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The paper presents the use of a method called Equivalent Thermal Network used to formulate mathematical model suitable for SDHW system analyses. Composed algorithms make it possible to perform computer simulations either of weather conditions or system parameters and to determine their influence on the system thermal performance and thus can be used by solar system designers. Steady state analysis...
The paper presents the results of studies on spray nozzles, placed on a spray boom, hanging over a patternator. It was found out that when the location of particular nozzles is changed, the variation coefficient of distribution of the fall of the sprayed liquid (C.V.) changes as well. The change of C.V. is especially high for the nozzles which are technically worn out. The studies showed that while...
As a result of plant tissue deformation irreversible physical processes that finally lead to the state of resistance, take place. One of these irreversible processes is cracking of the cell structure that occurs through cell wall breaking and losing cohesion in the layer of pectin lamella. As a result of these phenomena a signal of acoustic emission is emitted. In the present study the method of acoustic...
The reconstitutional properties of mushroom fruitbodies dried convectionally and sublimatically were analysed. The fruitbodies of nameko (Pholiota nameko) and shiitake (Lentinus edodes) which differ in the structure, chemical composition and growth rate were examined. It was found that the most important influence on the rehydration rapidity (time of rehydration) was exterted by the method of drying...
The state of knowledge about eggplant and the methods of its storage is the subject of the paper. In the experimental part, the effect of freezing treatment on eggplant fruits was investigated and the range of its cryoscopic temperature was determined.
The qualitative and quantitative evaluation of the content of volatile aroma compounds in the fruit bodies of two species of edible mushrooms: oyster (Pleurotus ostreatus) and nameko (Pholiota nameko) was performed by gas chromatography coupled with mass spectrophotometry. Both examined species of fungi differed from each other in the amounts of the main volatile substances. The most important components...
The paper presents the results of studies on ultrasound processing of meat after slaughter on the changes of texture properties after freezing and thawing. The studies were carried out on M.semimembranosus of young slaughter cattle with a liveweight of 450-500 kg. The samples were processed with ultrasounds of the frequency of 25 kHz and intensity of 2 W/cm2. After slaughter they were chilled, frozen...
Differential Scanning Calorimetry Method (DSC) was used for determining the parameters of garlic freeze drying process. Garlic with moisture content ranging from 17 to 87% in temperatures from -28 to 5°C (245-278 K) was investigated. The transitions, including change of water into ice (crystallization) and condensed inter-crystalline solution into amorphous solid, were considered. The melting point...
The paper deals with measurement and classification of the size of the splashed drops of rain using a new formula of classification. According to the new idea a measuring instrument was constructed, in which fast comparators are used. This method of classification offers more exact measurement of the number of drops in every class of size. The older apparatus lost some of the splashed drops, so estimation...
Results of compression tests of various strain rates with measurements of the total counts sum of the acoustic emission for the samples of six selected potato varieties with various appropriations have been presented. It was shown that an increase in the strain rate cause a decrease in failure strain and an exponential increase in the total counts sum. No influence of the strain rate on the failure...
The method of Differential Scanning Calorimetry (DSC) was used for determination of the garlic specific heat. The measurements were carried out in the range of material moisture from 17 to 87% and in the temperatures from 283 to 333 K (10-60°C). The analysis of measurement results, aided with the methods of mathematical statistics, summarises the complex behaviour of the change in specific heat versus...
Nowadays the lupine varieties contain less alkaloid what makes it possible to use them as feed components in larger proportions. The purpose of this paper is to provide some new possibilities of improving lupine seed quality, by application of simple mechanical hulling method. The influence of hulling conditions on the quality of final product was analyzed. Some factors that affect the hulling process...
Wheat and wheat-rye doughs, including those modified with ingredients, were frozen at -30°C in air recording their temperature with a digital thermometer. After preliminary baking the following were determined: dough and bakery efficiency, crump mass density, bakery volume, baking, total baking loss and crust-crump ratio. The rheological assessment was made after TPA test, while organoleptic evaluation...
Linear viscoelasticity of the studied material was assumed in the range of strain up to 0.08 mm/mm. A general Maxwell model was suggested to describe the reaction of apple sample to loading. In stress relaxation experiment two kinds of samples that had been cut from the same fruit were axially compressed. One specimen was free to expand in radial direction, while the other one was constrained in a...
The paper presents results of estimating the technical state of spray nozzles placed on a spray boom hanging over a patternator. Results of laboratory tests were analyzed considering the criteria of estimation binding in Poland in reference to electronic and manual patternators. Theoretical considerations are used to determine the equivalence of those criteria.
The paper presents the method of quantitative and qualitative evaluation of spray application based on deposit and coverage measurements on artificial targets. This relatively simple and fast method is proposed for small scale comparative field experiments with air-assisted orchard sprayers. Biological efficacy, being very important for the grower, is not enough informative method of evaluation of...
Poultry is particularly vulnerable to heat stress conditions. Birds have no possibility to loose the heat by sweating, thus losses by convection and respiration remain the only mechanisms for taking the heat out of them. Whereas there is common consensus among scientists and growers on optimum ambient temperature range for well feathered 4-6 weeks old broilers, there are considerable differences in...
The purpose of the research was to compare uncontrolled air exchange at nurseries with different air inlet solution. Four identical 400 m2 nursery departments were investigated. Three of them used porous ceiling as an air inlet, with different area of ceiling designed to be permeable. The areas of porous ceiling tested were 300, 150 and 75 m2 respectively. In fourth department ventilation air entered...
A directed air-jet sprayer (SEPIA) was compared with a conventional radial flow sprayer (TERMIT) to determine possible control of spider mites (Tetranychus urticae Koch) and currant rust (Cronartium ribicola J. C. Fisher) on black currants when using spray volumes 260, 400 and 600 dm3 ha-1 and different dose rates of chemicals. The Cumulative Infestation Index (CII) for spider mite and percentage...
The work presents characteristics of determination and prediction of the freezing point of agricultural products and food with some analytical methods. Using 11 models and special software this property was computed including 299 freezing cases of differentiated products. To obtain that the authors experiments (52 products) were made. The data concerning other cases were drawn from literature. Model...
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