Уточнить поиск
Результаты 451-460 из 2,008
Low-emission heat insulation for roof constructions
2012
Liepins, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lesinskis, A., Riga Technical Univ. (Latvia) | Iljins, U., Latvia Univ. of Agriculture, Jelgava (Latvia)
This research was carried out to start the discussion on the amount of harmful emissions that are emitted in producing building and insulation materials for roof constructions. Usually, for the improvement of energy efficiency of buildings and reduction of the embodied thermal energy, effective thermal insulation solutions for the external building envelope have to be provided. From the buildings available for the analysis, in Latvia there were selected multi-apartment buildings of separate series with a uniform composition of roof constructions. Within the context of renovation works, the reports of energy audit for the buildings contain recommendations referred to improvement of the thermal performance of roofs. Using mutually comparable energy efficiency report data, there was drawn up an averaged model of a five-storey multi-apartment residential house. There were taken into account legislative documents relating to thermal engineering of buildings: LBN 002-01 ‘Heat engineering of building boundary constructions’ and LVS EN ISO 6946: 2007 ‘Building components and building elements – Thermal resistance and thermal transmittance’, and moisture regime according to LVS EN ISO 13788: 2001 ‘Hygrothermal performance of building components and building elements – internal surface temperature to avoid critical surface humidity and interspatial condensation – calculation methods’, which states that the roof constructions should be free from possibility of water vapour condensation. In this study, there were calculated energy savings obtained by improving thermal resistance of the roof constructions and the opposite primary energy consumption for the production of building materials. As a result, there is obtained environmentally friendly roof construction.
Показать больше [+] Меньше [-]Assessment of bioindication methods in air pollution monitoring
2012
Kalnins, V., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of air pollution monitoring is a regular and continuous collection of information on air pollution to prevent hazards influencing ecosystem and its components, including humans. Nowadays, the main technology used for this purpose is electronic sensors. As they are designed for specific measurements, a lot of important factors cannot be evaluated – various pollutants diffusion or cumulative effect, exposure, dose, and bioaccumulation. As an alternative solution – bioindication – pollution level determination from its effect on certain indicator species can be used. So far potential usage of bioindication as current air pollution monitoring network’s equivalent solution has not been studied. Therefore, the aim of the research was to assess a variety of bioindication methods for air pollution determination and their applications in air pollution monitoring. During the research, commonly used bioindication methods based on their popularity in scientific literature in 2012 were selected, as well as they were assessed using theoretical analysis method in order to determine their strong and weak points in air pollution monitoring. Research results demonstrate that current bioindication methods are not suitable for monitoring purposes. Therefore, bioindication can be combined with citizen science approach. To incorporate citizen science approach in bioindication based air pollution monitoring, development of special, for this purpose designed bioindication methodology is needed.
Показать больше [+] Меньше [-]Public perception about landscapes of watermills and small-scale hydroelectric power plants in Latvia
2012
Lazdane, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
The landscape in Latvia is managed and planned in different levels and regulations. The survey has been undertaken in Latvia with the aim to assess the landscape as regards the aesthetical quality assessment in Latvian watermills and small-scale hydroelectric power plant territories by means of public perception. Duration of research was from May 2011 till March 2012. The method used in this survey is the public questionnaire method. Public notions concerning researched landscapes territories in Latvia reveal that the landscapes in these territories are mainly assessed critically; however, in the assessment of visual information from pictures taken in particular territories the results are different, and the value of these territories is mainly assessed positively. The contribution of Latvian people’s knowledge regarding improvement in the landscapes situations in researched territories of Latvia has to be realized.
Показать больше [+] Меньше [-]Miklouho-Maclay park - the object of historical, cultural and architectural heritage
2012
Markov, F., Zhytomyr National Agricultural Univ. (Ukraine)
The article is devoted to the analysis of historical, cultural, and architectural importance of Miklouho-Maclay park, a monument of landscape art. It examines the archive data about the family of the famous traveler, ethnographer, anthropologist Mykola Mykolayovych Miklouho-Maclay who lived in Malyn (Zhitomir district Ukraine) at the end of XIX and the beginning of XX century, his contribution to the development of landscape art. It is shown that the park contains 57 species of arboreal-shrub plants including 34 species of trees, 22 shrubs, and one shrubbу liana. 23 of them (40%) are introduced species. The author offers the direction of parkland reconstruction and points out recommendations on territory zoning.
Показать больше [+] Меньше [-]The influence of cropping systems differing in intensity on mineral nitrogen migration
2012
Guzys, S., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
The research was carried out on ASU WRI grounds in Juodkiškes village in Endocalcari Endohypogleyic Cambisol (CMg-n-w-can). Research basis is 3 different field studies. In Variant I an organic cropping system was used with manure and without mineral fertilizers and pesticides, in II - organic-mineral cropping system with manure and mineral fertilizers, using pesticides, in Variant III - mineral cropping system with mineral fertilizers and pesticides. Minimum mineral nitrogen content in soil was in the organic cropping system, and the total minimal field crop capacity - in the mineral cropping system. However, it has the highest energy efficiency of this system (ETK - 13). Minimal N-NO3 - concentration in drainage water was in the mineral cropping system. In the organic-mineral and organic cropping systems concentration of this compound increases by 11 percent (to 21.8 mg l-1). The minimal concentration of ammonia nitrogen was under organic cropping conditions. The organic cropping system showed the highest runoff and maximum leaching of nitrogen compounds by drainage.
Показать больше [+] Меньше [-]Basic factors of parliament election results in the rural areas of Latvia
2012
Paiders, J., University of Latvia, Riga (Latvia) | Paiders, Ju., University of Latvia, Riga (Latvia)
This work focuses on the demands of scientific and sociopolitical understanding of situation of Latvia where the interaction between different languages and cultures have produced the political map of today. The aim of this work was to determine the differences of election results between rural areas and the city area, as well as to determine the main factors affecting election results in rural areas. Results of the study show that the ethnic factor has a major role in interpretation of the distribution of election results. If the proportion of non-Latvians increased by one percent, then the proportion of voters for Harmony Centre would increase by 0.64 percentage points in Vidzeme and by 0.75 percentage points in Latgale. Conclusions of the study: election results in rural areas differ significantly from the results in towns and cities, but the difference between rural areas and small cities is smaller compared to the cities under state jurisdiction; in rural areas, the national composition of the population has the greatest influence on the election results.
Показать больше [+] Меньше [-]Risks in agriculture and their assessment methods
2012
Girdziute, L., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
Agriculture is a unique sector, because it is associated with negative outcomes stemming from imperfectly predictable biological and climatic variables. These variables include natural adversities (for example, pests and diseases), climatic factors are not within the control of agricultural producers. So in agriculture it is very important to identify and evaluate risk, only then decisions made in farm will bring profit and other positive results. Scientific literature distinguishes a lot of methods for risk evaluation, but it is not clear what methods could be adapted in agriculture sector. This article presents main risk types in agriculture and their features as well as introduces most popular risk evaluation methods and their possible use in assessing risks in agriculture.
Показать больше [+] Меньше [-]Policies related to volunteer work in Latvia
2012
Jaunmuktane, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Volunteer work has been identified as a relatively new kind of leisure activities. It plays an important role in various, at the same time it is a great possibility to learn, acquire new skills and accumulate human capital while taking part in volunteer activities. Therefore, the objective of the study is to research the policies related to voluntary work and their relevance in realization and development of volunteer work in Latvia. Theoretical literature shows that in Latvia the volunteer work is mentioned in some policies – economic, youth policies and civil society. In the framework of economic policy successful development of volunteering enhances the progress of economic processes in the state in two ways by making contributions to Gross Domestic Product; by accumulating person’s human capital, results illustrate that although the term “voluntary work” has a long history, infrastructure for realization of the voluntary work has not been developed in Latvia, and regulatory enactments do not cover voluntary work in an adequate manner. After the analysis the author believes that volunteering is widely discussed in the youth policy as there is law and a range of structured documents where aspects of volunteer work are mentioned. According to the results of research, in the frame of civil society it must be noted that in Latvia the voluntary work movement has to be examined in the context of the establishment of non-governmental organizations because voluntary work movement started to develop in a purposeful and organized manner only in 1998 in non-governmental organizations.
Показать больше [+] Меньше [-]Radial growth of Norway spruce in the polluted western part of Latvia
2011
Zalkalns, O., Latvia Univ. of Agriculture, Jelgava (Latvia)
Environmental pollution that has been one of the key issues for decades has still not lost any of its topicality. In order to study the impact of air pollution on the growth of Norway’s spruce (Picea abies (L.) Karst.), 31 sample plots were established at different distances and directions from the pollution points in the Western part of Latvia. The plots were established starting from the year 2008 summer-autumn season and finishing with the spring of 2009. The selected stands were 32 - 171 year old and of different forest site types. The selection was used in the State Forest Service database and cartographic materials. Empirical data was obtained from each of the plots which reflected the environmental effects on the trees. To ascertain the effect of air pollution on the growth of Norway spruce, the algorithm based on additional increment to volume was used. Air pollution affects eating, regardless of age and the type of growing conditions. Pollution effects are closely related to the distance from the source.
Показать больше [+] Меньше [-]Profitability of silver birch (Betula pendula Roth.) breeding in Latvia
2011
Jansons, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Gailis, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Donis, J., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Economic importance of Silver birch in Latvia has been increasing in last decade, triggering scientific research, dedicated to improvement of this species, including tree breeding. Bulk of progeny trials will reach the evaluation time in next few years; therefore, decisions for further tree breeding activities have to be made. The aim of our study is to evaluate profitability of silver birch breeding, based on current situation in the year 2010 and circumstances in Latvia and assess the factors that might notably influence the result. Analysis considers all available breeding material and links between tree breeding, seed orchards and end product – forest stand, regenerated with improved plants in order to evaluate profitability of different alternatives based on differential approach. Results reveal that differential benefits from forest regeneration with selected birch material in comparison to natural regeneration, in areas with highest site indexes (Ia-II) with 3% interest rate and at least part of the stands managed in order to maximize yield of large diameter trees at age of final felling, are positive. The highest profitability can be reached if selection of best individuals is done based on clonal testing, genetic gain is maximized and combined with proper silvicultural praxis and annual planting area (utilization of seeds from selected trees) are maximized.
Показать больше [+] Меньше [-]