18420 research outputs found
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Theoretical Mechanics for Students of Engineering Profile
No full textAbstract. The paper summarizes the experience of the Institute of Mechanics in teaching programs that prepare
students in Mechanical Engineering, Manufacturing Technology and Transport where Theoretical Mechanics is a
fundamental discipline. The paper analyzed the following main methods and tools used for training students in
Mechanical Engineering: lecture materials, including multimedia presentation, the system, which generates a
large number of engineering problems for individual work; application of the system for students’ individual
work; application of E-learning system ORTUS; individualization of the exchange of information between
students and teachers using modern technologies
Method for Synthesis Model-Reference Adaptronic Automatic Control System
No full textAbstract – this paper continues the authors’ former research. It is focused on modelling adapting device. The equations used for self-tuning or adaptive systems are adjusted to derive the mathematical model of an adaptronic system and the structural scheme of such system is built based on the scheme of self-tuning system. Adapter is described as open-loop automatic control system with two first-order aperiodic blocks and PI controller. As here the main attention is paid to the adapter and to simplify equations, blocks of the main loops are proportional (P) controllers. This is used to make a simulated computer model for adaptronic syste
Interaction of Socio-Economic Factors and Real Estate Market in the Context of Sustainable Urban Development
No full textThis article in general reflects the significance of socio-economic factors and the real estate market in sustainable urban development. The relevance of the research is being determined by the high ratio of the real estate market and construction industry in Latvian and Baltic economic structure, as well as well as their major impact on the state socio-economic status. The objective of the research
is to identify the major problems existing in the sustainable development of real estate industry for improvement of the situation. The particular attention will be paid to the problems of socio-economic aspects and related macroeconomic indicators. On the basis of the results of the research the proposals for advancement of sustainable an d competitive development are prepared. The subject of the research is an interaction of socio-economic factors and real estate market over the period from 2009 to 2013.The article reflects the impact of Latvian national economy and real estate market on the sustainable urban development, as well as the main trends in the real estate market and the socio-economic sphere of the country, in the overall context of the development of the Baltic States . The role of the state is reflected in the socio-economic processes regulation, nteraction of the economy and real estate market development, factors influencing the house
building, the main challenges and directions of Latvian sustainable development strategies, as well as the correlation of some macro-economic indicators in terms of sustainable development. On the basis of the conducted study, the main trends in the sustainable development of the real estate market and in the socio-economic sphere have been defined, as well as recommendations on improvement of the situation in the longer term and preventive measures have been developed. The historical, logical, analytical and comparative methods have been used in the article
Making Higher Mathematics Accessible: Experience from Riga Technical University
No full textRiga Technical University is the only technical university in Latvia and the first technical university in the Baltic countries with long lasting traditions, advanced teaching methods and around 15 000 students from Latvia and abroad. Number of high school graduates in Latvia is decreasing every year as well as their interest in STEM subjects during high school. As a result the university is facing insufficient level of student knowledge in mathematics which is one of core subjects in engineering sciences. This aspect leads to high dropout rate during the first year of studies. In order to overcome these problems we have analyzed data regarding student high school leaving exam marks and first semester math grades and decided upon a plan for helping weakest students to catch up with Higher Mathematics courses. Actions we are taking include conducting simple video lectures which are available online for free and compensative courses right before first semester in topics which are found to be most challenging for students in previous teaching experience. The paper covers educational data analytics, teaching strategies and lessons learned from evaluation of the results in Riga Technical University
Catalytic Wheat Straw Pyrolysis Investigation
No full textWheat straw has been known as an agricultural residue with a potential use as a biomass for valuable chemical compound production by use of such technological processes as pyrolysis and gasification. In this work catalytic pyrolysis process of wheat straw was investigated in order to obtain new information about the activity of different commercially available catalysts, and dolomite as a local material that could probably be useful for chemical production in future
Synthesis, Spectroscopic and Conformational Analysis of 1,4-Dihydroisonicotinic Acid Derivatives
No full textStructural and conformational properties of 1,4-dihydroisonicotinic acid derivatives, characterized by ester, ketone or cyano functions at positions 3 and 5 in solid and liquid states have been investigated by X-ray analysis and nuclear magnetic resonance and supported by quantum chemical calculations. The dihydropyridine ring in each of the compounds exists in flattened boat-type conformation. The observed ring distortions around the C(4) and N(1) atoms are interrelated. The substituent at N(1) has great influence on nitrogen atom pyramidality. The 1H, 13C and 15N NMR chemical shifts and coupling constants are discussed in terms of their relationship to structural features such as character and position of the substituent in heterocycle, N-alkyl substitution and nitrogen lone pair delocalization within the conjugated system
Efficiency Improvement of Road Haulage Using Long Vehicle Combinations
No full textLatvia has successfully met the EU requirements in road transportation and introduced in legislation main conditions regarding to technical parameters of road transport vehicles. Legislative acts of EU determine that Member States may allow circulation in their territory of vehicles or vehicle combinations for national transportation of goods, which are not in conformity with the some characteristics of Council Directives. There are two Member States fully allowing circulation in their territory of extra long vehicle combinations. This situation causes some misunderstanding for Latvian haulers. There are several pullbacks for introduction modular combinations in Latvia. Specific conditions are preconditions for research of opportunities to start use long vehicle combinations in Latvia. It is important to recognise the positive role that the vehicle modular combinations can play in a sustainable transport policy in Latvia and others Member States
