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Your search keyword '"Lascu, Cristian"' showing total 23 results
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23 results on '"Lascu, Cristian"'

1. Dobrogea: Movile Cave

Author

Sarbu, Serban M., Lascu, Cristian, Brad, Traian, LaMoreaux, James W., Series Editor, Ponta, Gheorghe M. L., editor, and Onac, Bogdan P., editor

Published
2019
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22. Sulfur Cave (Romania), an extreme environment with microbial mats in a CO2-H2S/O2 gas chemocline dominated by mycobacteria.

Author

Sarbu, Serban M., Aerts, Joost W., Flot, Jean-François, Van Spanning, Rob J. M., Baciu, Calin, Ionescu, Artur, Kis, Boglárka M., Incze, Reka, Siko-Barabasi, Sandor, Para, Zoltan, Hegyeli, Botond, Atudorei, Nicu-Viorel, Barr, Casey, Nealson, Kenneth H., Forray, Ferenc L., Lascu, Cristian, Fleming, Emily J., Bitter, Wilbert, and Popa, Radu

Subjects
*MICROBIAL mats, *MYCOBACTERIA, *VOLCANIC gases, *EXTREME environments, *MICROBIAL communities, *NUCLEOTIDE sequencing
Abstract

Sulfur Cave (Puturosu Mountain, Romania) is an extreme environment, unique for displaying life in a gas chemocline. The lower part of the cave is filled with CO2, CH4, and H2S of mofettic origin, while the upper part contains air that floats above the heavier volcanic gasses. S° and H2SO4 (from sulfur-oxidation) cover the cave wall at and below the CO2-H2S:O2 gas/gas interface. On the cave wall, near the interface the pH is <1 and unusual microbial biofilms occur on the rock's surface. We provide context information on the geology, mineralogy, chemistry and biology to better understand this unique environment. We have used X-ray diffraction, optical microscopy, scanning electron microscopy with EDAX capabilities, stable isotope analysis and 16S and 18S rDNA amplicon sequencing. The most common taxa in the microbial biofilms are Mycobacteria, Acidithiobacillus and Ferroplasmaceae. Liquid water in this system originates solely from condensation of water vapor onto the cave walls making inflow of organic carbon from outside unlikely. The most likely primary source of energy for this microbial community is sulfur oxidation with H2S and S° as main reductants and atmospheric O2 as the main oxidant. Ferric iron from the rock surface is another potential oxidant. In Sulfur Cave, gaseous CO2 (from mofettic emission) maintains the stability of the gas chemocline. Sulfur Cave biofilms can help the search for extreme life in the subsurface, near volcanic systems on Earth and Mars. The Sulfur Cave example shows that a habitable environment can be established underground in gas chemoclines near CO2-dominated gas discharge zones, where it can have a steady supply of water and energy. [ABSTRACT FROM AUTHOR]

Published
2018
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23. Highly efficient smart battery pack for EV drivetrains

Author

Mattia Ricco, Cristian Lascu, Branko Majmunovic, Remus Teodorescu, Radhika Sarda, Majmunovic, Branko, Sarda, Radhika, Teodorescu, Remu, Lascu, Cristian, and Ricco, Mattia

Subjects
Battery (electricity), Control and Optimization, Computer science, Energy Engineering and Power Technology, Drivetrain, Transportation, Topology (electrical circuits), 02 engineering and technology, battery management system, 01 natural sciences, Electronic mail, Hardware_GENERAL, 0103 physical sciences, Smart Battery, 0202 electrical engineering, electronic engineering, information engineering, Safety, Risk, Reliability and Quality, 010302 applied physics, Renewable Energy, Sustainability and the Environment, business.industry, Mechanical Engineering, 020208 electrical & electronic engineering, Electrical engineering, balancing, Battery pack, high efficiency, State of charge, Modeling and Simulation, Automotive Engineering, business, Voltage, EV
Abstract

This paper introduces a Smart Battery Pack (SBP) for Electric Vehicles (EV) application where many Li-ion battery cells connected in series are need to be balanced. The advantages of SBP over conventional methods are high effciency, low switching frequency, and simple topology. Solution is brought by connecting battery-cells using half bridges which allows inserting or bypassing a cell based on its current state of charge (SOC), thereby balancing. Consequently, the output voltage is reduced by the overall voltage of bypassed cells. Simulation results show comparison between SBP and series connected battery pack in terms of battery utilization and discharging time.

Published
2018

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