Christine Hecker - Academia.edu (original) (raw)

Papers by Christine Hecker

Festelektrolytsensoren auf Basis von Y-dotiertem ZrO 2 haben sich in der Praxis als robuste Senso... more Festelektrolytsensoren auf Basis von Y-dotiertem ZrO 2 haben sich in der Praxis als robuste Sensoren zu Bestimmung von Sauerstoffpartialdrücken bewährt. Ziel dieser Arbeiten ist die Herstellung eines langzeitstabilen und driftfreien Sensors zur kontinuierlichen Messung des Schwefelgehaltes im Zinnbad und Schutzgas für den Floatglas-Prozesses. Hierzu wurden einseitig geschlossene Rohre als Festelektrolytmembranen auf Basis von Y-dotiertem CaF 2 sowie La-dotiertem SrF 2 entwickelt.

Journal of Membrane Science, Mar 1, 2011

ABSTRACT The separation of higher alkanes from methane is a key aspect for conditioning natural g... more ABSTRACT The separation of higher alkanes from methane is a key aspect for conditioning natural gases and accompanying gases. Against this background, a systematic study on related separation performances of several MFI membranes in dependence on their synthetic origin is presented with this contribution. Basically, MFI slurry was used for the activation of inert Al2O3 supports for heterogeneous crystallization. The resulting MFI seed layer acts both as heterogeneous nucleation side and as flexible distance holder between support and MFI membrane suppressing defect formations during thermal template removal. For the purpose of further optimization, synthesis parameters like temperature, reaction time, pore size of the support and reactant ratios were varied. Characterization of the membranes via permporometry and single gas permeation using methane and n-butane gave first results on the characteristic properties of the membranes obtained. Also, the non isobar performed separations of C4/C1 binary 1:1 mixtures (pfeed=1bar, ppermeate=2bar) are discussed with respect to membrane synthesis. It was found that either selectivity (M10, α=11.3; J=128lm−2h−1bar−1 at 75°C) or permeation flux (M16, α=3.6; J=477lm−2h−1bar−1) optimized membranes can be generated via different synthetic routes. Both archetypes were tested in a simulated cascade like separation experiment for the isolation of n-butane from C4/C1=95:5 mixtures. Under elevated feed pressures (pfeed=2–11bar, ppermeate=1bar) only separation optimized membranes showed a promising applicability due to an increased separation performance also at a lower n-butane content of 6.8%. Increasing feed pressures induced an increase in separation factors from 2.0 to 13.9 at nearly constant permeances of 93–136lm−2h−1bar−1 making customized MFI membranes attractive for technological applications.

RSC Advances, 2014

The performance of porous membranes is tremendously influenced by desorption, as alkane separatio... more The performance of porous membranes is tremendously influenced by desorption, as alkane separations by a pressure stable MFI membrane revealed. High membrane selectivities as well as permeation fluxes are to be traced back to the fact that a reduced permeate pressure significantly decreases the loading gradient of the adsorbed molecules in the membrane.

Chemie Ingenieur Technik, Mar 13, 2013

ABSTRACT Die Abreicherung höherer Kohlenwasserstoffe aus Erdgas oder Erdölbegleitgasen ist ein un... more ABSTRACT Die Abreicherung höherer Kohlenwasserstoffe aus Erdgas oder Erdölbegleitgasen ist ein unablässiger Schritt vor der Einspeisung in das Endverbrauchernetz. Membrantechnologien könnten dabei als Ersatz für energieintensive und kostspielige Reinigungsmethoden eingesetzt werden. Vor diesem Hintergrund wurde die entsprechende Eignung zeolithischer MFI-Membranen untersucht und der Einfluss von Membranträgergeometrie, Gaszusammensetzung, Temperatur und Druck auf die Trennung von Methan/n-Butan-Mischungen getestet. The depletion of higher alkanes from methane is a key aspect during the conditioning of natural gases or accompanying gases. Membrane technologies could be used as alternative to energy and cost intensive purifications. Against this background the influence of membrane geometry, composition of the gas mixture as well as temperature and pressure was investigated in separation experiments for methane/n-butane mixtures using MFI membranes.

Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and strea... more Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and streaming current arise when pressure-driven fluid flow transport by advection induces both a potential and a current at the channel ends. This effect can be used as a sensor/transducer principle and also to generate electricity for sensor power supply and therefore represents a mechanism for converting mechanical work into electrical power. Electrokinetic sensors and energy harvester are simple to build, and can be easily integrated into nano-and microfluidic lab-on-chip systems.

Procedia Engineering, 2016

Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and strea... more Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and streaming current arise when pressure-driven fluid flow transport by advection induces both a potential and a current at the channel ends. This effect can be used as a sensor/transducer principle and also to generate electricity for sensor power supply and therefore represents a mechanism for converting mechanical work into electrical power. Electrokinetic sensors and energy harvester are simple to build, and can be easily integrated into nano-and microfluidic lab-on-chip systems.

Procedia Engineering, 2015

Under reducing conditions fluoride based solid electrolyte sensors with sulphur-sensitive auxilia... more Under reducing conditions fluoride based solid electrolyte sensors with sulphur-sensitive auxiliary electrodes are able to measure the sulphur content in liquid metals and gases at elevated temperatures. In this work CaF 2 doped with YF 3 and SrF 2 doped with LaF 3 were selected as solid electrolyte material, because of their high ionic conductivity. Solid electrolyte tubes were prepared from these materials by slip casting to apply them as electrochemical sensors e.g. in the float glass industry.

Journal of Materials Research

Sol–gel derived hydroxyapatite coatings on metallic implants are important to promote their osseo... more Sol–gel derived hydroxyapatite coatings on metallic implants are important to promote their osseointegration and biocompatibility. However, such coatings generally suffer from drawbacks that limit implant longevity. In this study, the sol gel process to prepare hydroxyapatite was optimized and used to deposit a hydroxyapatite layer on Ti6Al4V. Samples were pretreated by thermal oxidation, sol–gel coating, and anodization to produce titanium dioxide interlayers with various structures. The results of structural and thermal analysis have determined the optimal preparation parameters to produce monophasic and crystalline hydroxyapatite. The introduction of titanium dioxide intermediate layers produced crack-free hydroxyapatite films and promoted the adherence and integrity of the coating, where the adhesive strength was remarkably improved. Furthermore, potentiodynamic polarization tests in simulated body fluid revealed low corrosion rates and high protection property of the hydroxyapa...

The process is especially relevant for the processing of natural gas and associated petroleum gas... more The process is especially relevant for the processing of natural gas and associated petroleum gases. With the described method it is possible, dispensing of the permeate side sweep gas (sweep) hydrocarbons to separate from each other in practically relevant pressures. The invention has for its technical object to provide a process for the separation of natural gas or petroleum gas components to inorganic porous membranes, with the higher hydrocarbons can be continuously separated with high gas flow rates effectively without extensive cooling of the gases. The object is achieved by a method which is characterized by the following features: a) it is carried out bar with feed pressures greater than 5, wherein the pressure on the permeate side is lower than on the feed side. b) to increase the separation performance of a pressure-mediated, increased condensation of the higher hydrocarbons is used at the pores of the membrane c) meso and macroscopically dense inorganic membranes are used...

Separation and Purification Technology, 2018

Determination of the membrane charge using streaming potential measurements The membrane charge s... more Determination of the membrane charge using streaming potential measurements The membrane charge significantly depending on the pH value of the feed Specific adsorption of multivalent ions shifts the isoelectric point Due to streaming potential measurements, ion retention can be predicted If the TiO 2 NF-membrane is charged, then ions are retained, otherwise they pass through

Journal of Membrane Science, 2011

ABSTRACT The separation of higher alkanes from methane is a key aspect for conditioning natural g... more ABSTRACT The separation of higher alkanes from methane is a key aspect for conditioning natural gases and accompanying gases. Against this background, a systematic study on related separation performances of several MFI membranes in dependence on their synthetic origin is presented with this contribution. Basically, MFI slurry was used for the activation of inert Al2O3 supports for heterogeneous crystallization. The resulting MFI seed layer acts both as heterogeneous nucleation side and as flexible distance holder between support and MFI membrane suppressing defect formations during thermal template removal. For the purpose of further optimization, synthesis parameters like temperature, reaction time, pore size of the support and reactant ratios were varied. Characterization of the membranes via permporometry and single gas permeation using methane and n-butane gave first results on the characteristic properties of the membranes obtained. Also, the non isobar performed separations of C4/C1 binary 1:1 mixtures (pfeed=1bar, ppermeate=2bar) are discussed with respect to membrane synthesis. It was found that either selectivity (M10, α=11.3; J=128lm−2h−1bar−1 at 75°C) or permeation flux (M16, α=3.6; J=477lm−2h−1bar−1) optimized membranes can be generated via different synthetic routes. Both archetypes were tested in a simulated cascade like separation experiment for the isolation of n-butane from C4/C1=95:5 mixtures. Under elevated feed pressures (pfeed=2–11bar, ppermeate=1bar) only separation optimized membranes showed a promising applicability due to an increased separation performance also at a lower n-butane content of 6.8%. Increasing feed pressures induced an increase in separation factors from 2.0 to 13.9 at nearly constant permeances of 93–136lm−2h−1bar−1 making customized MFI membranes attractive for technological applications.

Chemie Ingenieur Technik, 2013

ABSTRACT Die Abreicherung höherer Kohlenwasserstoffe aus Erdgas oder Erdölbegleitgasen ist ein un... more ABSTRACT Die Abreicherung höherer Kohlenwasserstoffe aus Erdgas oder Erdölbegleitgasen ist ein unablässiger Schritt vor der Einspeisung in das Endverbrauchernetz. Membrantechnologien könnten dabei als Ersatz für energieintensive und kostspielige Reinigungsmethoden eingesetzt werden. Vor diesem Hintergrund wurde die entsprechende Eignung zeolithischer MFI-Membranen untersucht und der Einfluss von Membranträgergeometrie, Gaszusammensetzung, Temperatur und Druck auf die Trennung von Methan/n-Butan-Mischungen getestet. The depletion of higher alkanes from methane is a key aspect during the conditioning of natural gases or accompanying gases. Membrane technologies could be used as alternative to energy and cost intensive purifications. Against this background the influence of membrane geometry, composition of the gas mixture as well as temperature and pressure was investigated in separation experiments for methane/n-butane mixtures using MFI membranes.

The invention relates to a process for separating C In this case, a feed gas is passed under a pr... more The invention relates to a process for separating C In this case, a feed gas is passed under a pressure of 2 to 500 in a temperature range from -30 ° C to + 60 ° C over a membrane of a porous inorganic material or an organic polymer. The permeating C The separation takes place at practically relevant printing conditions without energy-intensive relaxation or cooling and with improved separation efficiency.

Proceedings Sensor 2017

Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and strea... more Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and streaming current arise when pressure-driven fluid flow transport by advection induces both a potential and a current at the channel ends. This effect can be used as a sensor/transducer principle and also to generate electricity for sensor power supply and therefore represents a mechanism for converting mechanical work into electrical power. Electrokinetic sensors and energy harvester are simple to build, and can be easily integrated into nano-and microfluidic lab-on-chip systems.

Procedia Engineering, 2015

Abstract Under reducing conditions fluoride based solid electrolyte sensors with sulphur-sensitiv... more Abstract Under reducing conditions fluoride based solid electrolyte sensors with sulphur-sensitive auxiliary electrodes are able to measure the sulphur content in liquid metals and gases at elevated temperatures. In this work CaF 2 doped with YF 3 and SrF 2 doped with LaF 3 were selected as solid electrolyte material, because of their high ionic conductivity. Solid electrolyte tubes were prepared from these materials by slip casting to apply them as electrochemical sensors e.g. in the float glass industry.

Dermatologic Surgery, 2015

Zusammenfassung Festelektrolytsensoren auf Basis von Y-dotiertem ZrO2 haben sich in der Praxis al... more Zusammenfassung Festelektrolytsensoren auf Basis von Y-dotiertem ZrO2 haben sich in der Praxis als robuste Sensoren zu Bestimmung von Sauerstoffpartialdrucken bewahrt. Ziel dieser Arbeiten ist die Herstellung eines langzeitstabilen und driftfreien Sensors zur kontinuierlichen Messung des Schwefelgehaltes im Zinnbad und Schutzgas fur den Floatglas-Prozesses. Hierzu wurden einseitig geschlossene Rohre als Festelektrolytmembranen auf Basis von Y-dotiertem CaF2 sowie La-dotiertem SrF2 entwickelt.

Bioengineering

With the growing demands for bone implant therapy, titanium (Ti) and its alloys are considered as... more With the growing demands for bone implant therapy, titanium (Ti) and its alloys are considered as appropriate choices for the load-bearing bone implant substitutes. However, the interaction of bare Ti-based implants with the tissues is critical to the success of the implants for long-term stability. Thus, surface modifications of Ti implants with biocompatible hydroxyapatite (HAp) coatings before implantation is important and gained interest. Sol-gel is a potential technique for deposition the biocompatible HAp and has many advantages over other methods. Therefore, this review strives to provide widespread overview on the recent development of sol-gel HAp deposition on Ti. This study shows that sol-gel technique was able to produce uniform and homogenous HAp coatings and identified the role of surface pretreatment of Ti substrate, optimizing the sol-gel parameters, substitution, and reinforcement of HAp on improving the coating properties. Critical factors that influence on the char...

Procedia Engineering, 2016

ABSTRACT The invention relates to a process for removing C2+ hydrocarbons from natural gas or gas... more ABSTRACT The invention relates to a process for removing C2+ hydrocarbons from natural gas or gas which accompanies mineral oil using membranes. This involves passing a feed gas under a pressure of 2 to 500 bar within a temperature range from -30°C to +60°C through a membrane composed of a porous inorganic material or an organic polymer. The C2+ gas permeates through the membrane as a preferred adsorbate or condensate and accumulates in the permeate space as a result of an increase in the amount controlled by the membrane to 1.5 times to 50 times the level in relation to the feed side. The condensate of C2+ hydrocarbons which results from the temperature going below the dew point is drawn off from the permeate side within the temperature range from -70°C to +50°C at a pressure of 1 to 360 bar. The separation is effected under practically relevant pressure conditions without energy-intensive expansion or cooling and with improved separation performances. The process can be used advantageously in relatively small mineral oil fields with a reduced level of process technology complexity. The use of natural gas in accordance with its delivery pressure is particularly advantageous.

Festelektrolytsensoren auf Basis von Y-dotiertem ZrO 2 haben sich in der Praxis als robuste Senso... more Festelektrolytsensoren auf Basis von Y-dotiertem ZrO 2 haben sich in der Praxis als robuste Sensoren zu Bestimmung von Sauerstoffpartialdrücken bewährt. Ziel dieser Arbeiten ist die Herstellung eines langzeitstabilen und driftfreien Sensors zur kontinuierlichen Messung des Schwefelgehaltes im Zinnbad und Schutzgas für den Floatglas-Prozesses. Hierzu wurden einseitig geschlossene Rohre als Festelektrolytmembranen auf Basis von Y-dotiertem CaF 2 sowie La-dotiertem SrF 2 entwickelt.

Journal of Membrane Science, Mar 1, 2011

ABSTRACT The separation of higher alkanes from methane is a key aspect for conditioning natural g... more ABSTRACT The separation of higher alkanes from methane is a key aspect for conditioning natural gases and accompanying gases. Against this background, a systematic study on related separation performances of several MFI membranes in dependence on their synthetic origin is presented with this contribution. Basically, MFI slurry was used for the activation of inert Al2O3 supports for heterogeneous crystallization. The resulting MFI seed layer acts both as heterogeneous nucleation side and as flexible distance holder between support and MFI membrane suppressing defect formations during thermal template removal. For the purpose of further optimization, synthesis parameters like temperature, reaction time, pore size of the support and reactant ratios were varied. Characterization of the membranes via permporometry and single gas permeation using methane and n-butane gave first results on the characteristic properties of the membranes obtained. Also, the non isobar performed separations of C4/C1 binary 1:1 mixtures (pfeed=1bar, ppermeate=2bar) are discussed with respect to membrane synthesis. It was found that either selectivity (M10, α=11.3; J=128lm−2h−1bar−1 at 75°C) or permeation flux (M16, α=3.6; J=477lm−2h−1bar−1) optimized membranes can be generated via different synthetic routes. Both archetypes were tested in a simulated cascade like separation experiment for the isolation of n-butane from C4/C1=95:5 mixtures. Under elevated feed pressures (pfeed=2–11bar, ppermeate=1bar) only separation optimized membranes showed a promising applicability due to an increased separation performance also at a lower n-butane content of 6.8%. Increasing feed pressures induced an increase in separation factors from 2.0 to 13.9 at nearly constant permeances of 93–136lm−2h−1bar−1 making customized MFI membranes attractive for technological applications.

RSC Advances, 2014

The performance of porous membranes is tremendously influenced by desorption, as alkane separatio... more The performance of porous membranes is tremendously influenced by desorption, as alkane separations by a pressure stable MFI membrane revealed. High membrane selectivities as well as permeation fluxes are to be traced back to the fact that a reduced permeate pressure significantly decreases the loading gradient of the adsorbed molecules in the membrane.

Chemie Ingenieur Technik, Mar 13, 2013

ABSTRACT Die Abreicherung höherer Kohlenwasserstoffe aus Erdgas oder Erdölbegleitgasen ist ein un... more ABSTRACT Die Abreicherung höherer Kohlenwasserstoffe aus Erdgas oder Erdölbegleitgasen ist ein unablässiger Schritt vor der Einspeisung in das Endverbrauchernetz. Membrantechnologien könnten dabei als Ersatz für energieintensive und kostspielige Reinigungsmethoden eingesetzt werden. Vor diesem Hintergrund wurde die entsprechende Eignung zeolithischer MFI-Membranen untersucht und der Einfluss von Membranträgergeometrie, Gaszusammensetzung, Temperatur und Druck auf die Trennung von Methan/n-Butan-Mischungen getestet. The depletion of higher alkanes from methane is a key aspect during the conditioning of natural gases or accompanying gases. Membrane technologies could be used as alternative to energy and cost intensive purifications. Against this background the influence of membrane geometry, composition of the gas mixture as well as temperature and pressure was investigated in separation experiments for methane/n-butane mixtures using MFI membranes.

Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and strea... more Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and streaming current arise when pressure-driven fluid flow transport by advection induces both a potential and a current at the channel ends. This effect can be used as a sensor/transducer principle and also to generate electricity for sensor power supply and therefore represents a mechanism for converting mechanical work into electrical power. Electrokinetic sensors and energy harvester are simple to build, and can be easily integrated into nano-and microfluidic lab-on-chip systems.

Procedia Engineering, 2016

Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and strea... more Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and streaming current arise when pressure-driven fluid flow transport by advection induces both a potential and a current at the channel ends. This effect can be used as a sensor/transducer principle and also to generate electricity for sensor power supply and therefore represents a mechanism for converting mechanical work into electrical power. Electrokinetic sensors and energy harvester are simple to build, and can be easily integrated into nano-and microfluidic lab-on-chip systems.

Procedia Engineering, 2015

Under reducing conditions fluoride based solid electrolyte sensors with sulphur-sensitive auxilia... more Under reducing conditions fluoride based solid electrolyte sensors with sulphur-sensitive auxiliary electrodes are able to measure the sulphur content in liquid metals and gases at elevated temperatures. In this work CaF 2 doped with YF 3 and SrF 2 doped with LaF 3 were selected as solid electrolyte material, because of their high ionic conductivity. Solid electrolyte tubes were prepared from these materials by slip casting to apply them as electrochemical sensors e.g. in the float glass industry.

Journal of Materials Research

Sol–gel derived hydroxyapatite coatings on metallic implants are important to promote their osseo... more Sol–gel derived hydroxyapatite coatings on metallic implants are important to promote their osseointegration and biocompatibility. However, such coatings generally suffer from drawbacks that limit implant longevity. In this study, the sol gel process to prepare hydroxyapatite was optimized and used to deposit a hydroxyapatite layer on Ti6Al4V. Samples were pretreated by thermal oxidation, sol–gel coating, and anodization to produce titanium dioxide interlayers with various structures. The results of structural and thermal analysis have determined the optimal preparation parameters to produce monophasic and crystalline hydroxyapatite. The introduction of titanium dioxide intermediate layers produced crack-free hydroxyapatite films and promoted the adherence and integrity of the coating, where the adhesive strength was remarkably improved. Furthermore, potentiodynamic polarization tests in simulated body fluid revealed low corrosion rates and high protection property of the hydroxyapa...

The process is especially relevant for the processing of natural gas and associated petroleum gas... more The process is especially relevant for the processing of natural gas and associated petroleum gases. With the described method it is possible, dispensing of the permeate side sweep gas (sweep) hydrocarbons to separate from each other in practically relevant pressures. The invention has for its technical object to provide a process for the separation of natural gas or petroleum gas components to inorganic porous membranes, with the higher hydrocarbons can be continuously separated with high gas flow rates effectively without extensive cooling of the gases. The object is achieved by a method which is characterized by the following features: a) it is carried out bar with feed pressures greater than 5, wherein the pressure on the permeate side is lower than on the feed side. b) to increase the separation performance of a pressure-mediated, increased condensation of the higher hydrocarbons is used at the pores of the membrane c) meso and macroscopically dense inorganic membranes are used...

Separation and Purification Technology, 2018

Determination of the membrane charge using streaming potential measurements The membrane charge s... more Determination of the membrane charge using streaming potential measurements The membrane charge significantly depending on the pH value of the feed Specific adsorption of multivalent ions shifts the isoelectric point Due to streaming potential measurements, ion retention can be predicted If the TiO 2 NF-membrane is charged, then ions are retained, otherwise they pass through

Journal of Membrane Science, 2011

ABSTRACT The separation of higher alkanes from methane is a key aspect for conditioning natural g... more ABSTRACT The separation of higher alkanes from methane is a key aspect for conditioning natural gases and accompanying gases. Against this background, a systematic study on related separation performances of several MFI membranes in dependence on their synthetic origin is presented with this contribution. Basically, MFI slurry was used for the activation of inert Al2O3 supports for heterogeneous crystallization. The resulting MFI seed layer acts both as heterogeneous nucleation side and as flexible distance holder between support and MFI membrane suppressing defect formations during thermal template removal. For the purpose of further optimization, synthesis parameters like temperature, reaction time, pore size of the support and reactant ratios were varied. Characterization of the membranes via permporometry and single gas permeation using methane and n-butane gave first results on the characteristic properties of the membranes obtained. Also, the non isobar performed separations of C4/C1 binary 1:1 mixtures (pfeed=1bar, ppermeate=2bar) are discussed with respect to membrane synthesis. It was found that either selectivity (M10, α=11.3; J=128lm−2h−1bar−1 at 75°C) or permeation flux (M16, α=3.6; J=477lm−2h−1bar−1) optimized membranes can be generated via different synthetic routes. Both archetypes were tested in a simulated cascade like separation experiment for the isolation of n-butane from C4/C1=95:5 mixtures. Under elevated feed pressures (pfeed=2–11bar, ppermeate=1bar) only separation optimized membranes showed a promising applicability due to an increased separation performance also at a lower n-butane content of 6.8%. Increasing feed pressures induced an increase in separation factors from 2.0 to 13.9 at nearly constant permeances of 93–136lm−2h−1bar−1 making customized MFI membranes attractive for technological applications.

Chemie Ingenieur Technik, 2013

ABSTRACT Die Abreicherung höherer Kohlenwasserstoffe aus Erdgas oder Erdölbegleitgasen ist ein un... more ABSTRACT Die Abreicherung höherer Kohlenwasserstoffe aus Erdgas oder Erdölbegleitgasen ist ein unablässiger Schritt vor der Einspeisung in das Endverbrauchernetz. Membrantechnologien könnten dabei als Ersatz für energieintensive und kostspielige Reinigungsmethoden eingesetzt werden. Vor diesem Hintergrund wurde die entsprechende Eignung zeolithischer MFI-Membranen untersucht und der Einfluss von Membranträgergeometrie, Gaszusammensetzung, Temperatur und Druck auf die Trennung von Methan/n-Butan-Mischungen getestet. The depletion of higher alkanes from methane is a key aspect during the conditioning of natural gases or accompanying gases. Membrane technologies could be used as alternative to energy and cost intensive purifications. Against this background the influence of membrane geometry, composition of the gas mixture as well as temperature and pressure was investigated in separation experiments for methane/n-butane mixtures using MFI membranes.

The invention relates to a process for separating C In this case, a feed gas is passed under a pr... more The invention relates to a process for separating C In this case, a feed gas is passed under a pressure of 2 to 500 in a temperature range from -30 ° C to + 60 ° C over a membrane of a porous inorganic material or an organic polymer. The permeating C The separation takes place at practically relevant printing conditions without energy-intensive relaxation or cooling and with improved separation efficiency.

Proceedings Sensor 2017

Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and strea... more Electrokinetic phenomena in charged micro-and nanochannels known as streaming potential and streaming current arise when pressure-driven fluid flow transport by advection induces both a potential and a current at the channel ends. This effect can be used as a sensor/transducer principle and also to generate electricity for sensor power supply and therefore represents a mechanism for converting mechanical work into electrical power. Electrokinetic sensors and energy harvester are simple to build, and can be easily integrated into nano-and microfluidic lab-on-chip systems.

Procedia Engineering, 2015

Abstract Under reducing conditions fluoride based solid electrolyte sensors with sulphur-sensitiv... more Abstract Under reducing conditions fluoride based solid electrolyte sensors with sulphur-sensitive auxiliary electrodes are able to measure the sulphur content in liquid metals and gases at elevated temperatures. In this work CaF 2 doped with YF 3 and SrF 2 doped with LaF 3 were selected as solid electrolyte material, because of their high ionic conductivity. Solid electrolyte tubes were prepared from these materials by slip casting to apply them as electrochemical sensors e.g. in the float glass industry.

Dermatologic Surgery, 2015

Zusammenfassung Festelektrolytsensoren auf Basis von Y-dotiertem ZrO2 haben sich in der Praxis al... more Zusammenfassung Festelektrolytsensoren auf Basis von Y-dotiertem ZrO2 haben sich in der Praxis als robuste Sensoren zu Bestimmung von Sauerstoffpartialdrucken bewahrt. Ziel dieser Arbeiten ist die Herstellung eines langzeitstabilen und driftfreien Sensors zur kontinuierlichen Messung des Schwefelgehaltes im Zinnbad und Schutzgas fur den Floatglas-Prozesses. Hierzu wurden einseitig geschlossene Rohre als Festelektrolytmembranen auf Basis von Y-dotiertem CaF2 sowie La-dotiertem SrF2 entwickelt.

Bioengineering

With the growing demands for bone implant therapy, titanium (Ti) and its alloys are considered as... more With the growing demands for bone implant therapy, titanium (Ti) and its alloys are considered as appropriate choices for the load-bearing bone implant substitutes. However, the interaction of bare Ti-based implants with the tissues is critical to the success of the implants for long-term stability. Thus, surface modifications of Ti implants with biocompatible hydroxyapatite (HAp) coatings before implantation is important and gained interest. Sol-gel is a potential technique for deposition the biocompatible HAp and has many advantages over other methods. Therefore, this review strives to provide widespread overview on the recent development of sol-gel HAp deposition on Ti. This study shows that sol-gel technique was able to produce uniform and homogenous HAp coatings and identified the role of surface pretreatment of Ti substrate, optimizing the sol-gel parameters, substitution, and reinforcement of HAp on improving the coating properties. Critical factors that influence on the char...

Procedia Engineering, 2016

ABSTRACT The invention relates to a process for removing C2+ hydrocarbons from natural gas or gas... more ABSTRACT The invention relates to a process for removing C2+ hydrocarbons from natural gas or gas which accompanies mineral oil using membranes. This involves passing a feed gas under a pressure of 2 to 500 bar within a temperature range from -30°C to +60°C through a membrane composed of a porous inorganic material or an organic polymer. The C2+ gas permeates through the membrane as a preferred adsorbate or condensate and accumulates in the permeate space as a result of an increase in the amount controlled by the membrane to 1.5 times to 50 times the level in relation to the feed side. The condensate of C2+ hydrocarbons which results from the temperature going below the dew point is drawn off from the permeate side within the temperature range from -70°C to +50°C at a pressure of 1 to 360 bar. The separation is effected under practically relevant pressure conditions without energy-intensive expansion or cooling and with improved separation performances. The process can be used advantageously in relatively small mineral oil fields with a reduced level of process technology complexity. The use of natural gas in accordance with its delivery pressure is particularly advantageous.