bluuebunny/crossref_metadata_2025 huggingface dataset:
EVALUATION OF THE LATVIAN FLAX GENETIC RESOURCES AND PERSPECTIVE OF THEIR UTILISATION
Authors: Grauda Dace , Stramkale Veneranda , Komlajeva Ļubova , Kolodinska Bratestam Agnese , Miķelsone Andra , Lapiņa Lita , Auziņa Aija , Rashal Isaak
Published: August 2015

Flax (Linum usitatissimum L.) is one of the oldest fibre and oil crop in Europe, including Latvia. In the middle of the last century growing areas of this crop was reduced dramatically. Nowadays flax attracted a great interest again as a fibre and oil processor, as well as a crop for diversification of agriculture and, in the same time, as a crop for producing high quality fibre for industry, high quantity oil for biofuel and high quality oil for feeding, food, and pharmacy (source of α-linolenic acid, linoleic acid and vitamins). We evaluated all available flax accessions of the Latvian origin and number of their hybrid lines. Agronomically important qualitative and quantitative traits, such as total plant height, technical plant height, number of seed vessels, logging resistance, vegetation period, yield of straws and seeds, 1000 seeds weight, bast fibre, number of seeds in a seed vessel, oil content and rust resistance gene L alleles L2 and L9 were recorded. Results of the field trials of two last years were summarized. Local accessions are useful as a source for breeding to adaptation of flax varieties to the local Latvian conditions. With use of molecular methods flax rust resistance allele L2 and L9 were found in eleven accessions.
SORPTION ROPERTIES OF LATVIAN CLAYS AND ENVIRONMENTAL PROTECTION SURVEY
Authors: Lakevičs Vitālijs , Bērziņa-Cimdiņa Līga , Ruplis Augusts , Pelšs Juris
Published: August 2015

The survey has been comprised in historical sequence. It has been attempted to group literature sources in a way that we consider to be the most relevant in the publication. Analysis of literature led to the following conclusions: during the last years most important and most advanced ways in investigations of Latvian clay surface characteristics have been found: Value determination of clay specific surface; Clay’s porous structure investigation; Cation exchange capacity determination; Characteristics of organoclays; Catalytic characteristics of Latvian clays; Practical usage of clays in waste water treatment; Usage of clays in adulterants elimination from vegetable oils; Clays as catalysts in of organic compound reactions; New type of sorbent from rapeseed oil treatment waste. Experimental measurements supplement data base about surface characteristics of Latvian clay samples.
RESTORATION OF LATVIAN ALFALFA (Medicago sativa) GENETIC RESOURCES PERSPECTIVE FOR BREEDING
Authors: Lapiņa Lita , Grauda Dace , Jansone Biruta , Jansons Aldis , Rashal Isaak
Published: August 2015

We have carried out restoring of some Latvian alfalfa genetic resources from seeds of accessions that did not germinate in soil at all. Two of them were repatriated from the N. Vavilov All-Russian Institute of Plant Industry (multiplied more than 40 years ago) and three from the Research Institute of Agriculture (Latvia) (multiplied 15-20 years ago). For germination of old seeds we used early elaborated in vitro culture conditions. Germination rate ranged 2-60%, depending from the genotype and seeds storage conditions. Plantlets with well developed roots and 2-3 leaves were planted in the substrate in small pots and grown in a greenhouse about a month, then replanted in the soil in field conditions and grown till the maturity. Restored accessions are available now for evaluation and involving in the alfalfa breeding programs.
INTRODUCTION OF LIGNOSILICON IN SOIL SIMULTANEOUSLY WITH SEEDS AND ITS INFLUENCE ON PRODUCTIVITY OF BUCKWHEAT IN ORGANIC FARMING
Authors: Ļebedeva G. , Teliševa G. , Tiltiņa L. , Rancāne S.
Published: August 2015

Lignosilicon (LSi) is biologically active product synthesized in the Latvian State Institute of Wood Chemistry on the basis of wood fuel bioethanol production waste – hydrolysis lignin. On the background of rather low dosages of LSi (40-120 kg/ha) introduced in soil simultaneously with seeds of cereals by mixing them in the box of sowing machine, plant root system developed faster and it’s volume increased significantly, plant development accelerated and the terms of corresponding stages shortened, the crop increased and it’s targeted quality went up, soil agrochemical characteristics improved as well. Due to productivity of cereals was directly connected with root system volume and it’s physiological activity, investigation of LSi effect on the agricultural plants with poorly root system as buckwheat was undertaken. The data obtained of proetein yield, content of aminoacids and dynamics of plant development have shown that lignosilicon has a good prospects for buckwheat cultivation in conditions of organic farming due to it’s ability to provide increase in crop and enhance it’s nutrition value.
EFFICIENCY OF NITROGEN FERTILIZER APPLICATION ON WHITE CABBAGE
Authors: Maļceva Marija , Vikmane Māra , Stramkale Veneranda , Stramkalis Aldis
Published: August 2015

Nitrogen is considered to be harvest-limiting element. Almost all investigations showed that under optimal nitrogen fertilizer harvest increases despite different and contrastive environmental conditions. There is a lack of research about changes of plant photosynthetic action under nitrogen fertilizer influence. During field and laboratory experiments changes of head cabbage (‘Ancoma F1’ variety) photosynthesis - related parameters under different nitrogen supply (50, 120, 190, 190 + 40 and 190 + 50 + 40 N kg ha-1) were observed. Results of field and laboratory experiments showed that optimal nitrogen fertilizer doses are 190 and 190 + 40 N kg ha-1. The conlusion is that chlorophyll content (in SPAD readings and mg.dm-2) and fluorescence parameters (Fv/Fm, Fv/Fo, RC/ABS and PI) can be used as early indicator for forseeing nitrogen fertilizer efficiency for head cabbage. Fluorescence parameters give precise view of nitrogen fertilizer role in plant physiological processes and nitrogen effect on plant growth and development.
THE ANALYSE OF AIR ENVIRONMENT QUALITY MONITORING IMPROVEMENT POSSIBILITIES
Authors: Noviks Gotfrīds , Skromulis Andris
Published: August 2015

Paper presents the results of air pollution analyses during last 8 years in Rezekne city. There is carried out a research of atmospheric dust particles, found correlations between concentrations of different air pollutants. Is given overview about air quality measurements in other countries, pointed out air ionization importance on air quality evaluation. The aim of the research – to ground the extension of air quality monitoring indicators including parameters of the air ionisation and to work out an action program to improve an air quality in working areas and recreating zones.
EVALUATION OF BROWNFIELDS IN LATVIA
Authors: Noviks Gotfrīds , Teirumnieks Edmunds , Lemešenoka Natālija , Matisovs Ivars , Teirumnieka Ērika , Miklašēvičs Ziedonis
Published: August 2015

Brownfields (contaminated or degraded territories) significantly pollutes environment, form derelict landscapes and affects people’s security and health. Formation of these sites depends on many factors such as bad industrial practise and economy, inadequate legislation, wastewater and waste management etc. Inventory and evaluation of these sites in Latvia is carried out according to Regulations issued by the Latvia Cabinet of Ministers. The sites are characterised with parameters which differs from accepted in the other European countries. For example, primary classification indicator in Latvia is a degree of ground and soil pollution in these fields and as a secondary factor – presence of destroyed and abandoned buildings. The paper presents the results of investigation the situation on brownfields in Latvia, especially in Rezekne city, analyses the reasons of their formation and develops recommendations for intensification revitalization process of brownfields.
EVALUATION OF LATVIAN FLAX VARIETIES BY SEED YIELD AND QUALITY
Authors: Stramkale Veneranda , Stramkalis Aldis , Komlajeva Ļubova , Selecka Māra , Vikmane Māra , Stalažs Arturs
Published: August 2015

Flax cultures give dual-purpose production – flax fibre and seeds. Flax varieties adapted to local climate conditions have breeded but up to now the profound research of its quality was not carried out. In our investigation we analysed flax varieties of Latvia selection for seed yield and quality in comparison with standard varieties ‘Vega 2’ and ‘Lirina’. In Latgale Agricultural Scientific Centre 10 Latvian flax varieties are cultivated and seed yield, 1000-seed weight, seed oil content (extracted by hot pressing method) and fatty acid content in flax seed oil (detected with gas chromatography method) have evaluated. Seed yields of fibre flax Latvian varieties are significantly higher in comparison with standard variety ‘Vega’. All analysed seed samples have high oil content (27- 47%) and there is high percentage of polyunsaturated fatty acids in oil (linoleic acid 10,6-16,9%, linolenic acid 54,7-62,1%). There is little difference in 1000-seed weight, content of oil in seeds, percentage of linoleic, linolenic, oleic, palmitic and stearic acid in oil between fibre flax and oil seed flax varieties. The difference between the varieties is more influential. Flaxes seeds from Latvian varieties are in high quality and can be used for food, medical and technical purposes.
SYSTEMATIC APPROACH TO BROWNFIELDS ASSESSMENT IN LITHUANIA
Authors: Velykienė Daiva
Published: August 2015

This paper describes situation of brownfields in Lithuania. The brownfields analysis was made according to the main aspects influencing brownfields redevelopment process the most. This paper presents the existing legislation system relative to brownfields and economic possibilities; the cleaning methods and most popular technologies in Lithuania.
INTELLECTUAL ANALYTICAL GEOINFORMATION SYSTEM “EARTH SCIENCE DATA FOR THE TERRITORY OF RUSSIA”
Authors: Berezko Аlexandr , Soloviev Anatoly , Krasnoperov Roman , Rybkina Alena
Published: August 2015

The present study is aimed at the integration of data on geography, geology, geophysics, geoecology and other Earth sciences in the comprehensive problem-oriented geoinformation system (GIS) including the intellectual superstructure for geoinformation analysis. At the present time GIS provide only limited opportunities for general analysis of geodata handled. At the same time, among the scientific community, dealing with the Earth sciences data, the requirement of more profound and comprehensive data analyzing and processing is constantly growing. The theory and methods of artificial intellect (AI) must become not only an integral, but the main core of a modern GIS. The methods of fuzzy mathematics correlate with a fuzzy character of geophysical data. The AI methods, developed by the authors, and presently applied to volcanic activity monitoring, search and interpretation of anomalies in geophysical fields, solving environmental, geodynamic and other problems, turned out to be a success.
GLOBAL WARMING AND CONSTRUCTION ASPECTS
Authors: Bassioni Ghada
Published: August 2015

The manufacture of cements with several main constituents is of particular importance with regard to reducing climatically relevant CO2 emissions in the cement industry. This ecological aspect is not the only argument in favor of Portland composite cements. They are also viable alternatives to Portland cement from the technical point of view. Substitution of ordinary Portland cement (CEM I) by Portland composite cements (CEM II) and (CEM III), which clearly possess different chemical and mineralogical compositions, results in changes of their reaction behavior with additives like superplasticizers. A common admixture to CEM I in that sense is limestone (industrial CaCO3). Its interaction with polycarboxylates is ignored and its inertness is taken for granted. This study provides a systematic approach in order to better understand the interaction of these polymeric superplasticizers with CaCO3 by adsorption and zeta potential measurements. The results give some fundamental understanding in how far the cement industry can reduce the production of cement clinker by replacing it with limestone as admixture and consequently the CO2-emission is reduced, which is of high political and environmental interest.
ECOLOGICAL EVALUATION OF ZOOPLANKTON GROUPS IN LAKE GERANIMOVAS-ILZAS AND LAKE GARAIS
Authors: Brakovska Aija , Škute Renāte
Published: August 2015

Lake Garais is the second deepest lake in Latvia. Its maximum depth is 56.0 meters, but its average depth is 16.5 meters. Lake Geranimovas-Ilzas is the fifth deepest lake in Latvia. Its maximum depth is 46.0 meters, but its average depth is 9.8 meters [13]. During the research of Lake Gernimovas-Ilzas and Lake Garais three zooplankton groups have been found, i.e. Rotatoria, Cladocera and Copepoda. Having analysed the quality composition of species the authors have concluded that the pollution level of these lakes is low, because there are such olygosoprobic zooplankton species as Keratella cochlearis, Keratella quadrata, Filinia longiseta, that die from lack of oxygen in few hours.
MODELLING OF AN A+B → A REACTION KINETICS IN CASE OF PARTICLES BIG FREE MEAN PATH
Authors: Gaigals Gatis , Kalniņš Juris Roberts
Published: August 2015

The aim of the work is to develop model and program for particle simulations working on laws of particle diffusion in expansion mode and, using approach of MonteCarlo, allows analyzing regularity in two-dimensional A+B → A reactions in case of B particle large mean free path, providing visualization of results and handy further processing of results, using data export ability. In the work are examined regularities in A+B → A reactions, special issues of these reactions, found approximate formula to determine velocity of reaction on centre of absorption surface using simulated data, developed program and made a lot of simulations of different reaction environments. Examined specific features of processed data and ways to enhance credibility and precision of results, also performed filtration of processed data to decrease specific of MonteCarlo method. Found out, that in comparison with nowadays personal computers, there is need for higher performance computing power to process simulation of particle interaction in acceptable timing.
RIGIDITY OF RUBBER-METAL ELEMENTS WITH THIN LAYERS AT COMPRESSION
Authors: Gonca Vladimirs , Svabs Jurijs , Kobrinecs Romans
Published: August 2015

There is described a method of generation the rigid feature “Force – Settlement” for thin- layer rubber-metal compensating elements, which consist of several rubber and non-elastomeric layers, operating when being pressed, taking into account the low compressibility of rubber layers and deformation of support non-elastomeric layers. Variational method of theory of elasticity for compressible materials is used. It is recommended to use the acquired analytic dependencies when analysing the element and designing multi- layer compensating elements, as well as when determining the value of Poisson coefficient for rubber-like materials.
EVOLUTIONARY ALORITHMS AT CHOICE: FROM GA TO GP
Authors: Grabusts Peter
Published: August 2015

Nowadays the possibilities of evolutionary algorithms are widely used in many optimization and classification tasks. Evolutionary algorithms are stochastic search methods that try to emulate Darwin’s principle of natural evolution. There are (at least) four paradigms in the world of evolutionary algorithms: evolutionary programming, evolution strategies, genetic algorithms and genetic programming. This paper analyzes present-day approaches of genetic algorithms and genetic programming and examines the possibilities of genetic programming that will be used in further research. The paper presents implementation examples that show the working principles of evolutionary algorithms.
MULTILANGUAGE WEBSITE CONCEPT FOR OPERATIONAL IT RISK RESEARCH
Authors: Romānovs Andrejs , Lektauers Arnis , Merkurjevs Jurijs , Klimovs Ruslans
Published: August 2015

The paper presents an approach of researches effective organization in sphere of operational IT risk governance. For this purpose, the application of digital multilanguage research area is advised, which can simplify discussion processes for users/researchers from different countries. The concept of multilanguage website is developed based on performed analysis of following modern IT application trends of website development: Web 2.0., social networks, blogs, wiki, etc. Then, practical solutions of advised concept realization are discussed. The presented concept is developed within the project, which is devoted to the research of operational IT risk governance in monetary and financial institutions. Still, the advised concept can be easily adapted for other research areas
INTRODUCING SUSTAINABLE DEVELOPMENT PHILOSOPHY INTO ENGINEERING EDUCATION
Authors: Vyshkin Euphym G.
Published: August 2015

The paper presents an effort to single out the basic issues of sustainability that could make it applicable for the relevant changes in engineering education .The universities are regarded as change agents and key actors in charge of promoting and achieving sustainable future because of their ability to promote importance of sustainable development (SD) through their scholarly work and public service.
METHODOLOGY OF ESTIMATING OF LIMNOLOGICAL CHARACTERISTICS SPATIAL DISTRIBUTIONS ABNORMALITY ON THE EXAMPLE OF LAKE LADOGA SURFACE WATER TEMPERATURE FIELDS
Authors: Timofejeva Larisa , Naumenko Mihail
Published: August 2015

Use of probabilistic approach for estimating of synoptic-scale abnormality is shown. Anomalous deviations of real in situ Lake Ladoga surface temperatures from typical ones were estimated with the data obtained during 43 expeditions 1960 – 2003. These deviations were mapped and statistically analyzed. A degree of spatiotemporal abnormality of real temperature fields, its features and heterogeneous character were revealed. The scales of thermal inhomogeneity are obtained from computation of two-dimensional spatial autocorrelation functions within the random function network. Ways of analysis of characteristics of anomalies fields’ correlation ellipses are given. Applicability of the methodology and the results is suggested.
Hydroelectric Power Plants ’ Re Servoirs And Their Impact On The Environment
Authors: Balzannikov M. I. , Vyshkin E. G.
Published: August 2015

The paper presents the analysis of different types of impact the hydroelectric power plants’ reservoirs could make on the environment. Hydroelectric power plants (HPP) produce ecologically safe energy and correspond to the modern striving for sustainability because they are operated on renewable energy sources. At the same time they can provoke various potential dangers for the environment. The objective of the investigation is to demonstrate the interrelation between the type and structure of a hydroelectric power plant and the way its reservoir may impact on the nature surrounding the plant. These effects may be direct and indirect, positive and negative and vary from insignificant that can be easily fixed to those that are irreversible and catastrophic. The latter should be taken into account during the design of HPP.
Coagulation Of Wood Pollutants From Model Wastewater By Aluminium Salts
Authors: Brovkina J. , Shulga G. , Ozolins J.
Published: August 2015

One of the stages of raw material preparation for plywood producing is hydrothermal treatment of birch wood. Wastewater from plywood hydrothermal basin is characterized by the high degree of contamination. The basic contaminating component of this wastewater is lignin, hemicellulose and extractive substances (LES), which are the main reason of a high level of chemical oxygen demand (COD) and color of water. The main objective of the present study is to investigate the influence of aluminium sulfate, aluminium chloride and poly aluminium chloride dose on coagulation of LES from model wastewater. It was established that the influence of coagulant dose on LES removal can be described by 3 regions: first region - the process of coagulation does not take place; second region is characterized by the sharp increase of efficiency of LES removal and the third region corresponds to decrease of efficiency of LES removal at the increase of coagulant dose.
Analysis Of Reed Resource Dynamics In Water Bodies Of Eastern Latvia
Authors: Čubars E. , Noviks G.
Published: August 2015

The paper shows the results obtained during the research of reed dynamics revealing that in Eastern Latvia 20 lakes and pisciculture farms are potentially important for the reed extraction. In 2008, the reed resources there covered a territory of approximately 2300 ha. The ortophoto images of potentially important water bodies made in 1997, 2005 and 2008 were analyzed using the computer program ArcMap. The reed growth develops differently in every water body, but in general the eutrophication of water bodies and the enlargement of reed-covered areas can be observed. The most rapidly the reed occupies new territories in pisciculture farms and shallow lakes. The analysis of reed resource dynamics show that reed-covered areas in this region are expanding every year. The main factors that influence the distribution of reed growths refer to human activities, climatic conditions, hydrological regime in water bodies and natural processes of eutrophication.
Specific of Hemp Fiber ’ S Plastic Composite Projection
Authors: Kirilovs Edgars , Soliženko Rita , Kukle Silvija
Published: August 2015

In the report there are reflected research results of new board type biocomposites creation for furniture and equipment manufacturing for public segment, replacing traditional petroleum-based components with fully or partly renewable, biodegradable raw materials as one of the major global environmental problems today is non-renewable resource depletion and waste of petroleum-based plastic products. Performed research of biopolymer composites development shows that they are cheaper, environmentally friendlier, lighter, more easily to recycle and to dispose at the end of the product life cycle. For biopolymer’s reinforcement industrial flax and hemp fibers in terms of mechanical qualities are competitive with the glass fiber, they are strong enough in many applications, CO2 neutral, have a relatively low cost, low production energy requirements. By creating new biocomposites it is taken into account that the designed material mechanical properties are mainly dependent on the fiber mass in the matrix, orientation and adhesion to the matrix material. The maximum theoretical amount of fiber weight in composite can reach 91%, specific weight of the fiber component used in practice is usually between 45-65%, but can reach also 70%. For improvement of the adhesion the chemical treatment and drying of the fibers need to be done, also adjuvants that promote development of the hydroxyl group links should be incorporated in the matrix.
The Effect of Steam Explosion Treatment on Technical Hemp Fibres
Authors: Kukle Silvija , Grāvītis Jānis , Putniņa Anna , Stikute Anete
Published: August 2015

As hemp is a renewable resource with the high biomass yield it could be considered as potential abundant local biomass material for a wide range of applications. In this article hemp fibres architecture as a source of high strength cellulose are analysed. In experimental part steam explosion technology is applied to disintegrate technical hemp fibres to elementary fibres with the aim to find out the best way of procedure without usage to environment harmful chemical pre-treatments and looking forward to solve problems on further nano-level environment friendly hemp cellulose disintegration.
Thixotropic Properties of Latvian Clays
Authors: Lakevičs Vitālijs , Stepanova Valentīna , Ruplis Augusts
Published: August 2015

This research studies Latvia originated Devon (Tūja, Skaņkalne), quaternary (Ceplīši), Jurassic, (Strēļi) and Triassic (Vadakste) deposit clays as well as Lithuania originated Triassic (Akmene) deposit clays. Thixotropic properties of clay were researched by measuring relative viscosity of clay in water suspensions. Relative viscosity is measured with a hopper method. It was detected that, when concentration of suspension is increased, clay suspension’s viscosity also increases. It happens until it reaches a certain boarder point when viscosity increases significantly – a dramatic rise is shown on the curve. It means that clay particles make a lace-like, easily broken structure. Impact of chemical reagents on clay suspensions’ thixotropic properties is researched. Experimental results obtained on the new materials with thixotropic properties will allow precise definition of production technologies and usage of a new approach in development of motivation products. Likewise, the results will make an important investment in establishing a thixotropic material description methodology.
Using of Indicators for Environmental Impact Assessment in Latvia and Necessity for Indicators Validation
Authors: Lieplapa Liga , Blumberga Dagnija
Published: August 2015

The EIA procedure in Latvia as it`s known today was implemented by the law „On environmental impact assessment” in 1998. The quantity assessment of expected environmental impact is provided by indicators giving the highest impartiality in this process. The choice of indicators and their approval in EIA projects in Latvia have not received the right attention, the issue is left upon the EIA performers. The problematic issues on necessity of indicator selection and validation are dealt with in the article. 39 environmental indicators were selected for EIA of motor road projects, with the evaluation of their significance and essence, as well as the analysis f application of these indicators in 14 reports concerning EIA of motor road projects. The results revealed the existing problems of indicator application and proved the assumption that there is no common indicator system for the assessment of impact of similar economic projects, proving the necessity of indicator validation to ensure good quality of assessment.
Overview Of The River Basin Management Plans In The Baltic Region Under The Waterpraxis Project
Authors: Mednis Māris , Matisovs Ivars , Teirumnieka Ērika , Martinovs Andris , Vaļģis Gundars
Published: August 2015

The paper provides brief overview of the river basin district management plans in the Baltic region within the WATERPRAXIS project, linked to the EU Water Framework Directive. Latvian experience in completion of the river basin district management plans is emphasized comparing to other regional cooperation partners. Article is based on the report documents, analysis of the available data and review of the development projects subject to implementation. To some extent also potential issues for discussion are outlined. Certain Baltic countries have had difficulties complying with the EU Water Framework Directive,and there are some potential areas of contention, which should be taken into account in further activities. In course of the administrative and territorial reform and compliance with other EU directives (e.g. in the renewable energy sector) modifications can be made to the status of spatial and also river basin management plans and for the purpose of sustainable development in the region.
The Technological Investigations Of Manufacturing Of Energy Chips
Authors: Miklašēvičs Ziedonis
Published: August 2015

The methodology in Latvia forest industry provide to determine the quality of energy chips only in long- term storage places before selling. Due to the lack of hard empirical data about the quality parameters of energy chips in different phases of manufacturing process, this research paper consists of: - the identification and analyses of the factors that influenced the values of energy chips quality features such as: bulk density, moisture content, ash content, higher and lower heating value according to actual moisture content and per dry mass of the chips; - the methodology for determination the quality parameters of energy chips by analysis the wood moisture content and by choice the method of the manufacturing of energy chips.
System Analysis in the Environmental Science
Authors: Noviks Gotfrids
Published: August 2015

The paper discusses the essence, structure, research objects, methods and aims of the environmental science. Due to interdisciplinary character of the environmental science, large scale term and vague boundaries with other sciences there are various definitions of environmental science and different concepts, sometime delusions in research fields and methods . Author analysed the current location of research objects in environmental science and their connection with other sciences and came to conclusion that up to nowadays there are not developed essential part of every independent science yet – general theoretical base of environmental science. It is necessary to find out perfect proper research fields and objects of environmental science, which differ from other natural , and technical sciencies. Analysis showed that the objects of environmental science must be neither nature nor technology itself but only contact zones between technosphere and biosphere –namely, between systems – technosystems and ecosystems . Exactly in these contact zones arises most environmental problems , conflicts and stresses between human activities and nature. The properties and processes in these zones obey to laws which must be determined, interpreted and used for mankind wealth. It is the aim of environmental science and the complex system analysis must be essential research methodology and accordingly system engineering as instrument for solving practical environmental problems.
Compacting Mechanisms of Common Reed Particles
Authors: Repsa E. , Kronbergs E. , Smits M.
Published: August 2015

The paper present experimental investigation results of common reeds (Phragmites australis) particle compacting in closed die. Common reeds are important natural biomass resource in Latvia. Compacting of biomass is very complicated process for solid biofuel production and there are many factors influencing to this process. The quality parameters of compacted biomass are described by European countries standards for solid biofuel. Density is the most important quality parameter of biomass compacting. The paper present results of common reeds particles compacting mechanism in closed die. Maximum pressure 212 MPa had been achieved in compacting. For compacting process evaluation has been determined pressing energy and density of briquettes. The minimum of density 0.87 g cm-3 have briquettes with particle size 12 – 13 mm, but maximum density 1.03 – 1.04 g cm-3 two particle sizes < 0.5 mm and 32 – 33 mm briquettes. Maximum value of energy consumption for compacting (~172 kJ kg-1) has been obtained for reed particle size 32 – 33 mm, minimum value (~53 kJ kg-1) for particle size less than 0.5 mm.
Determination and Separation of Diarylheptanoids From Alder Growing in Latvia
Authors: Roze Liga , Bikovens Oskars , Telysheva Galina
Published: August 2015

The composition of diarylhepatnoids fraction isolated from bark of two alder species (grey alder and black alder) was studied. The efficiency of three extraction methods used for isolation of diarylhepatnoids from alder bark was compared. Two diarylhepatnoids: 1,7-bis-(3,4-dihydroxyphenyl)-heptan- 3-one-5-O-β-D-xylopyronoside (oregonin) and 1,7-bis-(3,4-dihydroxyphenyl)-3-hydroxyheptane-5-O-β-D- xylopyranoside were isolated from the bark of grey alder. The phenolic components of the extracts were analyzed by high-performance liquid chromatography (HPLC). Quantitative determination of oregonin was performed using an internal standard method. The results obtained show that alder barks are rich source of diarylhepatnoids.
Water Quality Model Description
Authors: Ruskule Erika
Published: August 2015

Water wise use and conservation is one of the key prerequisites for economic sustainable development. Accession to the European Union, Latvia is committed to meeting the EU environmental requirements. Water Framework Directive (Directive 2000/60/EC, 2000) is a legal act, which provides water protection and sustainable management principles and tasks of the European Union. It provides uniform protection and management system for all waters: rivers, lakes, coastal waters and groundwater, providing that they must also achieve good water quality by 2015. year. The Directive provides for the identification of the current water situation and to obtain additional information by following the water monitoring and for basic background information to establish an action program to improve water quality. Therefore, the Latvian conditions are important to assess the flow of nutrients, their sources and amounts of Latvian detention basins using existing models and innovations in methods and model systems for the retention of part of the calculation. Therefore, in this publication are offered in various countries of the world models will be useful in Latvian processing of data.
Development of Municipal Solid Waste Management
Authors: Teibe Inara
Published: August 2015

This paper is based on an empirical work done by author on a series of case studies such us document studies and analyzing the best practices examples. The objective of this research is to find out barriers to reach regional waste management plan demands in three municipalities: Salacgriva, Saulkrasti and Ikskile. Author gives proposal with some recommendations for development of municipal waste management as well. There are several views and attitudes of local stakeholders such us municipality, waste producers, waste collectors and mediators on how to manage collection and transportation of solid waste in practice as well as on public involvement in the process.. Passivity of stakeholders to realize theirs needs and requirements mainly depend on the limited human and financial resources, but often political will, skepticism or lack of knowledge. A lot of problems could be solved faster and easier, if there existed better communication and collaboration among local stakeholders.
Use Of Plants To Remediate Soil Polluted With Oil
Authors: Telysheva G. , Jashina L. , Lebedeva G. , Dizhbite T. , Solodovnik V. , Mutere O. , Grigiškis S. , Baškys E. , Aikaite J.
Published: August 2015

In the present investigation the growing and development ability of various annual and perennial plants to grow on model peat substrate artificially polluted with oil products in the range of concentrations from 1 to 5% was evaluated. The highest tolerance towards peat contamination by oil products has been demonstrated by three annual crops (maize, oat and lupine). These plants were tested for phytoremediation of polluted black soil from the area of oil refinery plant (Mazeikiai, Lithuania), which was treated by association of oil oxidizing bacteria up to residual concentration of the oil products of 4.5 %. The maize plants revealed the highest remediation ability: oil content in the soil decreased by ~ 1.5 times in one month plant vegetation.
Environment Pollution With Oil Products and Review of Possibilities for Collection Thereof
Authors: Treijs Juris , Teirumnieks Edmunds , Mironovs Viktors
Published: August 2015

The largest global pollution nowadays gives oil and oil products. This contamination poses a danger to the environment and aquatic eco-systems. Not only seas but also small water bodies and watercourses, as well as coastal areas, soil and groundwater are contaminated with oil products. Contamination results in destruction of some plants or animals, but in events of high oil contamination also of the entire ecosystem. Latvia has inherited the oil pollution from both the Soviet Union large-scale industry and its military facilities, as well as at present the oil products are getting into environment from petrol stations, accidents, and from the cross-border pollution. In many cases of oil spills, people are trying to collect them in order to have no impact on the environment, but unfortunately very often, even in most cases this does not occur. Financial resources, as well as the lack of appropriate technologies or restricted possibilities for their application are the limiting factors. The article deals with the traditional methods of oil collection in water and also describes options for decontamination of polluted soil from the oil products. A brief insight is provided into application of ferromagnetic sorbents, which is a new method for collection of oil and oil products.
Agronomic Trait and Genetic Analysis of Latvian Flax Germplasm
Authors: Runģis Dainis , Ļubinskis Linards , Stramkale Veneranda
Published: August 2015

There is a long history of flax cultivation in Latvia, and breeding programs were active until 1970’s, when flax breeding in Latvia was halted. Since 1992, the Agriculture Science Centre of Latgale (ASCL) has repatriated Latvian flax germplasm from various genebanks, as well as renewed limited breeding activities in flax. Currently, the ASCL holds a collection of 497 flax accessions, as well as 9865 accessions of various lines and hybrids developed at the LLZC since 1993. To assist in the characterization of this Latvian flax germplasm, we have utilised DNA markers to assess genetic diversity and relatedness, as well as surveying functional polymorphism. We have utilised Simple sequence repeat (SSR) markers developed from both genomic libraries as well as expressed sequences. The results of the DNA marker survey were utilised to determine the genetic polymorphism and relatedness within Latvian flax germplasm, and these results were compared with the analysis of agronomic traits carried out in field trials at the ASCL. The development of DNA markers linked to traits of agronomic importance will assist in the development of a Latvian flax breeding program. The use of DNA marker technology will allow more efficient assessment and rational utilization of Latvian flax germplasm.
Analysis Of Invasive Flora In Cemetery Territories Of The City Of Daugavpils
Authors: Rutkovska Santa , Pučka Irēna , Novicka Ingūna
Published: August 2015

Alien species are reaching different areas, including also cemeteries. Inventory of invasive flora of cemeteries of the city of Daugavpils actually is the first such type of work to such level of detail on the Latvian scale. Field studies were conducted in 10 cemeteries of the city of Daugavpils. The obtained results are indicative of a comparatively high proportion of invasive plant species in the cemeteries. 49 invasive alien species were found. In the cemetery areas these are spreading mainly from greeneries, but there are also such taxa, which have accidentally reached the cemeteries. The most frequent plant in the Daugavpils cemeteries is Spiraea chamaedryfolia. Taking into account the trends of migration, sex-age structure of population, climate change, availability of exotic and new ornamental plants, it is most likely that the number of invasive species will grow in the future.
Using Of Information Technologies To Improve The Spatial Understanding Of Students
Authors: Vronskis Olafs , Vronska Natālija
Published: August 2015

It is possible to improve the development of students’ spatial thinking with various information technologies. We can improve students understanding with three dimensional models, created in the CAD program and special processing it in PowerPoint in the program, together with drafting in three planes. Gradually solving tasks in planes and explaining it in three dimensional models, the solution of concrete task is much clearer, because it is possible to look a situation together in planes and 3D models. The students of three faculties were polled that cognize the students’ opinions about teachers teaching methods in descriptive geometry lessons and analyze spatial understanding of students. A possibility to use information technologies to improve a descriptive geometry lectures have been researched in this work. The most important information about working out methodological materials has been generalized in discussion part. The results of research show that lectures with information technologies using improve students’ understanding of solved tasks during the lectures.
Estimations In Distribution And Growing Characteristics Of Wild Hypericum Perforatum L. (Hypericaceae) Populations During The Last Decade In Armenia
Authors: Abrahamyan Armine
Published: August 2015

The small mountainous country of Armenia has a rich flora of ca. 3600 species of vascular plants, which makes about half of entire Caucasian flora, distributed across desert and semi-desert, steppe, forest and alpine landscape. Anthropogenic threats to this biodiversity such as overpopulation, deforestation and urbanization have simultaneously hindered research and increased the need for it. Of the ca. 500 species in the Armenian flora with a record of medicinal and/or economic use, ca. 50 species are used in the folk medicine and include both wild-collected (Crataegus sp., Hypericum perforatum, Artemisia absinthium) and cultivated (Chamomilla recutita, Mentha piperita, Crocus sativus) species (1). Only limited information on the genetic biodiversity, population location, structure and size, and conservation status of most of these species is, however, at this time available. During 2007-2009, field studies were conducted to re-locate populations of wild Hypericum perforatum L. (common St. Johnswort, Hypericaceae) on the basis of historical (i.e. herbarium voucher, (2)) records, and to discover new populations. The plants habitat and phenological characteristics were estimated growing in different populations. GPS map of population distribution was created and its overall sizes were assessed. According to historical records this species had been widely distributed in the south regions of Armenia, however almost half of the populations no longer existed in the cited locations. However, 2 new populations were loacated in the south east regions. Evidence that the abundance and distributional range of H. perforatum is expanding in the north region was collected. This research provided baseline data that can be used for the development of further ex situ and in vitro strategies to conserve unique genotypes of this important medicinal and culinary species in Armenia.
Synthesis Of Reconfigurable Slotted Waveguide Array Antenna
Authors: Abrahamyan H. V.
Published: August 2015

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The Thermal Characteristics Of Gypsum Boards With Phase Change Materials (PCM)
Authors: Bajare D. , Kazjonovs J. , Korjakins A.
Published: August 2015

Two types of PCM were investigated for use in phase change gypsum boards: salt hydrate and paraffin. The transition temperatures, or melting temperatures, of the PCM is near to standard or suggested room temperatures 20-21 °C for heating-dominated climates or 25-27 °C for cooling-dominated climates. Phase change gypsum boards were produced by using three different methods: simple immersion for 1 hour and direct incorporation of raw and microencapsulated PCMs in 5 and 10% of composition mass. PCM were tested and the effects of energy conservation of PCM gypsum boards were determined. Also some physical and mechanical properties were determined to investigate the effect of PCM addition to gypsum boards.
Physical Properties of Latvian Hemp Fibres
Authors: Baltiņa I. , Zamuška Z. , Stramkale V. , Strazds G.
Published: August 2015

Each year more and more people focus on healthy, ecological and environmental-friendly living. Environmentally friendly lifestyle doesn’t mean that we are using only natural products, but attention is pointed to the manufacturing and production process also. The rapid development of recycled and biodegradable products causes expanding usage of hemp fibers both in household and technical textiles. The analysis of hemp cultivation and usage trends in the world and Europe shows that hemp cultivation and processing in Latvia has good perspectives. Product quality is influenced by raw materials. In this case it is hemp fiber descriptive characteristics. Hemp fibers are natural fibers and their properties varies according to plant growing regional climatic conditions, amount of manure, plant density, harvesting time and pre-treatment technological processes. There are studied the influence of above mentioned factors on chemical composition, geometrical and physical properties of the Latvian hemp fiber both local and foreign cultivars. The work was carried out in cooperation between Riga Technical University, Textile Technology and Design Institute and the Agriculture Science Centre of Latgale.
Assessment of Fish Health Status Under Long-Term Water Pollution : Vygozero Reservoir , North-West Russia
Authors: Belicheva Lidia A. , Sharova Julia N.
Published: August 2015

Environmental pollution and its effects on the health of aquatic ecosystems is a great problem that has been studied intensely in the last years. The Vygozero reservoir is one of the largest water bodies of the Karelian Republic. Its ecosystem has undergone significant changes since the 1930s mainly due to anthropogenic influence from the development of pulp and paper mill industry leading to accumulation of toxic contaminants and eutrophication. At present, the water body has been shown to be also polluted by hydrocarbon products and heavy metals. Among the huge changes in Vygozero ecosystem is the decrease of some fish populations and partial loose of commercial fishing importance. Despite the obvious changes in fish population the chronic biological effects of the Vygozero reservoir pollution on fish organism are poorly studied. This study is concerned with the evaluation of pollution influence on fish health status and establishment relation between fish health and environmental quality. The parameters selected for this aim were the occurrence of gills, liver and kidney alterations, as histopathological changes are widely used as biomarkers in the evaluation of the health of fish exposed to contaminants. Our findings confirm chronic pollution of the Vygozero reservoir. Histological analysis of fish tissues revealed a variety of progressive, regressive, inflammatory, circulatory disturbances and neoplastic changes. Observed histological alterations indicate that organism of fish from Vygozero reservoir responses to the impaired environment quality. Revealed histopathologies are sings of metabolic disorders, immunity suppression, compensatory reactions development and functional abnormalities in vital organs of studied fish. The results of the study correspond to the prior research devoted to ascertain tissue changes in different fish species taken from an area with chronic multiple anthropogenic impact. So it can be concluded that histopathological lesions are result of long-term effect of toxic xenobiotics.
The Productive Longevity Of Perennial Grasses Swards Depending On The Npk Fertilizer Rates
Authors: Berzins P. , Rancane S. , Svarta A.
Published: August 2015

The longevity and producing capacity of perennial grasses swards was studied on mineral soils at the LUA Research Institute of Agriculture in long-term experiment during 1974-2010. There were applied lime and mineral fertilizers with different NPK doses (0-400 kg ha-1) protractedly many years. In such way there formed soils with various content of P, K, organic matter content and pHKCl level as well. Research results showed that liming of soils and using of mineral fertilizer changed not only productivity of grass mixtures but also botanical composition. Mineral fertilizer N200P100K300 provided the highest yield of dry matter – 7.32 - 12.0 t ha-1 and optimal botanical composition of a sward during many years. On unlimed soils (pHKCL less then 4.0 in 1997) dry matter yields of grass sward was substantially lower and there was observed disappearance of seeded valuable grasses out of the sward and increase of herbs and non-seeded grasses –Festuca rubra L., Agrostis tenuis Sibth., Taraxacum officinale Wigg. and others. Liming of soils increased dry matter yield in treatments with high doses of N (300-400) fertilizer.