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Abstract

Office buildings are responsible for a great portion of total energy consumption. In this study, solar system based retrofitting measures such as daylighting control system (DCS), Trombe wall (TW) and photovoltaic (PV) systems are modeled to an office building located in Dayton, Ohio, United States. An energy modeling tool, eQuest is utilized to analyze the economic and environmental impacts of the proposed single retrofitting measures along with the combined measure to identify the optimized building energy reduction opportunity. Compared to the baseline energy consumption, adopting single energy efficiency measures such as PV, DCS, TW, and overhangs/fins to windows results in about 25, 10, 9, 1 percentages of energy reduction respectively. In terms of economic perspectives, overhang and fins provide the best simply payback time around 1 year. Other solar system based retrofitting measures such as TW, DCS and PV can provide economic simple payback with 1.5, 2.5, and 12 years respectively. PV turned out to be the most costly options although it provides the largest energy savings which lead to the largest CO2 reductions. Adopting the combined system along with 50 kW photovoltaic array to the rooftop results in 45 percent office building energy reduction.

Abstract

It is known the fact that buildings become one of the major energy consumers. In order to ensure thermal comfort in buildings, more and more complex heating, ventilation and air conditioning systems have been used over time, which are currently large primary energy consumers. At the same time, today, the main source of energy production is still the burning of fossil fuels, which is the process leading to significant emissions of greenhouse gases. That is why the current European Union directives enforce both reducing buildings energy consumption with 20% before 2020 and using an amount of 20% of renewable energy. One of the heating systems that best respond to the need to reduce the energy consumption of buildings is the low-temperature radiant heating system., This is the reason why the present paper presents a research project that concerns the use of TABS heating/cooling systems that harness the renewable geothermal energy of the ground provided by a ground-air heat pump in Romania. The experimental research building is one of the research laboratories of the Research, Development, Innovation Institut of Transilvania University of Brasov-Romania In the first cold season of activity for heating the experimental building (2017-2018), the system provided a thermal enegy of 48 MWh, covering 48 % from the amount of the heating load. During the monitored period, the average COP for heating of the heat pump was 4,6. The research will continue to take place, results regarding the economy for cooling the building in the warm season and for the year’s transition periods being expected to follow.

Abstract

The article presents the analysis of the automatic alternate current motor control system, carried out by the author. The automatic control system has been implemented on the existing laboratory stand, containing: the squirrel-cage asynchronous motor and the frequency inverter. The existing stand imposed one of the available speed control methods for the motor and the necessity of the appropriate elements selection for the automatic control system [1]. The automatic control system has been designed and created as the constant value follow-up digital controller. To designate the parameters of the control object the unit step method of was used. After registering the output changes caused by the unit step, the characteristic curve was received that allowed to determine the alternative transmittance of the control object which, in turn, has made possible to find the appropriate controller settings.

Abstract

The article, on the basis of the underwater vehicle ‘Głuptak’ intended to combat naval mines, outlines the general concept of the microprocessor system of registration of change of electricity stored in batteries for the underwater vehicle at the implementation time of the set task. Registration system the amount of energy allows you to optimize the implementation of the working time of the underwater vehicle drive system in conditions of interference type underwater sea current.

Abstract

The article presents an analysis of performance of an energy storage element used in uninterruptible power supply systems built with the use of supercapacitors. It describes the operation of the voltage balancing system during charging and discharging of the capacitors. Attention has been drawn to the energy conditions of the system's operation and solutions that provide enhanced energy efficiency have been described.

Abstract

This article is one of the series articles relating to the DiveSMART project conducted to improve coordination procedures used in international underwater rescue operations in the Baltic Sea. The project DiveSMART Baltic has received the ‘flagship status’.

The article is the third in the planned cycle of articles relating to efforts made at the Naval Academy within the framework of DiveSMART Baltic project. It includes scenarios of treating decompression sickness acquired by divers during a rescue operation or after completed their decompression. These issues are connected with the work package four ‘Medical treatment’ of the DiveSMART Baltic project: Identifies methods for different medical treatments in operational areas.

Abstract

NATO standardization documents are the basis for action in many areas of NATO military activity and their affiliated organizations. The development of the NATO standardization documentation has been on-going for more than 60 years, and their content provides a reliable basis for joint action in a unified manner, enabling interoperability in many areas of NATO operations. The article is divided into three parts, the first of which deals with the general principles of NATO standardization, the second part describes the standardization documents related to the measurement of the ship’s signatures in aspect of the mine countermeasures and the third describes the participation in research project of NATO — RIMPASSE 2011 Trial. One of the their task was to verify and update NATO standardization documents including AMP-15.

Abstract

This article is a continuation to the theme of the article Operational diagnostics synthesis of the naval gas turbines operated by the Polish Navy published in SJ of PNA No. 1/2017. This article presents examples of results of energy research carried out by the Polish Naval Academy in the years 1985–2016, for the purpose of operational diagnostics of this type of engine, operated by the Polish Navy. The research conducted since 1985 covered four types of naval gas turbines (DE 59, DR 76, DR 77 and LM 2500), with a total of 24 engines. Currently in operation there are four LM 2500 type engines. In the near future, another LM 2500 engine will commence operations, along with a project 661M patrol ship. The energy research covers the engine start-up process, their operation in idle mode and within the whole range of load variations, as well as the process of engine stopping. The article presents examples of characteristics specific to the above processes, determined based on the results of studies of individual types of engines. Currently ongoing studies allow for constructing strategies for naval gas turbines, operated in the Polish Navy, according to technical condition.

Abstract

Due to the growing interest in the problems of cooperation among unmanned vehicles, in the article the proposition of the system for launching a mini unmanned aerial vehicle (mini-UAV) from an unmanned surface vehicle (USV) has been presented. The solution differs from the previously used in this that instead of the commonly used rotorcrafts it concerns the ability to start the mini aircraft with the help of pneumatic or rubber launcher. The results of the computer simulation have con-firmed the possibility of implementation of that kind of system.

Abstract

The paper presents the first part of the final report on all the experiments with biomimetic autono-mous underwater vehicle (BAUV) performed within the confines of the project entitled ‘Autonomous underwater vehicles with silent undulating propulsion for underwater ISR’, financed by Polish National Center of Research and Development. The report includes experiments in the swimming pool as well as in real conditions, that is, both in a lake and in the sea. The tests presented in this part of the final report were focused on low-level control.