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G Dumpich - One of the best experts on this subject based on the ideXlab platform.
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tailored nanoparticle films from monosized tin oxide nanocrystals particle synthesis film formation and size dependent gas sensing properties
Journal of Applied Physics, 2003Co-Authors: M K Kennedy, Frank Einar Kruis, Sven Stappert, B.r. Mehta, Heinz Fissan, G DumpichAbstract:In order to investigate the change of gas-sensitive properties of undoped tin oxide nanoparticle films depending on particle size, a thin film synthesis technique has been developed. Well-defined tin oxide nanoparticles have been prepared using a gas-phase condensation method. Pure SnO was used as starting material and was evaporated at T=820 °C. The resulting particles were sintered and crystallized in-flight at T=650 °C. Size-selected nanoparticles ranging from 10 to 35 nm were produced to form a nanoparticle film by means of Electrostatic Precipitation or low pressure impaction. The effect of in-flight oxidation, sintering, and crystallization on the structure, size, and size distribution of nanoparticles have been studied in detail. The samples show n-type semiconductors’ behavior like bulk SnO2. The influence of particle size on gas sensitivity and response behavior is investigated for C2H5OH at operating temperatures 200–300 °C using silicon substrates having an interdigitated contact pattern and an...
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tailored nanoparticle films from monosized tin oxide nanocrystals particle synthesis film formation and size dependent gas sensing properties
Journal of Applied Physics, 2003Co-Authors: M K Kennedy, Frank Einar Kruis, Sven Stappert, B.r. Mehta, Heinz Fissan, G DumpichAbstract:In order to investigate the change of gas-sensitive properties of undoped tin oxide nanoparticle films depending on particle size, a thin film synthesis technique has been developed. Well-defined tin oxide nanoparticles have been prepared using a gas-phase condensation method. Pure SnO was used as starting material and was evaporated at T=820 °C. The resulting particles were sintered and crystallized in-flight at T=650 °C. Size-selected nanoparticles ranging from 10 to 35 nm were produced to form a nanoparticle film by means of Electrostatic Precipitation or low pressure impaction. The effect of in-flight oxidation, sintering, and crystallization on the structure, size, and size distribution of nanoparticles have been studied in detail. The samples show n-type semiconductors’ behavior like bulk SnO2. The influence of particle size on gas sensitivity and response behavior is investigated for C2H5OH at operating temperatures 200–300 °C using silicon substrates having an interdigitated contact pattern and an integrated heating system. In the range of 10–35 nm it has been shown unambiguously that decreasing the particle size of tin oxide particles leads to an increase of the sensitivity and a more rapid response on changing gas conditions. The effect is especially clear for films with a particle size of 20 nm or smaller.
M K Kennedy - One of the best experts on this subject based on the ideXlab platform.
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tailored nanoparticle films from monosized tin oxide nanocrystals particle synthesis film formation and size dependent gas sensing properties
Journal of Applied Physics, 2003Co-Authors: M K Kennedy, Frank Einar Kruis, Sven Stappert, B.r. Mehta, Heinz Fissan, G DumpichAbstract:In order to investigate the change of gas-sensitive properties of undoped tin oxide nanoparticle films depending on particle size, a thin film synthesis technique has been developed. Well-defined tin oxide nanoparticles have been prepared using a gas-phase condensation method. Pure SnO was used as starting material and was evaporated at T=820 °C. The resulting particles were sintered and crystallized in-flight at T=650 °C. Size-selected nanoparticles ranging from 10 to 35 nm were produced to form a nanoparticle film by means of Electrostatic Precipitation or low pressure impaction. The effect of in-flight oxidation, sintering, and crystallization on the structure, size, and size distribution of nanoparticles have been studied in detail. The samples show n-type semiconductors’ behavior like bulk SnO2. The influence of particle size on gas sensitivity and response behavior is investigated for C2H5OH at operating temperatures 200–300 °C using silicon substrates having an interdigitated contact pattern and an...
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tailored nanoparticle films from monosized tin oxide nanocrystals particle synthesis film formation and size dependent gas sensing properties
Journal of Applied Physics, 2003Co-Authors: M K Kennedy, Frank Einar Kruis, Sven Stappert, B.r. Mehta, Heinz Fissan, G DumpichAbstract:In order to investigate the change of gas-sensitive properties of undoped tin oxide nanoparticle films depending on particle size, a thin film synthesis technique has been developed. Well-defined tin oxide nanoparticles have been prepared using a gas-phase condensation method. Pure SnO was used as starting material and was evaporated at T=820 °C. The resulting particles were sintered and crystallized in-flight at T=650 °C. Size-selected nanoparticles ranging from 10 to 35 nm were produced to form a nanoparticle film by means of Electrostatic Precipitation or low pressure impaction. The effect of in-flight oxidation, sintering, and crystallization on the structure, size, and size distribution of nanoparticles have been studied in detail. The samples show n-type semiconductors’ behavior like bulk SnO2. The influence of particle size on gas sensitivity and response behavior is investigated for C2H5OH at operating temperatures 200–300 °C using silicon substrates having an interdigitated contact pattern and an integrated heating system. In the range of 10–35 nm it has been shown unambiguously that decreasing the particle size of tin oxide particles leads to an increase of the sensitivity and a more rapid response on changing gas conditions. The effect is especially clear for films with a particle size of 20 nm or smaller.
Herek L Clack - One of the best experts on this subject based on the ideXlab platform.
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further consideration of gas particle mass transfer simulation during Electrostatic Precipitation using lower order representations of particle size distributions variable size distributions
Journal of Electrostatics, 2020Co-Authors: Herek L ClackAbstract:Abstract A previous study identified the ratio of two characteristic time scales – hydrodynamic and Electrostatic particle Precipitation – as an indicator of whether gas-particle mass transfer during Electrostatic Precipitation could be modeled using a uniform particle size that represents the collective surface-to-volume ratio of the original polydisperse dispersion. The present investigation extends the earlier findings by examining the gas-particle mass transfer occurring during Electrostatic Precipitation of several log-normally distributed particle size distributions of varying mean particle diameters and geometric standard deviations. The results confirm that the ratio of hydrodynamic to Electrostatic particle Precipitation time scales can be used broadly for varying size distributions. The ratio can either be used to identify those conditions in which a lower-order representation of the particle size distribution can be used with little error, or outside of such conditions, to predict the relative error to be expected from substituting a computationally efficient uniform particle size in place of a fully resolved size distribution when predicting gas-particle mass transfer during Electrostatic Precipitation. In terms of computational time, using a uniform particle size results in more than an order of magnitude reduction in computational times using COMSOL™ Multiphysics. Such efficiencies could be attractive when iteratively designing processes for removing trace pollutants from combustion or for chemical and catalytic processes that rely on or are enhanced by manipulating particle suspensions.
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lower order representations of evolving particle size distributions for rapid gas particle mass transfer simulations during Electrostatic Precipitation
Fuel Processing Technology, 2018Co-Authors: Herek L ClackAbstract:Abstract The range of particle sizes typically present in combustion flue gas complicates predictions of gas-particle mass transfer processes. This complexity is amplified within Electrostatic precipitators where particle motion, abundance, and mass transfer characteristics are size dependent. The present study illustrates the utility of replacing explicit representations of particle size distributions in simulations of Electrostatic precipitators with an equivalent loading of monodisperse aerosols of diameter chosen to reproduce the same gas-particle mass transfer characteristics. Computational times are reduced by an order of magnitude using this approach, facilitating future incorporation of multiple particle types or heterogeneous chemical kinetics.
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numerical simulation of simultaneous Electrostatic Precipitation and trace gas adsorption electrohydrodynamic effects
Frontiers in Energy Research, 2017Co-Authors: Herek L ClackAbstract:Quasi-1-D analytical expressions for predicting the performance of Electrostatic precipitators (ESPs) were developed from first principles decades ago and still find use in the present day, although significant simplifying assumptions are employed and manufacturers and operators still incorporate adjustable parameters to match field data. ESPs tasked with simultaneous particulate removal and trace gas-phase pollutant removal, however, represent a significant departure from their original operational mission. The present study extends our previous study of such ESP operations and uses the same computational platform to examine details of the multi-phase flow phenomena within ESPs as a function of the strength of the electro-hydrodynamic (EHD) fluid flow phenomena that can occur under high current density operating conditions or low fluid velocities. In particular, the results show good agreement between numerical simulation and classical ESP performance prediction equations at low current densities, and increasing divergence in predicted performance at higher current densities. Under the influence of EHD phenomena, the acceleration of the fluid by electric body forces effectively increases average fluid velocities through the ESP channel with the expected reduction in PM removal efficiency. The impact on trace pollutant is mixed, with both promotion and inhibition mechanisms associated with EHD phenomena identified.
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particulate carbon emissions from Electrostatic precipitators used for mercury emissions control operational factors and implications
Air Quality Atmosphere & Health, 2014Co-Authors: Herek L ClackAbstract:Injection of powdered activated carbon (PAC) into the combustion flue gas of a coal-fired boiler is a leading approach to reducing anthropogenic mercury emissions. Small particle size and poor electrical properties are known to make carbonaceous particles more difficult to remove from a gas stream by Electrostatic Precipitation, by far the dominant particulate control technology for coal-fired boilers. The present analysis estimates PAC emissions from Electrostatic precipitators (ESPs) and considers both the operational factors driving such emissions as well as their implications in terms of adsorbed mercury concentrations and their potential to act as a climate forcing agent similar to black carbon. The results of the analysis find the potential for PAC to increase particulate carbon emissions by tens of percent to over 150 % in the worst-case scenario considered. Such emissions could increase the contribution of coal combustion to total anthropogenic emissions of particulate carbon by several percentage points. Elevated levels of mercury on such emissions can translate into gas-phase-equivalent mercury concentrations approaching 1 ppb. The most important uncertainty influencing these results is the removal efficiency within ESPs of PM2.5-activated carbon particles.
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Electrostatic Precipitation of powdered activated carbon and implications for secondary mercury adsorption within Electrostatic precipitators
Energy & Fuels, 2011Co-Authors: Vinit Prabhu, Herek L ClackAbstract:The injection of powdered sorbents, such as activated carbon, for mercury emissions control at coal-fired power plants has primarily taken place upstream of Electrostatic precipitators (ESPs), which far outnumber baghouses in the U.S. Although full-scale sorbent injection tests have demonstrated varying degrees of mercury removal efficiency, the actual behavior of powdered activated carbon (PAC) within an ESP has not been well-established, particularly as this behavior relates to adsorbing gas-phase mercury. In the present experimental investigation, results obtained in a lab-scale ESP indicate that the electrical properties of PAC may cause its collection in a full-scale ESP to be significantly different from that of the native fly ash. There appears to be potential for significant collection of PAC on the discharge electrode wires of an ESP. Because these wires are typically not rapped as frequently as collection electrodes in an ESP, over time, such behavior could potentially create a series of cylindr...
Marc A Reymond - One of the best experts on this subject based on the ideXlab platform.
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enhanced intraperitoneal delivery of charged aerosolized curcumin nanoparticles by Electrostatic Precipitation
Nanomedicine: Nanotechnology Biology and Medicine, 2021Co-Authors: Arianna Castagna, Alexandra J Zander, Iaroslaw Sautkin, Marc Schneider, Ranjita Shegokar, Alfred Konigsrainer, Marc A ReymondAbstract:Aims: To investigate the potential of curcumin-loaded polylactic-co-glycolic acid nanoparticles (CUR-PLGA-NPs), alone and with Electrostatic Precipitation, for improving tissue uptake during pressurized intraperitoneal aerosol chemotherapy (PIPAC). Methods: Positively and negatively charged CUR-PLGA-NPs were delivered as PIPAC into inverted bovine urinary bladders ex vivo. The experiment was repeated with the additional use of Electrostatic Precipitation pressurized intraperitoneal aerosol chemotherapy (Electrostatic PIPAC). Results: Positively charged CUR-PLGA-NPs increased depth of tissue penetration by 81.5% and tissue concentration by 80%. Electrostatic Precipitation further improved the uptake of positively charged CUR-PLGA-NPs by 41.8%. Conclusion: The combination of positive charge and Electrostatic Precipitation have significant potential to improve tissue uptake of nanoparticles during intraperitoneal chemotherapy.
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Electrostatic Precipitation pressurized intraperitoneal aerosol chemotherapy epipac first in human application
Pleura and peritoneum, 2016Co-Authors: Marc A Reymond, Cedric Demtroeder, Wiebke Solass, Guido Winnekendonk, Clemens B TempferAbstract:Background: Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) is a drug delivery technique with superior pharmacological properties for treating peritoneal metastasis (PM). Adding Electrostatic loading (ePIPAC) as an adjunct to aerosol and artificial hydrostatic pressure improved tissue uptake in a preclinical model. Methods: We report the first ePIPAC use in 3 patients with PM of hepatobiliary-pancreatic (HBP) origin. All 3 patients received concomitant palliative systemic chemotherapy that was discontinued in two patients. PIPAC with cisplatin 7.5 mg/m2 and doxorubicin 1.5 mg/m2 was applied intraperitoneally at a pressure of 12 mmHg and a temperature of 37% °C for 30 min. Additionally, a voltage 7,500-9,500 V and a current≤10 µA were applied over a stainless steel brush electrode emitting a stream of electrons. Results: ePIPAC was technically feasible. No intraoperative complication was noted. The procedures were well tolerated with no adverse event CTCAE > 2. Patient 1 with PM of unknown origin (CUP with HBP phenotype) showed an objective histological and radiological response and survived 11 months. Patient 2 with ductal pancreatic cancer underwent secondary resection after ePIPAC with no residual PM; however, tumor recurred 5 months later. Patient 3 with adenocarcinoma of the gallbladder showed a radiological regression of liver infiltration and is alive after 22 months without histological evidence of PM. Conclusion: ePIPAC is technically feasible, is well tolerated and can induce tumor regression of PM in HBP cancers with and without concomitant systemic chemotherapy. These preliminary results justify prospective clinical studies with ePIPAC.
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in vivo feasibility of Electrostatic Precipitation as an adjunct to pressurized intraperitoneal aerosol chemotherapy epipac
Annals of Surgical Oncology, 2016Co-Authors: Tinatin Kakchekeeva, Cedric Demtroder, Nirmitha I Herath, Dominic Griffiths, Jared Torkington, Wiebke Solas, Marie Dutreix, Marc A ReymondAbstract:Background Intraperitoneal chemotherapy is limited by tissue penetration. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has been shown to improve drug uptake by utilizing the physical properties of gas and pressure. This study investigated the effect of adding Electrostatic Precipitation to further enhance the pharmacologic properties of this technique.
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in vivo feasibility of Electrostatic Precipitation as an adjunct to pressurized intraperitoneal aerosol chemotherapy epipac
Annals of Surgical Oncology, 2016Co-Authors: Tinatin Kakchekeeva, Cedric Demtroder, Nirmitha I Herath, Dominic Griffiths, Jared Torkington, Wiebke Solas, Marie Dutreix, Marc A ReymondAbstract:Intraperitoneal chemotherapy is limited by tissue penetration. Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has been shown to improve drug uptake by utilizing the physical properties of gas and pressure. This study investigated the effect of adding Electrostatic Precipitation to further enhance the pharmacologic properties of this technique. A comparative study was performed using an in vivo porcine model. There were 3 cases in each group, PIPAC and Electrostatic Precipitation pressurized intraperitoneal aerosol chemotherapy (ePIPAC), plus 1 negative control comparing intraperitoneal distribution and tissue uptake of 2 tracer substances (toluidine blue and DT01). Tracer uptake was determined by measuring DT01 in tissue and peritoneal fluid at the end of each procedure. Electrostatic Precipitation of the aerosol was technically feasible in all ePIPAC animals. The aerosol was cleared completely from the visual field within 15 s in the ePIPAC group versus 30 min in the PIPAC group. The peritoneal surface was homogeneously stained in both groups. After 30 min, 1.5 % remaining DT01 was measured in samples of ePIPAC-treated peritoneal fluid versus 15 % in PIPAC animals (p = 0.01). Tissue concentration was increased after ePIPAC versus PIPAC (p = 0.06). ePIPAC is technically feasible and improves tissue uptake of 2 tracer substances compared to PIPAC by up to tenfold. Intraperitoneal distribution was homogeneous in both groups. ePIPAC has the potential to allow more efficient drug uptake, further dose reduction, a significant shortening of the time required for PIPAC application, and improved health and safety measures.
Heinz Fissan - One of the best experts on this subject based on the ideXlab platform.
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tailored nanoparticle films from monosized tin oxide nanocrystals particle synthesis film formation and size dependent gas sensing properties
Journal of Applied Physics, 2003Co-Authors: M K Kennedy, Frank Einar Kruis, Sven Stappert, B.r. Mehta, Heinz Fissan, G DumpichAbstract:In order to investigate the change of gas-sensitive properties of undoped tin oxide nanoparticle films depending on particle size, a thin film synthesis technique has been developed. Well-defined tin oxide nanoparticles have been prepared using a gas-phase condensation method. Pure SnO was used as starting material and was evaporated at T=820 °C. The resulting particles were sintered and crystallized in-flight at T=650 °C. Size-selected nanoparticles ranging from 10 to 35 nm were produced to form a nanoparticle film by means of Electrostatic Precipitation or low pressure impaction. The effect of in-flight oxidation, sintering, and crystallization on the structure, size, and size distribution of nanoparticles have been studied in detail. The samples show n-type semiconductors’ behavior like bulk SnO2. The influence of particle size on gas sensitivity and response behavior is investigated for C2H5OH at operating temperatures 200–300 °C using silicon substrates having an interdigitated contact pattern and an...
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tailored nanoparticle films from monosized tin oxide nanocrystals particle synthesis film formation and size dependent gas sensing properties
Journal of Applied Physics, 2003Co-Authors: M K Kennedy, Frank Einar Kruis, Sven Stappert, B.r. Mehta, Heinz Fissan, G DumpichAbstract:In order to investigate the change of gas-sensitive properties of undoped tin oxide nanoparticle films depending on particle size, a thin film synthesis technique has been developed. Well-defined tin oxide nanoparticles have been prepared using a gas-phase condensation method. Pure SnO was used as starting material and was evaporated at T=820 °C. The resulting particles were sintered and crystallized in-flight at T=650 °C. Size-selected nanoparticles ranging from 10 to 35 nm were produced to form a nanoparticle film by means of Electrostatic Precipitation or low pressure impaction. The effect of in-flight oxidation, sintering, and crystallization on the structure, size, and size distribution of nanoparticles have been studied in detail. The samples show n-type semiconductors’ behavior like bulk SnO2. The influence of particle size on gas sensitivity and response behavior is investigated for C2H5OH at operating temperatures 200–300 °C using silicon substrates having an interdigitated contact pattern and an integrated heating system. In the range of 10–35 nm it has been shown unambiguously that decreasing the particle size of tin oxide particles leads to an increase of the sensitivity and a more rapid response on changing gas conditions. The effect is especially clear for films with a particle size of 20 nm or smaller.