Browse

This paper presents a novel control system design for the wind turbine model with PIC microcontroller power control system. The system uses Doubly Fed Induction Generator (DFIG) for wind power generation to generate electricity. For controlling power generation process the system applies microcontrollers PIC operating in multitasking mode. The proposed PIC controlled DFIG not only provides a low cost solution to today?s electric power needs, but also is aimed at delivering better power quality, making it ideally s...

The study of sediment transport in the coastal zone under the influence of waves and currents makes it possible to predict changes in the ecosystem of the coastal zone under various hydrometeorological conditions and anthropogenic influences. River runoff and abrasion processes are one of the main sources of solid matter entering the coastal zone, as well as one of the factors determining the changes in the granulometric composition of bottom sediments. Since the rivers of the Western Crimea are heavily regulated,...

In this paper we focused at the analysis of the possible use of biomass ash coming from wood chips combustion as pozzolanic admixture in mortar mix design. Biomass ash was characterized by XRF, SEM, and EDS analyses. The pozzolanic activity of the ash was tested using a modified Chapelle test. As the examined ash was pozzolana active, it was used as partial PC replacement in the composition of cement-based mortars. The PC replacing ratio was 10 and 15 wt. %. For the hardened mortar samples, bulk density, matrix de...

Annually natural resources are disappearing more and more, particularly it concerned forest resources. Furniture, houses, carpentry and etc. are made from wood. Scientists gradually try to find options for replacing forest resources, produce products from other materials, but forest areas are declining. every year. For conservation and rational forest usage, it is necessary to change needs for certain assortments and harvesting of natural wood in the future, and it will be achieved by forest consumption optimizati...

Woodworking hand tools have served as the basis for further development of the woodworking manufacturing. Even in nowadays woodworking hand tools are widely used in wood crafting. Besides they are used in manufacturing too, to complete some operations of wood technological processing without electrical hand tools and wood working machines. The aim of the research is to create structure scheme subdividing the woodworking cutting hand tools, which provides cutting as a main function of tool, in main and subgroups wi...

We propose a theme analysis method that takes into consideration the perspectives of both a supplier (place) and a consumer (user) in unstructured place reviews written by users. To this end, ambiance on the place side and companion and time on the user side were considered as the theme elements. For the experiment, we used the review text data written in English provided by Yelp, and we selected coffee-related places (e.g., coffee shop, coffee house, etc.) from various place categories. From among them, we chose ...

Zarechensk barite-polymetallic deposit is located in the northwest part of Ore Altai megatrough, which has long-lasting history of its development and complicated geological structure. Within the ore district, which is the northwest part of the devonian Zmeinogorsk-Bystrushinsky trough, ore mineralization is associated with the system of northwest border faults and cross branch faults. At these deposit four main stages and five phases of minerogenesis were determined. The first stage is the stage of oregenesis beg...

A specific feature of thermal power plants (TPP) is the multivariate nature of their intense technogenic impact on the environment, including pollution of air, environmental waters, soils, as well as disturbance of the geologic environment. Besides, TPPs cause thermal, radiation, noise and electromagnetic pollution; they also induce physical littering of the terrain and problems associated with storage of ash waste. Due to the reasons stated above, a comprehensive study of environmental damage zones caused by TPP ...

Hydrobiological monitoring of selected pools (alluvial oxbow) was carried in the K?ran?-Hrb??kovy t?n? Nature Reserve (Czech Republic) between 2015 and 2017. The pools represent a residual aquatic ecosystems of original inundation floodplain of the Elbe River, before river stream regulation. The regular samplings were performed every four weeks and more than one-year cycle was covered. Water quality parameters (temperature, conductivity, pH, dissolved oxygen and transparency were measured in the field. The level o...