Sökresultat

As the global energy sector undergoes a necessary transition toward renewable sources, Mexico has committed to significantly expanding its clean energy capacity. The Baja California Peninsula, with its rich solar and wind resources, presents a unique opportunity to lead this shift. The peninsula is composed of two states: Baja California and Baja California Sur. Baja California operates one electr

To meet the aims of the Paris climate agreement, it is necessary to reduce energy use in buildings. Efficient HVAC systems are a critical part in achieving a low delivered energy use. However, there is a lack of comparative information of the best HVAC systems for apartment buildings, which represent an increasing share of newly built floor area in the Nordic countries. Elements of HVAC systems we

Though commonly used to calculate Q-factor and fractional bandwidth, the energy stored by radiating systems (antennas) is a subtle and challenging concept that has perplexed researchers for over half a century. Here, the obstacles in defining and calculating stored energy in general electromagnetic systems are presented from first principles as well as using demonstrative examples from electrostat

This paper presents a new analytical solution for the influence of regional groundwater flow on the performance of borehole heat exchangers. The solution concerns a vertical borehole. The transient thermal response for the fundamental case of a step-change in heat injection rate is given. The solution is remarkably simple and the formulas quite handy considering the complexity of the convective-di

In this work, a three-dimensional TiO2-graphene composite with large specific surface area is designed by freeze drying. In this architecture, primary TiO2 nanoparticles (less than 10 nm in size) are wrapped with graphene homogeneously, forming spherical secondary particles (≈100 nm), and the spherical TiO2 particles further agglomerate into platelet-like particles with several micrometers in size

The purpose of this thesis was to determine how a heavy duty vehicle manufacturer can create an economical viable business model for used batteries from electric buses and trucks. Heavy duty vehicles are responsible for 30% of on-road CO2 emissions in the European Union, but could be decreased if this sector would be electrified. One major barrier for this transition is the large cost for the batt

It is well known that Lithium-ion batteries in thermal runaway can emit gases with high hydrogen concentrations which, in case of delayed ignition, can cause a gas explosion. Aerosol suppression agents are sometimes used to suppress fires and/or prevent ignition of released gases in such situations. The agent has been studied for suppression of fires (diffusion flames), but less is known about the

Overdischarge poses severe challenges to the structural integrity and electrochemical performance of layered LiNixCoyMn1-x-yO2 (NCM) cathodes in lithium-ion batteries, yet the underlying degradation mechanisms remain insufficiently understood. Through a combined experimental and theoretical approach, this study systematically investigates how overdischarge destabilizes NCM cathodes with varying tr

This work demonstrates that hydrogen can be reversibly stored in a composite of NaF and Al. NaF and Al reacts to a mixture of Na3AlF6 and NaAlH4 via hydridofluoride phases of the form Na3AlH6-xFx. The analysis of thermodynamics based on literature standard enthalpies of formation yields the technically favourable enthalpy of reaction of roughly 35 kJ/mol H-2 for a theoretical gravimetric hydrogen