2020, Vol. 18, Special Issue 1

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/6026

Sirvi

Nüüd näidatakse 1 - 20 39

The advanced application of the wood-originated wastewater sludge
(2020) Brovkina, J.; Shulga, G.; Ozolins, J.; Neiberte, B.; Verovkins, A.; Lakevics, V.
The wood hydrothermal treatment is one of the plywood production’s stages, which resulting in the production of wastewater containing such components as hemicelluloses, lignin and wood extractive substances (HLES). It is necessary to improve the wastewater treatment technology with the aim to enhance the yield of sludge from plywood wastewater for its effective and rational recycling. In the present study, the optimal coagulation conditions for the HLES removal have been found using the developed aluminium salt-based coagulant. The developed composite coagulant is characterized by lower doses, a wide range of the work pH values, the insensitivity against temperature changes and a higher coagulation efficacy compared with traditional aluminium salts. The proposed treatment technology generates many tons of woodoriginated sludge – a biomass coagulate. It was found that the formed coagulate produced in the process of wastewater treatment can increase the sorption ability of clay. The optimal content of the dry coagulate in a clay sorbent does not exceed 0.11%. The sorption capacity of the developed sorbent for water, rapeseed and silicone oil increases by 35%, 31% and 21%, respectively, relative to the unmodified clay sorbent. The sorption efficiency of heavy metals from water solutions is also increased by 10–12%. The thermal treatment of the modified clay sorbent at the high temperature leads to an increase in its sorption capacity for oil products.
Airflow profile study of a compost dairy barn using a low-cost 3D-printed anemometer network
(2020) Vega, F.A.O.; Rios, A.P.M.; Damasceno, F.A.; Saraz, J.A.O.; Nascimento, J.A.C.
Mechanical ventilation is commonly used for environmental thermal regulation inside closed-field agricultural production systems. Analyzing the air distribution inside these facilities and the correct operation of the fans can be a challenging. This could be determined using cost prohibitive techniques as particle image velocimetry or deploying large wind sensors networks on-site. To avoid this limitation without a lack of measurement accuracy, this research was focused on developing and test a low-cost anemometer network based in low cost propeller’s anemometers, built using fused 3D-printed and open-hardware platforms. Four propeller anemometers with three to six blades were simulated using the 6-DOF method of ANSYS computer fluid dynamics software. Similar results were obtained for all the simulated models with minor differences. Anemometers were tested in an open circuit wind tunnel before to be evaluated in two open compost dairy barn building using high-volume low-speed and low-volume high-speed fans. Data were analyzed by employing contour maps, descriptive statistics and correlation. The results show that the anemometer network determines the fan’s wind profile for wind speeds over 0.7 m s-1 and it was possible to determine the facilities spots with ventilation problems. The proposed anemometer network and methodology are a good alternative to analyze the operating conditions of the tested agricultural facilities and optimize its performance.
Characterization of materials used in the manufacture of ceramic tile with incorporation of ornamental rock waste
(2020) Luiz, N.F.; Cecchin, D.; Azevedo, A.R.G.; Alexandre, J.; Marvila, M.T.; Silva, F.C.; Paes, A.L.C.; Pinheiro, V.D.; Carmo, D.F.; Ferraz, P.F.P.; Hüther, C.M.; Cruz, V.M.F.; Barbari, M.
The production of ceramic tiles, such as tiles, has a great environmental impact, either in the extraction of natural raw materials or gas emissions in the burning stages. The use of industrial solid waste in ceramic materials can contribute to the reduction of these impacts, according to the characteristics of solid waste and its interaction with ceramic materials in the processing steps. Thus, this study aimed to characterize the materials needed to make a ceramic tile with incorporation of ornamental rock waste (ORW), thus evaluating its main characteristics regarding the feasibility of this incorporation. The physical characterization of the clays used in the production of ceramic artifacts was performed, and for the waste the mineralogical analyzes were performed, through x-ray diffraction (XRD), microstructure analysis from confocal optical microscopy, after sintering the prototypes and chemical analysis by X-ray spectroscopy (EDX). Soon after the raw materials went through the step of conformation and preparation of the prismatic specimens by the process of extrusion of the ceramic mass, with an incorporation of the ORW in 0% and 15% of the ceramic mass, for its subsequent The prototypes were sintered at three different temperatures (850 °C, 950 °C and 1,050 °C). The specimens were submitted to technological tests of mechanical resistance, water absorption, firing shrinkage and porosity to evaluate the incorporation viability. The results indicated the presence of quartz particles in all raw materials, and also that the clays of the study region are predominantly kaolinitic. The presence of these materials in the ceramic masses directly influences the micrographs, because they result in the formation of liquid phase, inert particles that can turn the site into a stress concentration point and when incorporated in the ORW the specimens met the technical specifications of the Brazilian standard for application on ceramic tiles. The results found in the technological tests carried out, that the incorporation of 15% of ornamental rock waste in both clays did not affect the tile properties, indicating the feasibility of incorporating this waste in civil construction, minimizing the impacts generated.
Chemical analyses of lignocellulosic materials residue for cement panels reinforcement
(2020) Ferraz, P.F.P.; Mendes, R.F.; Ferraz, G.A.S.; Rossi, G.; Conti, L.; Barbari, M.
The use of lignocellulosic material residue in cement composites is on the rise as sustainable building materials in most developing countries. Besides, this alternative is seen as a good option for new cement panels formulations for indoor applications. Thus, the current paper aims to evaluate de chemical properties of five potential lignocellulosic materials residues to be used for cement panels reinforcement: Eucalyptus, sugarcane bagasse, coconut fibre, coffee rusk, and banana pseudostem. The following physical properties of the lignocellulosic materials were evaluated: lignin, extractives, ash, and holocellulose. To evaluate the similarity of the chemical composition of the lignocellulosic materials, Hierarchical Cluster Analysis (HCA) was used identified by using Ward’s method of cluster analysis. These compositions were grouped by dendrograms in which the similarity of these data was qualified. It was observed that there were statistical differences among all types of lignocellulosic materials related to the chemical composition. Coconut showed the smallest amount of extractives, and sugar cane the most significant amount. Eucalyptus and coffee husk presented the most similar chemical composition. All of the evaluated materials could be used in fibre cement production for indoor applications.
The co-influence of noise and carbon dioxide on humans in the work and living environment
(2020) Traumann, A.; Urbane, V.; Ievinš, J.; Tint, P.
The aim of the paper is to investigate the co-influence of noise and carbon dioxide on people in different situations (inside/outside houses/classrooms) depending on the traffic intensity, the fuel used for heating in residential buildings etc.). All the measurements and the questionnaire have been carried out during the autumn of 2019 (at the mean temperature of 5–10 °C). Riga has a more intensive traffic compared to Tallinn and has greater problems of exceeding the permissible noise levels. The levels of carbon dioxide inside classrooms are also very high in Latvia (1,500–2,000 ppm). The concentration of carbon dioxide outside buildings is low in the forest areas (measured in the south of Estonia), being 340–350 ppm. In regional towns, it is 500 ppm (measured in autumn-winter near a busy street). The co-influence of noise and carbon dioxide on the residents has been investigated by using the Weinstein questionnaire. High carbon dioxide levels cause fatigue. Although it was not particularly pointed out by the residents questioned in a panel house with small apartments, the air was considered to be stuffy. The house is situated near a busy street, so the problems with noise are higher. ANOVA statistics has been used for the questionnaire (p < 0.001, α = 0.93). The decrease of noise and carbon dioxide levels help people stay healthy and the environmental impact from the investigation is emphasising the necessity and providing possibilities to decrease the concentration of CO2 in the ambient air.
Comparison between the thermal properties of cement composites using infrared thermal images
(2020) Ferraz, P.F.P.; Mendes, R.F.; Ferraz, G.A.S.; Damasceno, F.A.; Silva, I.M.A.; Vaz, L.E.V.S.B.; Mendes, L.M.; Cecchin, D.; Castro, J.O.
The use of agribusiness residual lignocellulosic fibres can be a good alternative in the development of lignocellulosic composites. The current work aimed to investigate the thermal performance of cement-based composites with lignocellulosic materials: Eucalyptus, sugarcane bagasse, coconut fibre in comparison with commercial gypsum board to be used as internal partitions of the building using infrared thermal images. Three repetitions for each kind of lignocellulosic material were made, and three commercial gypsum boards were used. In the production of the panels, the following parameters were applied: material and cement ratio, 1:2.75; water and cement ratio, 1:2.5; hydration water rate of 0.25; additive, 4% (based on cement mass). The calculations were performed for a nominal panel density of 1,200 kg m- ³. The thermal analysis was performed in a chamber composed of MDP (Medium-Density Particleboard) and with an internal layer of rock wool and the heat source (thermal resistance). For the superficial temperature measurement, a FLIR E75 camera was used to capture the infrared images. When the internal temperature of the chamber stabilized at 50 °C, an infrared thermal image was collected from each side of the composite. Thermal properties were analysed: thermal conductivity, resistivity, resistance, and transmittance. Based on the results, sugar cane cement composites were characterized by higher values of thermal conductivity. Related to thermal resistivity, thermal resistance, and thermal transmittance, only the coconut panel presented similar behaviour to the commercial gypsum board. Thus, cement composite using coconut can be a potential alternative that might solve energy and environmental concerns simultaneously.
Comparison of airflow homogeneity in Compost Dairy Barns with different ventilation systems using the CFD model
(2020) Fagundes, B.; Damasceno, F.A.; Andrade, R.R.; Saraz, J.A.O.; Barbari, M.; Vega, F.A.O.; Nascimento, J.A.C.
In the pursuit of high milk productivity, producers are using confinement systems in order to improve performance and animal welfare. Among the housing systems, the Compost bedded-pack barns (CBP) stand out. In these barns a bedding area is provided inside, where cows move freely. Generally this area is covered with carbon source material (such as sawdust or fine dry wood shavings) which together with manure, thanks a regular mechanically stirring, ensures the aerobic composting process. The ventilation in these facilities has the function of dehumidifying the air, improving the air quality, drying the bedding, improving the thermal comfort conditions of the confined animals. This work aimed at validating a computational model using Computational Fluid Dynamics (CFD) to determine the best homogeneity of airflows generated by different forced ventilation systems used in CBP barns. Two CBP barns were compared with different ventilation systems: high volume low speed (HVLS) and low volume high-speed (LVHS) fans. The results showed that the proposed model was satisfactory to predict the flows generated by both types of fans. It was concluded that the use of HVLS fans produced a more homogeneous airflow when compared to LVHS fans. The use of mechanical ventilation in tropical conditions is necessary for the proper functioning of the system. In this study, the systems used promoted the increase in air speed to levels close to adequate.
Comparison of phosphorus removal efficiency of conventional activated sludge system and sequencing batch reactors in a wastewater treatment plant
(2020) Denisova, V.; Tihomirova, K.; Neilands, J.; Gruskevica, K.; Mezule, L.; Juhna, T.
The aim of this study was to evaluate the effectiveness application of sequencing batch reactors (SBRs) for phosphorus removal compared to the conventional activated sludge (CAS) treatment system. The results showed that the removal efficiency of phosphorus reached about 99% at wastewater treatment plant with CAS system. At the same time, the maximum phosphorus removal efficiency can be achieved to 88% if the SBRs system operating parameters are optimized. Finally, this study demonstrated that even if granules are not fully developed, the SBR system is working with a good efficiency.
A control method for increasing the heat usage efficiency of nearly-zero-energy buildings with heat pumps
(2020) Pihlap, Heino; Annuk, Andres; Lehtonen, M.; Muiste, Siim; Tooming, Allan; Allik, Alo; Estonian University of Life Sciences. Institute of Technology. Chair of Energy Application Engineering
In the retrofitting of older buildings with central heating into nearly zero-energy buildings more and more air to water heat pumps are used. These heat pumps are normally connected to heating systems, producing heat only on demand. The greatest demand for heat occurs when the outside temperature and therefore the COP of the pump is lowest. Outside temperature varies during the day, meaning it is possible to save energy by producing and storing heat in a situation where the COP is higher. To determine the periods with higher COP values weather forecast data and COP curves are used. The data enables to rank and select time periods for heat production. This in conjunction with the heat demand curve of the building enables to create an operation schedule for the heat pump. The aim of the study is to develop heat pump control methods for renovated buildings to comply with nearly zero energy building codes. Dependant on the heat pump and weather conditions, up to 10 % of the electricity demand for heating can be decreased.
Design and data comparison of the photovoltaic power plants in the southern and northern hemispheres
(2020) Daneček, M.; Havrlík, M.; Beránek, V.; Šafránková, J.; Libra, M.; Poulek, V.; Sedláček, J.; Belza, R.
We have recently developed a unique monitoring system for photovoltaic power plants and have gradually improved it in recent years. The system is installed at about 80 power plants in several European countries and at one power plant in Chile. We collect and evaluate all data in our laboratory. In this paper we describe the unique design of a photovoltaic power plant in the southern hemisphere in Chile with photovoltaic panels installed on tracking stands. We present the evaluated data and we discuss their comparison with photovoltaic power plants installed in Europe. We also discuss different solar conditions of these locations.
Development of hemp hurd particleboards from formaldehyde-free resins
(2020) Alao, P.; Tobias, M.; Kallakas, H.; Poltimäe, T.; Kers, J.; Goljandin, D.
Low density of hemp hurd (Cannabis Sativa L), better end of life impact, performance comparable to wood chips and low energy requirement for cultivation make it a suitable alternative raw material for particleboards (Pb). However, due to concerns about sustainability and formaldehyde emissions, it is essential to develop the new bio-based resins from renewable resources. In this research, the mechanical and physical properties of Pb produced from hemp hurds (HH) and a variety of resins: Urea-formaldehyde (UF), formaldehyde-free acrylic resin (Acrodur®) and bio-based soy resin (Soyad™) were compared to those of wood particles (WP) bonded with UF. The results indicate that boards from HH are generally lighter than WP with a 5.6% variation between HH+UF and WP+UF. Hemp boards based on soy-resin showed higher tensile performance, with an average of 0.43 MPa compared to the 0.28 MPa and 0.24 MPa of (HH+UF) and (WP+UF) respectively. Nevertheless, thickness swelling (TS) of HH+UF (27%) was the least, while there was no significant difference in the water absorption (WA) compared to HH+Soyad4740, both were still lower than that of WP+UF. The overall outcome shows that bio-based soy resin can be a suitable alternative to UF as a binder in Pb production.
Effect of concentrate feeding technology on nutrient digestibility in Latvian Dark-Head lambs
(2020) Šenfelde, L.; Kairiša, D.; Bārzdiņa, D.
Research has been conducted to evaluate the effect of concentrate feeding technology on nutrient digestibility in Latvian Dark-Head lambs. Twenty-four purebred Latvian Dark-Head lambs (rams) were divided into three study groups (four lambs in each group). Concentrate was offered with different feeding technologies: group 1 – ad libitum once per day (ADL); group 2 – five times per day (5TD); group 3 – three times per day (3TD). Lamb live weight at the start of research was 24.6 kg (ADL), 24.1 kg (5TD) and 25.6 kg (3TD), the average age – 83 ± 1.4 days (ADL; p < 0.05), 75 ± 1.4 days (5TD) and 75 ± 1.6 days (3TD). Research data were collected over three periods and two repetitions during lamb fattening in July, August and September, 2019. During the data collection period lambs were transferred to cages with slatted wooden floor and a container with a grid under it. The highest concentrate intake in all data collection periods was found in ADL lambs (1.25 ± 0.106 kg – 1.75 ± 0.092 kg on average per lamb). Hay intake was not equal (90–350 g in average per lamb).The highest average faecal production was found in 3TD and 5TD lambs (F – 0.98 ± 0.102 kg (3TD), S – 1.13 ± 0.060 kg (5TD) and T – 0.99 ± 0.070 kg (5TD)).The least urinal production was found in 3TD lambs (0.24 ± 0.038 kg (F), 0.61 ± 0.078 kg (S) and 0.47 ± 0.033 kg (T)). Dry matter digestibility was 66.54–80.39%. Faecal consistency was soft for ADL and 5TD lambs and solid for 3TD lambs.
The experimental investigation of the mechanical properties of steel fibre-reinforced concrete according to different testing standards
(2020) Ryabchikov, Alexander; Kiviste, Mihkel; Udras, Sten-Maikel; Lindpere, Mart; Vassiljev, Anatoli; Korb, Nikolai; Estonian University of Life Sciences. Institute of Forestry and Rural Engineering. Chair of Rural Building and Water Management
Steel fibre-reinforced concrete (SFRC) is widely applied in the construction of civil infrastructure projects, including the following: industrial floors, slabs, walls, and foundations. The application of steel fibres in the reinforcement of concrete remarkably improves the postcracking behaviour of such concrete. In order to estimate this property, the energy involved in absorption is measured by using several valid testing standards: EVS-EN 14651:2005, EVS-EN 14488-5:2006, and ASTM C1550-12a. The objective of this study was to carry out a comparable analysis of the results that have been obtained using previously-mentioned standards and to be able to find a more reliable method for the determination of the fracture toughness of SFRC specimens. Experiments were carried out in accordance with the chosen standards. It was concluded that procedure involved in the ASTM standard provides a smaller variability of results with better levels of repeatability, therefore a smaller volume of specimens can be tested in one series in order to achieve reliable results.
Features of the influence of copper nanoparticles and copper oxide on the formation of barley crop
(2020) Seregina, T.; Chernikova, O.; Mazhaysky, Yu.; Ampleeva, L.
In addition to modern methods of agricultural technology, currently the achievements of selection and genetics are widely used, as well as modern nanotechnology and nanomaterials, to improve food production. One of the forms of biologically active nanomaterials is metal nanopowders and their derivatives. The application is carried out in minimal doses that can significantly reduce costs in agricultural production. Improving the yield and quality of crops by optimizing nutrition and plant protection using nanotechnology and nanomaterials will solve not only the problems of increasing the yield and quality of farmed products, but also environmental problems. The purpose of this research was to determine the effect of copper and copper oxide nanoparticles on the formation of a barley crop. Under the conditions of a lysimetric experiment, the effect of presowing treatment of spring barley seeds by nanoparticles of copper and copper oxide on the growth and development of plants, yield, and their nutritional value was studied. The used nanoparticles have the following characteristics: Cu - 40–60 nm, phase composition: Cu - 100%; CuO - 40–60 nm, phase composition: CuO - 100%. A suspension of nanoparticles was obtained by dispersion by ultrasound in an aqueous solution. Nanopowders of copper and copper oxide in the solution contained 0.01 g per hectare seed rate. Barley seeds were soaked 30 minutes before sowing in double distilled water (control variant), as well as in a suspension of nanoparticles. Presowing treatment of barley seeds by Cu nanoparticles contributed to the intensification of growth processes, as well as an increase in green mass. The use of copper nanoparticles contributed to an increase in grain yield by 17.3% compared with the control, while there was no decrease in nutritional value: metabolic energy, feed units, digested protein. Based on the research results, it is preferable to use copper nanoparticles in comparison with copper oxide nanoparticles to obtain a higher barley yield.
Hydrogen sulfide emissions from cattle manure: experimental study
(2020) Vtoryi, V.; Vtoryi, S.; Gordeev, V.
Animal waste products, manure, in particular, are the sources of gases harmful to human and animal health. Hydrogen sulfide (H2S), which is produced from the breakdown of organic matter in animal faeces, is one of them. Its concentration in the cow barn air should not exceed 5 mg m−3 . A special laboratory setup was designed and the level of hydrogen sulfide emissions from the cow manure was determined depending on the time and manure temperature and moisture content. The most intensive emission of hydrogen sulfide from manure was in the first 24 hours – the increment of H2S concentration was 0.168 mg m−3 per hour average. During the next 24 hours, it was 0.021 mg m−3 per hour. When the manure temperature increased, H2S concentration increased also; when the temperature manure decreased, H2S concentration decreased also. In 48 hours, the hydrogen sulfide concentration was 1.1 mg m−3 at the manure temperature of +3.0 °C. At the manure temperature of +23.4 °C and 21.3 °C, H2S concentration was 6.53 mg m−3 and 4.97 mg m−3 , respectively. The higher was the manure moisture content, the lower was the emission of hydrogen sulfide into the environment. After 24 hours under the manure moisture content of 88.5% and 92.5% and its temperature of 21 °С ± 0.3 °С, the difference in the hydrogen sulfide concentration was 1.18 times depending on the manure moisture content. The selected regression equations described the dependence of the hydrogen sulfide concentration on the considered factors. The determination coefficients and Student's criteria proved the reliability of the results obtained at the significance level P ≤ 0.05.
Investigation in fuel consumption of a hybrid and conventional vehicle
(2020) Šmigins, R.; Pīrs, V.; Berjoza, D.
During the last decade the introduction of more environmentally friendly technologies were raised more rapidly by the decline in the global fossil energy resources and the increased negative environmental impact of conventional vehicles. One of such technology is the hybrid, which is currently making the transition from conventional vehicle with internal combustion engine to an electric vehicle. At this time there exist a lot of offers of such vehicles from different manufacturers, but there do not exist many researches connected with real hybrid performance in different road cycles and conditions allowing evaluate its real economical performance. This research was realized with the aim to evaluate performance and fuel consumption of hybrid electric vehicle and its conventional internal combustion engine analogue in laboratory conditions. Tests were realized with two new Toyota Yaris vehicles in Alternative Fuels and Research Laboratory on chassis dynamometer MD-1750 using AVL KMA Mobile system. The results showed better adaptation of Toyota Yaris Hybrid to urban operation, demonstrating 21.3% lower fuel consumption than Toyota Yaris conventional gasoline vehicle, accordingly 7.29 and 8.84 L (100 km)-1.
Investigation of dual varying area flapping actuator of a robotic fish with energy recovery
(2020) Tipans, I.; Viba, J.; Irbe, M.; Vutukuru, S.K.
Autonomous under-water vehicles (AUV) performing a commanded task require to utilize on-board energy sources. At the time when on-board power source runs low during operation, the vehicle (AUV) is forced to abort the mission and to return to a charging station. The present work proposes the technique of an energy recovery from surrounding medium. This effect is studied for dual action actuator movement that obtains energy from fluid. It is realized that a flapping or vibrating actuator can be used for energy extraction phenomenon apart from the non-traditional propulsive technique. In the present work a simple dual flapping actuator that can switch between simple flat plate and perforated plate at extreme end positions (angles) by using an efficient mechatronic mechanism that would help in overcoming viscous forces of the operating medium is extensively studied. The main objective of the present article is to develop a new approach for energy gain and recharge power pack of on-board sources from the surrounding medium and to create a robotic fish that would work autonomously by using unconventional drive along with the possibility of energy restoration by using dual varying area type vibrating actuator. At the time of recharge, the robotic fish would project its tail (actuator) out of water and use surrounding medium (air) to scavenge the energy. All the equations describing the process are formed according to classical laws of mechanics. The mechatronic system is explained and the results obtained are discussed in detail for air as the operating fluid to scavenge energy.
Investigation of the anticorrosion performance of lignin coatings after crosslinking with triethyl phosphate and their adhesion to a polyurethane topcoat
(2020) Dastpak, A.; Wilson, B.P.; Lundström, M.
This study investigates the anticorrosion properties of sustainable organic coatings, which were prepared by dissolution of two different types of technical lignins - organosolv lignin (OL) and kraft lignin (KL) - in an organic solvent and applied onto iron-phosphated steel by airassisted spray coating. Influence of triethyl phosphate (TEP) as a crosslinking agent for lignin and its effect on the anticorrosion properties of coatings during 24 h of immersion in 3.5% NaCl were investigated. Results obtained from electrochemical impedance spectroscopy (EIS) of coated steels suggest that the initial protection performance (1 h immersion) of non-crosslinked OL is higher than that of KL. Nevertheless, KL coatings that contained TEP and were heat-treated at elevated temperature (180 °C) demonstrated the best overall anticorrosion performance. In contrast, a similar trend was not observed for OL coatings, which indicates that the structural properties of lignin may be a crucial factor in applicability of TEP as a crosslinking agent. In addition, a layer of polyurethane was applied on all the different types of lignin coatings prepared and their adhesion characteristics were studied by crosscut adhesion measurements (ISO 2409). These adhesion results revealed that neither KL-TEP nor OL-TEP coatings demonstrate proper adhesive characteristics with a polyurethane (PU) topcoat and consequently these coatings are not suitable for utilization as a primer coating for the PU topcoat studied.
Lighting and noise levels in compost dairy barns with natural and forced ventilation
(2020) Andrade, R.R.; Tinôco, I.F.F.; Damasceno, F.A.; Barbari, M.; Valente, D.A.; Vilela, M.O.; Souza, C.F.; Conti, L.; Rossi, G.
The housing system, called compost barn, is attracting the interest of several farmers. It allows dairy cows to remain in free movement inside a shed without any containment partitions like those used in freestall barns. In Brazil the compost barns with open sides are very common, but recently some closed barns with climatic control systems have been implemented. The objective of this work was to evaluate and compare lighting and noise levels in an open compost barn with natural ventilation and in a closed compost barn with a climate control system. The latter one is based on tunnel ventilation: inlet of air trough evaporative cellulose panels and exit through fans placed on the opposite wall. Through analysis of the collected data it was observed that the sound pressure recorded inside both analysed buildings did not exceed the ranges of noise discomfort recommended for the rearing of animals. However, the sound pressure amplitude inside the barn with climate control system was greater than in the open barn. The light intensity was significantly lower in the closed barn when compared to the open barn (84.96 and 1,413.58 lx, respectively). The artificial lighting system distributed throughout the closed barn was not sufficient to maintain brightness within the recommended range for lactating cows. In addition, it was found that in the closed building with forced ventilation, the highest brightness values are located near the exhaust fans.
Morpho-physiological effects of Stymjod foliar application on Dactylis glomerata L.
(2020) Sosnowski, J.; Jankowski, K.; Truba, M.; Novák, J.; Zdun, E.; Skrzyczyńska, J.
The aim of the experiment was to study the effects of foliar application of a growth regulator containing iodine nanoparticles, with the trade name of Stymjod, on morphometrics, photosynthetic activity and chlorophyll content of Dactylis glomerate L. The following parameters were determined: the weight of fresh and dry matter of plants, leaves and roots, the number of shoots and leaves, potential (FV/Fm) and effective (F/Fm’) quantum efficiency of photosystem, photochemical (qP) and non-photochemical (qN) quenching, as well as chlorophyll a and chlorophyll b content in leaf blades. The pot experiment was carried out in a breeding room. Stymjod was applied at 1.5%, 3% and 4.5% concentrations in the spray solution. It is a nanotechnology-based growth regulator, with easily assimilable forms of mineral and organic ingredients, favorably affecting plant ontogenesis. Plants were treated twice with a single dose of 50 mL of spray per pot. They were sprayed till they were completely covered with the liquid. Distilled water was used to spray control plants. The results were statistically processed using analysis of variance, while the significance of the differences between means was determined with Tukey's test with P = 0.05. In the experiment it was found that different concentrations of Stymjod in the spray resulted in different response of plants. The best morphological effects were obtained using the concentration of the product exceeding 3%. In the test conditions Stymjod applied to D. glomerata increased the efficiency of the photosynthetic apparatus and the content of chlorophyll pigments.

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