A test of seeds germination was carried out by checking out the effects every 12 hours and then appropriate value of the germination time index was assumed to each seed. The above features and indexes were compared with the use of t test for independent tests and the correlation analysis. It was stated that germinated and non-germinated seeds differ statistically significantly only on account of their thickness. Some improvement of the germination ability of the seed material may be obtained by separating lighter seeds therefrom. In the tested seed material, obtaining 65% of germination ability was related to losses of seeds, which correctly produce sprouts at the level of approx 27%.
The paper presents research results concerning the influence of ultrasound pre-treatment on the process of distillation of essence from caraway seeds. Tests were carried out in two variants. In the first one, whole seeds were subjected to distillation process, and in the second one ground seeds. An ultrasound processor (Sonic VC 750) with a head of 19 mm diameter operating with frequency 20 kHz was used for generating ultrasounds. The following parameters of initial sonification of seeds were applied: treatment time from 20 to 60 minutes, intensity of ultrasounds: 28 and 42 W•cm-2. It was found out that the initial ultrasound treatment of caraway considerably speeds up the rate of obtaining essence and increases the final efficiency of the process. Depending on the time and intensity of ultrasounds the increase of efficiency from 9 to 40% was reported. Moreover, a significant impact of seeds fragmentation on the kinetics of the distillation process was reported.
The paper presents the research results concerning the impact of the degree of crushing of dried herbs on the content of essential oils. Herbaceous waste from lemon balm, garden sage and camomile was used for the research. Raw material was divided into fractions with the use of a laboratory pneumatic separator LPS 200 MC. Dried herbs, which stayed at the sieve of meshes provided below, was selected for analysis: 100μm and 250μm. Determination of the content of essential oil in dried herbs was carried out according to the recommendations of a norm BN-88/8192-04. It was stated that the degree of crushing of herbs influences the content of essential oil. Higher values of essential oils were reported in a fraction of a lower degree of crushing. The obtained results prove that the obtained herb waste may be used for further processing into essential oils.
The aim of the research was optimization of the shape of the milk part of claw chamber using Computational Fluid Dynamics (CFD) software. The results of the liquid flows simulation in claw models of various shapes, in particular with different aspect ratios (height to diameter ratios) were presented. The velocity of the fluid and the interactions between different streams of liquid flowing out of the inlets were analyzed. Research was carried out at a flow of fluid from 0 to 10 kg•s-1, a vacuum of 38 to 50 kPa, simulating air injection into the model of the claw. It was found that the best conditions are for models with an aspect ratio of about 3. Computed liquid flow rate ranged from 0.05 to 1.2 m•s-1.
This paper elaborates upon the use of Computational Fluid Dynamics (CFD) tools in the engineering practice as an integral part of progress of the chemical engineering of smoke-drying taking into consideration the technical progress and smoke-drying methods. The use of tools connected to CDF modeling allowed collecting crucial information concerning the performed process of smoke-drying for the assortment geometrically shaped similarly to a piece of oval ham. A single truck chamber was a base construction for solutions of the suggested modification of the powering elements (nozzles) as well as for the computer model geometry of the construction of an empty chamber and a full chamber itself. Discretization has been made in the ANSYS Mechanical APDL 12.1 software and on this basis a model of the suggested solution for construction of power nozzles as well as nozzles spreading the smoke substance inside the smoking chamber has been prepared. On the basis of simulating models and received feedback we can unequivocally say, that more advantageous conditions of spreading the smoke substance in the smoking chamber had been found. The tests performed in the real conditions with the use of modified power nozzles in comparison to the classical arrangement confirm dependences obtained during simulation.
The objective of the study was reduction of PAHs compounds content in meat products subjected to industrial conditions of smoking in the chamber when changing the feed nozzle structure in a mixture of smoke. Smoked meat products of geometrical form of an oval taken from two primary smoke chambers of different structure of supply nozzles and nozzles diffusing the smoke mixture constituted material samples. Qualitative and quantitative analysis of PAHs was carried out with the use of liquid chromatography with a selective detector (HPLC-FLD-DAD). Research on the content and compounds of PAH group in meat products, smoked with the use of a modified feed nozzle compared to a traditional system of nozzles, indicate clearly on more favorable conditions for distribution of a mixture of smoke in the smoking chamber due to their reduced level.
The paper presents methodology and results of the measurement of the research on the process of cutting a beetroot Beta vulgaris L in laboratory conditions, where values of the maximum cutting force of beetroot tissues collected from specific layers (upper layer, central layer, lower layer) were analysed. Variable parameters in the experiment were: angle of knife sharpening (2.5°; 7.5°; 12.5° and 17.5°) and velocity of its relocation (0.83 mm•s-1, 1.66 mm•s-1, 2.49 mm•s-1, 4.15 mm•-1 and 10 mm•s-1). The obtained data were subject to mathematical analysis with the use of Excel and Statistica 6.0 software. Statistical analysis of results proved significant dependence of the value of the maximum cutting force on the changes of mechanical properties of tissues in relation to the place of collecting samples, angle of knife sharpening and its relocation. The highest value of force was obtained during cutting with a knife of the sharpening angle ɸ=17.5° and the lowest during the use of a knife with ɸ=2.5°. Along with the increase of the velocity of knife relocation, the cutting force decreased. The best quality of samples was obtained with the use of the velocity which was 2.49 mm•s-1 and 4.15 mm•s-1 with knives with a cutting angle 2.5° and 7.5°.
The paper presents the results of the studies on the unevenness of covering the sprayed objects with the use of one and double-stream nozzles. Tests were carried out in laboratory conditions with the use of sprayer carrier. In order to facilitate interpretation of the results of studies on unevenness of covering and showing the existing relations, authors used an index of mean degree of the sprayed objects, which is a relation of a total covering of particular sprayed objects with the amount of these objects. Despite the use of the same conditions of experiment for all researched sprayers the obtained results of mean covering and unevenness of covering were characterised with high differences for particular nozzles. Analysis of the research results did not show any direct relation between mean degree of coverage of the sprayed objects and a ratio unevenness of the coverage. Both in case of one and double-stream nozzles, for which the smallest and the biggest coverage was determined, were characterized with a similar ratio unevenness of coverage.
The paper presents research results concerning differences in basic separating features of batches of pea, which enable efficient separation of material fractions of high germination ability. It was found out that based on differences in such properties, such as: dimensions, mass and critical velocity of lifting seeds, this technological operation may not be sufficiently carried out. In order to solve a practical problem, an attempt was made to determine possible differences in external friction coefficients of seeds on bases made of; steel, gum and linen, polar and cotton-linen). It was determined that statistically significant differences for this feature occur only for steel. It was suggested that in practice for selection of pea seeds of high germination ability, a sailor's whipping should be used.
The objective of the paper was to obtain the impact of the velocity of measuring head on measuring values of basic differentiators of the profile analysis of texture (TPA) such as: hardness I and II, cohesiveness, adhesiveness, elasticity, chewability and gumminess as well as resilience. The investigated material was subject to double compression to 50% of original height at the following head speeds: 0.5; 0.83 1.0; 1.2; 1.5 (mm•s-1). Cubic samples of cream cheese of Italian type Capresi with the side length of 15 (mm) were analysed. The obtained test results proved that statistically significant differences (at α=0.05) were reported only in few cases between the results obtained for particular analysed levels of the measuring head speed. However, one may report clear trends of changes of TPA differentiators values with increase or decrease. The increase of hardness differentiators I and II may be reported with the increase of the measuring head speed (however without confirmation of statistically significant differences at α=0.05). A similar trend may be also reported for gumminess and chewability differentiator on account of the head speed from 1.0 to 1.5 (mm•s-1).
The paper presents results of the research on efficiency of removing the protein deposits by using foam cleaning technique. Eight surfaces used in the food industry (tiles, linoleum, antibacterial and traditional tiles and stainless steel) constituted the research object. Surfaces were contaminated by protein derived from milk and egg proteins and they were cleaned by foam technique at variable parameters of compressed air pressure and the contact time of the detergent with the tested surface. The results of the research confirmed that compressed air pressure of cleaning solutions has the highest influence on the protein deposits removal.
The paper presents results of the studies on the removal of protein impurities from the system components of transmission installation in an ultrasonic cleaner. Contamination was removed from the places susceptible to underwashing in Clean In Place systems, from elbows, flap and ball valves and tees. The aim of this study was to evaluate the effectiveness of the cleaning process in an ultrasonic cleaner depending on the power of ultrasound, a chemical (NaOH), temperature, and duration of the process. To evaluate the effectiveness of the method of cleaning Clean-Trace™ Surface Protein Plus visual tests were applied, which were based on the color reaction of copper and the protein complexes in the 5-point scale. Application of ultrasound and clean water does not completely remove protein contaminants from the cleaned surfaces. Application of chemical and high temperature improves the efficiency of the process. The fastest maximum cleaning efficiency was achieved in an ultrasonic cleaner at full load and 40°C of ultrasound.
The paper presents the research results concerning the impact of varietal properties of apples on the efficiency of pressing juice. The research was carried out on eight apple cultivars from the crop of 2011 and 2012 after three month storing in a cold store with a controlled atmosphere. Pressing was carried out in one cycle with the use of a laboratory bucket press. It was reported that varietal properties significantly influence the pressing efficiency. The highest efficiency was obtained in case of Idared cultivar and the lowest for Elise and Boiken variety. Moreover, it was proved that the content of essence, pH value of juice, dynamic viscosity and the juice thickness depend on the varietal properties of apples. The obtained juice was characterised with the content of essence exceeding Brix 10o, which indicated usefulness of all the investigated cultivars for production of cloudy juices.
Energy consumption demand, which is still growing along with civilization development facing depletion of traditional resources - mainly fossil fuels (coal, petroleum, natural gas) and accompanying increase of pollution of natural environment result in the increase of interest in the use of energy from renewable sources. The paper presents the significance of renewable energy sources in the energy balance of the country. Special attention was paid to basic sources of renewable energy in Poland, that is to biomass. Types of biomass were described and general energy and physico-chemical properties of basic plant materials obtained for energy purposes were provided. Possibilities of using biomass for production of electric energy and heat and the applied methods of its conversion into biofuels were discussed. Moreover, advantages and threats related to the use of plant biomass for energy purposes were emphasised.
The aim of this research was to determine how water content and water activity influence on the selected electrical honey parameters. Experimental data obtained for fifty samples of honey collected on the territory of Poland were used for research. These were nectar honeys, nectar-honeydew as well as honeydew honeys. Chemical and electrical parameters were determined for each sample: conductivity of 20 percentage water and honey solution, conductivity and impedance of liquid honey. Then, with the use of artificial neural networks multi-dimensional mathematical models, describing relationships between electrical and chemical properties were constructed. Based on these models, with the use of the knowledge of networks structure and values of synaptic weights, degree of the impact of particular input parameters on output parameters of the model were determined. The tests which were carried out proved that water activity and content influence impedance more than conductivity of liquid honey and solution.
The paper presents research results concerning the use of commercial software used for calculations in the fluid mechanics. With the use of numerical methods of CFD in the selected elements of pipe installations, pressure, speed and shear stress distribution on their walls were presented and analysed in the aspect of cleaning conditions in the CIP system. The tests which were carried out constitute part of the tests concerning conditions of cleaning installations of production installations financed from the research subsidy. The obtained research results have an interdisciplinary character whereas their interpretation with reference to the cleaning conditions confirms rightness of using the CFD method for forecasting and hygienic modelling of food industry devices.
The objective of the paper was to draw up a mathematical model of heat and mass exchange in air inside a big-size greenhouse, where a commodity cultivation of plants is carried out. During formulation of the model, inter alia, models described in literature and results of experimental research were used. A developed mathematical model was implemented to MATLAB/Simulink programme and simulations carried out with a computer model were used for carrying out graphical and statistical validation of a model. Analysis of simulation results allows statement of logical correctness of the developed model and makes possible to determined critical points of failure to adjust the model. Degree of simplification of the developed heat exchange model influences precision of the developed model. In order to use the developed model e.g. for control purposes, it requires to be more detailed.
The paper presents the analysis of possibilities of recovering and storing thermal energy from a cooling installation of the fluidization tunnel freezer and then its storing. A plate heat exchanger placed behind a section of compressors was used for heat recovery and the heated water that leaves the exchanger transferred heat through a pipe coil to the heat dispenser. The amount of heat possible to be recovered from cooling installation in relation to burdening of the cooling tunnel and the change of water temperature in a dispenser during the process was determined.
In the tests, which were carried out, results of measurements of surface thrusts of Awocado Fuerte cultivar in the radial compression test between flat panels at the constant load value including time factor were presented. The test was carried out with the use of Instron 5566 testing machine. On the bottom panel, under the compressed Awocado fruit a sensor of Tekscan system number 5076 was placed. It allowed a constant observation of contour lines of surface thrusts on the contact surface and determination of distribution of surface thrusts between Awocado with a bottom panel of the testing machine. Contour layers and distribution of the surface thrusts in different stages of creep test were determined. It was proved that the maximum and average values of the surface thrusts are subject to minimum changes during the whole test. Distribution of surface thrusts has a shape typical for contact issues in a spring scope of deformation, where maximum values are in the central zone of contact and have distribution similar to the even number curve. At the end of the test, distribution of thrusts on the contact surface of Awocado with a working element of the testing machine took place at the end of the test.
The aim of the study was scientific consideration of an alternative of using mechanization services by farms in comparison to the purchase of new or used technical equipment on the example of grains combine harvesters. Two typological groups of grain combine harvesters were created. In selected groups following makes and models responded to an average combine harvester: A – Bizon Z056; B – John Deere 1450 CWS. Border points balancing the price of service in working hours and surface designed to harvest were established. Investigations showed, that the purchase of a new combine harvester will be rational only in these farms, where minimum acreage of grains and technologically similar plants will achieve: group A – 128 ha; group B – 173 ha. If these services are unavailable, farms can afford purchase of the used equipment for an average price which does not exceed: PLN 89,530 for group A and PLN 17,6315 for group B.
The objective of the studies was to determine the influence of spray volume and a nozzle type on product deposition and distribution in apple tree canopies, as well as spray coverage on leaves obtained in different phenological growth stages. The spray volumes 250, 500 and 750 l∙ha-1 were applied with fine spray and coarse spray nozzles generating droplets of VMD around 150 µm and 400 µm respectively. A cross-flow sprayer Munckhof was used at driving velocity 5.0 km∙h-1 to apply fluorescent dye as a spray liquid. During flowering the greatest deposition was obtained at the spray volume 250 l∙ha-1 applied with the coarse spray nozzles. The spray volume 750 l∙ha-1 resulted in the best coverage in the tree centre. During development of fruit, deposition in the canopy centre was at a constant level irrespective of the spray volume and a droplet size. At the stage of fruit maturity the best coverage was observed for fine spray nozzles and spray volumes 500 and 750 l∙ha-1. The use of coarse spray nozzles resulted in coverage reduction by 50%.
The aim of the work was assessing the dependence between some physical properties of cereal grain and energy consumption. Grain of common wheat, spelt and triticale of 15% of moisture was ground using a cylinder mill. Relation between energy consumption and vitreousness, thousand kernel weight, test weight and ash content has been determined. Unit energy consumption depended on vitreousness, test weight and ash content in grain. Unit energy consumption increases with the increase of vitreousness and test weight, and decreases with grain ash content. Vitreousness influenced the consumption of energy more considerably than the test weight and grain ash content.