Volume 16 (2018)
  Number 4

Full text of the journal: Volume 16 Number 4

Contents


Pages

1569-1579 A.H. Alami, K. Aokal, D. Zhang, M. Tawalbeh, A. Alhammadi and A. Taieb
Assessment of Calotropis natural dye extracts on the efficiency of dye-sensitized solar cells
Abstract |
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Assessment of Calotropis natural dye extracts on the efficiency of dye-sensitized solar cells

A.H. Alami¹²*, K. Aokal², D. Zhang¹², M. Tawalbeh¹, A. Alhammadi¹ and A. Taieb¹

¹University of Sharjah, Sustainable and Renewable Energy Engineering Department, AE2727272 Sharjah, United Arab Emirates
²University of Sharjah, Centre for Advanced Materials Research, AE27272 Sharjah, United Arab Emirates
*Correspondence: aalalami@sharjah.ac.ae

Abstract:

This work presents the construction and testing of solar cells sensitized with natural dyes extracted from plants indigenous to the desert. Calotropis plants are self-sufficient as they grow in very harsh environments, and yet are not consumed by humans or livestock due to their irritating agents to the skin and eyes. The energy generators of these plants are the leaves, which are crushed and processed to produce the dye solution. Also, the Calotropis leaves are covered in a white powder that is thought to aid in mitigating the heat by scattering incident radiation. This powder material is examined and added to the dye as it proved advantageous for the overall cell efficiency, which reached 0.214% compared with 0.108% for cells with no powder. The produced cells are also compared with ones sensitized by spinach, another common natural sensitizer for dye-sensitized solar cells, and the performance proved to be significantly better. The fact that Calotropis is a non-food plant is an added advantage to utilizing it as a dye source, along with its intrinsic heat resistance that allows it to survive the harsh desert conditions all year round.

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1580-1589 J. Bradna, J. Šimon, D. Hájek and D. Vejchar
The impact of weather conditions on microclimate in storage facilities
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The impact of weather conditions on microclimate in storage facilities

J. Bradna*, J. Šimon, D. Hájek and D. Vejchar

Research institute of Agricultural Engineering, p. r. i., Drnovská 507, CZ16101 Prague 6 - Ruzyně, Czech Republic
*Correspondence: jiri.bradna@vuzt.cz

Abstract:

The key to maintaining good qualitative parameters of stored grain on farms is to achieve and maintain suitable storage temperatures relative to the outside temperature. In the framework of this research, the main focus was on typical representatives of grain storage facilities used in the Czech agriculture. In the post-harvest period after the crops were stored in the chosen storage facilities, the temperature of the material was monitored at 15-minute intervals using an external temperature probe as well as the temperature and dew point of the outdoor air. A simple linear regression model was used for data analysis. The correlated temperature dependence of the stored grain varies considerably in the monitored storage facilities. The storage halls were characterized by a low dependence (r = 0.2208) of the temperature of the material on the outside air temperature in the first 4 months following the harvest when the grains were being stabilized by active aeration. In addition to the grain and the air temperature, the second focus was monitoring the dew point, i.e. assessing the risk of water vapour condensation on the surface in the upper layer of the stored grain, which is very undesirable for maintaining the quality of the stored grain. The results show that the monitored storage hall can be characterized by the ability to maintain the required climate due to outdoor climatic conditions. In general, this ability mainly depends on the type and design of the storage facility, the aeration system and also the storage capacity. Mainly during spring the dew point and water vapour condensation can often happen within the grain, therefore the need to focus on appropriate measures such as reduced aeration or increased grain mixing, and thus avoiding the formation of critical spots.

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1590-1606 V. Bulgakov, S. Nikolaenko, M. Arak, I. Holovach, Z. Ruzhуlo and J. Olt
Mathematical model of cleaning potatoes on surface of spiral separator
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Mathematical model of cleaning potatoes on surface of spiral separator

V. Bulgakov¹, S. Nikolaenko¹, M. Arak², I. Holovach¹, Z. Ruzhуlo¹ and J. Olt²*

¹National University of Life and Environmental Sciences of Ukraine, Heroyiv Oborony street 15, UA03041Kyiv, Ukraine
²Estonian University of Life Sciences, Institute of Technology, Kreutzwaldi 56, EE51006 Tartu, Estonia
*Correspondence: jyri.olt@emu.ee

Abstract:

Cleaning potato tubers from soil impurities and plant debris after digging them out of soil is a topical problem in the work process of potato production. Therefore, the engineering of new designs of potato heap separators necessitates the further studying of them and the optimisation of their kinematic and design parameters, which must not only ensure the high quality of cleaning, but also rule out the possibility of damaging the tubers. The aim of this study is to determine the design and kinematic parameters of the improved design of the spiral potato separator, which will ensure the high quality of cleaning and rule out the possibility of damaging the tubers, on the basis of the development of the new theory of potato tuber’s motion on the surface of the separator. An analytical study has been carried out resulting in the construction of the equivalent schematic model of the interaction between the potato tuber and separator, the tuber being approximated by a material point on the surface formed by the two cantilevered spirals, which are the separator’s tools. The separator’s spirals are driven to rotate and at the same time they can perform oscillations in the vertical and axial plane under the action of the varying load generated by the continuous feeding of the potato heap for separation. In the model, the forces acting on the potato tuber’s body are applied to it, the coordinate axes that have been selected and appropriately oriented are shown. A system of equations has been set up for the constructed equivalent schematic model, comprising three differential equations of the potato tuber body’s motion on the surface of the trough formed by the two cantilevered spirals. The determined kinematic and design parameters will allow to raise the quality of cleaning potato tubers from soil impurities and plant debris.

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1607-1613 M. Buřič, P. Novák, and J. Hůla
Effect of PTO- driven tillage machines on soil particles transfer
Abstract |
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Effect of PTO- driven tillage machines on soil particles transfer

M. Buřič, P. Novák*, and J. Hůla

Czech University of Life Sciences Prague, Faculty of Engineering, Kamýcká 129, CZ165 21 Prague 6 – Suchdol, Czech Republic
*Correspondence: novakpetr@tf.czu.cz

Abstract:

Displacement of soil particles by erosion can be seen as a major threat to the quality of agricultural land in the conditions of Czech Republic. While the effects of water and wind erosion have long been investigated and reported, the effect of soil tillage technology on soil particles translocation are relatively new area of agriculture research. Soil tillage may contribute to the undesirable translocation of soil particles towards lower-lying parts of fields especially on slopes. The effect of soil tillage implements on soil particle translocation has not been sufficiently explained yet. The object of this research was to assess the influence of PTO (power takeoff)-driven tillage machines on soil particle translocation during secondary tillage (soil preparation). Measurements to determine the displacement of soil particles were performed in location Nesperská Lhota in the Central Bohemia Region. Measurements were performed on a sandy loam cambisol after harvest winter cereals (winter wheat). To indicate displacement of soil particles was used grit of white limestone (size 10–16 mm). Limestone was put down into the trench with known position orthogonal to the direction of working operations. Subsequently were performed working operations in the specified sequence. Limestone particles were counted and weighed in each section. It was detected by measuring the different nature of displacement for each machine. Statistical significance of differences in the weight of translocated particles was evaluated for different type of machines.

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1614-1621 D.V. Cao and P. Kic
Analysis of indoor temperature in the workshop building during the summer: a pilot study
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Analysis of indoor temperature in the workshop building during the summer: a pilot study

D.V. Cao* and P. Kic

Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Technological Equipment of Buildings, Kamýcká 129, CZ165 21, Czech Republic
*Correspondence: caodoan2006@gmail.com

Abstract:

The aim of this paper is the presentation of measurements’ results and the calculation
method for analysis and evaluation of climate conditions as well for using of natural illuminance
in two large simple buildings during summer which could be used to calculate power demand for
the air cooling to reduce the indoor temperature caused by solar radiation. In this research, we
carried out experiments of measuring the indoor temperature at level of working place which is
1.1 m, in two similar large workshops with floor area 260 m2 and height 6.5 m, during several
hot summer days. The indoor conditions were strongly influenced by the solar radiation as the
buildings have large wall and roof windows. The indoor air temperatures in the first building
achieved 39.5 °C, which caused the heat stress for workers. The indoor air temperatures in the
second building achieved only 29.5 °C. The calculated power demand for the air cooling to reduce
the indoor temperature to 25 °C is 25.6 kW in the first building, the cooling power for second
building is 14.9 kW. We investigated measured construction of the workshop and we set up the
formula in order to calculate thermal balance. The measurement results and calculated results in
two buildings are compared and summarized in the tables and in the graphs for analysis. As a
general conclusion, it must be said that solar radiation has a big influence on the air temperature
and methods of passive air-conditioning should be more applied also on the production buildings
in industry, agriculture and other branches of civil engineering to release heat increasing air
temperature inside the building.

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1622-1629 V. Denisova, K. Tihomirova and L. Mezule
Extended use of Sphagnum peat as a biosorbent for Zn(II): repetitious sorption-desorption process
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Extended use of Sphagnum peat as a biosorbent for Zn(II): repetitious sorption-desorption process

V. Denisova*, K. Tihomirova and L. Mezule

Riga Technical University, Research Centre for Civil Engineering, Water Research Laboratory, P. Valdena street 1-204, LV-1048 Riga, Latvia
*Correspondence: viktorija.denisova@rtu.lv

Abstract:

In this study, continuous biosorption-desorption cycles in a fixed-bed column were performed to evaluate the extended use of sphagnum peat as biosorbent material to remove Zn(II) ions from aqueous solutions. Biosorption-desorption studies revealed that the sphagnum peat as biosorbent could be regenerated using 0.1M HCl as eluting agent with more than 70% recovery in four successive biosorption-desorption cycles. The results showed that the sphagnum peat should be used as an alternative, effective and low-cost biosorbent for Zn(II) ions removal from polluted aqueous solution.

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1630-1641 I. Dimante and Z. Gaile
Assessment of potato plant development from Minitubers
Abstract |

Assessment of potato plant development from Minitubers

I. Dimante¹²* and Z. Gaile¹

¹Latvia University of Life Sciences and Technologies, Faculty of Agriculture, Liela street 2, LV 3001, Jelgava, Latvia
²Institute of Agricultural Resources and Economics, Priekuli Research centre, Zinatnes street 2, Priekuli, LV 4126, Latvia
*Correspondence: ilze.dimante@arei.lv

Abstract:

In production of minitubers, manipulation of their weight by modifying production method is common. Under field conditions plant development from minitubers can be affected by their weight, as well as cultivar. This objective of this study was to compare plant development from four minituber weight classes (MtC) (3 to 4.99 g, 5 to 9.99 g, 10 to 19.99 g, and > 20 g) with broken apical dominance of cultivars ‘Monta’, ‘Prelma’ and ‘Mandaga’. ‘Prelma’ and ‘Mandaga’ had a similar development pattern, and minitubers > 20 g required significantly less growing degree days (GDD) to emerge than minitubers from the lightest classes. The heaviest minitubers needed on average 176 GDD for 50% emergence and 207 GDD were needed for the lightest class. The difference in GDD between the marginal MtC was more pronounced in period between 50 and 80% emergence. MtC did not affect the final rate of emergence. Number of above ground stems (1.4–4.0) was significantly affected by MtC. ‘Monta’ had significantly different development – delayed emergence, lower emergence rate, less above ground stems, faster canopy closure. Our study showed that plant development was significantly affected by MtC and cultivar. Differences between MtC were more pronounced under adverse meteorological conditions.

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1642-1648 V. Dubrovskis, I. Plume and I. Straume
Suitability of Common nettle (Urticadioica) and Canadian goldenrod (Solidagocanadensis) for methane production
Abstract |
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Suitability of Common nettle (Urticadioica) and Canadian goldenrod (Solidagocanadensis) for methane production

V. Dubrovskis*, I. Plume and I. Straume

Latvia University of Life Sciences and Technologies, Faculty of Engineering, Institute of Energetics, Cakstesblvd. 5, LV3001 Jelgava, Latvia
*Correspondence: vilisd@inbox.lv

Abstract:

Support for biogas production in Latvia was decreased. There is an urgent need to investigate the suitability of various inexpensive renewable biomass resources for energy production. Also, itis necessary to explore the possibilities to improve the anaerobic fermentation process with the help of various catalysts. Biocatalyst Metaferm produced in Latvia was used in previous studies with other biomass and showed increase in biogas and methane production. The article shows the results of studies on biogas (methane) production from chopped fresh Common nettle (Urtica dioica) and Canadian goldenrod (Solidago canadensis) biomass and effect of catalyst Metaferm in anaerobic fermentation process. The anaerobic digestion process was performed in 0.75 L laboratory digesters, operated in batch mode (38 ± 1.0 °C, 35 days). The average specific biogas or methane production per unit of dry organic matter added (DOM) from Common nettle was 0.709 L g-1DOM or was 0.324 L g-1DOM respectively. Average specific biogas or methane volume produced from chopped Canadian goldenrod in anaerobic fermentation was 0.548 L g-1DOM or 0.267 L g-1DOM respectively. Average biogas or methane yield from digestion of chopped Common nettle with 1 mL Metaferm was 0.752 L g-1DOM or 0.328 L g-1DOM respectively. Average specific biogas or methane yield from anaerobic fermentation of chopped Canadian goldenrod with 1 mL Metaferm was 0.624 L g-1DOM or 0.276 L g-1DOM respectively. Adding of catalyst Metaferm increases methane yield from chopped nettle or Canadian goldenrod by 1.2% or 3.4% respectively. All investigated biomass resources can be used for methane production.

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1649-1659 C.H. Galeano Mendoza, I. Cerón-Souza and L.V. Arango
Agronomic evaluation of a Colombian passion fruit (Passiflora edulis Sims) germplasm collection
Abstract |

Agronomic evaluation of a Colombian passion fruit (Passiflora edulis Sims) germplasm collection

C.H. Galeano Mendoza¹*, I. Cerón-Souza² and L.V. Arango¹

¹Centro de Investigación Palmira, Corporación Colombiana de Investigación Agropecuaria – AGROSAVIA. Diagonal a la intersección de la Carrera 36A con Calle 23, Palmira, Valle del Cauca, Colombia
²Centro de Investigación Tibaitatá, Corporación Colombiana de investigación Agropecuaria – AGROSAVIA. Km 14 vía Bogotá-Mosquera, Cundinamarca, Colombia
*Correspondence: cgaleano@corpoica.org.co

Abstract:

Passion fruit (Passiflora edulis Sims) is one of the most promissory crops in Colombia with approximately 7,400 ha cultivated, an average production of 89,000 t and an average yield of 15 t ha-1. However, low yields as well as harvest problems including fruit quality, generate important losses, mainly due to lack of improved cultivars with particular characteristics for each market (fresh consumption, agroindustry) and specific adaptations to biotic and abiotic stress factors in producer areas. Therefore, as a pre-breeding phase, this study aimed at characterizing preliminary the production and physiochemical characteristics of 60 passion fruit germplasm accessions maintained in Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA). We cultivated these accessions in the field for 22 months between 2014 and 2015, measuring 17 variables associated to both yield production and fruit quality. We analysed data using phenetic and multivariate methods to establish levels of genetic diversity. Additionally, we constructed a selection index (SI) with the most informative variables to select individuals according to fruit weight, shape and colour, as well as juice percentage. Results of genetic grouping and principal components showed a broad genetic diversity across the working collection, without any population substructure. Fruit volume, pulp and seed weight were the variables that explained 80% of the phenotypic variation. Finally, we identified 30 promissory accessions as parental for the first cycle of recurrent selection using the SI. We conclude that this core collection represents the diversity included in the working collection with promissory accessions to initiate an intra-population recurrent selection program.

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1660-1667 A. Heydarian, H.R. Tohidi Moghadam, T.W. Donath and M. Sohrabi
Study of effect of arbuscular mycorrhiza (Glomus intraradices) fungus on wheat under nickel stress
Abstract |
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Study of effect of arbuscular mycorrhiza (Glomus intraradices) fungus on wheat under nickel stress

A. Heydarian¹, H.R. Tohidi Moghadam¹, T.W. Donath² and M. Sohrabi²*

¹Islamic Azad University Varamin- Pishva Branch, Department of Agronomy, IR 33817-74895, Varamin, Iran
²Kiel University, Department of Landscape Ecology, Institute for Natural Resource Conservation, Olshausenstr. 75, DE24118 Kiel, Germany
*Correspondence: msohrabi@ecology.uni-kiel.de

Abstract:

In many regions of the world soils are contaminated with heavy metals and therefore restricted in their use. For instance, the absorption of nickel (Ni) in the tissue of plants increase the plant’s metabolism and cause physiological disorders or even death. Arbuscular mycorrhizal fungi are known to enhance the tolerance of host plants to abiotic and biotic stress. Thus, we investigated the potential of the arbuscular mycorrhizal fungi Glomus intraradices to mitigate deleterious effects of Ni in wheat. The experiment was conducted using four levels of Ni (0, 60, 120 and 180 mg per kg of soil) and two levels of mycorrhizal fungi application (with and without Glomus intraradices). Nickel stress significantly decreased seed number per spike, thousand-seed weight, seed yield per plant, concentration of chlorophyll a and b. At the same time, we found increased catalase (CAT) enzyme activity and dityrosine (DT) treatments. Mycorrhizal fungi application attenuated Ni effects, i.e. fungal presence increased seed number per spike, thousand-seed weight, chlorophyll a and b. Furthermore mycorrhizal fungi application reduce CAT enzyme activity and DT. In general, our results suggest that mycorrhizal fungi application reduces harmful effects of Ni stress in wheat.

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1668-1676 M. Hruška
Assessment of the actual hand position on the steering wheel for drivers of passenger cars while driving
Abstract |
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Assessment of the actual hand position on the steering wheel for drivers of passenger cars while driving

M. Hruška

Czech University of Life Sciences, Faculty of Engineering, Department of Technological Equipment of Building, Kamýcká 129, CZ165 21 Prague 6, Czech Republic
*Correspondence: jabko@tf.czu.cz

Abstract:

This work deals with the assessment of the actual position of the hands on the steering wheel of drivers of passenger cars in specific driving modes. The findings are compared with the location that is generally considered to be optimal in terms of both active and passive safety, and the long-term effects on the health of the driver. The research described in this work was carried out on a sample of randomly selected drivers in the Czech Republic. For all of the measurements, one identical neutral passenger middle-class vehicle, with which none of the test subjects had previous experience, was selected. The reason for this research was to model a normal situation where the driver controls a vehicle with his hands on the steering wheel in a position that is only the result of his or her own intuition and the subjective sense of the driver’s comfort. On the basis, of a statistical evaluation of the obtained data, it was found that the introductory hypothesis, which states that a significant part of the tested sample of drivers holds the steering wheel in an unsuitable manner, can be confirmed. This fact negatively impacts not only on the reduction of active and passive safety, but also affects the health of drivers who drive a large amount of kilometres annually. The results of this work can be used in the design of cabs and modern passenger car systems that will be able to motivate the driver to hold the steering wheel in an optimal way. This will directly affect road safety and positively influence the health of drivers.

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1677-1685 J. Iejavs, U. Spulle, V. Jakovlevs, E. Buksans and A. Zelmenis
Effect of environmental temperature on bending strength of the finger jointed aspen lumber
Abstract |
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Effect of environmental temperature on bending strength of the finger jointed aspen lumber

J. Iejavs¹, U. Spulle²*, V. Jakovlevs², E. Buksans² and A. Zelmenis³

¹Forest and Wood Products Research and Development Institute, Dobeles iela 41, LV-3001 Jelgava, Latvia
²Latvia University of Life Sciences and Technologies, Forest faculty, Department of Wood Processing, Dobeles iela 41, LV-3001 Jelgava, Latvia
³ “4 Plus” Ltd. Abula iela 6B, Valmiera, LV-4201; Merķeļa iela 20, Alūksne, LV-4301, Latvia
*Correspondence: uldis.spulle@llu.lv

Abstract:

Glued sauna wall boards are used as non-load-bearing structures. These products are subject to aggressive microclimate impact and very often for the gluing in length and width thermoplastic polyvinyl acetate adhesives (PVAC) are used.
In the performed research sauna wall boards made of common aspen (Populus tremula L.) with mean wood moisture content 8% were used. For the gluing in length with finger joint PVAC glue of D4 (LVS EN 204) group was used.
The aim of the research is identifying the impact of the environmental temperature on the strength of finger jointed aspen timber in 4 point static bending (in compliance with standard LVS EN 408). As a result of the study it was established, that after holding the finger jointed testing pieces visible in flat wise for 3 hours at the temperature of 100 oC, the mean bending strength decreased by 56% or 31.7 MPa in comparison to that held in the standard atmosphere. In case of the aspen timber with finger joints visible in edge wise held for 3 hours at the temperature of 100 oC, the bending strength decreased by 60% or 29.3 MPa in comparison to the testing pieces of the same type held in the standard atmosphere.

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1686-1697 A. Kabutey, D. Herak, C. Mizera and P. Hrabe
Mathematical description of loading curves and deformation energy of bulk oil palm kernels
Abstract |
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Mathematical description of loading curves and deformation energy of bulk oil palm kernels

A. Kabutey¹*, D. Herak¹, C. Mizera¹ and P. Hrabe²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Mechanical Engineering, Kamycka 129, CZ16521 Prague, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Material Sciences and Manufacturing Technology, Kamycka 129, CZ16521 Prague, Czech Republic
*Correspondence: kabutey@tf.czu.cz

Abstract:

The study aimed at describing the experimental and theoretical relationships between the force and deformation curves as well as the deformation energy of bulk oil palm kernels under compression loading. Vessel diameters of 60, 80 and 100 mm with initial pressing heights of the bulk kernels measured at 40, 60 and 80 mm were examined by applying a maximum compressive force of 200 kN and a speed of 5 mm min-1. For the theoretical description of the force and deformation curves, the tangent curve mathematical model was applied using the MathCAD 14 software where the force coefficient of mechanical behaviour, A (kN), the deformation coefficient of mechanical behaviour, B (mm-1) and the fitting curve function exponent, n (-) were determined respectively. The determined coefficients in addition to the maximum deformation values obtained from the compression test were used for the estimation of the theoretical or analytical deformation energy. The determined regression models expressing the deformation, numerical energy and theoretical energy as well as the tangent model coefficients A and B dependent on the vessel diameter and pressing height were statistically significant (P < 0.05) or (F-ratio > F-critical). Improving the mechanical pressing of oil extraction for both domestic and industrial applications still remain a concern of researchers and engineers.

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1698-1707 D. Kairisa and E. Aplocina
Efficiency of the use of field beans in fattening lambs
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Efficiency of the use of field beans in fattening lambs

D. Kairisa and E. Aplocina

Latvia University of Life Sciences and Technologies, Faculty of Agriculture, Institute of Agrobiotechnology, Liela street 2, LV 3001 Jelgava, Latvia
*Correspondence: daina.kairisa@llu.lv

Abstract:

The breeding and feeding of self produced pulses to livestock is one of the important directions of research for reducing the production costs of livestock products. Experiment on the effective using of the field beans to lambs for fattening was arranged in three replications using the Latvian Dark-headed breed male lambs. The mixture of concentrated feed consisted of 50% of bean and 50% of oat. Lambs were weighed at the starting and ending of the trial. Carcass quality was assessed according to the European standard for the classification of carcasses of sheep. The fattening period lasted from 37 to 94 days, on average 63 ± 3.6 days. The average live weight gain per day was 247.4 ± 13.85 g, and live weight increased on average by 15.3 ± 0.94 kg. Significantly higher (P < 0.05) growth rate during fattening period reached lambs of 3rd group, where lambs started fattening above 27 kg of live weight, reaching a 276.8 ± 26.26 g daily live weight gain. The quality of the obtained carcasses was an average, and score for musculature was from R to O class, but the average score for fat deposition was from 3 to 4 points. The mixture of field beans and oats provided 19.3% of crude protein and 12.1 MJ of metabolizable energy per 1 kg of dry matter, and its unlimited feeding provided medium lamb’s growth rate. The level of feed conversion was 7.56 kg of dry matter.

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1708-1719 H. Kalkis, Z. Roja and S. Babris
Faults and the physical workload in sawing and packing-related woodworking processes when considering potential ergonomic solutions
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Faults and the physical workload in sawing and packing-related woodworking processes when considering potential ergonomic solutions

H. Kalkis¹²*, Z. Roja³ and S. Babris⁴

¹Riga Stradiņš University, Faculty of European Studies, Dzirciema street 16, LV-1007 Riga, Latvia
²University of Latvia, Faculty of Business Management and Economics, Aspazijas blvd 5, LV-1050 Riga, Latvia
³University of Latvia, Ergonomic Research Centre, Jelgavas street 1, LV-1004 Riga, Latvia
⁴BA School of Business and Finance, K. Valdemara 161, LV-1013 Riga, Latvia
*Correspondence: henrijs.kalkis@gmail.com

Abstract:

The forest sector is a high-risk economic sector in Latvia, one in which manual work, awkward postures, the tightening up of individual muscle groups, and work monotony still exists. The aim of this study was to analyse the physical workload and fault modes, and their effects on the sawing and packing processes in woodworking when considering potential ergonomic solutions. Results show that packing operators and saw operators alike are exposed to severe loads, and these results coincide with survey results in which employees in these professions complain about the physical load and mention lower back pain. Fault modes and their effects on the sawing and packing processes were analysed using Failure Mode and Effects Analysis, and the main errors which were revealed in packing operations were related to machinery and lifting equipment, as well as to ergonomics and errors involving the human factor. The risk priority was calculated in terms of a figure. Financial indices were compared before and after any potential improvement in the sawing and packing processes. Analysis proves that investments in the improvement of ergonomics in relation to the automation of the production process saves human resources and is economically favourable when it comes to ensuring the sustainable development of the business in question.

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1720-1727 P. Kic, L. Ruzek and E. Popelarova
Concentration of air-borne microorganisms in sport facilities
Abstract |
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Concentration of air-borne microorganisms in sport facilities

P. Kic¹*, L. Ruzek² and E. Popelarova²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamycka 129, CZ165 21 Prague, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Microbiology, Nutrition and Dietetics, Kamycka 129, CZ165 21 Prague 6, Czech Republic
*Correspondence: kic@tf.czu.cz

Abstract:

This paper is focused on the microclimatic research in several buildings and rooms used for sport at the University. The attention is paid mainly to the problems of dimensions of space, capacity and activity of sportsmen, and influence of space ventilation. The air samples for microbiological analyses were taken by the microbial air sampler Merck Mas-100 Eco and cultivated by potato-dextrose agar and nutrient agar. Captured microorganisms, are expressed as colony forming units per m3 (CFU m-3). Measurement results showed that bacteria average quantity was statistically significantly less without students (562 CFU m-3) than with students (1,024 CFU m-3). The students inside the rooms increased the bacteria concentration. From this point of view the ventilation is not adequate for the removal of bacteria from ventilated spaces. From the results we can conclude that the great importance on the air quality in terms of a specific bacteria concentration has the specific volume of the room per one athlete. The worst situation is in rooms with the smallest volume, which has the largest biological load of the space. The lowest quantity of bacteria was in the swimming pool all year round (152 to 300 CFU m-3). The opposite situation was in average quantity of filamentous fungi, which was with students and ventilation (57 CFU m-3) and without students but without ventilation (109 CFU m-3). The pollution of air by fungi was higher without ventilation.

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1728-1741 D. Kļava, S. Kampuse, L. Tomsone, T. Kince and L. Ozola
Effect of drying technologies on bioactive compounds maintenance in pumpkin by-products
Abstract |

Effect of drying technologies on bioactive compounds maintenance in pumpkin by-products

D. Kļava, S. Kampuse*, L. Tomsone, T. Kince and L. Ozola

Latvia University of Life Sciences and Technologies, Faculty of Food Technology, Riga street 22, LV-3004 Jelgava, Latvia
*Correspondence: skampuse@inbox.lv

Abstract:

During the pumpkin processing large amounts of waste material as a combination of pumpkin peel, seeds and the flesh between seeds has produced. Therefore it is important to investigate the possibilities for using the pumpkin residues. The aim of this research was to investigate the effect of different drying technologies on maintenance of bioactive compounds in pumpkin by-products. Two pumpkin residue products of Hubard group pumpkins were used to obtain pumpkin powder: residue products formed in the process of extracting industrial pumpkin purée by heating it in a heat exchanger and treating through a sieve of pulpier; residues resulting from pumpkin juice extraction process mechanically pressed from fresh, chopped pumpkins. In order to be able to choose the most suitable drying technology pumpkin by-products were dried in the microwave-vacuum, convective (at 40, 50, 70 and 80 °C) and freeze-drying type dryers. For all samples total carotenes, the ascorbic acid, total phenols content (TPC) and antiradical activity (DPPH˙, ABTS˙+) were determined by using standard methods. The highest total carotenes content was retained in freeze-dried pumpkin powders. The most suitable drying method for obtaining pumpkin powder with the highest ascorbic acid, total phenolic content and antiradical activity is drying in convective type drying at 80 °C temperature.

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1742-1751 O. Kotomenkova and A. Vinogradova
Biostability of cotton fibers with different natural colors and selection
Abstract |
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Biostability of cotton fibers with different natural colors and selection

O. Kotomenkova¹ and A. Vinogradova¹²

¹Peter the Great St. Petersburg Polytechnic University, Institute of Industrial Management, Economics and Trade, High economic and trade school, Street Polytechnicheskaya 29, RU195251 St. Petersburg, Russia
²Saint Petersburg National Research University of Information Technologies, Mechanics and Optics, Faculty of Technological Management and Innovation, Kronverksky Prospect 49, RU197101 St. Petersburg, Russia
Correspondence: kot-og@yandex.ru, ann-vin@yandex.ru

Abstract:

Biodamageability is one of the weak sides of the cotton-plant fiber. Economic loss from the cotton damage caused by microorganisms is significant. Toxic chemical compounds are used to preserve the cotton fiber. This has a negative impact on environment and cotton consumers. The degree of the cotton biodamage depends on selection variety, types of cultivation, storage conditions and other factors. One of the directions in cotton planting is selection of the boll-stained cotton. It was established that naturally colored cotton of different varieties has high biostability. It allows to product hypoallergenic, eco-friendly textile and reduces impact on the environment. The purpose of the work is stability evaluation for microbiological damage of different cotton varieties including those naturally colored during long-term storage in different temperature and humidity conditions. The research lasted for 10 years. The species composition of the cotton microflora was determined, the impact of fiber on microorganisms and dynamics of samples biodamage was studied in the work. The results obtained show preservation of microflora viability on cotton fiber when storing it under normal conditions for a long-term period. With an increase in temperature and humidity necessary for microorganisms’ growth, the fiber destruction processes are amplified. It was established that cotton damage degree depends on the regimes and terms of its storage as well as the color of the fiber. Nature-colored cotton is more resistant for microorganisms, some varieties inhibit the growth of mold fungi.

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1752-1761 M. Kroulik, J. Hula and V. Brant
Field trajectories proposals as a tool for increasing work efficiency and sustainable land management
Abstract |

Field trajectories proposals as a tool for increasing work efficiency and sustainable land management

M. Kroulik¹*, J. Hula¹ and V. Brant²

¹Czech University of Life Sciences Prague, Faculty of Engineering, Department of Agricultural Machines, Kamycka 129, CZ16500 Prague, Czech Republic
²Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Agroecology and Biometeorology, Kamycka 129, CZ16500 Prague, Czech Republic
*Correspondence: kroulik@tf.czu.cz

Abstract:

Together with the requirement for higher productivity the average performance and the weight of agricultural machines are increasing. Agricultural land is increasingly exposed to pressures caused by agricultural machinery. The heavy agricultural machinery passes across a field are frequently associated with technogenic soil compaction. Soil compaction is one of the main problems of modern agriculture. From the previous measuring of the traffic intensity it was found 86.13% of the total field area was run-over with a machine at least once a year, when using conventional tillage and 63.75% of the total field area was run-over when using direct seeding technology, with dependence on the working width of the machines. Field passes are inevitable in present agriculture. As a result of the increase of total machines weight, it is necessary to optimize the traffic lines trajectories and limit the entries of the machines in the field. At present, the choice of traffic lines direction is based primarily on the experience of drivers or the practice of farmers. There are a number of influences that affect the machine work efficiency. Monitoring of the tractor, on an irregular 8 fields showed the following results. Eight-meter working width tiller or seeder brought shortening of total length of turns at headlands with the change in trajectory azimuth. For purposes of measuring the monitored tractors were equipped with monitoring units ITineris. An overview of the chosen directions of the trajectories and the lengths of working and non-working passes was obtained. Based on the shape of the plot, the trajectory of the lines was also modelled. Suitable traffic lines directions in terms of the ratio of work and non-work passes were searched.
Based on records of real trajectories, the ratio of working and non-working path ranged between 6.3 and 15.2%. It was obvious from the results that the shortening of non-working passes and turns in comparison with the originally chosen trajectory directions was achieved by optimization. This was especially valid for complex shapes of fields. Trajectory optimization leads to a reduction of total length of path in all cases. The reduction in total length of path ranged from 69.7 m to 1,004.8 m. Changing the length of the working path ranged from 10.9 m to 264.9 m with the change in azimuth. The extension was observed in three cases. The highest part on the change of the overall length of the path presented nonworking rides.

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1762-1770 D.G. Maksimov and H. Kalkis
Ergonomic modelling parameters and the influence of ergonomics on planning workplaces
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Ergonomic modelling parameters and the influence of ergonomics on planning workplaces

D.G. Maksimov¹* and H. Kalkis²

¹Udmurt State University, Institute of Economics and Management, Universitetskaya street 1, bld. 4, RU426034 Izhevsk, Russia
²Riga Stradins University, Faculty of European Studies, Dzirciema street 16, LV 1007 Riga, Latvia
*Correspondence: maksim.dan.gen@gmail.com

Abstract:

Modern economic research divides all economics into structural levels: mega-economics, macroeconomics, meso-economics, micro-economics, and nano-economics. From the point of such traditional divisions, the research is topical in the primary economic structure of society – nano-economics – and thanks to this work operations can be subdivided into workplaces in the form of transformation processes. The aim of the research is to develop ergonomic modelling parameters and to discover the influence of ergonomics on the planning of workplaces based on a case study. The research involved a study of workplace ergonomic planning methods and principles. Solutions for a series of problems which are related to the improvement of workplace ergonomics may be discovered in the following ways: improving work organisation in every workplace by using work process-related micro-elemental methods and a determination of work expenditure, the levels of physical strenuousness involved in the work, the complexity of the work, and the social importance of the workplace. These parameters will allow the workplace quantity characteristics to be discovered, such as in terms of a generalised parameter which conforms to the requirements which describe a workplace, and in terms of operational management via the condition of workplaces and the salary systems being utilised. The research provides a case study in which ergonomic modelling parameters are developed and concrete workplace interventions are introduced.

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1771-1780 E. Merisalu, D. Mugur and P. Kic
Importance of microclimate conditions and CO2 control in educational buildings: a case study
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Importance of microclimate conditions and CO2 control in educational buildings: a case study

E. Merisalu¹*, D. Mugur¹ and P. Kic²

¹Estonian University of Life Sciences Tartu, Institute of Technology, Fr. R. Kreutzwaldi 56/1, EE51006 Tartu, Estonia
²Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ165 21 Prague, Czech Republic
*Correspondence: eda.merisalu@emu.ee

Abstract:

Current efforts to minimize energy losses and maximize energy savings for heating of all houses are most often gained by insulating facades and replacing windows. However, these measures can have a significant negative impact on human health and these problems can occur in buildings with a high concentration of people, such as school buildings. The aim of this paper is to analyse the results of measurements of air temperature, relative air humidity and carbon dioxide in winter period in the classrooms of two universities, Estonian University of Life Sciences (EULS) in Tartu and Czech University of Life Sciences (CULS) in Prague. The measurements have carried out in 2017-2018 in eight classrooms of the EULS and two classrooms of the CULS. The external and internal temperature, relative humidity and concentration of carbon dioxide have measured in the classrooms during a few days in the winter period. In the lecture rooms of CULS, when the air conditioning was off, the levels of CO2 exceeded the recommended levels about two times. The average internal temperature and CO2 concentrations in the classrooms of EULS follows the norms and refers on good ventilation. The extremely low relative humidity in the classrooms of EULS at 17.1 ± 2.6% refers to a high risk of allostatic load and respiratory symptoms among students. It is important to pay attention on regular ventilation and relative air humidity control in the teaching rooms, especially with high number of students to prevent seasonal sickness of upper respiratory tract.

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1781-1795 L. Ozola and S. Kampuse
The influence of drying method to the changes of bioactive compounds in lingonberry by-products
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The influence of drying method to the changes of bioactive compounds in lingonberry by-products

L. Ozola* and S. Kampuse

Latvia University of Life Sciences and Technologies, Faculty of Food Technology, Riga street 22, LV-3004 Jelgava, Latvia
*Correspondence: lieneozola8@inbox.lv

Abstract:

The aim of this research was to evaluate the effect of different drying methods on industrially obtained lingonberry pulp juice by-products. For investigations, by-product was dried using hot air dryer (at temperatures 80 °C, 60 °C and 40 °C), microwave-vacuum dryer and freeze-dryer. The freshly defrosted by-product was used as control. All samples were analysed on the basis of their moisture content, colourimetric attributes (CIE L*a*b* colour system), content of vitamin C (iodometric method), content of total carotenes (TC), total phenol content (TPC), total anthocyanin content (TA) and antiradical activity (DPPH, ABTS+).
The obtained data on content of vitamin C showed a 10% decrease between control and sample dried in hot air at 80 °C. Similar changes were noticed with total anthocyanin content, the lowest amount was also foun in this sample (306.72 ± 18.32 mg 100 g-1 DW). Total carotenes content was higher in freeze-dried sample (5.61 ± 0.16 mg 100 g-1 DW) which was very close to control sample. A significant loss of total phenol content was noticed after drying, up to 80%, similar tendencies were noticed with changes of antiradical activity. After evaluating the obtained data, the use of hot air dryer at 80 °C temperature resulted in the lowest amount of vitamin C and anthocyanins in lingonberry by-products, which makes this method unsuitable for drying by-products of these berries. However, vacuum assisted microwave drying and freeze drying showed less damaging impact on dried material.

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1796-1808 Z. Pacanoski and A. Mehmeti
POST herbicide programme for effective weed control in winter wheat (Triticum aestivum L.)
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POST herbicide programme for effective weed control in winter wheat (Triticum aestivum L.)

Z. Pacanoski¹ and A. Mehmeti²*

¹University Ss. Cyril and Methodius, Faculty for Agricultural Sciences and Food, 16-ta Makedonska brigada 3, MK1000 Skopje, Republic of Macedonia
²University of Prishtina, Department of Plant Protection, Bill Clinton p.n., XK10000 Prishtina, Republic of Kosovo
*Correspondence: arben.mehmeti@uni-pr.edu

Abstract:

Field experiments were conducted during two winter wheat-growing seasons to evaluate the efficacy of some new POST herbicides and herbicide combinations for those effective controls of weeds in winter wheat crops in the Republic of Macedonia. The weed population consisted mainly of annual winter and spring and some perennial weeds. Weediness comprised 116 and 208 plants m-2 in 2012–2013 and 2013–2014, respectively, in the Skopje region, and 93 and 114 plants m-2 in 2012–2013 and 2013–2014, respectively, in the Probištip region. All POST herbicides effectively reduced dominant weeds density (> 93%) in the Skopje region in both years, as well as in the Probištip region in 2012–2013, but not in 2013–2014. In this year, lower temperature directly following application decreased efficacy of POST applied herbicides, which provided control of Lolium perenne that was between 76 and 84%; control of A. ludoviciana was less than 85%; control of B. radians was no more than 83% and no one treatment controlled P. convolvulus more than 82%. Wheat yields in the Skopje region were not significant among years for the different POST herbicide applications and ranged between 3,580 and 3,720 kg ha-1 in 2012–2013, and between 3,760 and 3,910 kg ha-1 in 2013–2014. A significant treatment by year interaction resulted in two distinct years for wheat yields in the Probištip region with POST herbicides. In 2012–2013, wheat yields were between 3,230 and 3,390 kg ha-1, but in 2013–2014, wheat yields ranged from 3,060 to 3,490 kg ha-1 and weed-free control showed a significant higher wheat yield compared to all evaluated herbicides.

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1809-1823 G. Petaja, M. Okmanis, K. Polmanis, J. Stola, G. Spalva and J. Jansons
Evaluation of greenhouse gas emissions and area of organic soils in cropland and grassland in Latvia – integrated National forest inventory data and soil maps approach
Abstract |

Evaluation of greenhouse gas emissions and area of organic soils in cropland and grassland in Latvia – integrated National forest inventory data and soil maps approach

G. Petaja*, M. Okmanis, K. Polmanis, J. Stola, G. Spalva and J. Jansons

Latvian State Forest Research Institute “Silava” Rigas street 111, LV–2169 Salaspils, Latvia
*Correspondence: guna.petaja@silava.lv

Abstract:

The aim of the research was to assess distribution of organic soils in farmlands for the time period between 1990 and 2015, as well as to carry out a recalculation of GHG emissions from organic soils in grassland and cropland. We evaluated the area of typical organic soils using digitized soil maps created between 1960s and 1980s there were 183,000 ha of cropland and grassland on organic soils. A selected number of areas on organic soils intersecting with the National forest inventory (NFI) plots were surveyed. We found that 66 ± 10% of surveyed plots still conforms to criteria for organic soils according to Intergovernmental Panel on Climate Change (IPCC) guidelines; in the rest of plots soil organic matter has been mineralized and these areas do not conform to IPCC criteria of organic soils. The following distributionof organic soils was estimated in cropland – 6.3 ± 3.3% in 1990 and 4.1 ± 3.4% in 2015, but in grassland – 11.6 ± 3.6% in 1990 and 7.7 ± 3.9% in 2015. The annual reduction of GHG emissions due to reduction of area of organic soils in cropland in 2015 corresponds to 1,400,000 tonnes CO2 eq. in comparison to 1990 and in grassland – to 1,100,000 tonnes CO2 eq. The estimated reduction of the GHG emissions due to conversion of organic soils into mineral soils, comparing the average value in 2005–2009 with the projection for 2021–2030 on average will correspond to 313,000 tonnes CO2 eq. annually, however LULUCF sector still won’t become a net CO2 sink according to the GHG inventory data on other land use categories and carbon pools.

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1824-1829 M. Polák
Application of conversion model for designing hydrodynamic pumps in turbine mode
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Application of conversion model for designing hydrodynamic pumps in turbine mode

M. Polák

Czech University of Life Sciences in Prague, Faculty of Engineering, Kamýcká 129, CZ16521, Praha 6, Czech Republic
Correspondence: karel@tf.czu.cz

Abstract:

The use of the smallest water resources has been coming again to the centre of interest in recent years. A water engine – turbine, is the heart of these power plants. This is usually the highest expense for the investor, in terms of cost. The effort is therefore to seek investment less demanding alternatives. One of them is the use of hydrodynamic pumps in reverse turbine operation. This paper provides a methodology for conversion of parameters of the smallest power pumps (micro hydro sites) to turbine operation. The conversion model is based on the results of experimental research at the author’s workplace and is suitable for pumps with low specific speeds and outputs. The pump design process for turbine mode is complemented by a practical example for a specific deployment site. This example also serves to verify the accuracy of the conversion model.

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1830-1836 J. Priekulis, A. Aboltins, A. Laurs and L. Melece
Farm manure amount calculation using statistical data in Latvia
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Farm manure amount calculation using statistical data in Latvia

J. Priekulis¹, A. Aboltins¹*, A. Laurs¹ and L. Melece²

¹Latvia University of Life Sciences and Technologies, Institute of Agricultural Machinery, Cakstes blvd. 5, LV-3001 Jelgava, Latvia
²Institute of Agricultural Resources and Economics, Struktoru street 14, LV-1039 Riga, Latvia
*Correspondence: aivars.aboltins@inbox.lv

Abstract:

To calculate ammonia emissions caused by production, storage and application of farm manure, it is necessary to know the amount of farm manure obtained in the country and also the kinds of manure. For this purpose, methodology and computer software are developed to calculate the amount of farm manure based on the data of the Central Statistical Bureau, the technology of farm animal handling in the country and the respective valid normative documents. Upon calculating the amount of farm manure produced in Latvia in 2016, it was stated that approximately a half of the manure is litter manure, one third – liquid manure, and one fifth – manure left in the pastures. The most of manure in Latvia (69% of the total amount) is obtained from milk cows, their calves and young stock.

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1837-1853 R. Põldaru, A.-H. Viira and J. Roots
Optimization of arable land use to guarantee food security in Estonia
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Optimization of arable land use to guarantee food security in Estonia

R. Põldaru*, A.-H. Viira and J. Roots

Estonian University of Life Sciences, Institute of Economics and Social Sciences, Department of Business Informatics and Econometrics, Fr. R. Kreutzwaldi 1, EE51006 Tartu, Estonia
*Correspondence: Reet.Poldaru@emu.ee

Abstract:

Agricultural and food sector has an important role to play in ensuring food security. A competitive agricultural sector warrants food security through increasing level of self-sufficiency in food, and export of surplus production in the sub-branches where it has a comparative advantage. One of the strategic tasks of the state is to secure food supply for the population. To perform this task, the state should estimate if the agricultural producers have the necessary capacity and resources to produce food to meet the needs of population. Mathematical modelling can be used as a tool in solving this analytical problem. The paper demonstrates possibilities of implementing linear programming model in optimizing the use of arable land for ensuring the food demand of Estonian population. The Estonian arable land use optimization model is essentially a static balancing model that simulates the demand and supply of basic food products (meat, dairy products, cereal products and potatoes). The basis for the demand side in the model is Estonian population, divided into 10 groups according to gender and age. The energy and protein needs of the respective population groups are taken into account. The supply side of the model is a typical agricultural production model that guarantees the consistency of crop and livestock farming. The model consists of 163 variables and 178 constraints (equations). The objective of the model is to minimize the use of arable land for field crops to ensure fodder for animal feed, and food for human food consumption. The model is used to analyse various land use strategies. According to the modelling results for ensuring food security of Estonia and to maintain export of dairy products, for which Estonia has a comparative advantage, in the 2016 volume, the total optimal arable land equals to 490,688 ha. There should be 83,600 dairy cows (with average milk yield 9,000 kg cow-1). It is necessary to grow 755,700 piglets per year in order to secure 40 kg of pork per inhabitant. Land use optimization results indicate that Estonian agriculture is able to supply Estonian people with the minimum necessary main food products to guarantee food security, and allows to export essential products (cheese, butter, skimmed milk powder, whole milk powder).

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1854-1861 S. Salazar, F. Bayas-Morejón, Z. Niño, J. Guevara, M. Ruilova, O. Merino, W. Donato and J. Guamán
Morphological and biochemical indicators of Fusarium oxysporum f sp. fragariae in strawberry crops (Fragaria x ananassa Duch) in the province of Pichincha, Ecuador
Abstract |
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Morphological and biochemical indicators of Fusarium oxysporum f sp. fragariae in strawberry crops (Fragaria x ananassa Duch) in the province of Pichincha, Ecuador

S. Salazar¹, F. Bayas-Morejón¹*, Z. Niño², J. Guevara¹, M. Ruilova¹, O. Merino¹, W. Donato² and J. Guamán¹

¹Estatal de Bolívar, Facultad de Ciencias Agropecuarias Recursos Naturales y del Ambiente, Departamento de Investigación. Centro de Investigación y Desarrollo Biotecnológico, EC020150 Guaranda, Ecuador
²Universidad Estatal de Bolívar, Facultad de Ciencias Agropecuarias Recursos Naturales y del Ambiente, Departamento de Investigación. Centro de Investigación del Ambiente, EC020150 Guaranda, Ecuador
*Correspondence: isba@doctor.upv.es; fbayas@ueb.edu.ec

Abstract:

Fusarium oxysporum f. sp. fragariae is a fungal pathogen, transmitted by soil in crops of strawberry (Fragaria x ananassa Duch.), which causes wilt disease that, kill the strawberry cultivars. The disease caused by Fusarium oxysporum f. sp., fragariae is hard to detect as the of the symptoms are similar with other soil-borne diseases. In spite of detection methods targeted F. oxysporum using molecular criteria have been developed, they have not been shown to successfully identity the unique identity of F. oxysporum strain that causes this disease. In Ecuador, the cultivation of strawberry has acquired great importance for the consumption, promoting the increase of its production. However, the process of importing plant material from producing countries for the purpose of improving production has contributed to the spread of the fungus. The objective of this study was to identify the presence of the Fusarium oxysporum f. sp fragariae by means of morphometric identification and the application of biochemical methods (BIOLOG) in the province of Pichincha. Fifty-two diseased strawberry plants and 52 asymptomatic plants were analyzed. Of these, 13 isolates were identified by morphometry as F. oxysporum. However, through BIOLOG four strains were identified as F. oxysporum, 5 as Fusarium sp., 2 F. lateritium, 1 F. udum and 1 strain as F. sacchari. The results obtained through the identification and evaluation confirmed the presence of F. oxysporum f. sp., fragariae in evaluated strawberry cultivars, thus determining the high risk to exist if the pathogen spreads in new plantations in Ecuador.

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1862-1876 J. Sepp, K. Reinhold, M. Järvis and P. Tint
Human factors and ergonomics in safety management in healthcare: building new relationships
Abstract |

Human factors and ergonomics in safety management in healthcare: building new relationships

J. Sepp¹*, K. Reinhold², M. Järvis² and P. Tint²

¹Tallinn Health Care College, Kännu 67, EE13418 Tallinn, Estonia
²Tallinn University of Technology, Ehitajate 5, EE19086 Tallinn, Estonia
*Correspondence: jaana.sepp@ttk.ee

Abstract:

Human factors are playing an essential role in ensuring occupational health and safety at work. In the healthcare sector, relevant factors include optimizing the interaction of humans with their technical, social working environment, and human characteristics such as knowledge and motivation. Those factors affect the ability to provide good quality of healthcare and safety performance. The aim of this paper is to analyse factors related to safety knowledge, communication and professional competence among caregivers in nursing homes. A group of professionals studied (n = 241, includes nurses and caregivers) completed a validated questionnaire. Descriptive statistics and correlation analyses were applied, using SPSS Statistics 24.
Our study revealed that over half of the respondents possess an occupational certificate and the majority of employers organize regular in-service training at workplaces. Respondents who claimed that in-service trainings are not regular still stated that they generally receive safety and ergonomic related trainings, trainings for working with special equipment. However, only a quarter of respondents have access to occupational safety trainings that focus on specific risks at work.
Based on the results of the study, we emphasize the need of integrating human factors in the safety management system in nursing homes with a special focus on adequate safety training in order to develop necessary skills and knowledge of workers. This would enhance employees’ ability to cope successfully with the elderly and people with special needs, to provide safe and high-quality care as well as confidence and the knowledge how successfully they manage conflicts in order to keep good relationships at work.

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1877-1884 M. Soonberg, M. Kass, T. Kaart, R. Leming and D.R. Arney
Additional concentrates do not affect feeding times of cows, but social positions of cows do
Abstract |
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Additional concentrates do not affect feeding times of cows, but social positions of cows do

M. Soonberg¹*, M. Kass¹, T. Kaart², R. Leming¹ and D.R. Arney¹

¹Estonian University of Life Sciences, Department of Animal Nutrition, Fr. R. Kreutzwaldi 46, EE51006 Tartu, Estonia
²Estonian University of Life Sciences, Department of Animal Breeding and Biotechnology, Fr. R. Kreutzwaldi 46, EE51006 Tartu, Estonia
*Correspondence: maria.soonberg@student.emu.ee

Abstract:

In robotic milking dairy systems lack of control over intakes can be problematic for balancing the forage and concentrate portions of diets. This can lead to problems associated with high concentrate intakes and concomitant low forage intakes. To check this as a problem, the feeding behaviour of cows was observed: the number of daily visits to the feed barrier, the duration of these visits and actual feeding, of high and low yielding cows. The cows were robot-milked and fed a ration comprising, separately, concentrate feed from a robot and a feeder, and a grass/clover silage mix forage at the feed barrier. Individual variation in visiting times and times spent at the feed barrier were greater than the effect of level of production. There was no evidence that cows with higher milk yields are differentially motivated to feed from forage. But more dominant cows spent more time feeding than submissive cows.

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1885-1895 I. Szabó, M. Hushki, Z. Bártfai, A. Lágymányosi and L. Kátai
Modelling of operator’s focusing scheme along working hours: Windrowing and cultivating operations
Abstract |

Modelling of operator’s focusing scheme along working hours: Windrowing and cultivating operations

I. Szabó, M. Hushki, Z. Bártfai, A. Lágymányosi and L. Kátai*

Szent István University, Faculty of Mechanical Engineering, Institute of Mechanics and Machinery, Páter K. street 1, HU2100 Gödöllő, Hungary
*Correspondence: katai.laszlo@gek.szie.hu

Abstract:

Enhancing productivity and cost reduction are two main targets for any production operation. In the agricultural field; It is the role of researchers to come out with reliable models and make it available to be used in modern farming management organizations as well as to the rural farmers. When it comes to the Human Machine Interface it is essential to assess the system in term of the Human Cantered Design aspects. This research is focusing on the developing simple models for the operator’s focusing scheme as a human behaviour inside an off-road vehicle cabin based on the operator’s focusing scheme measuring along working hours using proven and up to date technologies. The results of this research provide the decision makers with reliable inputs using proven methodology regarding the change of operator’s focusing scheme along working hours in two agricultural operations ‘windrowing and cultivating’. Both operations are requiring continuous physical involvement of the operator for checking the attached tool and steering of the vehicle in the planned track, which is directly related to the accumulated passive fatigue as a main contributor of resulted data.

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1896-1904 K. Tamm, I. Bender, E. Nugis, L. Edesi and T. Võsa
The impact of the termination technology of agro-ecological service crops on soil properties in open field vegetable production
Abstract |
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The impact of the termination technology of agro-ecological service crops on soil properties in open field vegetable production

K. Tamm*, I. Bender, E. Nugis, L. Edesi and T. Võsa

Estonian Crop Research Institute, J.Aamisepa 1, EE48309 Jõgeva, Jõgeva Vald, Estonia
*Correspondence: kalvi.tamm@etki.ee

Abstract:

The agro-ecological service crops (ASC) are introduced in the agro-ecosystems to provide or enhance ecological services, thus promoting the whole soil-plant system equilibrium. To avoid competition with the subsequent cash crops, the growth of the interposed ASC is terminated in advance of the cash crop planting. The traditional, most widespread technique to terminate the ASC is incorporation as green manure into the soil by tillage (GM). However, since tillage includes energy and labour consuming and soil disturbing operations, the use of no/reduced tillage techniques (as the roller crimping technology-RC) has received increasing interest.
An international research consortium (SOILVEG) including Estonian Crop Research Institute, was established in 2015 with the aim to study among others the impact of ASC termination on soil dry bulk density (BD), water content, soil structure and microbiological activity. Data are collected from Estonian trials in 2016 and 2017 at Jõgeva.
The physical properties of 0–40 cm soil layers were determined. Higher BD in soil layers (0–20 cm) of plots with ASC and RC was determined comparing to the GM and control plots. Bigger water content in same layer of plots with ASC and the RC was determined comparing to the GM plots. The use of the ASC-s helped to arise ratio of agronomically preferred soil particles.
Microbial activity was estimated by assessing of enzyme dehydrogenase activity in 0–20 cm soil layer. There were no statistically relevant differences in soil dehydrogenase activity (DHA) between the RC and GM treatments.

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1905-1914 A. Trūpa, B. Ošmane and I.H. Konošonoka
Fodder beans and peas in the diet of dairy cows
Abstract |
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Fodder beans and peas in the diet of dairy cows

A. Trūpa¹*, B. Ošmane² and I.H. Konošonoka²

¹Latvia University of Life Sciences and Technologies, Liela iela 2, LV-3001 Jelgava, Latvia
²Institute of Agricultural Resources and Economics, Priekuli Research Centre, Zinatnes iela 2, LV-4130 Priekuli, Priekulu parish, Priekulu district, Latvia
*Correspondence: aiga.trupa@llu.lv

Abstract:

The Holstein-Friesian Black-and-White cows were grouped into four treatments groups according to the analogue principle (n = 4 × 5). Lactating dairy cows were included in the trial in the initial lactation phase with the average milk yield of 23.00 kg per day, fat content 4.10% and 3.20% protein content in milk. The analyses of the chemical composition of legume grains show, that crude protein and undegraded intake protein (UIP) were higher in fodder beans than in peas, respectively 29.97% and 25.04% of dry matter but UIP content, respectively 40.51% and 39.69% of crude protein. There was a total of 17 amino acids detected in legume grains and soybean meal. The highest concentration of arginine, leucine, glutamic acid, aspartic acid and isoleucine was in fodder beans, respectively 0.76%, 0.58%, 0.67%, 0.42% and 0.29% more than in peas. Even though the daily milk yields decreased for all the cow groups during the experiment, which was normal during the lactation period, yet the milk yield decreases for the trial groups. The highest total amount of amino acids in milk was detected in 3rd and 2nd trial cow groups, respectively, 4.00 g kg-1 and 3.90 g kg-1 which was fed fodder beans and peas. The milk sale and feed cost summary records for the trial that lasted 90 days show that economic efficiency of peas plus beans has been positive.

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