O sektorze kosmicznym, jego kondycji i potencjale

ROZMOWA Z KRZYSZTOFEM KANAWK

Fuel cells for mobile applications

Fuel cells (FCs) are electrochemical devices, which produce electricity (and sometimes heat) without any intermediate step. These units are known for their high total and electrical efficiency, low emission levels, silent operations and scalability. There are several types of fuel cells, which operate at different temperatures, require different fuels and levels of servicing. Some of FC types can be also used for mobile applications - e.g. Unmanned Aerial Vehicles (UAV). Auxiliary Power Units (APU) or main power source is for FC vehicles. Recently, there has been a growing interest in research on mobile applications of fuel cells, both for civilian and military purposes. Several commercial companies focusing on fuel cells have been established, performing their R&D activities in their niches. In addition, there are special dedicated research funds for fuel cell and hydrogen research in countries such as USA, China, Japan, France and Germany. Moreover, the European Commission devotes funds for the fuel cell activities through a public-private partnership. This trend is predicted to continue in coming years, as fuel cells become smaller, easier and cheaper to operate and manufacture. This paper focuses on the current "state of the art" in fuel cell research, both commercial and governmental/military. In addition, some examples of mobile applications, focusing on fuel cell vehicles, spacecrafts and UAVs are presented, together with a predicted outcome for following years

Designing one span reinforced concrete framework bridge

W artykule przedstawiono zagadnienia związane z projektowaniem żelbetowych mostów ramowych. Porównano typowe wiadukty ramowe współpracujące z gruntem do aktualnie projektowanych i budowanych mostów integralnych. Opisano obciążenia przyjmowane w analizie tego typu konstrukcji. Omówiono krajowe i zagraniczne zasady wyznaczania parcia gruntu na ściany podporowe. Zwrócono uwagę na zasady obliczania mostów ramowych usytuowanych w skosie. Omówiono współpracę konstrukcji z gruntem za pomocą pali fundamentowych. Przedstawiono przykład analizy wiaduktu ramowego pod kątem budowy modelu numerycznego, przyjmowania obciążeń i interpretacji wyników.This paper presented the issues related to the design of reinforced concrete framework bridge. Compared to the typical framework bridges for cooperating with the land currently designed and constructed integral bridges. Described the analysis of the load received this type of construction. Discussed national and international rules for determining earth pressure on the supporting wall. Drew attention to the rules for calculating diagonally located framework bridges. Discussed the structure cooperation with the ground by means of foundation piles. Presented an example of framework bridge analysis for the numerical model construction, taking loads and interpretation calculations results

LTE/GNSS IOT technology as a backbone for airport ground handling operations

The necessity of a positioning service for various ground handling assets is key to improving airport performance. Reported in this article is a system named “Ground Eye”, designed to be a test of a possible implementation of the independent LTE-based communication system and GNSS-based location services. The test campaign used a total of nine prototype devices for a period of one month at Gdańsk airport (Poland). The main goal of this demonstration was to verify the possibility of using the GNSS/LTE system as a fast-deployment option in the airport environment, as well as to evaluate its positioning and communication capabilities in conjunction with React.JS/Deck.GL/Node.JS dedicated application. The test campaign verified that even with simple processing and relatively simple single-frequency measurements, multi-constellation GNSS receivers, it is possible to obtain location with precision reaching better than 2.5 metres. This precision should be good enough for all ground handling operations at modern airports, without the need for additional fixed infrastructure