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Analysis of the main indicators of pollution in the Dotnuvele and Smilga stream
2016
Miseviciene, S., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
Due to intensive agricultural activities being developed in Middle Lithuania, the water quality of rivers in this region significantly decreases. Rivers, flowing through the town territory, should provide aesthetic delight to the residents, however, because of pollution, especially at the end of summer; they are usually covered in duckweed and algae layer. The paper presents the change of the main water pollution indicators (BOD7, Ntotal, NH4 -N, NO3 -N, Ptotal, PO4 -P and O2) in Dotnuvele and Smilga streams during 2013 – 2015. The aim of research is to determine the change of the main surface water pollution factors in Dotnuvele and Smilga streams, depending on the meteorological conditions. Data analysis showed that dissolved oxygen, nitrate and total nitrogen concentrations are affected by air temperature: the lower of the air temperature, and the more of these elements were found in the water of the streams, (r = -0.61), (r = -0.83) and (r = -0.64) respectively. An increasing precipitation was also increasing the amount of O2 and NO3 -N in stream’s water, (r = 0.44), (r = 0.49) respectively. Meteorological conditions did not have a significant impact on concentrations of other chemical elements, however, correlation analysis showed that concentrations of BOD7 in streams’ water were increasing as precipitation level was falling (r = 0.41), and PO4 -P – when air temperature was increasing (r = 0.46). It was determined that in every spring the stream’s water quality according to the concentrations of Ntotal and N-NO3 was in a bad or average ecological condition. This was caused by the farming fields from which these streams are collecting drainage water during the spring melt.
Показать больше [+] Меньше [-]Ground-penetrating radar (GPR) screening in shallow Engure and Pape lagoon lakes
2016
Purmalis, O., University of Latvia, Riga (Latvia);Institute for Environmental Solutions, Riga (Latvia) | Alksnis, A., Institute for Environmental Solutions, Riga (Latvia) | Taskovs, J., Institute for Environmental Solutions, Riga (Latvia) | Burlakovs, J., University of Latvia, Riga (Latvia);Linnaeus University (Sweden). Faculty of Health and Life Sciences
Geophysical studies in mapping and screening applications are widely applied for archaeological, environmental, geological, hydrological and many other applications. Ground-penetrating radar (GPR) is one of methods from geophysical toolbox that is also called a ground-probing radar, subsurface radar, surface-penetrating radar and ‘georadar’ or impulse radar – it is a non-invasive and non-destructive technique. Pulsed electromagnetic signal is recording the reflected energy and scattering from subsurface objects. Studies were performed in former Littorina Sea lagoons that became lakes after the further Limnea Sea stage in the Baltic Sea established with comparatively lower absolute sea level that is close to present day situation. Characterization of sediments as well as full sediment core description for comparison with GPR signals were performed. Major results show that GPR as non-destructive method in combination with geological coring followed by laboratory analysis of sediment properties can be successfully used to describe layering conditions, topography and depth of shallow lakes. Although there are some limitations regarding the electromagnetic (EM) noise and similar EM properties of analysed sediments, proper treatment of data gives complementary insight thus diminishing the necessity of dense coring network establishments in analysed areas of lakes. The aim of this screening study is to analyse potential advantages of GPR use for mapping sediments and topography of sandy bottom in shallow lagoon lakes as well as pinpoint problems during field and cameral works considering electromagnetic, geological and topographical disturbances.
Показать больше [+] Меньше [-]The abandoned block-cut peat extraction field influence on the natural raised bog hydrological regime
2016
Purmalis, O., University of Latvia, Riga (Latvia);Institute for Environmental Solutions, Riga (Latvia) | Grinfelde, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Valujeva, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Burlakovs, J., University of Latvia, Riga (Latvia);Linnaeus Univ. (Sweden). Faculty of Health and Life Sciences
Peat is still mined in many parts of the world for production of peat substrates and energy. Many peatlands were affected by drainage in the past also for forestry and agricultural needs. Nowadays a raised attention to peatlands is focused, especially to drained peatlands due to their carbon reserves and their potential influence to the climate on the one hand, but on the other hand - due to raising awareness on protection of environment, habitats and biotopes. There are many examples on restoration activities in peatlands found worldwide, especially their water regime is the subject of regulation, which plays the major role to bring back original functions. In most cases in Latvia as the aim for protection and restoration of degraded peatlands was protection of EU biotopes and habitats. Of course, peatlands play an important role in emissions of the greenhouse gases CO2, CH4 and N2O, produced during mineralization of the drained peat organic matter. In literature, we can find only few cases where hydrological regimes are described for natural raised as well as restored block-cut peat extraction fields. This research analyses block-cut peat extraction field water level fluctuation influence on naturally raised bog hydrological regimes. Hourly data is analysed for six groundwater monitoring wells as well as for determination needs of water level fluctuations in excavated peat quarry as a response to precipitation.
Показать больше [+] Меньше [-]Harmful factors in the workplaces of tractor drivers
2016
Butkus, R., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Vasiliauskas, G., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
Results of various studies show that the most prevailing risk factors on workers of agricultural sector are noise and vibration. These hazards are especially important in transportation and most field works. Results from previous studies show that vibro-acoustic environment in tractors operated in Lithuania usually cannot be attributed as acceptable, but technical solutions implemented by manufacturers had definitely positive influence on working conditions. Noise level reduced from 90 dB(A) (tractors of 1980 – 1990 years of manufacture) to 73 dB(A) (tractors manufactured from year 2000). As renewal of tractors is not sufficient, there is still a large number of old machinery i.e. noise levels might be as high as 92 dB(A) which allows to work safely only one hour per day without personal protection. It was found that values of whole body vibration (WBV) during ploughing operation might be as high as 1.5 m∙sE-2 which excess the vibration limit value of 1.15 m•sE-2, while hand-arm vibration (HAV) did not exceed the vibration action value of 2.5 m•sE-2. Significant effect of tyre pressure was noticed on vibration values measured on driver’s seat. Vibration acceleration values may be reduced to safe 0.5 m•s-2 by selecting appropriate tyre pressure.
Показать больше [+] Меньше [-]Weather impact on the household electric energy consumption
2016
Jakusenoks, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Laizans, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the article is to ascertain the interaction between weather conditions and electric energy consumption in the Latvia household. The electric energy consumption data in the Saurieši village, Riga region, Latvia, for the year 2012 were collected, and the climate data for the same period including the duration of the sun-shine, ambient air temperature, precipitation intensity, and wind speed were obtained. The research hypothesis that there is strong relation between weather conditions and electric energy consumption was proved partially – there is rather strong correlation between household electric energy consumption and air temperature (r = 0.91), and medium correlation between household electric energy consumption and precipitation (r = 0.61), as well as between household electric energy consumption and duration of the sunshine (r = 0.67). Correlation found between weather conditions and electric energy consumption in the household allows to forecast the trends in energy consumption based on weather measurements, and even to use the weather forecasts for electric energy future demand trends development. The equations developed explain the household energy consumption patterns in Latvia with its geographical location and economic conditions, but the methodology developed can be applied for any region if necessary data are available.
Показать больше [+] Меньше [-]Classification of different forest types with machine learning algorithms
2016
Sabanci, K., Karamanoglu Mehmetbey Univ., Karaman (Turkey) | Uenlersen, M.F., Necmettin Erbakan Univ., Selçuklu, Konya (Turkey) | Polat, K., Abant Izzet Baysal Univ., Gölköy Yerleşkesi, Merkez, Bolu (Turkey)
In this study, forest type mapping data set taken from UCI (University of California, Irvine) machine learning repository database has been classified using different machine learning algorithms including Multilayer Perceptron, k-NN, J48, Naïve Bayes, Bayes Net and KStar. In this dataset, there are 27 spectral values showing the type of three different forests (Sugi, Hinoki, mixed broadleaf). As the performance measure criteria, the classification accuracy has been used to evaluate the classifier algorithms and then to select the best method. The best classification rates have been obtained 90.43% with MLP, and 89.1013% with k-NN classifier (for k=5). As can be seen from the obtained results, the machine learning algorithms including MLP and k-NN classifier have obtained very promising results in the classification of forest type with 27 spectral features.
Показать больше [+] Меньше [-]The role of digitized services to improve international activities of banks
2016
Kliedere, E., Latectus, Ltd., Valdlauci, Kekava parish, Kekava Municipality (Latvia) | Jurgelane, I., Riga Technical Univ. (Latvia)
Due to the globalization, the financial sector has undergone major changes in the way services are provided and delivered. Customers increasingly prefer to receive services remotely, which is a more convenient and faster way, but the majority of European banks are not ready to provide it. 90% of European banks invest less than 0.5% of total spending on service digitization; therefore, only 20 – 40% of the processes are digitized. The service digitization can be a major challenge for banks in the future. Only banks that provide a full range of digitized services will be able to increase profitability and revenues and reduce costs. Therefore, it is necessary to analyse the satisfaction of international corporate customers and define the role of digitized services to improve international activities of banks. Quantitative and qualitative research methods, including the statistical data analysis, graphical analysis, linear and multiple regression analysis, correlation, comparison and grouping methods, as well as survey have been used for the research, and SPSS 20 has been used for data processing. So far there are no analyses of the digitized services in Latvia that would be based on international customer experience and needs. The results of the research concluded that the higher usefulness indicator, the higher is the possibility that international corporate customers will continue to use internet banking services. The digitized services strategy ensures the availability of essential daily digitized services in internet banking and ensures the savings in time and in financial resources for the bank and its international corporate customers.
Показать больше [+] Меньше [-]Effect of conformation traits on longevity of dairy cows in Latvia
2016
Cielava, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Paura, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
Cow lifespan is one of most important economical traits in every dairy farm and is affected by different environmental factors. One of genetic factors that affect longevity is cow conformation traits, which varies within different breeds, farms and animals. The aim in this study was to determine how stature and linear conformation traits affect cow lifespan and lifetime milk productivity. In the study, data about 34806 crossbred Holstein Black and White and 38201 Red cow group breed cows, which ended at least one full lactation, and were culled from 2002 – 2012 year were analysed. Data about cow productivity and culling was obtained from Latvian Agricultural Data centre. In the study, data about cow stature, udder depth, central ligament, teat length, and rear and front teat placement were analysed. Conformation traits were distributed in 3 groups. The average lifespan of analysed cows was 1869.9 days in which average 18550.8 kg energy corrected milk (ECM) was obtained. Holstein Black and White cows characterize with shorter lifespan (1833.7 days) than red breed group cows, but lifetime productivity is for 2339.1 kg ECM higher than for average red breed cow. Significantly longer (p is less than 0.05) lifespan – 2031.6 days was in cow group with stature 100 – 135 cm, but in cow group with stature more than 146 cm there is significantly higher lifetime and life day productivity. There is a significant difference between lifetime milk productivity and rear and front teat placement. Significantly higher productivity was given by cows with teat placement inside of quarter (linear evaluation 6- 9 points).
Показать больше [+] Меньше [-]Analysis of heifers rearing from different lactation dairy cows
2016
Eihvalde, E., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The research was conducted in Latvia University of Agriculture Research and Study Farm ‘Vecauce’ in 600 dairy cows herd, in the period from 2009 to 2013. Within the framework of the research, growth indicators (from birth till the first delivery) of 102 dairy cow calves were analysed. Live weight and hip height of the heifers were found out at birth, at the age of 6 and 12 months, at first insemination and first calving. Heifers born to primiparous cows in both breed groups had notably lower live weight (42.0 and 42.4 kg), as compared to the 4th group heifers born to mature cows (p is less than 0.05). At the age of one year, the greatest weight among the red breed animals was recorded for the 4th group heifers born to mature cows (on average 354.8 ± 7.09 kg), while in Holstein breed those were heifers born to mothers calving on average for the 2nd time (on average 363.0 ± 6.47 kg). The 4th group heifers born to mature Holstein cows had notably greater hip height at birth – on average 78.1 ± 0.9 cm (p is less than 0.05). Heifers of red and Holstein breeds on average were inseminated at the age of 14.6 – 14.8 months as they reached live weight 395 – 396.5 kg. Heifers of red breeds on average calved at the age of 25.8 months, whereas Holstein heifers - of 26.4 months. The research aimed at analysing growth rates of heifers born to dairy cows at different age.
Показать больше [+] Меньше [-]Different beef breed cattle fattening results analysis
2016
Muizniece, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
In Latvia, different breeds of beef cattle are grown; therefore, it is important to explain their suitability to organic farming systems, because most Latvian beef cattle breeders work with organic farming methods. The aim of this research was to compare fattening of different beef breed bulls (Bos Taurus) in organic farming system at similar housing and feeding conditions. In the research, there were included Blonde d’Aquitaine (BA), Hereford (HE), Simmental (SI) and crossbred (CB) bulls. Fattening period started after calf weaning from suckler cows at 7 – 8 months of age. Fattening results were significantly affected by factors like breed, live weight and age before fattening, but slaughter results were significantly affected by breed, live weight and age before slaughter. During the fattening period the biggest daily weight gain was showed for SI breed bulls (849 g), but the biggest live weight increase was recognized for BA breed bulls (295 kg). The required slaughter weight the fastest was reached for XG bulls, which average slaughter age was 532 days (p is less than 0.05). The greatest slaughter weight – 342 kg (p is less than 0.05) and dressing percentage (58% (p is less than 0.05)) was recognized for BA breed bulls; also, carcass conformation score in muscle development was the highest for BA bulls (2.0 points (p is less than 0.05)). The greatest economic benefit was from CB bulls, income calculated per one rearing day from CB bulls was - EUR 1.80.
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