Publications related to Isentropic process

Selection and Optimal Use of Nanoporous Materials for Adsorption Energy Technologies

Due to the large waste of heat in the power and industrial sectors, our use of energy is inefficient. Moreover, it relies on rapidly depleting and greenhouse-gas-emitting sources such as fossil fuels. While the scarcity of energy resources is a relevant so ...

EPFL2023

Fast and Durable Lithium Storage Enabled by Tuning Entropy in Wadsley-Roth Phase Titanium Niobium Oxides

Kangning Zhao, Yuehui Li, Liping Zhong, Rui Xia

Wadsley-Roth phase titanium niobium oxides have received considerable interest as anodes for lithium ion batteries. However, the volume expansion and sluggish ion/electron transport kinetics retard its application in grid scale. Here, fast and durable lith ...

WILEY-V C H VERLAG GMBH2023

A 3.3-Gb/s SPAD-Based Quantum Random Number Generator

Edoardo Charbon, Pouyan Keshavarzian, Francesco Gramuglia, Mario Stipcevic

Quantum random number generators (QRNGs) are a burgeoning technology used for a variety of applications, including modern security and encryption systems. Typical methods exploit an entropy source combined with an extraction or bit generation circuit in or ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Enhanced rate performance of lithium-ion battery anodes using a cobalt-incorporated carbon conductive agent

Xile Hu, Albert Claude Jean-Pierre Daubry, Ming Yang

Lithium-ion batteries with enhanced rate performance are of crucial importance for practical applications. Extensive studies on the structural design and surface modification of electrode materials with the aim of improving the rate performance have been r ...

ROYAL SOC CHEMISTRY2022

Luminescent and electronic properties of perovskite solar cells

Brian Irving Carlsen

Perovskite solar cells show great promise to serve as an alternative for traditional silicon-based solar cells, however several problems present obstacles for their commercialization. Standard perovskite cells contain lead, which is toxic to humans and har ...

EPFL2022

Spin Evolution in the Born-Oppenheimer Approximation

Jean-Philippe Ansermet, François Reuse, Klaus Maschke

The first part of this article attempts to highlight in chronological order some prominent papers that have direct connexion with the Born-Oppenheimer approximation. This timeline successively points to the role of level crossing, the notions of gauge fiel ...

WILEY-V C H VERLAG GMBH2022

Conjugate heat transfer in isolated granular clusters with interstitial fluid using lattice Boltzmann method

Mehrdad Kiani Oshtorjani

The conjugate heat transfer in mixtures of a fluid and single granular clusters is studied in this paper using a novel lattice Boltzmann method (LBM) programmed for parallel computation on the graphics processing unit (GPU). The LBM is validated for heat c ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Orb5: A global electromagnetic gyrokinetic code using the PIC approach in toroidal geometry

Laurent Villard, Stephan Brunner, Emmanuel Lanti, Sébastien Jolliet, Alberto Bottino, Thibaut Vernay, Ben McMillan, Paolo Angelino, Julien Stanislas Pierre Dominski, Noé Thomas Elie Ohana, Claudio Gheller, Aaron Lewis Scheinberg

This paper presents the current state of the global gyrokinetic code Orb5 as an update of the previous reference (Jolliet et al., 2007). The Orb5 code solves the electromagnetic Vlasov–Maxwell system of equations using a PIC scheme and also includes collis ...

2019

Multi-objective optimization of turbo-ORC systems for waste heat recovery on passenger car engines

Jürg Alexander Schiffmann, Kévin Rosset, Eliott Philippe Guenat, Violette Mounier

Waste heat recovery from passenger car internal combustion engines by means of an organic Rankine cycle (ORC) system is promising for reducing CO2 emissions. In this study, different cycle configurations capable of converting waste heat from both coolant a ...

2018

Interaction of a rotating two-phase flow with the pressure and torque stability of a reversible pump-turbine operating in condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto, Pierre Leroy

The operation of a reversible pump-turbine in condenser mode requires to dewater the impeller by closing the guide vanes and injecting compressed air in the draft tube cone to reduce the friction torque on the impeller blades. A water discharge is injected ...

2019

Data-Driven Pre-Design Tool for Small Scale Centrifugal Compressors in Refrigeration

Jürg Alexander Schiffmann, Cyril Picard, Violette Mounier

Domestic scale heat pumps and air conditioners are mainly driven by volumetric compressors. Yet the use of reduced scale centrifugal compressors is reconsidered due to their high efficiency and power density. Recent work has demonstrated the technical feas ...

2018

ORC Driven Heat Pump Running on Gas Bearings for Domestic Applications: Proof of Concept and Thermo-Economic Improvement Potential

Jürg Alexander Schiffmann, Violette Mounier

ORC driven Heat Pumps (HP-ORC) offer a promising technology of thermally driven heat pumps (TDHPs) for domestic applications. Recently, a 40 kW HP-ORC unit based on gas supported turbomachinery has been investigated in which the ORC radial turbine drives t ...

2017

Analysis and Removal of Product Gas Contaminants Present in Gasification Processes

Sven Philip Edinger

Energy demand and economic development are intrinsically linked. Earlier economic development came at the price of serious environmental pollution, posing a risk to life on earth. Thus, a transition from fossil to renewable energy is needed. Among the rene ...

EPFL2017

Design, modeling and experimental validation of a novel finned reciprocating compressor for Isothermal Compressed Air Energy Storage applications

Alfred Rufer, Mahbod Heidari

Considering the need for a reliable and environmentally friendly energy storage solution for addressing renewable energy intermittency issue and following the developments on Isothermal Compressed Air Energy Storage (I-CAES) systems, a new finned piston co ...

Pergamon-Elsevier Science Ltd2017

Heat Pump driven by a Small-Scale Oil-Free Turbocompressor – System Design and Simulation

Jürg Alexander Schiffmann, Adeel Javed

Small-scale oil-free turbocompressors driven by high-speed electric motors and supported on refrigerant vapor bearings represent a promising technology to increase the performance of domestic heat pumps. Gas bearings enable high rotational speeds with low ...

2017

The DTT device: Power and particle exhaust

Holger Reimerdes

The possible scenarios at full power of the DTT (Divertor Test Tokamak) device with the standard single null (SN) and X divertor (XD) configurations have been analysed for the aspect of safely handling the power to be exhausted on the divertor targets. In ...

Elsevier Science Sa2017

An overview of some recent results on the Euler system of isentropic gas dynamics

Elisabetta Chiodaroli

This overview is concerned with the well-posedness problem for the isentropic compressible Euler equations of gas dynamics. The results we present are in line with the programof investigatingthe efficiency of different selection criteria proposed in the li ...

Springer Heidelberg2016

Ophthalmic contact lens with a compressible affinity matrix

Philippe Renaud, Amélie Barbara Hildegarde Béduer, Thomas Michael Braschler

The invention relates to a contact lens for use in the treatment of ocular inflammatory pathologies. The contact lens comprises a soft porous material coupled, in certain embodiments, with detoxifying agents. Said material and/or agents contact and neutral ...

2016

Global Ill-Posedness of the Isentropic System of Gas Dynamics

Elisabetta Chiodaroli, Camillo De Lellis

We consider the isentropic compressible Euler system in 2 space dimensions with pressure law p () = (2) and we show the existence of classical Riemann data, i.e. pure jump discontinuities across a line, for which there are infinitely many admissible bounde ...

Wiley-Blackwell2015

Modeling and Experimental Investigation of an Oil-Free Microcompressor-Turbine Unit for an Organic Rankine Cycle Driven Heat Pump

Jürg Alexander Schiffmann, Antonio Rubino, Jonathan Demierre

Domestic heating and cooling will more and more have to rely on heat pumps (HPs) in order to support a more rational use of primary energy consumption. The HP market is mainly dominated by electrically driven vapor compression cycles and by thermally drive ...

American Society of Mechanical Engineers2015