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Concept

1,1,1,2-Tetrafluoroethane

Related publications (26)

Formation of carbonyl compounds during ozonation of lake water and wastewater: Development of a non-target screening method and quantification of target compounds

Urs von Gunten, Joanna Maria Houska

Ozonation of natural waters is typically associated with the formation of carbonyl compounds (aldehydes, ketones and ketoacids), a main class of organic disinfection byproducts (DBPs). However, the detection of carbonyl compounds in water and wastewater is ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Water use efficiency: A review of spatial and temporal variability

Gabriele Manoli, Sara Bonetti

Water Use Efficiency (WUE) expresses the trade-off between carbon assimilation (or subsequent carbon storage) and water release, two concurrent gas fluxes essential for plant functioning. Here, we review metrics that have been introduced to quantify WUE ac ...

Elsevier2023

Application of UV absorbance and electron-donating capacity as surrogates for micropollutant abatement during full-scale ozonation of secondary-treated wastewater

Urs von Gunten

Ozonation of secondary-treated wastewater for the abatement of micropollutants requires a reliable control of ozone doses. Changes in the UV absorbance of dissolved organic matter (DOM) during ozonation allow to estimate micropollutant abatement on-line an ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Impact of large tip clearance ratios on the performance of a centrifugal compressor

Jürg Alexander Schiffmann, Markus Diehl

Ultra-compact and fast spinning turbomachinery is a key technology to increase performance of domestic heating applications and to address decentralization of power and heat as a consequence of the rise of renewable energy sources. Recently, a heat pump us ...

2019

Non-target screening to trace ozonation transformation products in a wastewater treatment train including different post-treatments

Urs von Gunten

Ozonation and subsequent post-treatments are increasingly implemented in wastewater treatment plants (WWTPs) for enhanced micropollutant abatement. While this technology is effective, micro pollutant oxidation leads to the formation of ozonation transforma ...

2018

Comparison of methylisoborneol and geosmin abatement in surface water by conventional ozonation and an electro-peroxone process

Urs von Gunten, Gang Yu

In this study methylisoborneol (MIB) and geosmin abatement in a surface water by conventional ozonation and the electro-peroxone (E-peroxone) process was compared. Batch tests with addition of ozone (03) stock solutions and semi-batch tests with continuous ...

Elsevier2017

Pressure drop prediction in annular two-phase flow in macroscale tubes and channels

John Richard Thome, Andrea Cioncolini

A new prediction method for the frictional pressure drop in annular two-phase flow is presented. This new prediction method focuses on the aerodynamic interaction between the liquid film and the gas core in annular flows, and explicitly takes into account ...

Pergamon-Elsevier Science Ltd2017

Effect of O2 migration in Pt/HfO2/Ti/Pt structure

Giovanni De Micheli, Pierre-Emmanuel Julien Marc Gaillardon, Maxime Victor Thammasack

In this paper, we study the post-fabrication phenomenon of natural oxidation of the Ti layer observed in a Pt/HfO2/Ti/Pt Resistive Random Access Memory (OxRRAM) stack with no external influence. We identify that the resistance ratio decreases by ...

Springer Verlag2017

An updated three-zone heat transfer model for slug flow boiling in microchannels

John Richard Thome, Mirco Magnini

This work proposes a novel physics-based model for the fluid mechanics and heat transfer associated with slug flow boiling in horizontal circular microchannels to update the widely used three-zone model of Thome et al. (2004). The heat transfer model has a ...

Pergamon-Elsevier Science Ltd2017

Innovative low-mass cooling systems for the ALICE ITS Upgrade detector at CERN

Manuel Gómez Marzoa

The Phase-1 upgrade of the LHC to full design luminosity, planned for 2019 at CERN, requires the modernisation of the experiments around the accelerator. The Inner Tracking System (ITS), the innermost detector at the ALICE experiment, will be upgraded by r ...

EPFL2016

Combination of UV absorbance and electron donating capacity to assess degradation of micropollutants and formation of bromate during ozonation of wastewater effluents

Urs von Gunten

In this study, the changes in UV absorbance at 254 nm (UVA(254)) and electron donating capacity (EDC) were investigated as surrogate indicators for assessing removal of micropollutants and bromate formation during ozonation of wastewater effluents. To meas ...

Elsevier2015

Flow boiling data and prediction method for enhanced boiling tubes and tube bundles with R-134a and R-236fa including a comparison with falling film evaporation

John Richard Thome, Eugene van Rooyen

New enhanced boiling tubes from Wolverine Tube Inc. (Turbo-B5) and Wieland-Werke AG (Gewa-B5) were investigated using R-134a and R-236fa as test fluids. The tests were done at saturation temperatures of 5 and 15 degrees C, mass flow rates from 4 to 35 kg m ...

Elsevier Sci Ltd2014

Pressure drop data and prediction method for enhanced external boiling tube bundles with R-134a and R-236fa

John Richard Thome, Eugene van Rooyen

The pressure drops of external flow over enhanced tube bundles were experimentally obtained at both adiabatic and diabatic conditions using R-134a and R-236fa as test fluids. The tests were carried out at saturation temperatures of 5 and 15 degrees C, mass ...

Elsevier2013

Ozonation of iodide-containing waters: Selective oxidation of iodide to iodate with simultaneous minimization of bromate and I-THMs

Urs von Gunten

The presence of iodinated disinfection by-products (I-DBPs) in drinking water poses a potential health concern since it has been shown that I-DBPs are generally more genotoxic and cytotoxic than their chlorinated and brominated analogs. I-DBPs are formed d ...

Elsevier2013

CO2 and R410A: Two-phase flow visualizations and flow boiling measurements at medium (0.50) reduced pressure

John Richard Thome

The conversion to more environmentally friendly refrigerants is of prime importance for refrigeration and air-conditioning industries. A first option for the substitution of the fluids which use was banned could be natural refrigerants, such as CO2, or HFC ...

Pergamon-Elsevier Science Ltd2012

Prototype of a thermally driven heat pump based on integrated Organic Rankine Cycles (ORC)

Daniel Favrat, Samuel Henchoz, Jonathan Demierre

The concept studied in this work is a low power ORC-ORC heat pump system (providing about 20 kW heat at the condenser) and that is composed of an ORC power cycle driving a reversed ORC heat pump cycle, both cycles using the same fluid. The centrifugal comp ...

2012

Two-phase frictional pressure drops in U-bends and contiguous straight tubes for different refrigerants, orientations, tube, and bend diameters: Part 1. Experimental results (RP-1444)

John Richard Thome, Ricardo Lima

Over the years, much research has been conducted on two-phase flows in straight tubes because these tend, in length, to be predominant in two-phase systems. However, two-phase heat exchangers can also have singularity elements, where the most common type i ...

Taylor & Francis Inc2012

Falling film evaporation on enhanced tubes, part 1: Experimental results for pool boiling, onset-of-dryout and falling film evaporation

John Richard Thome, Marcel Christians

Horizontal falling film evaporators have the potential of displacing flooded evaporators as the standard in the refrigeration industry due to compelling advantages, such as smaller refrigerant charge and lower pressure drop. However, there is a need to imp ...

2012

Film Condensation of R-134a and R-236fa, Part 2: Experimental Results and Predictive Correlation for Bundle Condensation on Enhanced Tubes

John Richard Thome, Marcel Christians

Local test results for two enhanced condensing tubes (next-generation versions of the Wieland Gewa and Wolverine Turbo enhanced condensing tubes) are obtained for refrigerants R-134a and R-236fa on the center row of a three row-wide tube bundle. The "bundl ...

Taylor & Francis2010

Prototype of a thermally driven heat pump based on integrated organic Rankine cycles (ORC)

Daniel Favrat, Samuel Henchoz, Jonathan Demierre

The concept studied in this work is a low power ORC-ORC system (about 20 kW heat at the condenser) which is composed of an ORC engine cycle driving a reversed ORC heat pump cycle, both using the same fluid. The radial compressor and turbine are directly co ...

2012