CONTENTS & ABSTRACTS
InEnglish. Summaries in Estonian
Proceedings of the Estonian Academy of Sciences.
Engineering
Volume 11 No. 3September 2005
Microstructuralevolution and mechanical properties of nanostructured copper;187–197
Lembit Kommel, Irina Hussainova, Olga Volobueva andRünno Lõhmus
Abstract. Nanostructuredmetallic materials exhibit outstanding mechanicalproperties. Pure copper was chosen as a test material and was subjected to anequal channel angular pressing to produce a nanostructure. The paper analysesdevelopment of the microstructure during severe plastic deformation of copperand mechanical properties of the metal. Tests show that the nanocristallinecopper possesses high tensile strength and microhardness as well as highplasticity after hard cyclic viscoplastic deformation. However, heat treatmentand method of deformation influence the properties to a large extent.Dependence of the changes in structural parameters and properties on thedeformation process and heat treatment are studied.
Key words: nanocrystallinecopper, nanostructure, mechanical properties, severe plastic deformation.
Simulationand analysis of thermal performance of an apartment building;198–206
Kadi Kusnetsov and Teet-Andrus Kõiv
Abstract. The paper describes results of the computer simulation of thethermal performance of an apartment building. Results concerning heatrequirements, heating load and indoor climate simulation are given. Applying heating load analysis inapartment buildings without individual temperature control, it is possible toreduce heat consumption for heating.
Key words: apartment building, thermal performance, simulation, TRY.
Investigationof the domestic hot water consumption in apartment buildings;207–214
Alvar Toode and Teet-Andrus Kõiv
Abstract. Domestic hot water consumption profile in fiveapartment buildings is investigated. Consumption profiles in 1973 and 2003 arecompared. Domestic hot and total water consumption data within the last fiveyears are presented. Decrease in domestic hot water consumption is one of themain reasons for decrease in the heat requirements in typical apartmentbuildings.
Key words: domestic hot water, consumption profile.
Behaviour of wind speed fronts;215–225
Teolan Tomson and Maire Hansen
Abstract. This article describesmethods for determining wind speed increments in relation to wind fronts andtheir dependence on the height of measurement, average wind speed and winddirection. Wind directions and speeds, which can produce the most powerful windfronts, significant for the performance of the Estonian power system, areanalysed. The impact of wind speed fronts to the behaviour of a grid of windturbine generators is assessed.
Key words: wind speed front,frequency distribution function, power system.
Group-mode performance of wind turbinegenerators; 226–233
Teolan Tomson
Abstract. in thepaper the influence of the wind power increments on the group-mode performanceof wind turbine generators (WTG) has been studied. It is proved that withincreasing distance between WTGs, the suppression of global wind powerincrements in the group will increase. Wind power increments in the shelteredlandscape (inland) are lower than in the coastal zone and the positive effectof group-mode performance is reduced.
Key words: wind power, wind turbine generator, group-mode performance.
Analgorithm of the formation of waste load in industrial effluents;234–244
Jüri Säärekõnno
Abstract. Nowadays industry isfacing significant new challenges as the production processes must become moresustainable. Therefore the environmental impact assessment is necessary for anycompany. In this study an algorithm, describing the formation of the load ofresidue substances in industrial effluents, is presented. The algorithm,expressed in the form of a limiting state equation, enables assessment of theenvironmental impact either of the total effluent of the company (integrallevel of analysis) or of one effluent from each water use unit (differentiallevel). This analysis represents a part of the wider (total) environmentalimpact assessment of the company that may be carried out together with theproduct life cycle assessment.
Key words: industrialeffluents, pollutant substances, waste load, modelling, limiting state equation,environmental impact assessment.
Profilesof waves from high-speed ferries in the coastal area of Tallinn Bay;245–260
Tarmo Soomere, Reio Põder, Kalev Rannat and AndresKask
Abstract. The shape and properties of long ship-generated wavesapproaching shallow coastal areas of Tallinn Bay are studied based onrecordings of water surface time series. For typical leading wake wavesnon-linear effects become significant at depths of 10–15 m. A large partof waves (with the height over 0.4 m) have theshape of cnoidal waves in shallow areas with depths of 4–5 m. The shapesof the largest wake waves are close to the solitary wave solutions of theKorteweg–de Vries equation. Such waves excite considerably largervelocities of water particles than sinusoidal waves of equal height and length.
Key words: fast ferries, ship wash, cnoidal waves, wave measurements.
Instructionsto authors; 261–263
CopyrightTransfer Agreement; 264
