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Pollution analysis of surface (rain) water from pig-breeding enterprise production territory
2015
Miseviciene, S., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
Pollution of surface (rain) wastewater forming in the production territory of a pig-breeding enterprise was investigated in the period 2007–2011. The surface water is collected from the production territory from yards with a hard covering and from roofs, enters the rain sewerage, and is released untreated into the natural environment. The aim of this work is to find out what influence on the environment is exerted by surface wastewater released into the natural environment from the production territory of pig-breeding enterprises. Surface wastewater pollution indices and the research frequency were identified according to the requirement to carry out surface water monitoring: surface wastewater samples are collected three times per year. Because of the uneven rainfall distribution during the year, less surface wastewater runoff occurred during the cold period; however, concentrations of indices were higher compared to the end of the warm period (TSS – 18 %, BOD7 – 39 %, Ntotal – was unchanging, oil products – 12.5 %). Only Ptotal concentrations were higher in the end of the warm period in 14 %. The organic pollution in surface wastewater was increased by total suspended solids. The increased concentrations of TSS and biochemical oxygen demand (BOD7 ) were related to a higher precipitation level. The indices’ TSS, BOD7 , Ntotal, Ptotal and oil products concentrations in the surface wastewater runoff from the pig breeding enterprise‘s production territory complied with the requirements for surface water which is collected from this area and released into the environment.
Показать больше [+] Меньше [-]Research of deformation processes in regulated stream channels of Lithuania
2015
Vaikasas, S., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Baublys, R., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Geguzis, R., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
Deformations occurred in natural and regulated stream change beds lateral and longitudinal profiles. This is particularly evident in regulation furrows, where their initial state is known. Research showed that landslips of the upper slopes in regulated watercourses is the most common deformation (72.8% of studied cases), and the largest deformation occurs in the lower part of the slope (63.4%), where the accumulation of the moved silt and soil is. It was found that the deformation changes the bed plan as well. 59.1% of regulated streams distort furrows and make meanders due to deformation effects. The analysis of river beds widths and depths ratio relationship with discharge of channel running flow observed that ratio B/H increases with increasing flow evenly in regulated beds, while the above-mentioned ratio varies unevenly in the natural watercourse. Cross-sectional shape also varies in regulated and natural beds: heterogeneous form beds dominated in natural beds, while parabolic cross section shape is approaching during the deformation in regulated beds, what is more favourable for the living environment.
Показать больше [+] Меньше [-]Impact of household electric energy usage trends on electrical power supply net power factor
2015
Jakusenoks, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Laizans, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The article deals with the research results of the household electric energy usage trends impact on the electric power supply grid power factor. The amount of household appliances has increased tremendously during the last 20 to 30 years, substantially raising the electric energy consumption in private sector. As a serious technological development of household appliances took place, for example, LED lamps, inverters for power supply of TV sets and computers, the introduction of microcontrollers and automated systems, as well as efficiency requirements increase for the devices used in household have led to a reduced specific energy consumption per device and increased overall energy consumption. Analytic and experimental research assured that all these changes have a substantial impact on electric grid quality, particularly on the power factor value. Filed research data proved the theoretical analysis results that there is a trend from minor inductive power factor towards considerably high capacitive power factor, thus reducing power supply grid quality. This trend must be considered seriously by the electric grid operators in order to keep high quality of energy supplied to the end users.
Показать больше [+] Меньше [-]Information literacy in community development
2015
Holma, B., University of Latvia, Riga (Latvia) | Pakalna, D., University of Latvia, Riga (Latvia)
The purpose of this paper is to describe the information literacy of people as essential competencies required for the generation of social capital and use of social capital in sharing and obtaining information, which in its turn, is considered to be an important resource in the community’s development. The paper analyses the terms: social capital, information literacy and their mutual influence, as well as describes the research where informational literacy of the population of Latvia, its levels and the determined groups of knowledge and skills, which need to be improved in order to contribute to the generation and use of the social capital, through various methods (population surveys, focus group discussions, information literacy knowledge assessment questionnaires and performing practical tasks) were assessed. The research is based on the UNESCO Media and Information Literacy (MIL) Competency Matrix and UNESCO MIL Assessment Framework. The main conclusions of research are the following: information literacy is an important competence for developing social capital; but based on the completed research there are skills of information literacy – processing of information, critical assessment of information resources, legally correct use of information sources, as well as effective use of information technologies – which should be improved. The research was conducted within the framework of the European Social Fund project ‘Development of Innovative Diagnostic Instruments for Regional Growth’ (No.2013/0057/1DP/1.1.1.2.0/13/APIA/VIAA/065).
Показать больше [+] Меньше [-]Methods and indicators for evaluation of forest ecosystem services in riparian buffer strips
2015
Saklaurs, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Krumins, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
In the research evaluation of the ecosystem services provided by riparian forests in Latvia has been studied. The aim of this research is to investigate the methods and indicators for assessing the value of ecosystem services of riparian forests and to establish the most appropriate methods of ecosystem service valuation in the case of Latvia. The study is based on analysis of scientific publications, special literature and reports of international organizations, studying results of previously performed qualitative and quantitative research methods in the field of ecosystem service evaluation. The results of this study revealed several methods that could be applied for evaluation of ecosystem services provided by riparian forests, taking into account that the set of available data may be limited and considering the costs and span of time that may be necessary to collect the missing data. The results also show that the majority of ecosystem service evaluation indicators can be applied if appropriate earlier studies have been performed and feasible data for similar territories or conditions are available. The knowledge of the methods and indicators for evaluation of ecosystem services is a crucial factor in the decision making process, when decisions on economic development or sustainable management of ecosystem services are made.
Показать больше [+] Меньше [-]Grey alder Alnus incana (L.) Moench additional growth changes after thinning in Aegopodiosa site type
2015
MiezIte, O., Latvia Univ. of Agriculture, Jelgava (Latvia) | Liepa, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sereiko, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Luguza, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
Grey alder stands Alnus incana (L.) Moench have a number of distinctive features. In fertile soils it successfully forms productive forest stands without any human intervention. Therefore, relatively few publications can be found on the thinning effects on stand reaction after thinning. It is possible that due to the highly intensive circulation of substances in the ecosystems of grey alder (high photosynthesis and canopy thinning, withering and breaking off of the lower branches, litter decomposition within a few years, thereby ensuring a continuous and stable plant mineral nutrition substance complementarity in the soil) response reaction of the remaining trees and management of grey alder forest stands could be different comparing to other tree species. The study analyses stock volume additional increment dynamics during 10-year period after the thinning in 24-year-old grey alder pure stands in Aegopodiosa site type. Thinning of grey alder forest stands have caused a moderate positive reference reaction – during 10 years, in addition to the total increase, 3.17 m**3 haE-1 have been added. During the valuation interval response reaction differs among the years. In the first four years it is relatively small as accumulation of the growing potential is taking place. From the fifth to seventh year after felling an intensive growing takes place, which results in repeatedly additional annual increment. Starting from the eighth year, the trees show tendency to return to a steady state as it was before the thinning.
Показать больше [+] Меньше [-]Birch growth responses to the insect injury simulations
2015
Araminiene, V., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania) | Varnagiryte-Kabasinskiene, I., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania)
The tree growth compensation followed by insect damage is important for tree survival. Insect damage by making 3 and 6 holes per each leaf, and clipping one third of a leaf were simulated for one-year old silver birch (Betula pendula Roth) seedlings once, at the beginning of the vegetation season. The height, aboveground and root biomass, root length, stem diameter and leaf area were measured for all damaged and control seedlings. The aim of the study was to examine the effects of different insect-damage simulations on silver birch growth. Our study demonstrated that leaf dry mass decreased in response to leaf perforations and clipping one third of leaf. However, at the end of the experiment, the cumulative dry mass reached the level of the control. We found no statistically significant effect on the aboveground and total biomass of damaged seedlings compared to the control. The leaf clipping decreased the leaf area and stem diameter compared both to the treatment with hole-damaged seedlings and the control. The induced birch growth response showed that tree seedlings were able to compensate their growth up to the control level after the insect damage in eight weeks.
Показать больше [+] Меньше [-]Effect of thermal modification on wood colour
2015
Cirule, D., Latvian State Inst. of Wood Chemistry, Riga (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Kuka, E., Latvian State Inst. of Wood Chemistry, Riga (Latvia)
Colour and colour homogeneity are of special importance for establishing the quality of wood products. In the present study the effect of thermal treatment at 140 °C and 170 °C on colour and its homogeneity was studied for aspen (Populus tremula L.), grey alder (Alnus incana Moench) and ash (Fraxinus excelsior) wood. Wood colour was monitored and evaluated by spectrophotometrical measurements of reflectance spectra and colour parameter calculations using CIELAB colour model with L* as the lightness, and a* and b* as the chromatic parameters. Wood colour changed substantially and all studied types of wood acquired quite similar colour due to the thermal treatment with greater discolouration and almost the same colour detected for treatment at 170 °C. The average colour difference within a board surface as well as among boards of one species was found to be less than 3 DEab units for all thermally treated specimens which can be regarded as hardly perceptible colour difference. However, noticeable differences in colour were detected between the surface and inner layers of thermally treated wood boards. Greater colour heterogeneity throughout the depth of a board was detected for woods treated at 140 °C.
Показать больше [+] Меньше [-]Manufacturing and application studies of Sots pine bark pellets
2015
Spalvis, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Daugavietis, U., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
This paper describes the use of Scots pine (Pinus sylvestris L) bark humus and fine fractions for animal litter pellet manufacture, and the efficacy of various additives in improving absorbency. In Latvia is no researches about litter pellet manufacture of pine bark, and possibilities of increasing water absorbency; in internationals research papers there is also no information about the possibilities of improving water absorbency of pine bark pellets with various additives. The additives tested were fresh and fallen leaves, tree needles, dried hogweed and sawdust. Pellets were manufactured with a ZLSP200B granulator at Adazi city, Latvia, in 2014. The results indicated that production of small diameter pine bark pellets could be problematic. Absorbency of the pellets was tested both by rinsing and soaking the pellets, and results were compared to woodchip particle litter pellets. It was found that the best absorbency was achieved with adding up to 30% sawdust, which increased pellet absorbency both by rinsing and soaking. The results indicate that it is possible to manufacture pellets using Scots pine (Pinus sylvestris L.) bark humus and fine fraction with good absorbency which can be disposed of in sewerage systems.
Показать больше [+] Меньше [-]Absorption of EU funds and the development of rural areas in Latvia and Poland
2015
Stawicki, M., Warsaw Univ. of Life Sciences (Poland)
The article presents the findings of research aiming to discover the links between absorption of European funds and the development of rural areas in Latvia and Poland. Based on statistical data and Latvian territorial development index at local level, the value of index for Polish local communities was calculated showing a slightly bigger difference in local development in Poland. Absorption of EU funds was rather concentrated in both countries and its highest level was connected with major infrastructural projects as construction of roads, motorways, etc. The use of EU funds under Cohesion Policy is not correlated with the level of development, neither in Latvia nor in Poland. The only significant negative correlation can be observed between the development and the use of funds under Common Agricultural Policy and Fisheries Policy in Latvia.
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