In Latvia, use of unheated cow sheds with lowered environmental temperature is growing. In such circumstances, cooling of the milking equipment washing liquid is more rapid and quality of the washing equipment decreases. However, it may be eliminated by coating the milk and washing liquid piping with heat insulation. A mathematical model of the milking equipment washing liquid by which the end temperature of the washing liquid cooling can be determined is developed. Two types of heat insulation materials are under the trial. Laboratory experiments on cooling of the washing liquid are carried out and the experimental coefficients of the mathematical model are determined.

The article discusses investigations in a flat rectangular contact area of two elastic solids (brake friction lining and disc) using a theoretical method. The solids are in free as well as in forced movement. The investigations have resulted in correlations describing deformation and stiffness parameters of solid flat joint in different loads: transference of the centre of cross section delta0 the angle of turning phi of one solid in relation to the other (as a result of friction lining deformation), and tension sigmax in any cross section of the contact area. The results of the investigations make it possible to analyze the stiffness of the contact of solids, test the strength of the contact areas, optimize the contact are of solids, and prognosticate even wear out of friction lining.

Biodiesel is renewable and environmentally friendly fuel, which can be used as a substitute for diesel in compression ignition (CI) engines. Nowadays it is also successfully used not only in transport sector, but also in commercial construction equipment and space heating. As the production of biodiesel (rapeseed methyl ester RME) is started now and is planned to grow rapidly, it is necessary to investigate biodiesel impact on engine performance and exhaust gas composition. This paper describes results of the investigation the aim of which was to find out the impact of biodiesel and its blends on an engine's dynamical, economical and ecological parameters in laboratory conditions on an engine test bench. The experimental work was done with an XD2P diesel engine in the Motor testing and biofuels laboratory of the Motor Vehicle Institute of Latvia University of Agriculture. The engine was fuelled on fossil diesel, rapeseed methyl ester (RME) and on blends of 5 (5RME) and 35 (35RME) percent RME/diesel fuel. The results indicated that power for biodiesel and blends was lower than with ordinary petrol diesel on average. 7.9% on 100RME and 3.6% on 35RME. The reduction in torque and increase in fuel consumption was observed. Experimental results showed that the addition of RME to diesel can significantly reduce oxides of nitrogen (NOx), carbon monoxide (CO), and absorption coefficient.

The paper gives the data about the mineralization process (sum of ions) and the amount of nutrient ions (nitrogen, phosphorus) contained in water of two streams (basin areas 1.63 square km and 2.02 square km) located in soils of different texture in the karst zone. As the study results have shown, higher amounts of DIN (dissolved inorganic nitrogen) were determined under the conditions of higher humus content in the soil (more humus (0.8-3.0%) was observed in glacial lacustrine soils), uneven runoff distribution (when its formation process is interrupted), and increasing DIN concentrations in silt. N-NO3 purification coefficient in stream water was higher when the stream was flowing via non-drained wood-covered area, also under the conditions of higher air temperatures. TP (total phosphorus) concentrations contained in stream water mostly depended on large amount of precipitation (especially in summer) as well as on phosphorus contained in silt: higher P2O5 concentrations contained in silt determined lower TP concentrations in water (determination coefficient of the relation r**2=0.24-0.30).

The paper presents the results of investigations on wastewater formation and its treatment in constructed wetlands (CW) with horizontal flow. The investigations were carried out on a dairy farm in the period of 1995-2004. On farmsteads containing cattle sheds, the pollution of wastewater is 2-3 times higher compared with domestic wastewater. The largest amount of slowly decomposing organic pollutants is retained during wastewater filtration via a septic tank (62.7% according to CODCr). During wastewater filtration through a horizontal CW, the amount of retained organic pollutants biochemical oxygen demand (BOD5) and chemical oxygen demand (CODCr) is 93.6%. During wastewater filtration through CW, nutrients (Ntotal and Ptotal) treatment efficiency on the dairy farms, where Ntotal concentration is 101.0 mg lE-1, is one the average 61.4% of nutrient load, and 41.4% of P where Ptotal concentration is 21.5 mg lE-1. The analyzed wastewater treatment facilities (septic tank + CW) are distinct for their buffering capabilities. They are affective enough, however due to limited P removal processes in sustainable natural environment, additional P-removal means are to be used in wastewater treatment facilities arranged on dairy farms.

The changes taking place in economics, its internationalisation, development of information and progress of science and technique determine the necessity to raise the country's economic competitiveness, as the result of it the level of life will rise. It is relevant for Latvia to be aware of its advantages and potential competitiveness in order to carry out appropriate macroeconomic policy and favour the introduction of appropriate macroeconomic as well as social policy. The main advantage for providing more rapid development is the fact that Latvia is a small country, able to adopt flexibly, the demand of economic environment where it is easier to achieve a compromise with society. As well as the fact that it is characteristic for the population of Latvia to have a constant tendency towards better life. The way in which Latvia will be able to use its comparative advantages in context of EU market will determine the progress of the national economy including agriculture. At the moment, several problems, which are to be solved, have already appeared in agriculture. The more rapid introduction of technologies of information communication (ICT) in agriculture could be one of the ways to solve the problem. It would provide the development for both economic and social spheres motivating exchange of information, expanding of the market, increasing of production quality, improving work organisation in enterprises, and providing more possibilities for education. To carry out the questioning of students of the Latvia University of Agriculture in the course of study in order to find out the level of ICT application among students, as well as to obtain information about ICT application in the process of education.

The research paper summarizes the results of the influencing factors of small and medium enterprises development: government's policy, access to short and long term financing with reasonable interest rate, investments, tax system, geographical environment, business environment and infrastructure, experience and knowledge. Most of all the small and medium enterprises development is influenced by the investments but also other factors have very significant role.

The paper is aimed at the assessment of opportunities for the financing of innovative activities in Latgale region. The analysis is based generally on the case of Rezekne. Firstly, the problem is determined - Latgale is the weakest region in Latvia from economical development point of view. Secondly, the overview of the financial resources for innovative activities is given. Finally, the author argues his opinion on necessity to develop innovative business in order to improve the situation in Latgale. One of the most important aspects that hamper Latgale's development is the lack of financial resources. The optimal schemes for the financing of innovative business are offered. The research lead to the conclusion that finances for sustainable development of innovative business could be attracted through the Latgale's small enterprises (SMEs) cooperation with regional higher education institutions (Rezekne Higher Education Institution, Daugavpils University), business support centres and Rezekne Special economical zone structures.

In the article there are used statistical data about Latvia rural private households of the years 2001 and 2003. The distribution of natural households in Latvia countryside is investigated. The possibilities of the use of input-output models in the research of natural rural household economy are investigated. Making use of private household "Galakrogs" input-output tables for the years 1999, 2000, and 2001 published by A.Eglite, corresponding input-output models are compiled and their informative analysis is performed.

The aim of the present study was to investigate the application possibilities of berries marc in wheat bread making to improve its quality. Sensory evaluation was used to determine the liking degree of bread with berries marc. Twenty samples of wheat bread with raspberries, white currants, gooseberries and seabuckthorn marc were produced by using standard technology. A 9 point hedonic scale was used to find out the degree of liking. The sensory data were analyzed using analysis of variance (ANOVA) and Tukey's test. The results of hedonic scaling show that berries marc (5-10% of the flour mass) can be used in baking wheat bread.