Analysis of the efficiency of a hybrid foil tunnel heating system

The paper analyzes the efficiency of the hybrid system used to heat the foil tunnel. The tested system was built on the basis of heat gain in a cascade manner. The first step is to heat the water in the storage tank using the solar collectors. The second stage is the use of a heat pump (HP) in order to heat the diaphragm exchangers. The lower HP heat source is a cascade first stage buffer. In the storage tank, diaphragm exchangers used for solar collectors and heat pumps are installed. The research was carried out at a research station located in the University of Agriculture in Cracow. The aim was to perform an analysis of the efficiency of a hybrid system for the heating of a foil tunnel in the months from May to September. The efficiency of the entire hybrid system was calculated as the relation of the effect obtained in reference to the electrical power used to drive the heat pump components (compressor drive, circulation pump), circulation pumps and fans installed in the diaphragm heaters. The resulting effect was the amount of heat supplied to the interior of the object as a result of the internal air being forced through the diaphragm exchangers

Analysis of the efficiency of a hybrid foil tunnel heating system

The paper analyzes the efficiency of the hybrid system used to heat the foil tunnel. The tested system was built on the basis of heat gain in a cascade manner. The first step is to heat the water in the storage tank using the solar collectors. The second stage is the use of a heat pump (HP) in order to heat the diaphragm exchangers. The lower HP heat source is a cascade first stage buffer. In the storage tank, diaphragm exchangers used for solar collectors and heat pumps are installed. The research was carried out at a research station located in the University of Agriculture in Cracow. The aim was to perform an analysis of the efficiency of a hybrid system for the heating of a foil tunnel in the months from May to September. The efficiency of the entire hybrid system was calculated as the relation of the effect obtained in reference to the electrical power used to drive the heat pump components (compressor drive, circulation pump), circulation pumps and fans installed in the diaphragm heaters. The resulting effect was the amount of heat supplied to the interior of the object as a result of the internal air being forced through the diaphragm exchangers

The Influence of Artificial Lighting Systems on the Cultivation of Algae: The Example of Chlorella vulgaris

Microalgae are a practical source of biological compounds for biodiesel production. This study examined the influence of three different light-emitting diode (LED) systems on the biomass production of green algae Chlorella vulgaris BA0002a. The cultivation was carried out in a photobioreactor illuminated from the bottom with a single side light jacket (PBR I), in a photobioreactor illuminated from the bottom with a double side light jacket (PBR II) and in a photobioreactor illuminated only from the top (PBR III). Research has shown that the intensification of algae cell production and growth depends on the light distribution and exposure time of a single cell to radiation. In the experiment, the highest growth of algae cells was obtained in the photobioreactor with double jacket and lower light panel. The lowest cell growth was observed in the photobioreactor illuminated only from above. For cultures raised in the PBR I and PBR II photobioreactors, increased oxygen production was observed, which was directly related to the increased production of biomass, which in turn was dependent on the increased amount of radiant energy

Design Solution for a Device to Determine the Energy Consumption of Sawing Wood with Chain Saws

Cutting wood chips is one of the common work procedures in the course of processing wood with a saw chain. This paper presents the conceptual design of the device and the design of the device for determining the energy demand of such a process. The preparation is designed with the given parameters to achieve the most realistic conditions for sawing wood. It must contain the original cutting device from the STIHL MS 261 chainsaw. It consists of several calculations to determine the cutting moment and the loaded points of the preparation, which define the possible place of damage. In the conceptual design, calculations for cutting force Fr = 924 N and tensile force Fn = 290 N are processed in the work. From the calculated forces, it is possible to determine the resulting stress at the attachment or critical points. For comparison, a finite element method analysis was created in Creo Parametric. The results of the analysis confirm the appropriate selection of material and parameters for the application of the preparation to the test device. The resulting voltages, corresponding to a maximum value of 132 MPa, are negligible for this type of preparation in terms of safety and durability

The concept of a construction solution of a robot for harvesting strawberries

Strawberry fruit products are of high commercial and consumption value, while difficult to harvest due to their very low mechanical strength and difficulties in identifying them within the plants. Therefore, robots harvesting strawberries should connect four subsystems: vision of detection, delivery arm (manipulator), effector (harvesting head), and finally- a platform increasing the working space adapted to the size of the farm. The presented work of the conceptual working section of a combine for harvesting strawberry fruit from crops, carried out in rows or cultivation ridge, from cultivation on field and/ or under covers will meet the requirements for: work productivity, quality of harvested fruit, reduction of the amount of pollution. To requirements have been met, the developed concept of constructions adopted the principle of operation during the first phase of the harvesting (in the natural distribution of fruit within the plants of strawberries) and the working of the work arm head (based on image analysis, initially general, and in the last phase of detailed) maneuvering in surrounded by harvested fruit and machine

The use of artificial neural networks for determining values of selected strength parameters of Miscanthus Giganteus

The aim of this paper is to develop neural models enabling the determination of biomechanical parameters for giant miscanthus stems. The static three-point bending test is used to determine the bending strength parameters of the miscanthus stem. In this study, we assume the modulus of elasticity bending and maximum stress in bending as the dependent variables. As independent variables (inputs of the neural network) we assume water content, internode number, maximum bending force value and dimensions characterizing the cross-section of miscanthus stem: maximum and minimum stem diameter and stem wall thickness. The four developed neural models, enabling the determination of the value of the modulus of elasticity in bending and the maximum stress in bending, demonstrate sufficient and even very high accuracy. The neural networks have an average relative error of 2.18%, 2.21%, 3.24% and 0.18% for all data subsets, respectively. The results of the sensitivity analysis confirmed that all input variables are important for the accuracy of the developed neural models—correct semantic models

The influence of organic vanadium complexes on an antioxidant profile in adipose tissue in wistar rats

One of the aspects of biological activity of vanadium is its influence on carbohydrate metabolism. For more than 30 years, various vanadium complexes have been tested as antidiabetic agents. This study researched organic vanadium complexes with bipyridinium ligands and their influences on metabolic rate, as well as on the antioxidant activity of adipose tissue. The effects of sodium (2,2′-bipyridine) oxidobisperoxovanadate (V) octahydrate (known as the V complex), bis(2,2′-bipyridine) oxidovanadium (IV) sulfate dehydrate (known as the B complex), and bis(4.4′-dimethyl-2,2′-bipyridine) oxidovanadium (IV) sulfate dihydrate (labelled as the BM complex) were assessed. Solutions of the tested complexes were introduced intraperitoneally with a probe to animals fed with either a control diet or a high-fat diet. The BM complex had a significant influence on the increase in ferric reducing antioxidant power, as well as on the concentration of glutathione in the adipose tissue of rats fed with a high-fat diet. The V complex increased the concentration of glutathione in the adipose tissue of rats fed with control fodder, as well as significantly reduced the relative change in rat weight for the high-fat diet. Furthermore, the presence of each tested vanadium complex had an impact of statistically significant increase in basal metabolic rate, regardless of applied diet. Further research on these organic vanadium complexes is necessary to understand the mechanisms responsible for their ability to affect adipose tissue