The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

Andreas Seidelmorgenstern - One of the best experts on this subject based on the ideXlab platform.

  • transport of butane in a porous vycor glass membrane in the region of Condensation Pressure
    Journal of Membrane Science, 2007
    Co-Authors: Petr Uchytil, R Petrickovic, Andreas Seidelmorgenstern
    Abstract:

    Abstract The transport and the separation efficiency in porous membranes can be strongly influenced by the Condensation of permeating gases. An accurate experimental monitoring of permeating vapors and condensates in small pores of membranes is very desirable. The dynamic permeation method is one of the methods which can be used to perform a corresponding study. The following experimental arrangement was applied: a constant higher Pressure P 1 was set on an open side of the membrane; on the opposite closed side the change of a lower Pressure P 2 was measured. The dynamic permeation set-up was used at first in transport measurements of a noncondensable gas through a Vycor glass membrane (mean pore radius around 2 nm). The obtained data were compared with the results of alternatively performed steady state permeation measurements. Subsequently, the permeability was studied for the condensable gas butane through the Vycor glass membrane, particularly for elevator Pressure conditions near the saturated vapor Pressure. Also for this purpose the dynamic permeation experiment was found to be very convenient. It enables to measure the mass transport for very small Pressure gradients across the membrane. The permeation results obtained correspond well with the liquid butane permeability of Vycor membrane quantified previously in independent pervaporation experiments. This agreement confirms the presence of liquid butane in small pores of Vycor glass during the transient gas transport at relatively high Pressures.

  • Transport of butane in a porous Vycor glass membrane in the region of Condensation Pressure
    Journal of Membrane Science, 2007
    Co-Authors: Petr Uchytil, R Petrickovic, Andreas Seidelmorgenstern
    Abstract:

    The transport and the separation efficiency in porous membranes can be strongly influenced by the Condensation of permeating gases. An accurate experimental monitoring of permeating vapors and condensates in small pores of membranes is very desirable. The dynamic permeation method is one of the methods which can be used to perform a corresponding study. The following experimental arrangement was applied: a constant higher Pressure P1 was set on an open side of the membrane; on the opposite closed side the change of a lower Pressure P2 was measured. The dynamic permeation set-up was used at first in transport measurements of a noncondensable gas through a Vycor glass membrane (mean pore radius around 2 nm). The obtained data were compared with the results of alternatively performed steady state permeation measurements. Subsequently, the permeability was studied for the condensable gas butane through the Vycor glass membrane, particularly for elevator Pressure conditions near the saturated vapor Pressure. Also for this purpose the dynamic permeation experiment was found to be very convenient. It enables to measure the mass transport for very small Pressure gradients across the membrane. The permeation results obtained correspond well with the liquid butane permeability of Vycor membrane quantified previously in independent pervaporation experiments. This agreement confirms the presence of liquid butane in small pores of Vycor glass during the transient gas transport at relatively high Pressures. Copyright © 2007 Elsevier B.V. All rights reserved. [accessed 2013 November 26th

Mohammad Hossein Nekoofar - One of the best experts on this subject based on the ideXlab platform.

  • the effect of Condensation Pressure on selected physical properties of mineral trioxide aggregate
    International Endodontic Journal, 2007
    Co-Authors: Mohammad Hossein Nekoofar, G Adusei, M S Sheykhrezae, S J Hayes, Susan Bryant, P M H Dummer
    Abstract:

    Aim  To examine the effect of Condensation Pressure on surface hardness, microstructure and compressive strength of mineral trioxide aggregate (MTA). Methodology  White ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN, USA) was mixed and packed into cylindrical polycarbonate tubes. Six groups each of 10 specimens were subjected to Pressures of 0.06, 0.44, 1.68, 3.22, 4.46 and 8.88 MPa respectively. The surface hardness of each specimen was measured using Vickers microhardness. Cylindrical specimens of 4 mm in diameter and 6 mm in height were prepared in polycarbonate cylindrical moulds for testing the compressive strength. Five groups of 10 specimens were prepared using Pressures of 0.06, 0.44, 1.68, 3.22 or 4.46 MPa. Data were subjected to one-way anova. The microstructure was analysed using a scanning electron microscope (SEM) after sectioning specimens with a scalpel. Result  A trend was observed for higher Condensation Pressures to produce lower surface hardness values. A Condensation Pressure of 8.88 MPa produced specimens with significantly lower values in terms of surface hardness than other groups (P < 0.001). A Condensation Pressure of 1.68 MPa conferred the maximum compressive strength; however, it was not statistically different. Higher Condensation Pressures resulted in fewer voids and microchannels when analysed with SEM. In specimens prepared with lower Condensation Pressures distinctive crystalline structures were observed. They tended to appear around microchannels. Conclusion  Condensation Pressure may affect the strength and hardness of MTA. Use of controlled Condensation Pressure in sample preparation for future studies is suggested.

  • The effect of Condensation Pressure on selected physical properties of mineral trioxide aggregate.
    International endodontic journal, 2007
    Co-Authors: Mohammad Hossein Nekoofar, G Adusei, M S Sheykhrezae, S J Hayes, Susan Bryant, P M H Dummer
    Abstract:

    Aim  To examine the effect of Condensation Pressure on surface hardness, microstructure and compressive strength of mineral trioxide aggregate (MTA). Methodology  White ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN, USA) was mixed and packed into cylindrical polycarbonate tubes. Six groups each of 10 specimens were subjected to Pressures of 0.06, 0.44, 1.68, 3.22, 4.46 and 8.88 MPa respectively. The surface hardness of each specimen was measured using Vickers microhardness. Cylindrical specimens of 4 mm in diameter and 6 mm in height were prepared in polycarbonate cylindrical moulds for testing the compressive strength. Five groups of 10 specimens were prepared using Pressures of 0.06, 0.44, 1.68, 3.22 or 4.46 MPa. Data were subjected to one-way anova. The microstructure was analysed using a scanning electron microscope (SEM) after sectioning specimens with a scalpel. Result  A trend was observed for higher Condensation Pressures to produce lower surface hardness values. A Condensation Pressure of 8.88 MPa produced specimens with significantly lower values in terms of surface hardness than other groups (P 

P M H Dummer - One of the best experts on this subject based on the ideXlab platform.

  • the effect of Condensation Pressure on selected physical properties of mineral trioxide aggregate
    International Endodontic Journal, 2007
    Co-Authors: Mohammad Hossein Nekoofar, G Adusei, M S Sheykhrezae, S J Hayes, Susan Bryant, P M H Dummer
    Abstract:

    Aim  To examine the effect of Condensation Pressure on surface hardness, microstructure and compressive strength of mineral trioxide aggregate (MTA). Methodology  White ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN, USA) was mixed and packed into cylindrical polycarbonate tubes. Six groups each of 10 specimens were subjected to Pressures of 0.06, 0.44, 1.68, 3.22, 4.46 and 8.88 MPa respectively. The surface hardness of each specimen was measured using Vickers microhardness. Cylindrical specimens of 4 mm in diameter and 6 mm in height were prepared in polycarbonate cylindrical moulds for testing the compressive strength. Five groups of 10 specimens were prepared using Pressures of 0.06, 0.44, 1.68, 3.22 or 4.46 MPa. Data were subjected to one-way anova. The microstructure was analysed using a scanning electron microscope (SEM) after sectioning specimens with a scalpel. Result  A trend was observed for higher Condensation Pressures to produce lower surface hardness values. A Condensation Pressure of 8.88 MPa produced specimens with significantly lower values in terms of surface hardness than other groups (P < 0.001). A Condensation Pressure of 1.68 MPa conferred the maximum compressive strength; however, it was not statistically different. Higher Condensation Pressures resulted in fewer voids and microchannels when analysed with SEM. In specimens prepared with lower Condensation Pressures distinctive crystalline structures were observed. They tended to appear around microchannels. Conclusion  Condensation Pressure may affect the strength and hardness of MTA. Use of controlled Condensation Pressure in sample preparation for future studies is suggested.

  • The effect of Condensation Pressure on selected physical properties of mineral trioxide aggregate.
    International endodontic journal, 2007
    Co-Authors: Mohammad Hossein Nekoofar, G Adusei, M S Sheykhrezae, S J Hayes, Susan Bryant, P M H Dummer
    Abstract:

    Aim  To examine the effect of Condensation Pressure on surface hardness, microstructure and compressive strength of mineral trioxide aggregate (MTA). Methodology  White ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN, USA) was mixed and packed into cylindrical polycarbonate tubes. Six groups each of 10 specimens were subjected to Pressures of 0.06, 0.44, 1.68, 3.22, 4.46 and 8.88 MPa respectively. The surface hardness of each specimen was measured using Vickers microhardness. Cylindrical specimens of 4 mm in diameter and 6 mm in height were prepared in polycarbonate cylindrical moulds for testing the compressive strength. Five groups of 10 specimens were prepared using Pressures of 0.06, 0.44, 1.68, 3.22 or 4.46 MPa. Data were subjected to one-way anova. The microstructure was analysed using a scanning electron microscope (SEM) after sectioning specimens with a scalpel. Result  A trend was observed for higher Condensation Pressures to produce lower surface hardness values. A Condensation Pressure of 8.88 MPa produced specimens with significantly lower values in terms of surface hardness than other groups (P 

Petr Uchytil - One of the best experts on this subject based on the ideXlab platform.

  • transport of butane in a porous vycor glass membrane in the region of Condensation Pressure
    Journal of Membrane Science, 2007
    Co-Authors: Petr Uchytil, R Petrickovic, Andreas Seidelmorgenstern
    Abstract:

    Abstract The transport and the separation efficiency in porous membranes can be strongly influenced by the Condensation of permeating gases. An accurate experimental monitoring of permeating vapors and condensates in small pores of membranes is very desirable. The dynamic permeation method is one of the methods which can be used to perform a corresponding study. The following experimental arrangement was applied: a constant higher Pressure P 1 was set on an open side of the membrane; on the opposite closed side the change of a lower Pressure P 2 was measured. The dynamic permeation set-up was used at first in transport measurements of a noncondensable gas through a Vycor glass membrane (mean pore radius around 2 nm). The obtained data were compared with the results of alternatively performed steady state permeation measurements. Subsequently, the permeability was studied for the condensable gas butane through the Vycor glass membrane, particularly for elevator Pressure conditions near the saturated vapor Pressure. Also for this purpose the dynamic permeation experiment was found to be very convenient. It enables to measure the mass transport for very small Pressure gradients across the membrane. The permeation results obtained correspond well with the liquid butane permeability of Vycor membrane quantified previously in independent pervaporation experiments. This agreement confirms the presence of liquid butane in small pores of Vycor glass during the transient gas transport at relatively high Pressures.

  • Transport of butane in a porous Vycor glass membrane in the region of Condensation Pressure
    Journal of Membrane Science, 2007
    Co-Authors: Petr Uchytil, R Petrickovic, Andreas Seidelmorgenstern
    Abstract:

    The transport and the separation efficiency in porous membranes can be strongly influenced by the Condensation of permeating gases. An accurate experimental monitoring of permeating vapors and condensates in small pores of membranes is very desirable. The dynamic permeation method is one of the methods which can be used to perform a corresponding study. The following experimental arrangement was applied: a constant higher Pressure P1 was set on an open side of the membrane; on the opposite closed side the change of a lower Pressure P2 was measured. The dynamic permeation set-up was used at first in transport measurements of a noncondensable gas through a Vycor glass membrane (mean pore radius around 2 nm). The obtained data were compared with the results of alternatively performed steady state permeation measurements. Subsequently, the permeability was studied for the condensable gas butane through the Vycor glass membrane, particularly for elevator Pressure conditions near the saturated vapor Pressure. Also for this purpose the dynamic permeation experiment was found to be very convenient. It enables to measure the mass transport for very small Pressure gradients across the membrane. The permeation results obtained correspond well with the liquid butane permeability of Vycor membrane quantified previously in independent pervaporation experiments. This agreement confirms the presence of liquid butane in small pores of Vycor glass during the transient gas transport at relatively high Pressures. Copyright © 2007 Elsevier B.V. All rights reserved. [accessed 2013 November 26th

R Petrickovic - One of the best experts on this subject based on the ideXlab platform.

  • transport of butane in a porous vycor glass membrane in the region of Condensation Pressure
    Journal of Membrane Science, 2007
    Co-Authors: Petr Uchytil, R Petrickovic, Andreas Seidelmorgenstern
    Abstract:

    Abstract The transport and the separation efficiency in porous membranes can be strongly influenced by the Condensation of permeating gases. An accurate experimental monitoring of permeating vapors and condensates in small pores of membranes is very desirable. The dynamic permeation method is one of the methods which can be used to perform a corresponding study. The following experimental arrangement was applied: a constant higher Pressure P 1 was set on an open side of the membrane; on the opposite closed side the change of a lower Pressure P 2 was measured. The dynamic permeation set-up was used at first in transport measurements of a noncondensable gas through a Vycor glass membrane (mean pore radius around 2 nm). The obtained data were compared with the results of alternatively performed steady state permeation measurements. Subsequently, the permeability was studied for the condensable gas butane through the Vycor glass membrane, particularly for elevator Pressure conditions near the saturated vapor Pressure. Also for this purpose the dynamic permeation experiment was found to be very convenient. It enables to measure the mass transport for very small Pressure gradients across the membrane. The permeation results obtained correspond well with the liquid butane permeability of Vycor membrane quantified previously in independent pervaporation experiments. This agreement confirms the presence of liquid butane in small pores of Vycor glass during the transient gas transport at relatively high Pressures.

  • Transport of butane in a porous Vycor glass membrane in the region of Condensation Pressure
    Journal of Membrane Science, 2007
    Co-Authors: Petr Uchytil, R Petrickovic, Andreas Seidelmorgenstern
    Abstract:

    The transport and the separation efficiency in porous membranes can be strongly influenced by the Condensation of permeating gases. An accurate experimental monitoring of permeating vapors and condensates in small pores of membranes is very desirable. The dynamic permeation method is one of the methods which can be used to perform a corresponding study. The following experimental arrangement was applied: a constant higher Pressure P1 was set on an open side of the membrane; on the opposite closed side the change of a lower Pressure P2 was measured. The dynamic permeation set-up was used at first in transport measurements of a noncondensable gas through a Vycor glass membrane (mean pore radius around 2 nm). The obtained data were compared with the results of alternatively performed steady state permeation measurements. Subsequently, the permeability was studied for the condensable gas butane through the Vycor glass membrane, particularly for elevator Pressure conditions near the saturated vapor Pressure. Also for this purpose the dynamic permeation experiment was found to be very convenient. It enables to measure the mass transport for very small Pressure gradients across the membrane. The permeation results obtained correspond well with the liquid butane permeability of Vycor membrane quantified previously in independent pervaporation experiments. This agreement confirms the presence of liquid butane in small pores of Vycor glass during the transient gas transport at relatively high Pressures. Copyright © 2007 Elsevier B.V. All rights reserved. [accessed 2013 November 26th