2020, Vol. 18, Special Issue 1

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

Sirvi

Nüüd näidatakse 1 - 20 39

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.
Sustainability indicators in cooperative management of recyclable materials
(2020) Aramian, C.B.; Barcelos, F.; Silva, F.C.; Cecchin, D.; Azevedo, A.R.G.; Carmo, D.F.
Following the promulgation of the National Solid Waste Policy in 2010, legal provisions, government programs and sectoral agreements have been implemented, but without the expected efficiency in relation to recycling. It should be noted that Cooperatives of Recyclable Material Pickers (CRMP) should play a leading role in this regard, but they do not have adequate management to be economically, socially and environmentally sustainable, depending on assistance to maintain the activity. Aiming to elucidate this issue, in this paper was made an institutional diagnosis of the category of waste pickers using the Gramacho region in the city of Duque de Caxias (Rio de Janeiro) as a case study. It was carried out an evaluation of the historical context of the neighbourhood, and it was drawn up a semi-structured questionnaire in 12 of the 18 cooperatives in the region. The data were interpreted through a SWOT matrix and the Venn diagram. A matrix was proposed and elaborated with 15 sustainability indicators specific to the CRMC reality in order to evaluate and monitor the management of cooperatives. After collecting the primary data, it was possible to validate the matrix of indicators with indexes of cultural, economic, political and ecological sustainability of the cooperatives. It was found that the matrix of indicators facilitated the understanding of the data and the comparison between the indicators. This tool can help decision-making, creation of action plans and identification of demands by the cooperative waste pickers themselves, without the presence of an analyst or technician.
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.
Study of transhydrogenase systems features in the mutants of the yeast pachysolen tannophilus for the production of ethanol and xylitol from agricultural wastes
(2020) Bolotnikova, O.; Bazarnova, J.; Aronova, E.; Bolotnikova, T.
The key catabolic enzymes of D-xylose, an important structural component of different agricultural wastes, were studied in cells of mutant strains of the xylose-assimilating yeast Pachysolen tannophilus. The evaluation of catalytic activity and cofactor specificity of xylose reductase (ЕС 1.1.1.307) and xylitol dehydrogenase (ЕС 1.1.1.9) confirmed the dependence of intracellular catabolic pathway for D-xy lose on the NAD×H/NADP×H ratio, formed under microaerobic conditions. The study of total activity of some NAD+ /NAP×H-dependent dehydrogenases revealed the metabolic characteristics of the yeast cells, which could ensure selective ethanol or xylitol production. Thus, the efficient involvement of D-xylose into the Embden–Meyerhof–Parnas pathway provided not only the high activities of xylose reductase and xylitol dehydrogenase, but also of 1-glycerophosphate dehydrogenase (EC 1.1.1.8) and lactate dehydrogenase (ЕС 1.1.1.27), respectively. The inhibition of activity of these enzymes led to selective production of xylitol from D-xylose. On the base of the experimental results, the principles of metabolic engineering of xylose-assimilating yeasts were formulated. The possibility of bioethanol and xylitol production from different agricultural wastes using xyloseassimilating yeasts are discussed.
Utilization of fused deposition method 3D printing for evaluation of discrete element method simulations
(2020) Hnízdil, P.; Chotěborský, R.; Kuře, J.
FDM 3D printing is used for designing prototype assessment in engineering production. It is usually used to verify the functionality of kinematics mechanisms. It can also be used for innovation in agricultural production, eg. the development of new mechanisms for agriculture tools. Such a mechanism as well as the entire components is printed using FDM and they are made of plastics. This whole can be experimentally verified in a laboratory trough. The article deals with the verification of the possibilities of using FDM technology for the design of agricultural tools. The material properties, namely stress-strain, of the plastics after printing are entered into the Ansys mechanical library, and the DEM results are also imported into Ansys mechanical. Material properties of plastics for FDM technology such as PLA, PETG show that its mechanical properties limited their using for validation.
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.
Non-Invasive measurer for methane and carbone dioxide emissions in bovine cattle through TRIZ
(2020) Silva-Martínez, K.L.; Cruz-Rivero, L.; Arrieta-González, A.; Purroy-Vasquez, R.
Greenhouse gases (GHG), mainly methane (CH4) and carbon dioxide (CO2), can be generated in agricultural activities, not only in waste but also in the process of breathing of livestock. The Theory of Inventive Problem Solving (TRIZ) is an innovative Russian methodology that allows finding the solution to a problem raised. This paper presents the use of two TRIZ tools to design a non-invasive prototype that detects CH4 and CO2 emitted by cattle in real time. The tools were the matrix of technical contradictions and the nine-screen analysis with which the parameter to be improved (A) was found and the best possible solution to design a prototype that allows quantifying gases for animal welfare, Final Ideal Result (IFR) a wireless module with a sensor system for each of the gases placed on the bovine head, which convert the detected gas into an electrical signal to be sent wirelessly to a range of 1.5 km in free space at a receiver for its visualization representing the parts per million (ppm) of CH4 and CO2 that the bovine is generating during the measurement.
Variable velocity system for evaluating effects of air velocity on Japanese quail
(2020) Vilela, M.O.; Gates, R.S.; Zolnier, S.; Barbari, M.; Teles Junior, C.G.S.; Andrade, R.R.; Rocha, K.S.O.; Tinôco, I.F.F.; Souza, C.F.; Conti, L.; Rossi, G.
This study documents the design and performance of a system to apply different magnitudes of air velocity to Japanese quail, to evaluate the combined effects of velocity, temperature and humidity on bird behaviour, performance and welfare. The system was developed to simulate observed field conditions ocurring in regions with high winds where quail are raised in curtain-sided housing. System performance consisted of characterizing air velocity distribution in cages downstream of the air velocity which was directed at the front of the cages. The system consisted of two fans attached to a 25 cm PVC tube, one at each end, with the outlet airflow directed through a continuous slot over the cage front at the feeder. The design and performance of this experimental system was evaluated, with six such systems were built and utilized in research trials. To assess system performance, air velocity was measured at 275 points per cage uniformly arranged along the three dimensions (length, width and height) in eight cages with zero, 1, 2 or 3 m s-1 nominal velocity setpoints. Spatial distribution of velocity was analysed by mapping and from descriptive statistics, with attention to the zone closest to the feeder where birds must go to eat. There was no significant difference (P > 0.05) found in mean paired difference of air speed data measured for pairs of front portion cages with similar velocities. A significant positive correlation was found (P < 0.001) between the measured air velocity at paired points in the cages subjected to the same velocity treatment. A comparison of measured mean air velocity to the nominal setpoint values used for experiments indicated that careful attention to outlet adjustment is important, especially at higher nominal velocity setpoint as 3 (± 0.10) m s-1 which was difficult to achieve with the system. An example of the use of the deployment of the variable velocity system in controlled environment chambers with Japanese quail is provided.
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.
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.
Theoretical study on motion of potato tuber on surface of separator
(2020) Bulgakov, V.; Nikolaenko, S.; Ruzhylo, Z.; Fedosiy, I.; Nowak, J.; Olt, Jüri; Estonian University of Life Sciences. Institute of Technology
The aim of the study was to determine the optimal design and kinematic parameters of the separator that cleans potatoes from impurities and has a design of the spiral type. The authors have devised a highly efficient design of the spiral type potato heap separator, in which the motion of the potato tubers takes place in the channel formed by two spiral members made in the form of cylindrical spiral springs. In order to substantiate the optimal kinematic and design parameters of the new spiral type potato heap separator, the authors have generated a mathematical model of the motion of a single potato tuber on the cleaning surface formed by two spirals. As a result of solving the obtained analytical expressions, the graphical relations between the parameters of the investigated process of the motion of a single potato tuber body situated between two adjacent spirals have been plotted, which has enabled selecting the optimal design and kinematic parameters of the spiral separator. It has been established in the completed investigation that the angular velocity of rotation of the cleaning rolls has to be within the range of 27 40 rad s -1 in order to ensure the efficient transportation and cleaning of the potato tuber with a diameter of 50 mm that moves on the surface of the spiral with a radius of 75 mm wound from the round bar with a diameter of 15 mm, in case the spirals are mounted with an eccentricity of 10 mm. By analysing the kinematics of motion of the potato tuber on the surface of the spiral type cleaning machine, in case the tuber contacts the spirals at two points, it has been established that the increase of the angular velocity of rotation of the spirals results in the respective growth of the transportation capacity of the cleaning tool, while the separating efficiency at the same time becomes reduced to some extent.
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.
Towards a business and production engineering concept for individual beer brewing applying digitalization methodologies
(2020) Schlechter, T.; Froschauer, R.; Bronowicka-Schlechter, A.
Individualization is a common trend in many fields of production across the industries. Also in the food sector, significant changes can be observed. For many products, individual offerings towards the customer are meanwhile either mandatory or at least help to increase the sales and revenue. Somehow, individual product design and production contradicts scaling effects, which are especially important for food production. On the other hand, as digitalization is implemented in a fairly limited way in the food sector, currently great chances can be observed to build a unique selling proposition and consequently gain market share by implementing appropriate measures to enable a digital food factory. This is where the proposed idea comes into the game. The starting point is the idea to produce individually developed beer and ship it to the individual customer. The beer can be designed on a web page based on typical parameters, like beer type, bitterness, colour, or alcohol concentration. In an expert mode, individual beer creations may be thoughtful, allowing the creation of completely individual recipes (for sure, not guaranteeing the customer a perfect drinking experience). In any way, the data from the web page is directly fed to the brewing equipment in the brewing facility. There, using newly to be developed specialized machines, the individually ordered beer will be produced automatically. In this paper we discuss the individual challenges at each point in the production cycles and propose solutions to those.
Psychosocial risks analysis for employees in public administration
(2020) Pastare, D.; Roja, Z.; Kalkis, H.; Roja, I.
Nowadays psychosocial risks at work have a serious impact not only on the health of employees, but also on the economic performance of organisations, and this is the biggest challenge in working environment. In Latvia, employees in public administration comprise 11% of the total population. Hence the aim of this study was to analyse the causes of psychosocial risks and the differences in their prevalence among inspectorate officials employed in the State Administration compared to office staff employed by the State Administration. A modified Copenhagen Psychosocial Questionnaire from the Danish National Research Centre for the Working Environment was used to assess psychosocial risks at work. One public administration organisation was selected for the study, which involved 111 staff (60 inspecting officers and 51 office staff). The analysis of the results of the psychosocial risk assessment shows that there are statistically significant differences in the assessment of four out of 11 psychosocial risks to the working environment. The most common psychosocial work environment risk factor among inspectors is the inadequate attitude of management, but the most common risk factor among office employees is the lack of impact on work. To reduce the spread of psychosocial risks more effectively, an individual approach is required for each worker.
Tensile properties of wood plastic composites based on plant-filled polyvinyl chloride/poly(3-hydroxybutyrate-co-3- hydroxyhexanoate) matrices
(2020) Samuilova, E.O.; Podshivalov, A.V.; Fokina, M.I.; Chursina, V.S.; Strelnikova, I.E.; Uspenskaya, M.V.
The article considers the obtaining and studying of microcomposites based on polyvinyl chloride (PVC)/poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) polymer matrix, filled with a various faction of different natural plant fillers. In work, such plant fillers as wood flour without lignin, spruce flour and rice husk were used. Microcomposites were obtained by melt rolling processing method with subsequent analysis of their morphology and mechanical tensile properties. It is shown that the filler particles were strongly oriented in the direction of the melt rolling process and have a different aspect ratio depending on the filler type. The tensile strength of materials strongly depends on the particle’s aspect ratio. When the aspect ratio of the particles is 4.25, the material has a strength value comparable to a pure PVC/PHBHHx matrix.
Separation of reducing sugars from lignocellulosic hydrolysate: Membrane experiments & system dynamic modelling
(2020) Weerasuriya Arachchige, A.R.P.P.; Mezule, L.; Juhna, T.
Separation of fermentable sugars after hydrolysis of lignocellulosic biomass plays a vital role in second-generation biofuel production. Byproducts and solid fractions generated during pretreatment and hydrolysis can have adverse effects on fermentation efficiency. Previous studies have shown that a maximum of 40% (w/w) of sugar yield can be obtained by sequential UF and NF permeate recovery. This study aimed to introduce a multi-step membrane filtration process to recover fermentable sugars while removing inhibitory bi-products. Fermentable sugar recovery was investigated using a recirculation flow between various stages of separation. The experimental results demonstrated that by introducing NF permeate recirculation to the UF unit a sequential UF/NF system can achieve 60% (w/w%) recovery of reducing sugars. Based on the experimental results, a ‘Simultaneous ultrafiltration and nanofiltration model’ was developed using system dynamics. The model was used to predict the final sugar concentration and sugar yield using sugar permeability in each membrane as the dynamic variability. The model predicts that high sugar permeability (or selective permeability) through the ultrafiltration mostly affects the efficiency of the system, which still is a challenge.
Reliability of camera systems to recognize facial features for access to specialized production areas
(2020) Vošahlík, J.; Hart, J.
The article deals with ergonomics and reliability of camera systems for recognition of facial features and identify person for access to specialized areas. The monitoring of areas relates not only to crime, but it is also an integral part of access to specialized production areas (pharmaceutical production, chemical production, specialized food production, etc.). It is therefore important to adequately secure these premises using the relevant system. One of them is a system based on user identification using specific facial features. For this purpose, there are CCTV systems for recognition of facial features of different price categories (conventional cameras, semi-professional and professional) on the world market. However, problematic situations may occur when identifying. For example, by having the user partially masked face. This research is focusing on the problem. The main goal of the research is establishing the scale of negative impact, in case the identified person has partially masked face, on camera systems recognizing facial features, primarily on recognition time. The results are evaluated in detail. Some camera systems are not suitable in specialized production areas due to their insufficient recognition ability. From all the tested devices, the HIKVISION iDS-2CD8426G0 / F-I camera identification system has proved to be optimal for identification purposes. In the case of designing, it is therefore necessary to choose suitable camera systems that have ergonomics and reliability at a level that will guarantee their sufficient use in the mentioned areas, while decreasing comfort and user-friendliness as little as possible. By measuring the ergonomics and reliability of these CCTV systems, it can be stated that there are statistically significant differences between conventional, semi-professional and professional systems, and it’s not just a design change, but also a more efficient recognition method.
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.
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.

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