The introduction of invasive aquatic species in new environments has been identified as one of the four biggest threats to the world's oceans causing serious threats and harm to both ecology and human health. There is a major exchange of ship’s ballast water over longer distances between continents and regional seas, and it has been known for decades that ballast water transfers organisms to new ecosystems, where the strongest, most aggressive and adaptable species can survive and become invasive under favourable conditions. The focus of the research is to study available ballast water control technologies to determine their suitability and effectiveness in the reduction of harmful aquatic organisms and compounds in the Baltic Sea.
MIMO-OFDM models of RPAS communication channels based on LTE Standard were built. Dependencies of the BER on the SNR for Extended Pedestrian A and Extended Vehicular A models using 2-by-2 multiple antennas were obtained. Dependencies of the BER on the SNR for different levels of Frequency Offset at satellite transponder were studied.
Electronic Chart Display and Information Systems (ECDIS), which are used on vessels and can replace paper charts, allow to obtain and display on electronic charts information from basic and additional data sources. For the certified use of ECDIS instead of paper charts, it is necessary to ensure constant updating of Electronic Navigation Chart (ENC) data provided to vessels for use. The known visual and satellite observation systems intended for cartographic information update are costly, have low accuracy and do not allow to quickly update navigational charts in real-time mode. The stand-alone use of remotely piloted aircraft (RPA) will make it possible not only to substantially reduce costs and increase the accuracy of monitoring, but also to provide information in real-time mode.
In this article the necessity of measuring wind at its different heights is discussed. The economical optimization of tower height is impossible without such measurement. In places where land is relatively flat, for example, in deserts or swamps, smaller wind turbines are more profitable, while in forest zones bigger turbines are more profitable. In both cases, to make a correct decision on the optimal tower height, it is very important to know exactly the wind profile law. Even for places where land is expensive, the measurement of the wind at different heights can influence the correct decision regarding the optimal size and number of needed turbines for getting the required power. For places with cheaper land, this dependence is even stronger. This analysis refutes a common misconception: “the bigger – the better”.
In the field of security in transport distinguish risks related to flight safety and aviation security. Safety of flights is ensured through the reliability of aviation equipment and the qualification of the personnel who services and operates it, aviation security is a condition of protection from illegal interference in its activity. Risk management in civil aviation in the field of security is a relatively new direction of activity. Deep research in this area began only at the beginning of the XXI century. It is quite difficult to use the existing experience of risk management, accumulated in other spheres, as civil aviation has significant features. Various methods and schemes can be used to assess risks. The article discusses various options for predicting risks using the “event tree” and “risk factor tree” methods.
Original models of RPAS communication channels based on IEEE 802.11b Standard, including both Base Station transmission within the Radio Line of Sight, and through the satellite using Beyond Radio Line of Sight, were built. Dependencies of the Bit Error Rate on the Signal-Noise Ratio for different payload data rates were obtained. Transponder nonlinearity and Base Station antenna diameter impact were analysed.
The target of analyse was to determine the exposure levels to the staff on the vessel and ensure adequate measures are in place to minimize the exposure when necessary. Noise levels through the vessel will be compared to the noise code detailed in section 2 of this report. The measurement data results obtained at this survey will be analysed against the codes, as shown below. In addition, the measurement result table has the readings from 2007 during sea trials at the shipyard, Brodogradilište d.o.o. – Split. The analyse is to measure the exposure levels, through the accommodation and machinery spaces to determine the risk to staff working in these areas as well as making recommendations that could reduce the exposure levels.
aviation industry develops so fast that manufacturers are unable to supply components in time. Aviation companies work on improvement of their warehouses by introducing various mathematical and statistical methods. These methods calculate component safety life. In accordance with the regulations of the European Aviation Safety Agency (EASA) all suppliers and maintenance organizations shall comply with certain restrictions. The study provides information on the basic principles of mathematical and statistical methods of component safety life. The article gives information about the warehouse work in accordance with EASA requirements.
The article describes the impact of the gas turbine engine low-pressure turbine blade shroud shelf on the blade profile stress position. Attention is focused directly on the impact of the location of the gravity centre of the shroud shelf on blade stress distribution at the three most critical points of the profile. The paper describes the details of the calculation and the required expressions provided, as well as the results of the calculation example with clear graphical dependencies.
The paper presents a method of calculation gas turbine engine compressor or low-pressure turbine working blade profile for student training. This method of calculation was prepared for working blades with and without shroud shelves. This method provides a calculation technique to reduce the load on blade root part and the determination of blade profile stress distribution and the comparison before and after reduction of load.