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Road landscape modelling
2018
Vugule, K., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Mengots, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Stokmane, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
Road landscapes can be considered important resources for place development. They create impression about the infrastructure of places and transport, which is an important aspect of attracting investment and tourism development. Yet this field of landscape planning and design is hardly studied and needs more attention in Latvia. Institutions at different planning levels and from several fields of expertise are involved in road landscape development. In order to achieve successful cooperation among all the parties involved, it is necessary to reflect the information about road landscape development in the way that it can be easily perceived and understood. Studies in landscape perception prove that people perceive visual information about landscape design and planning better than textual information and regular maps. The purpose of the paper is to introduce with a method of three dimensional (3D) road landscape modelling, developed by authors as a tool for road landscape design aesthetic evaluation, which can be used to demonstrate design variants to wider public and stakeholders. We demonstrate what kind of data are necessary for road landscape modelling, how they are obtained and processed, why certain modelling programs are chosen. The methodology, problems, which occurred during the modelling, and the chosen solutions are described. Results show that chosen methodology is appropriate for large scale projects. The experience gained from the project helps to evaluate the suitability of certain computer programs for road landscape planning and design.
Показать больше [+] Меньше [-]Increasing cyclone efficiency by using a separator plate
2018
Galins, J., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Laizans, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Galins, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
The aim of the work is to increase the efficiency of cyclone technology by using a separator plate. Cyclone technology is used not only in the processing of various agricultural products, but also in air purification from dust. Air flow trajectories and the movement of dust particles inside the cyclone unit were simulated and analysed using Computational Fluid Dynamics (CFD) and particle study analyses. The separator plate was designed in certain sizes and placed inside the cyclone, thus increasing the efficiency of the cyclone. The angle of position of the separator plate significantly affected the obtained results. The experimental equipment was assembled together to test the simulation results. Wood ash was used to determine the efficiency of the cyclone. Studies have shown that the effect of the separator plate on increasing the efficiency of the experimental equipment is less than that shown in the simulations. Most of the experiments used ash particles that were greater than 20 μm, thus cyclone efficiency was 98.9 ± 0.05%. This confirms the compliance of CFD simulations with the physical model. More detailed research should be carried out in order to use the separator plate effectively for the filtration of very small dust particles.
Показать больше [+] Меньше [-]Quality of specialty coffee: balance between aroma, flavour and biologically active compound composition: review
2018
Laukaleja, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Kruma, Z., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
Specialty coffee, according to Specialty Coffee Association of America (SCAA) standards, is coffee which has been standardized from the coffee plantation process until its delivery to the consumer, in compliance with all quality standards, to highlight the characteristics of the beverage. With increasing coffee consumption, more attention is focused not only on the flavour and texture of the drink, but also on the impact of coffee on health. The beneficial effects of coffee on human health are mainly based on a wide range of biologically active components. The coffee composition of the biologically active compounds and flavour compounds are influenced differently by almost all technological processes. The aim of this review was to summarize recent scientific developments about composition of aroma, flavour and biologically active compounds in specialty coffee and evaluate the best possibilities to balance health promoting and flavour attributes. Specialty coffee mainly focuses on fruity, floral, sweet and acidic notes in coffee, which are opposite to phenolic compound aroma characteristics during roasting process. In conclusion, roasting temperature significantly influences all biologically active compounds and important aroma, flavour volatiles in coffee. All compound concentration, except coffee melanoidins, decreases during roasting process. Light-medium roast level could provide stability among floral, fruity aroma, flavour notes and biologically active compounds (phenolic compounds and coffee melanoidins) in coffee.
Показать больше [+] Меньше [-]Dynamics of Coxiella burnetii DNA in milk and phase-specific serological response in dairy cows
2018
Ringa-Karahona, G., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Antane, V., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)) | Grantina-Ievina, L., Institute of Food Safety, Animal Health and Environment „BIOR”, Riga (Latvia) | Steingolde, Z., Institute of Food Safety, Animal Health and Environment „BIOR”, Riga (Latvia) | Trofimova, J., Institute of Food Safety, Animal Health and Environment „BIOR”, Riga (Latvia)
In dairy cows shedding of Coxiella burnetii in milk can be persistent, sporadic to absent. Persistent heavy shedder cows are mostly highly-seropositive. Serological response due to C. burnetii antigenic phase demonstrates acute or chronic infection (serological response to phase II (PhII) or phase I (PhI) antigen, respectively). The aim of this study was to detect dynamics of C. burnetii DNA in milk and phase-specific serological response. In this study, the sera samples from 46 animals and milk samples from 34 were collected initially. Milk and sera samples from 36 animals were collected repeatedly. Samples were collected in five herds with previous history of C. burnetii infection from different parishes in Latvia – in 2017 and 2018. Milk samples were tested by detection of C. burnetii DNA by realtime PCR amplification using ‘ADIAVET™ COX REALTIME’ (ADIAGENE). Sera were tested by ‘VetLine Coxiella Phase1 and Phase2 ELISA’ (NOVATEC). Three cows (9%) in the first sampling and five (14%) in second sampling demonstrated shedding of C. burnetii DNA in milk . Six cows (13%) in the first sampling and eight (22%) in second sampling demonstrated positive serological response to PhI. Three cows (7%) in the first sampling and one (3%) in second sampling demonstrated a questionable serological response to PhI. Two cows (6%) in the second sampling demonstrated a questionable serological response to PhII . In herds with previous history of C. burnetii infection the number of animals demonstrating PhI positve serological response increases significantly (p0.05) during six months. In cows demonstrating positive serological response to PhI it continues and mostly remains unchanged during six months.
Показать больше [+] Меньше [-]Impact of inulin on production of methane, carbon dioxide and gastrointestinal canal functionality in calves
2018
Jonova, S., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Ilgaza, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)) | Grinfelde, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Zolovs, M., Daugavpils Univ. (Latvia)
Ruminants produce a large amount of methane (CH4 ) and carbon dioxide (CO2 ) in their foregut. These gases cause greenhouse effect. There are a lot of studies about different feed additives which can reduce the production of greenhouse gases in ruminants. Prebiotics can also change the amount of bacteria in animal gastrointestinal tract and reduce the occurrence of diarrhoea. The aim of this study was to test whether the prebiotic inulin affects the production of CH4 and CO2 in calves’ rumen and whether it affects the bacteria count in the rumen fluid and bacterial overgrowth in intestines. We used the flour of Jerusalem artichoke (Helianthus tuberosus L.) containing 50% of inulin. Approximately fifty days old, Holstein Friesian crossbreed calves were used in this study. Eight were in the control group, 8 received 12 g of flour and 8 received 24 g per day. On the 28th and 56th day of the research, we measured the amount of CH4 and CO2 in calves’ rumen took rumen fluid samples for bacterial analysis and urine to measure the level of phenol and indican. We concluded that adding the flour of Jerusalem artichoke at doses 12 g and 24 g did not significantly impact the production of CH4 and CO2 in calves’ rumen, the prebiotic inulin may suppress the growth of anaerobic microorganisms in the rumen at concentration 12 g of inulin reaching 56th day of experiment. The amount of phenol and indican in calves’ morning urine did not correlate with the faecal consistency of calves.
Показать больше [+] Меньше [-]Biodiversity of weeds and soil seed bank in organic and conventional farming systems
2018
Berbec, A.K., Institute of Soil Science and Plant Cultivation – State Research Inst., Pulawy (Poland) | Feledyn-Szewczyk, B., Institute of Soil Science and Plant Cultivation – State Research Inst., Pulawy (Poland)
The aim of the study was to compare weed species diversity in organic and conventional farms in Poland. The study was carried out between 2012 and 2014 on production fields located in Lublin province, one of the easternmost regions of Poland. The results showed that diversity and abundance of weeds in spring cereals were generally higher in organic farming system than in conventional one. No significant differences between systems were found in 2013, because local flooding of fields in spring made impossible the execution of agricultural weed management treatment for some farmers. Both above-ground and soil seed bank weed communities were the mainstay of valuable weed species, which is confirmed by the presence of the species threatened with extinction, for example, summer pheasant’s-eye (Adonis aestivalis), poorman’s blue weatherglass (Anagallis foemina) and others in both tested farming systems. Dwarf everlast (Helichrysum arenarium) was the only found species that is subject to partial protection by Polish law. Both organic farms, run under CAP policy and support, and conventional extensive farms of the province of Lublin were the mainstay of biodiversity. Future rural development and CAP should be adapted and implemented regionally. Traditional extensive farms could contribute to the biodiversity and valuable plant species conservation.
Показать больше [+] Меньше [-]Productivity of crop rotation measured as energy produced by included plants: a review
2018
Darguza, M., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Gaile, Z., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
The most important reason for growing field crops is food consumption. Only some of the total amounts of field crop species are mostly used for cultivation in the largest part of arable land. These crops ensure high economic income. This is the reason why biological diversity has decreased. Crop rotation is considered to be an instrument of sustainable cropping system and this is confirmed again nowadays. Higher cereal yields have been gained by including oil crops or pulses in the rotation. Each field crop has its own calorific value (MJ kgE-1). Grains/seeds and above-ground biomass may have different calorific values because of their chemical composition. Research results from literature confirm that the average net calorific value of winter wheat (Triticum aestivum) and triticale (Triticosecale) grain and straw are ~17 MJ kgE-1, but the net calorific values for oilseed rape (Brassica napus ssp. oleifera) seeds and straw are – 25.70 MJ kgE-1 and 16.37 MJ kgE-1, respectively. Oilseed rape is also known as energy rich crop. It is reported that diversified crop rotations also have greater energetic productivity from above-ground biomass (grain/seed yield and by-products) if compared with crops grown in repeated sowings or in monoculture. Crop rotation in combination with different tillage methods (conventional tillage, reduced or minimum tillage and no-tillage) is the way to improve soil quality, but it is not clear whether the soil treatment method has a significant impact on the overall crop rotational energy productivity.
Показать больше [+] Меньше [-]Leaf optical properties reflect changes of photosynthetic indices in apple trees
2018
Lauzike, K., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania) | Samuoliene, G., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania);Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
The impact of light penetration into crown and the effect of rootstocks and distance between trees on photosynthetic behaviour were analysed. Apple cultivar ‘Auksis’ was grafted onto dwarfing rootstock P60 and super-dwarfing rootstock P22 and planted at different distances (3 × 1 m, 3 × 0.75 m and 3 × 0.5 m). Nitrogen balance index and photochemical reflectance index were measured at two heights: 0.8 m above ground inside the canopy and 1.5 m above ground outside the canopy; specific leaf area, fresh and dry weight were evaluated from all canopy. The significantly positive effect of dwarfing rootstock P60 on all tested indices was observed comparing to P22 rootstock. Increasing density between trees lead to a decreased specific leaf area and increased nitrogen balance index. The dry and fresh weight ratio and photochemical reflectance index were also significantly affected, but no general tendency was identified. Photochemical reflectance index was not affected by light penetration into canopy, but the nitrogen balance index significantly decreased in the upper part of the canopy. Summarizing, it can be stated that decreasing light penetration into the crown results in an increase in the specific leaf area and photochemical reflectance index, and leads to a decrease in dry and fresh weight ratio and nitrogen balance index.
Показать больше [+] Меньше [-]The effects of LED lighting on nitrates, nitrites and organic acids in tatsoi
2018
Simanavicius, L., Lithuanian Research Centre for Agriculture and Forestry;Akademija, Kedainiai distr. (Lithuania);, Akademija, Kedainiai distr. (Lithuania);Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Virsile, A., Lithuanian Research Centre for Agriculture and Forestry
Progressive type of controlled environment horticulture, such as plant factories, enables the precise control of cultivation environment parameters. The experiments were performed at the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry in the year of 2017. The aim of this study was to evaluate the effects of different irradiance levels produced by solid state light-emitting diodes (LEDs) on nitrates, nitrites and organic acids contents in tatsoi (Brassica rapa var. rosularis), cultivated in the controlled environment chambers. Plants were cultivated under combinations of red (640, 660 nm), blue (445 nm) and far red (731nm) LEDs at photosynthetic photon flux density (PPFD) level of 200 µmol mE-2 sE-1. At the pre-harvest stage, PPFD was increased to 300 µmol mE-2 sE-1 by elevating the fluxes of different spectral components for 3 days. The contents of nitrates, nitrites and organic acids were evaluated. The results propose the metabolic interface between nitrates, nitrites and organic acids in green vegetables, sensitive for lighting conditions. The higher intensity of LED light at pre-harvest stage led to decreased contents of nitrates in tatsoi. The increased intensity of blue 455 nm light led to lower contents of nitrates and higher of organic acids in comparison to red 640 nm. In addition, the increased intensity of red 640 nm led to significantly higher (p≤0.05) contents of nitrites. The target management of LED light spectra and intensity at pre-harvest stage could be used to reduced nitrates and increased organic acids in tatsoi.
Показать больше [+] Меньше [-]The effect of LED lighting dosage on photosynthetic indices in tatsoi
2018
Kaciusis, M., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania) | Samuoliene, G., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
Plant factories provide possibilities to get optimal yield of green leafy vegetables entire year independent from the season. The technology of light-emitting diode (LEDs) light has become one of the most powerful tools in photophysiological researches of various horticultural plants. In order to manage plant physiology and improve productivity, it is necessary to develop new LEDs technologies in horticulture. The aim of the study was to investigate different lighting intensities and elevated red light (660 nm) effect on tatsoi photosynthetic parameters. All plants were grown under the same light sources where overall photosynthetic photon flux density (PPFD) varied from 200 to 300 µmol mE-2 sE-1. Three days before harvesting red light intensity (640 and 660 nm) was increased until 132 µmol mE-2 sE-1 and 660 nm until 188 µmol mE-2 sE-1 at 16 hours photoperiod. In the last treatment merely 24 hours photoperiod was applied. The photosynthetic indices in tatsoi were determined by non-destructive methods using LI-6400XT portable photosynthesis system, OS5p fluorometer, DUALEX optical sensor and CID leaf spectrometer. Research was performed in 2017 – 2018 winter season. The obtained data revealed that the total photosynthetic photon flux density (PPFD) at level of 200 µmol mE-2 sE-1 was sufficient for optimal CO2 assimilation in tatsoi plants. The increased PPFD of LED light at pre-harvest stage resulted in reduced photosynthetic parameters of plants.
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