2019, Vol. 17, No. 5

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/5508

Sirvi

Nüüd näidatakse 1 - 20 29

Determining external friction angle of barley malt and malt crush
(2019) Vagová, A.; Hromasová, M.; Linda, M.; Vaculík, P.
This paper deals with determining the amount of external friction angle of barley malt and malt crush depending on the load size. Barley malt is a basic raw material for production of the traditional Czech Pilsner type of beer. The angle of internal and external friction is one of the basic parameters of bulk materials. Friction among individual grains of material, i.e. a connection with the forces, applied between individual material particles, includes the internal friction angle. Conversely, the external friction angle is the angle in which the bulk material begins to move on the other material (steel). A two-roll mill (or disc mill and hammer mill) was used for the malt crush manufacture, which is used in the traditional malt processing in beer production. During crushing on this machine, we used the passage of the milled material through a gap between two counter-rotating cylinders. The results of barley malt and malt crush external friction angle, depending on the load size of the barley malt and the malt crush on mobile prototype device, are from 8 to 22°. The mobile prototype device is based on the following principle: a square chamber filled with a loaded material moves on the pad (steel).
Compost-bedded pack barns in the state of Minas Gerais: architectural and technological characterization
(2019) Oliveira, V.C.; Damasceno, F.A.; Oliveira, C.E.A.; Ferraz, P.F.P.; Ferraz, G.A.S.; Saraz, J.A.O.
Compost bedding pack (CBP) barns have been receiving increased attention as an alternative housing system for dairy cattle. Thus, a systematic investigation of the primary management practices of dairy cattle in CBP barns in the state of Minas Gerais (Brazil) has proven to be of environmental and economic relevance. The aim of this research was to summarize the compost bed data, barn dimension data and to determine the major interactive factors in the success of bed composting from qualitative and quantitative methods. Data for this study was collected from 16 CBP barns, distributed throughout the southern state of Minas Gerais (Brazil) between March 2017 and July 2018. These data were used to describe the building layouts and dimensions, to identify barn management practices, and to characterize the compost bedding material concerning moisture content. The majority of these barns had feed alleys and driveways; overshot ridges with frequent orientation from NE to SW; bedding process and aeration using mechanical tillage. The average bedding moisture content was found to be 36.9 ± 5.2% (w.b.). Based on the information found, it is possible to evaluate that there is still no defined construction pattern, with a high variation of size and technologies employed.
Research of the movement of agricultural aggregates using the methods of the movement stability theory
(2019) Bulgakov, V.; Kaletnik, H.; Goncharuk, T.; Rucins, A.; Dukulis, I.; Pascuzzi, S.
The theory of the movement stability is of crucial practical importance for mobile agricultural machines and machine aggregates, since it determines how qualitative and stable their performance is in a particular technological process. It is especially urgent To ensure stable movement for operation at high speeds of contemporary agricultural aggregates. The aim of this investigation is detailed examination of criteria for the stability assessment of a mechanical system used in agriculture, enabling their wide application in order to study the performance of the system in the case when it is affected by random forces that were not taken into account in the original model. The considered calculation methods and examples of their application make it possible to evaluate the performance of complex dynamic systems without numerical solution of complicated differential equations of the movement in the presence of external disturbances. The considered example of the stability determination of the movement of a trailed cultivator showed that this research method can be successfully used for practical purposes. Besides, a differential equation of disturbed movement has been composed for an actually symmetrical trailed agricultural machine with a particular mass, which moves at a constant forward speed under the impact of summary resistance force running along the symmetry axis of the cultivator and is applied at its centre of gravity. Reduced to normal Cauchy form, this equation was solved on the PC, which made it possible to determine immediately the conditions for stable movement of the trailed cultivator.
Reliability of palms security under difficult conditions
(2019) Hartová, V.; Hart, J.; Kotek, M.
Reliability of biometric identification systems is a much discussed topic and nowadays security of premises is very important. The work is focused on palms security research and reliability of the system under adverse conditions, the aim of the measurement was to determine the reliability of readers under adverse conditions that may occur in an industrial environment. Difficult conditions include dirty surface of hand by water, dust, oil and writing accessories. First, a sample measurement was carried out, where the hands of the subjects were washed and thoroughly dried. This measurement was used to compare with measurements under adverse conditions. The results show that the more viscous the fluid the lower the reliability and also dusty hands caused considerably distorted results. The reliability of biometric systems still needs to be improved, as it often happens that the real values do not match the parameters that are declared by the manufacturers. Certain conditions must be met for the proper functioning of palms security, so that identifying persons are allowed access to the protected areas and have not been repeatedly denied.
Development of intelligent system of mobile robot movement planning in unknown dynamic environment by means of multi-agent system
(2019) Nemeikšis, A.; Osadčuks, V.
Through the ages the world has conceived the projects which are aimed at creating diverse models of robots that would be beneficial for exploration of different dangerous surfaces where human participation is excluded. Therefore, the main task of the study of this article is to develop the researches, the object of which is mobile robot movement in unfamiliar environment, based on multi agent apparatus system and neural networks. The aim of the research is to develop methods for creating intellectual systems for planning mobile robot movement in unfamiliar environment applying the methods of multi agent apparatus and neural networks ensuring the robot executes the planned and adjusted on the way safe trajectory in an environment with unknown obstacles. Accordingly, the entire study of the article is based on a two-stage process. The first stage involves determination of distance between the robot and the obstacles in its operating area as well as classification of the possible location of obstacles, based on the information received from distance sensors, using the model of multilayer neural networks. During the second stage bypassing obstacles, wall tracking, movement-to-destination as well as speed management agents are developed. As the result of the study, a method was suggested for creating neural network model for classification of environment into agents and their consistent switching, which, according to the classification table compiled, involves all the possible locations of obstacles occurring on the robot’s movement trajectory and allows reducing the number of unfamiliar environment situations that are necessary to identify.
The effect of application of potassium, magnesium and sulphur on wheat and barley grain yield and protein content
(2019) Hlisnikovský, L.; Čermák, P.; Kunzová, E.; Barłóg, P.
The objective of our experiment was to study the effect of mineral fertilizers, rich mainly in the K, Mg and S content, and compare their effect on grain yield and protein content of winter wheat and winter barley with fertilizer treatments without these elements. The analyzed fertilizer treatments were 1) Control, 2) mineral nitrogen treatment (N), 3) mineral nitrogen with phosphorus (NP), 4) NP with potassium, magnesium, and sulphur (NP+KMgS), and 5) NP with magnesium, sulphur and minor part of manganese (4%) and zinc (1%) (NP+MgSMnZn). The experiment was established in Lukavec experimental station (the Czech Republic) in 2013 and lasted until 2017. The crop rotation consisted of four arable crops: winter wheat, winter barley, rapeseed, and potatoes, but only winter wheat and winter barley are analyzed in this paper (grain yields and crude protein content). In comparison with the Control, the application of mineral fertilizers significantly increased grain yield and protein content of both kinds of cereal. Comparing mineral fertilizers, no significant differences were recorded between N, NP, NP+KMgS and NP+MgSMnZn treatments, showing that nitrogen was the most limiting factor affecting yield and protein content, and initial concentrations of K and Mg were suitable and capable to cover cereal’s demands. However, application of fertilizers has increased the K and Mg soil content and thus prevents the soil from the element’s deficiency, which does not has to be recognized in the early stages by visual observation of arable plants. The effect of the year was also significant as two out of four seasons were characterized by high temperatures and drought.
Assessment of luggage compartment parameters based on the preferences of a heterogeneous driver group
(2019) Hruška, M.
This work deals with the assessment of driver preferences in the area of passenger car luggage compartments. The data collected is compared to that of real vehicles from the full range of passenger cars available on the European market. The data used for the research described in this work was obtained using a questionnaire survey on a large heterogeneous group of drivers in the Czech Republic. All of the research participants had three categories of vehicles available during testing - for better imagination and the possibility of personal comparison of parameters. The collected data was subsequently subjected to statistical evaluation, where mainly statistically significant dependencies in the preferences of individual drivers were sought out given their personal and anthropometric parameters. On the basis of the statistical evaluation of the obtained data, a difference was found in the preferences of the types and dimensions of the individual luggage compartments for the individual respondents depending on the selected parameters. The results of this work can be used in the process of designing luggage compartments of passenger cars, in particular with regard to the specific needs of drivers. The results of the work could thus contribute to improving the safety in handling cargo in the luggage compartments of vehicles and to improving health protection.
Variation in Eurostat and national statistics of accidents in agriculture
(2019) Merisalu, Eda; Leppälä, J.; Jakob, M.; Rautiainen, R.H.; Estonian University of Life Sciences
Agriculture is known as a hazardous industry worldwide, although there are great challenges in enumerating the size of the workforce and numbers of accidents at work. The aim of the study was to characterize variation in agricultural accident statistics in European countries and opportunities to improve collection and reporting of accident data in agriculture on the national and European levels. This study explored the incidence of fatal (FA) and non-fatal work accidents (NFA) in agriculture (excluding forestry and fishing) in selected European countries, using Eurostat and national sources in 2013. Eurostat reported highest NFA rates (per 100,000 workers) in Finland (5331) and lowest in Greece (5). The highest FA rate was reported in Malta (51), while zero fatalities were reported in Estonia, Greece, Luxembourg, Slovenia, Sweden and Iceland. Eurostat and national statistics differed in many cases. Some variations were observed in European and national statistics. Germany reported 89 fatalities (rate 2.3/100,000) in Eurostat and 160 (rate 16.3/100,000) in national sources. Poland, with a similar land area and five times more farms and workers as Germany, reported only 4 fatalities in agriculture in Eurostat. The Estonian Labour Inspectorate (2013) registered 785 NFAs per 100,000 agricultural workers, while the rate in Eurostat was more than twice as high (1914/100,000). Finland and Sweden with similar agricultural structures had a ten-fold difference in NFA rates in Eurostat; Finland 5,331 and Sweden 554 per 100,000 workers. These examples illustrate the large variation in agricultural accident statistics due to: a) farm structure, b) use of reference populations, c) under-reporting, d) different inclusion/exclusion criteria and e) interpretation by users. Some inconsistencies are structural due to lacking social insurance schemes for farmers, family labour and undocumented workers. Some inconsistencies could be addressed by better implementation of ESAW harmonizing rules. Alternative methods, such as standardized surveys, could be considered to augment Eurostat statistics.
A holistic vision of bioeconomy: the concept of transdisciplinarity nexus towards sustainable development
(2019) Zihare, L.; Muizniece, I.; Blumberga, D.
Current issue of bioeconomy development has been largely addressed on a linear or interdisciplinary level, however holistic view of bioeconomy requires a transdisciplinary system analysis. Developed methodology clarifies vision on bioeconomy definition, bioeconomy disciplines and disciplinary definition in context of nexus interlinkage, in the result concept of transdisciplinary approach connection to bioeconomy is determined as processes for sustainable bioeconomy, that not only replace fossil resources with biobased resources, but strengthens different disciplines, taken into account interlinkages, knowledge, and stakeholders and limitations set by planetary boundaries, different dimensions should be included in transition towards sustainable bioeconomy. Methodology bases on critical literature analysis. Different bioeconomy disciplines are defined and the obtained results are represented graphically. The obtained results can be used for further research as a transdisciplinarity basis of the bioeconomy, studying specific systems, factors influencing them and evaluating potential scenarios and their impacting tools. Results from implementing holistic vision would provide practical benefit to policy makers and industry actors by providing an analysis how to improve industrial practice, policy and how more effectively transfer to sustainable bioeconomy.
The nutrition value of soybeans grown in Latvia for pig feeding
(2019) Degola, L.; Sterna, V.; Jansons, I.; Zute, S.
Soybean products are excellent sources of protein for pigs because their amino acid profiles complement those of cereal grains. Soy protein is rich in the limiting amino acids lysine, threonine, and tryptophan that are present in relatively low concentrations in the most commonly fed cereal grains. Amino acids in soy protein are more digestible than amino acids in most other plants proteins, which results in less nitrogen being excreted in the manure from pigs fed diets containing soybean meal than if other protein sources are used. The phosphorus in soy products is bound to phytic acid, which has a low digestibility to pigs, but the digestibility of phosphorus in soy products may be increased to more than 60% if diets are supplemented with microbial phytase. There are no much results about nutrition value of soybean growing in Latvia. Therefore the aim of study was determined chemical composition of soybeans growing in Latvia and evaluates their potential in pig feeding. Research object were soybeans growing in Latvia. In the studied samples content of protein, fat, ash, fibre, composition of amino acids were determined and metabolizable energy were calculated. Evaluated that protein content varied from 32.7 till 40.7%, fat content was from 18.4–21.4% and significantly differed (p < 0.05) among growing places, but the sum of essential amino acids in the soy beans determined 115–125 g kg-1 , and were not differed significantly by varieties. The content of lysine in protein were determined 5.1–5.5 g 100 g -1 . Concluded that soy bean growing in Latvia provides equilibrium high metabolizable energy for pigs – from 13.2 to 17.6 MJ kg-1 and could be used in feed.
Effect of multi-component fertilizers on seeds yield, yield components and physiological parameters of winter oilseed rape (Brassica napus L.)
(2019) Stankowski, S.; Bury, M.; Jaroszewska, A.; Michalska, B.; Gibczyńska, M.
Subject of the discussed studies was an analysis of the impact of mineral multicomponent fertilizers, from Polish and foreign producers, on the yield and yield components of winter oilseed rape (Brassica napus var. oleifera). Two field experiments were carried out in 2015–2017 in Lipnik. The experimental crop was winter oilseed rape, hybrid cultivar DK EXPLICIT. Two factors were studied in the experiment A: 4 multi-component mineral fertilizers - two Belarusian (1 i 2), one Russian and one Polish (Polifoska 6) and 4 doses of fertilization (250, 500 and 750 kg ha-1 ). In the experiment (B) were compared two factors: 3 multi-component mineral fertilizers - Belarusian, Russian and Polish production - Polifoska 8 and 4 doses of fertilization (200, 400 and 600 kg ha-1 ). The fertilizers applied in the experiments, manufactured in Belarus, Russia and Poland, did not show variations in the amount of yield of winter rape. The number of winter rapeseed plants on the area unit (in autumn and spring) was independent of the type of fertilizers. In the experiment B, higher number of rapeseed siliques was obtained after application of Polifoska 8, than other fertilizers. Rapeseed grown on soil with the fertilizers manufactured in Belarus showed a lower value of greenness index (SPAD) and leaf area index (LAI). As a result of the application of multi-component fertilizers, manufactured in Belarus, Russia and Poland, the recorded differences in the winter rapeseed yield, yield components and physiological parameters did not exceed 10%.
Use of ethanol production and stillage processing residues for biogas production
(2019) Dubrovskis, V.; Plume, I.; Straume, I.
In Latvia, ethanol is produced mainly from wheat grains. The production process involves the formation of the by-products of wheat bran, grains residues and stillage. By-products from production of alcohol distilling dregs (stillage) contain much organic matter therefore could be useful for the production of the biogas The product with high protein content usable for feed can be produced from the stillage too. A liquid residue is formed during the production process. Purpose of study is the assessment of the methane volume obtainable from the stillage processing residue mixed with wheat brans and grains residues in anaerobic fermentation process and from wheat brans and grains residues mixed only with inoculum. Investigation was provided in 16 bioreactors operated in batch mode at 38°C. Stillage processing residues mixed with the wheat brans and inoculum were filled into 4 bioreactors, mixed with grains residues were filled into 4 bioreactors and only inoculum was filled into two bioreactors for control. Wheat brans with inoculum were filled into 3 bioreactors. Into others 3 bioreactors were filled grains residues with inoculum. The yield of biogas from wheat brans was 1.151 L g -1 DOM and methane 0.593 L g -1 DOM after 30 days of anaerobic digestion. The yield of biogas from wheat brans with stillage processing residue was 1.098 L g -1 DOM and methane 0.600 L g -1 DOM. The yield of biogas from grains residues was 0.915 L g -1 DOM and methane 0.451 L g -1 DOM. The yield of biogas from grains residues with stillage processing residue was 1.01 L g -1 DOM and methane 0.523 L g -1 DOM. The study demonstrates that the investigated products are very good raw material for the production of methane. Stillage processing residue acted as a catalyst for the process.
Occurrence of archaeophytes in agrophytocoenoses – field survey in the Czech Republic
(2019) Tyšer, L.; Kolářová, M.; Hoová, T.T.
Archaeophytes are alien plants introduced to the Czech Republic before the year 1500. Their occurrence is strongly connected with agricultural production. The aim of this study was to assess the occurrence of archaeophytes in arable fields in the Czech Republic in terms of applied management systems (conventional and organic farming), crops (winter cereals, spring cereals, wide-row crops) and environmental site conditions at different altitudes. In 2006–2018, a phytocoenological survey was conducted in selected farms across the Czech Republic. Totally, 180 weed species were found, of which 48.89% were considered as archaeophytes (88 species). In view of the invasive status, 5 archaeophytes were considered as invasive, the other 83 species were regarded as naturalized. The net effects of all variables studied on the occurrence of archaeophytes were statistically significant. The majority of the variation was explained by altitude, followed by crop and type of farming. Incidence of archaeophytes increases with an increasing altitude and is also related to their affinity with environmental factors. The highest occurrence of archaeophytes was found in cereals, some species, however, occur more frequently in wide row crops. The higher occurrence of archaeophytes was observed in organically managed fields.
Benchmarking the GHG emissions intensities of crop and livestock–derived agricultural commodities produced in Latvia
(2019) Lenerts, A.; Popluga, D.; Naglis-Liepa, K.
With the production of grain and livestock–derived agricultural commodities increasing, the agricultural sector has become one of the main sources of greenhouse gas emissions (GHG) in Latvia. In 2016, the agricultural sector contributed to 23.6% of the total GHG emissions originated in Latvia (266.4 kt CO2eq), and therefore the mitigation of the emissions is important. Considering the new indicative target, Latvia must reduce its GHG emissions in the non-ETS sectors by 2030 (Regulation 2018/842) so that the emissions do not exceed the 2005 level. The research aims to estimate the emissions intensities (EI) of grain and livestock-derived commodities produced in Latvia and benchmark the EI against those for other countries. The GHG EI were analysed per kilogram of product (kg CO2eq kg-1 ) and per hectare currently in use agricultural land (kg CO2eq ha-1 ). The main part of the GHG emissions of crop production originated from fertilizer application (direct N2O emissions) and soil liming (direct CO2 emissions). The main part of the GHG emissions of livestock–derived production originated from livestock enteric fermentation (direct CH4 emissions) and from manure management systems (direct CH4 and N2O emissions). The EI per hectare of industrial crops and grain were 550.5 and 438.4 kg CO2eq ha-1 , respectively. The yield and fertilizer application had a strong impact on the EI per kilogram of product. Pulses had a lower EI (0.003 kg CO2eq kg-1 ), while industrial crops (0.17 kg CO2eq kg-1 ) and grain (0.09 kg CO2eq kg-1 ) had the highest EI. A comparison of the GHG EI of crop and livestock–derived agricultural commodities per kilogram of product between Latvia and other EU Member States showed: Latvia had the lowest grain EI (0.09 kg CO2eq kg-1 ), but one of the highest cattle meat EI (25.18 kg CO2eq kg-1 ) and milk EI (0.64 kg CO2eq kg-1 ).
Theoretical analysis of force, pressure and energy distributions of bulk oil palm kernels along the screwline of a mechanical screw press FL 200
(2019) Kabutey, A.; Herak, D.; Mizera, C.; Hrabe, P.
The present study is a follow-up of the previously published study on the mathematical description of loading curves and deformation energy of bulk oil palm kernels under compression loading, aimed at determining theoretically the amounts of force, pressure and energy along the screw lamella positions 𝑆𝐿𝑝 of the screw press FL 200 by applying the tangent curve mathematical model and the screwline geometry parameters (screw shaft diameter, screw inner and outer diameters, screw pitch diameter and the screw thickness). The fitting curve value 𝐹𝑣 of the tangent mathematical model was further examined at 𝐹𝑣 = 2 and 𝐹𝑣 = 3 by identifying the force, deformation, stress and compression coefficients at varying vessel diameters 𝐷𝑣 and initial pressing heights 𝐻𝑡 of the bulk oil palm kernels. Based on the results of the stepwise regression analysis, the amounts of the theoretical deformation energy 𝑇𝐷𝐸 in linear pressing as well as the theoretical force 𝐹𝑟 , pressure 𝑃𝑟 and energy 𝑆𝐿𝐸 of the screw press FL 200 were statistically significant (P-value < 0.05) or (F-value > significance F) in relation to the predictors (𝐻𝑡 , 𝐷𝑣 , 𝐹𝑣 and 𝑆𝐿𝑝). The coefficient of determination (R2 ) values between 61 and 86 % were observed for the determined regression models indicating that the responses 𝑇𝐷𝐸, 𝐹𝑟 , 𝑃𝑟 and 𝑆𝐿𝐸 can accurately be predicted by the corresponding predictors. The normal probability plots of the responses approximately showed a normal distribution.
Particle size and shape characterization of feedstock material for biofuel production
(2019) Chaloupková, V.; Ivanova, T.; Krepl, V.
Particle size and shape are key factors influencing the properties of particulate and agglomerated materials, and having an impact on a quality as well as utilization of a final product. In case of plant biomass particle morphology is greatly irregular. Large errors at most determinations of biomass particle sizes are caused by simplification on a single parameter of size, assuming particle sphericity or circularity. Thus, the aim of a present research was to determine the particle size in a complex way. Pine sawdust as an experimental material and typical biofuel feedstock was ground by a hammer mill to a fraction size of 12 mm. The dimensional features of such ground sawdust particles were identified for all particles individually via photo-optical analysis, a method based on a digital image processing that is sensitive to irregular particles’ shapes. The particles were described mainly by variables of length, max width, equivalent diameter, max and min feret diameter, sphericity, roundness, circularity together with length/width ratio and aspect ratio. Data were analysed by descriptive statistics, i.e. by arithmetic means, medians, minimum and maximum values, variance and standard deviation. The obtained results may contribute to a better knowledge of material properties needed for designing an optimal technology for the production of quality biofuels.
Farm health and safety adoption through engineering and behaviour change
(2019) McNamara, J.; Griffin, P.; Phelan, J.; Field, W.E.; Kinsella, J.
The agriculture sector is one of the most hazardous occupations worldwide. The EU farming population is predominantly self-employed, who are largely outside the scope of EU occupational safety and health (OSH) legislation. Utilising effective communications approaches to transmit clear messages is a possible way of motivating farmer OSH adoption. The Public Health Model (PHM) of accident causation conceptualises an accident as occurring due to multiple interacting physical and human factors while the Social-Ecologic Framework enhances the PHM by defining various levels of the social environment which are influential on persons’ OSH actions. A knowledge gap exists in how farmers conceptualise accident causation. The aim of this study is to report findings of a Score Card exercise conducted among Irish farmers (n = 1,151) to reveal knowledge on farmers’ conceptualisation of accident causation where farmers ranked in order of importance up to five causes of farm accidents. First ranked items related to ‘machinery/ vehicles’, ‘organisational’ and ‘livestock’ as accident causation factors (92%). Overall rankings for up to five ranked causes identified six causes: ‘machinery/ vehicles’, ‘organisational’, ‘livestock’, ‘slurry related’, ‘trips, falls, buildings-related’ and ‘electrical’ (96.5%). The study data indicated that farmers’ perceptions of accident causes were inaccurate when compared with objective fatal farm accident data. The study concluded that communicating accurate and contemporary OSH messages to farmers has potential to assist with farm accident prevention. Based on the multiple and interacting risk factors arising in agriculture it is suggested that more elaborate study of farm accident prevention is warranted.
Results of experimental investigations of a flexible active harrow with loosening teeth
(2019) Bulgakov, V.; Kaletnik, H.; Goncharuk, I.; Ivanovs, S.; Usenko, M.
Soil tillage processes significantly affect the growth of cultivated plants; therefore, improvement of various designs and combinations of ploughs is still an actual practical and scientific task. This paper presents investigations of the design of a soil tillage machine consisting of three plough bodies equipped from the lateral side with a module with a flexible active harrow driven by a support wheel. The technological process of tillage by this machine is carried out in such a way that the module of the flexible active harrow is installed at a certain depth of soil tillage. The purpose of this work is an experimental comparative investigation of the quality indicators of the work of a design of the soil tillage working body with a flexible active harrow having loosening teeth. In the process of comparative experimental investigations of the operation of ploughs with a standard flexible harrow and an experimental active harrow having loosening teeth, the soil lumpiness (characterising the quality of crumbling) and water permeability of the obtained soil structure were estimated. An experimental model of this working tool was tested under the production conditions, and it showed advantages of loosening and crumpling the soil compared to the conventional harrows. This can be explained by the fact that the harrow tines, freely mounted on the axes of its links, ensure their oscillatory movements when moving in two different planes, thereby creating conditions for more intense soil disintegration.
Yeast performance characterisation in different cider fermentation matrices
(2019) Rosend, Julia; Kuldjärv, Rain; Arju, Georg; Nisamedtinov, I.
Nitrogen content management before fermentation is often used in cider production to avoid sluggish fermentations. In addition to enhanced fermentation rates, the proper nitrogen content in the apple must may have an impact on the flavour characteristics of cider. This research aimed to assess yeast performance in two different commercially available musts with similar non-limiting yeast available nitrogen (YAN) content. In addition to fermentation kinetics, volatile ester production by yeast, and sensory properties of the final product were evaluated. The results showed that the fermentation rate and consumption of sugar and nitrogen sources by yeast did not vary between the two different musts. Yeasts consumed more malic acid in the environment of higher initial malic acid content. The content of volatile esters and sensory properties of the final products varied significantly. The occurrence of intense sulfur off-flavour was noted in one of the products.
Biological features of formation of perennial binary grass crops
(2019) Gasiev, V.; Khokhoeva, N.; Mamiev, D.
The paper deals with the impact of binary mixtures of perennial grasses on the productivity and quality of forage crops that differ in their species composition. The studies have shown that mixed crops exceeded single-species crops in all indicators of forage crops productivity. In total over five years binary crops of Poterium polygamum exceeded singlespecies ones in all productivity indicators. The plants safety by the end of vegetation was also slightly lower than in single-species crops, which can be explained by greater competition for light, moisture and nutrients. So the safety of Medicago sativa L. was 81.8%, Onobrýchis – 83.6%, Galéga orientális L – 89.7%, Poterium polygamum – 74.6%, which is lower than that of legumes in single-species crops. In all years of herbage use, the binary crops exceeded singlespecies ones. On average, for 5 years of research, the yield of Poterium polygamum was 25.5 t ha-1 , Medicago sativa L. – 22.5 t ha-1 , Onobrýchis – 23.7 t ha-1 . Among legumes, the maximum yield had Galéga orientális L agrocenosis – 26.1 t ha-1 . Mixed crops of burnet with leguminous grasses were characterized for yielding the vegetative mass on average 28.5–30.9 t ha-1 . Maximum values of binary Poterium polygamum crops characterized crops with the leguminous plant component of goat’s rue in all years of research. Mixed crops also showed maximum values of dry matter per unit area and amounted respectively 33.52–36.74 t ha-1 . The same pattern continued in the yield of fodder units, digestible protein and metabolic energy, their maximum was obtained at the variant Poterium polygamum+ Galéga orientális L.

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