Dean Tompkins - Academia.edu (original) (raw)

Papers by Dean Tompkins

Research paper thumbnail of A Finite Element Heat Transfer Model of Ferromagnetic Thermoseeds and a Physiologically-Based Objective Function for Pretreatment Planning of Ferromagnetic Hyperthermia

Research paper thumbnail of Effect of implant variables on temperatures achieved during ferromagnetic hyperthermia

International Journal of Hyperthermia, 1992

Effects of ferromagnetic implant variables on steady-state temperature were studied in both in vi... more Effects of ferromagnetic implant variables on steady-state temperature were studied in both in vitro (phantom) and in vivo (rabbit hind limb musculature) models. Thermoseed implant variables included: (1) the presence and number of thermoseed sleeves; (2) variations in thermoseed alignment within the oscillating electromagnetic field; (3) generator power levels of 300 W, 600 W, and 1200 W; and (4) separation of thermoseed tracks by 0.8 cm versus 1 cm. When the thermoseeds were aligned parallel to the electromagnetic field, temperature distributions in the in vivo model using bare thermoseeds and thermoseeds encased in a single sleeve (0.1 mm wall thickness) of polyethylene tubing were statistically higher than in tests performed with thermoseeds encased in a double sleeve (0.25 mm over 0.1 mm wall thickness) of tubing (p = 0.006). Nonetheless, average steady-state temperatures above a therapeutic minimum (greater than or equal to 42 degrees C) were achieved at all generator power levels using thermoseeds encased in a double sleeve of tubing and aligned parallel to the electromagnetic field. Gross misalignment of thermoseeds with the electromagnetic field was partly compensated for by utilizing higher generator power levels. Thermoseed tracks separated by 0.8 cm and aligned parallel to the electromagnetic field yielded average steady-state temperatures that were 0.4-2.2 degrees C higher than those obtained with a thermoseed track separation of 1 cm.

Research paper thumbnail of Photocatalytic oxidation in the presence of microwave irradiation: observations with ethylene and water

Journal of Photochemistry and Photobiology A-chemistry, May 1, 2002

Microwave irradiation was employed in the heterogeneous photocatalytic oxidation (PCO) of a test ... more Microwave irradiation was employed in the heterogeneous photocatalytic oxidation (PCO) of a test compound, ethylene, in the gas phase on TiO 2 /ZrO 2 mixed oxide thin films prepared via sol-gel processing. This approach was taken to study the rate of PCO of these compounds as a function of water concentration by perturbing the presence of water on the surface of the catalyst. PCO experiments were conducted with two types of reactor assemblies (Approaches 1 and 2). In Approach 1 when microwave plasma lighting was applied, microwave irradiation increased the rate constants by 15% (α = 1) and 26.9% (α = 0.5) corrected for light irradiance in studies conducted at 15% relative humidity (RH), but had a negligible effect at 0 and 5% RH. In Approach 2, with the light source external to the microwave chamber, the degradation of ethylene with 3 l liquid water injection proceeded faster (83.9%) in the presence of the microwave irradiation than in the absence. Measurements of water adsorption indicated that microwave irradiation facilitated the removal of excess water from the catalyst surface treated with UV illumination in studies with the RH above 15%, but excess water removal was not observed in studies with the RH lower than 5%. Contact angle measurements helped to elucidate the effect of surface wettability of TiO 2 /ZrO 2 catalyst films on the observed results.

Research paper thumbnail of Effect of Fluorescent Illumination on Bacteria Supported on Glass Slides

Journal of Advanced Oxidation Technologies, 1998

The photocidal effect of exposing S. aureus BC12041 to UVA-rich fluorescent light is demonstrated... more The photocidal effect of exposing S. aureus BC12041 to UVA-rich fluorescent light is demonstrated. In UVA-exposure studies with appropriate controls, CFUs of S. aureus BC 12041 are reduced by approximately two logarithms in a high humidity environment 85% RH) and by one logarithm in moderate humidity (~ 50% RH) over a 30-min treatment period. In similar studies at the high humidity, no differential effect was observed between test and control studies with B. subtilis ATCC 6633. Thus, it appears that UVA-rich fluorescent lighting may be a useful side effect obtained when employing an UVA-activated photocatalyst for the degradation of volatile organic compounds (VOCs) in indoor air.

Research paper thumbnail of Temperature Distributions During Thermoradiotherapy: A Sensitivity Study With a Transient Numerical Model of the Rabbit Eye

Journal of biomechanical engineering, May 1, 1997

An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromag... more An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromagnetic hyperthermia. The study herein discusses results with a numerical thermal model of a choroidal melanoma in the rabbit eye as treated with episcleral, thermoradiotherapy plaques. The sensitivity of a temperature–dependent blood perfusion model is investigated.

Research paper thumbnail of Erratum to “Photocatalytic oxidation of acetone vapor on TiO2/ZrO2 thin films”

Applied Catalysis B-environmental, Feb 1, 2000

The Publisher regrets that this article was erroreously published as a Review article. It is a Re... more The Publisher regrets that this article was erroreously published as a Review article. It is a Research article.

Research paper thumbnail of Temperature-dependent versus constant-rate blood perfusion modelling in ferromagnetic thermoseed hyperthermia: results with a model of the human prostate

International Journal of Hyperthermia, 1994

Finite-element solutions to the Pennes bioheat equation are obtained with a model of a tumour-con... more Finite-element solutions to the Pennes bioheat equation are obtained with a model of a tumour-containing, human prostate and surrounding normal tissues. Simulations of ferromagnetic hyperthermia treatments are conducted on the tissue model in which the prostate is implanted with an irregularly spaced array of thermoseeds. Several combinations of thermoseed temperatures with different Curie points are investigated. Non-uniform, constant-rate blood perfusion models are studied and compared with temperature-dependent descriptions of blood perfusion. Blood perfusions in the temperature-dependent models initially increase with tissue temperature and then decrease at higher temperatures. Simulations with temperature-dependent versus constant-rate blood perfusion models reveal significant differences in temperature distributions in and surrounding the tumour-containing prostate. Results from the simulations include differences (between temperature-dependent and constant-rate models) in (1) the percentage of normal tissue volume and tumour volume at temperatures > 42 degrees C, and (2) temperature descriptors in the tumour (subscript t) and normal (subscript n) tissues including Tmax.t, Tmin.t and Tmax.n. Isotherms and grey-scale contours in the tumour and surrounding normal tissues are presented for four simulations that model a combination of high-temperature thermoseeds. Several simulations show that Tmin.t is between 1.7 and 2.6 degrees C higher and Tmax.n is between 2.1 and 3.3 degrees C higher with a temperature-dependent versus a comparable constant-rate blood perfusion model. The same simulations reveal that the percentages of tumour volume at temperatures > 42 degrees C are between 0 and 68% higher with the temperature-dependent versus the constant-rate perfusion model over all seed combinations studied. In summary, a numerical method is presented which makes it possible to investigate temperature-dependent, continuous functions of blood perfusion in simulations of hyperthermia treatments. Simulations with this numerical method reveal that the use of constant-rate instead of temperature-dependent blood perfusion models can be a conservative approach in treatment planning of ferromagnetic hyperthermia.

Research paper thumbnail of Effects of localised, low-voltage pulsed electric fields on the development and inhibition ofPseudomonas aeruginosabiofilms

Biofouling, 2006

This work describes the use of low-voltage (0.5 - 5 V) pulsed electric fields to prevent Pseudomo... more This work describes the use of low-voltage (0.5 - 5 V) pulsed electric fields to prevent Pseudomonas aeruginosa biofilm development. Interdigitated electrodes (IDEs) with 29-mum spacing between 22-mum-wide electrodes, were used as a platform where the effect of localised, high-strength electric fields could be tested. Alternating current, square-wave pulses were applied to the IDEs in 1 sec intervals. A two-level, three-variable factorial design experiment was used to detect the effects of applied voltage, frequency, and pulse duty ratio (i.e. percentage of pulsing time over one cycle) on the inhibition of biofilm formation. The observations indicated that a pulse configuration of 1% duty ratio, 5 V, and 200 Hz frequency reduced the area of the electrodes covered by biofilm by 50%. In general, the application of low-duty ratio pulses had a positive effect on preventing biofouling. Comparatively, frequency and applied voltage were observed to have less influence on biofouling.

Research paper thumbnail of Photocatalytic oxidation of acetone vapor on TiO2/ZrO2 thin films

Applied Catalysis B-environmental, Oct 1, 1999

The photocatalytic oxidation of acetone vapor on TiO 2 /ZrO 2 thin films is presented in this stu... more The photocatalytic oxidation of acetone vapor on TiO 2 /ZrO 2 thin films is presented in this study. Acetone conversion data collected using a non-circulating tubular reactor are analyzed using a general power law model and a Langmuir-Hinshelwood-Hougen-Watson (LHHW) model; the LHHW model provides a slightly better fit than the 1/2 order power law model. The effects of reaction temperature and relative humidity on the rate of reaction are presented. Using either kinetic model, increasing the reaction temperature from 30 to 77 • C (in a dry feed stream) significantly increases the reaction rate constant at a 95% confidence level; however, increasing the temperature from 77 to 113 • C does not have a significant effect. The addition of water vapor (50% relative humidity) to the feed stream at 77 • C significantly increases the reaction rate constant at a 95% confidence level. Also, at three different temperatures and a single reaction condition, the conversion of acetone is enhanced in the presence of water vapor. No byproducts are detected in the effluent stream of the photocatalytically active reactor.

Research paper thumbnail of Use of Power-Temperature Data in Finite-Element Model of Ferromagnetic Thermoseeds

Radiation Research: A Twentieth-century Perspective, 1991

Research paper thumbnail of A device that converts aqueous ammonia into nitrogen gas

Aquacultural Engineering, 2009

Research paper thumbnail of A finite element heat transfer model of ferromagnetic thermoseeds and a physiologically-based objective function for pretreatment planning of ferromagnetic …

Browse by Title. MINDS@UW Home >; Browse by Title. Browse by Title. 0-9; A; B; C; D; E; F; G; ... more Browse by Title. MINDS@UW Home >; Browse by Title. Browse by Title. 0-9; A; B; C; D; E; F; G; H; I; J; K; L; M; N; O; P; Q; R; S; T; U; V; W; X; Y; Z. Or enter first few letters:Browse for items that begin with these letters. Sort by: issue date ...

Research paper thumbnail of Effect of Fluorescent Illumination on Bacteria Supported on Glass Slides

Journal of Advanced Oxidation Technologies, 1998

The photocidal effect of exposing S. aureus BC12041 to UVA-rich fluorescent light is demonstrated... more The photocidal effect of exposing S. aureus BC12041 to UVA-rich fluorescent light is demonstrated. In UVA-exposure studies with appropriate controls, CFUs of S. aureus BC 12041 are reduced by approximately two logarithms in a high humidity environment 85% RH) and by one logarithm in moderate humidity (~ 50% RH) over a 30-min treatment period. In similar studies at the high humidity, no differential effect was observed between test and control studies with B. subtilis ATCC 6633. Thus, it appears that UVA-rich fluorescent lighting may be a useful side effect obtained when employing an UVA-activated photocatalyst for the degradation of volatile organic compounds (VOCs) in indoor air.

Research paper thumbnail of Evaluation of photocatalysis for gas-phase air cleaning- Part 2: Economics and utilization. Discussion

Ashrae Transactions, 2005

... Third, a study based on a consortium of semi-conductor companies demonstrated that the cost o... more ... Third, a study based on a consortium of semi-conductor companies demonstrated that the cost of ownership of PCO for point-of-use (POU) applications is not likely to cost less on a “per CFM basis” than existing end-of-pipe (EOP) technologies. ... Marc A. Anderson, PhD ...

Research paper thumbnail of Methods for Removing Contaminants from Aqueous Solutions Using Photoelectrocatalytic Oxidization

Research paper thumbnail of Shedding light on photocatalysis. Discussion

Ashrae Transactions, 2005

Research paper thumbnail of Radiation therapy and ferromagnetic hyperthermia in the treatment of murine transgenic retinoblastoma

Archives of Ophthalmology, Nov 1, 1996

Combined modality therapy for childhood retinoblastoma holds the potential of decreasing treatmen... more Combined modality therapy for childhood retinoblastoma holds the potential of decreasing treatment-related morbidity while maintaining excellent tumor control rates. To evaluate the efficacy of external beam radiation therapy (EBRT), ferromagnetic hyperthermia (FMH), and the combination of both modalities in the control of ocular tumors in a transgenic murine model of retinoblastoma. One hundred sixty-six mouse eyes from 4-week-old animals transgenically positive for simian virus 40 large T antigen were treated with a total dose of 10, 15, 20, 30, 40, 45, or 50 Gy of EBRT in 5-Gy fractions twice daily, with 48 degrees C or 54 degrees C FMH for 20 minutes, or with combined EBRT at 10 or 30 Gy and 48 degrees C or 54 degrees C FMH for 20 minutes. Serial histologic sections, obtained 8 weeks after treatment, were examined for the presence of tumor. The tumor control dose for 50% of eyes (TCD50) treated with EBRT occurred at 27.6 Gy. Ferromagnetic hyperthermia at 48 degrees C cured 30% (6/20) of eyes, while 54 degrees C FMH resulted in a 100% (20/20) cure rate. Combined treatment with 48 degrees C FMH and EBRT exhibited a TCD50 at 3.3 Gy. The thermal enhancement ratio was 8.4. Ferromagnetic hyperthermia at 54 degrees C exhibited tumor cure in all animals, but 25% of eyes were lost owing to secondary treatment complications. This represents the first documentation of tumor control via EBRT, ocular FMH, and a combination of these treatment modalities in this murine transgenic retinoblastoma model. The extent of treatment synergy in this model suggests that combined treatment application may allow a reduction in total ocular and periocular radiation dose while maintaining excellent local tumor control.

Research paper thumbnail of Evaluation of photocatalysis for gas-phase air cleaning- Part 1: Process, technical, and sizing considerations

Ashrae Transactions, 2005

... Third, a study based on a consortium of semi-conductor companies demonstrated that the cost o... more ... Third, a study based on a consortium of semi-conductor companies demonstrated that the cost of ownership of PCO for point-of-use (POU) applications is not likely to cost less on a “per CFM basis” than existing end-of-pipe (EOP) technologies. ... Marc A. Anderson, PhD ...

Research paper thumbnail of Temperature Distributions During Thermoradiotherapy: A Sensitivity Study With a Transient Numerical Model of the Rabbit Eye

Journal of Biomechanical Engineering, 1997

An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromag... more An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromagnetic hyperthermia. The study herein discusses results with a numerical thermal model of a choroidal melanoma in the rabbit eye as treated with episcleral, thermoradiotherapy plaques. The sensitivity of a temperature–dependent blood perfusion model is investigated.

Research paper thumbnail of Thermoradiotherapy of intraocular tumors in an animal model: Concurrent vs. sequential brachytherapy and ferromagnetic hyperthermia

International Journal of Radiation Oncology*Biology*Physics, 1995

Purpose: To compare concurrent vs. sequentiai ferromagnetic tbermoradiotberapy in vivo. Methods a... more Purpose: To compare concurrent vs. sequentiai ferromagnetic tbermoradiotberapy in vivo. Methods and Materiak Greene melanomas were implanted subretinally in rabbits and observed until they were 3-S mm in diameter. Episclerai plaques were assembled with '*'I seeds for radiation therapy, or with ferromagnetic (FM) tbermoseeds and nonradioactive I seeds for bypertbermia. Rabbits were impbutted by centering a plaque over tbe intraocuiar melanoma. After a given dose of radiation bad heen deiivered, the plaque was removed and a nonradioactive piaque containing FM thermoseeds was h~rted into tbe same extrascierai space. One hour later, bypertbermia (46-47'C at the pbque-sclerai interface) was buthued and continued for a period of 1 b by placing the rabbits in a magnetic brduction COB powered to 1200 W. Tumor size was determined at l-to 2-week intervais by bulirect opbtbahnoscopy and by ultrasound. Resuits: Dose-response anaiysis of 27 treated eye mebmomas showed 50% iocai tumor control at 43 Gy for IsI aione and 29.4 Gy for '=I foiiowed by FM hypertbermia. The thermai enhancement ratio was 1.4. Concbtsion: Comparison with a previously pubiisbed tbermai enhancement ratio of 4.4 (for concurrent lzI and FM bypertbermia) leads us to conclude that thermai enhancement of '=I bracbytberapy is more efficient in this tumor model system when bypertbermia is deiivered during, rather than after, the irradiation process.

Research paper thumbnail of A Finite Element Heat Transfer Model of Ferromagnetic Thermoseeds and a Physiologically-Based Objective Function for Pretreatment Planning of Ferromagnetic Hyperthermia

Research paper thumbnail of Effect of implant variables on temperatures achieved during ferromagnetic hyperthermia

International Journal of Hyperthermia, 1992

Effects of ferromagnetic implant variables on steady-state temperature were studied in both in vi... more Effects of ferromagnetic implant variables on steady-state temperature were studied in both in vitro (phantom) and in vivo (rabbit hind limb musculature) models. Thermoseed implant variables included: (1) the presence and number of thermoseed sleeves; (2) variations in thermoseed alignment within the oscillating electromagnetic field; (3) generator power levels of 300 W, 600 W, and 1200 W; and (4) separation of thermoseed tracks by 0.8 cm versus 1 cm. When the thermoseeds were aligned parallel to the electromagnetic field, temperature distributions in the in vivo model using bare thermoseeds and thermoseeds encased in a single sleeve (0.1 mm wall thickness) of polyethylene tubing were statistically higher than in tests performed with thermoseeds encased in a double sleeve (0.25 mm over 0.1 mm wall thickness) of tubing (p = 0.006). Nonetheless, average steady-state temperatures above a therapeutic minimum (greater than or equal to 42 degrees C) were achieved at all generator power levels using thermoseeds encased in a double sleeve of tubing and aligned parallel to the electromagnetic field. Gross misalignment of thermoseeds with the electromagnetic field was partly compensated for by utilizing higher generator power levels. Thermoseed tracks separated by 0.8 cm and aligned parallel to the electromagnetic field yielded average steady-state temperatures that were 0.4-2.2 degrees C higher than those obtained with a thermoseed track separation of 1 cm.

Research paper thumbnail of Photocatalytic oxidation in the presence of microwave irradiation: observations with ethylene and water

Journal of Photochemistry and Photobiology A-chemistry, May 1, 2002

Microwave irradiation was employed in the heterogeneous photocatalytic oxidation (PCO) of a test ... more Microwave irradiation was employed in the heterogeneous photocatalytic oxidation (PCO) of a test compound, ethylene, in the gas phase on TiO 2 /ZrO 2 mixed oxide thin films prepared via sol-gel processing. This approach was taken to study the rate of PCO of these compounds as a function of water concentration by perturbing the presence of water on the surface of the catalyst. PCO experiments were conducted with two types of reactor assemblies (Approaches 1 and 2). In Approach 1 when microwave plasma lighting was applied, microwave irradiation increased the rate constants by 15% (α = 1) and 26.9% (α = 0.5) corrected for light irradiance in studies conducted at 15% relative humidity (RH), but had a negligible effect at 0 and 5% RH. In Approach 2, with the light source external to the microwave chamber, the degradation of ethylene with 3 l liquid water injection proceeded faster (83.9%) in the presence of the microwave irradiation than in the absence. Measurements of water adsorption indicated that microwave irradiation facilitated the removal of excess water from the catalyst surface treated with UV illumination in studies with the RH above 15%, but excess water removal was not observed in studies with the RH lower than 5%. Contact angle measurements helped to elucidate the effect of surface wettability of TiO 2 /ZrO 2 catalyst films on the observed results.

Research paper thumbnail of Effect of Fluorescent Illumination on Bacteria Supported on Glass Slides

Journal of Advanced Oxidation Technologies, 1998

The photocidal effect of exposing S. aureus BC12041 to UVA-rich fluorescent light is demonstrated... more The photocidal effect of exposing S. aureus BC12041 to UVA-rich fluorescent light is demonstrated. In UVA-exposure studies with appropriate controls, CFUs of S. aureus BC 12041 are reduced by approximately two logarithms in a high humidity environment 85% RH) and by one logarithm in moderate humidity (~ 50% RH) over a 30-min treatment period. In similar studies at the high humidity, no differential effect was observed between test and control studies with B. subtilis ATCC 6633. Thus, it appears that UVA-rich fluorescent lighting may be a useful side effect obtained when employing an UVA-activated photocatalyst for the degradation of volatile organic compounds (VOCs) in indoor air.

Research paper thumbnail of Temperature Distributions During Thermoradiotherapy: A Sensitivity Study With a Transient Numerical Model of the Rabbit Eye

Journal of biomechanical engineering, May 1, 1997

An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromag... more An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromagnetic hyperthermia. The study herein discusses results with a numerical thermal model of a choroidal melanoma in the rabbit eye as treated with episcleral, thermoradiotherapy plaques. The sensitivity of a temperature–dependent blood perfusion model is investigated.

Research paper thumbnail of Erratum to “Photocatalytic oxidation of acetone vapor on TiO2/ZrO2 thin films”

Applied Catalysis B-environmental, Feb 1, 2000

The Publisher regrets that this article was erroreously published as a Review article. It is a Re... more The Publisher regrets that this article was erroreously published as a Review article. It is a Research article.

Research paper thumbnail of Temperature-dependent versus constant-rate blood perfusion modelling in ferromagnetic thermoseed hyperthermia: results with a model of the human prostate

International Journal of Hyperthermia, 1994

Finite-element solutions to the Pennes bioheat equation are obtained with a model of a tumour-con... more Finite-element solutions to the Pennes bioheat equation are obtained with a model of a tumour-containing, human prostate and surrounding normal tissues. Simulations of ferromagnetic hyperthermia treatments are conducted on the tissue model in which the prostate is implanted with an irregularly spaced array of thermoseeds. Several combinations of thermoseed temperatures with different Curie points are investigated. Non-uniform, constant-rate blood perfusion models are studied and compared with temperature-dependent descriptions of blood perfusion. Blood perfusions in the temperature-dependent models initially increase with tissue temperature and then decrease at higher temperatures. Simulations with temperature-dependent versus constant-rate blood perfusion models reveal significant differences in temperature distributions in and surrounding the tumour-containing prostate. Results from the simulations include differences (between temperature-dependent and constant-rate models) in (1) the percentage of normal tissue volume and tumour volume at temperatures > 42 degrees C, and (2) temperature descriptors in the tumour (subscript t) and normal (subscript n) tissues including Tmax.t, Tmin.t and Tmax.n. Isotherms and grey-scale contours in the tumour and surrounding normal tissues are presented for four simulations that model a combination of high-temperature thermoseeds. Several simulations show that Tmin.t is between 1.7 and 2.6 degrees C higher and Tmax.n is between 2.1 and 3.3 degrees C higher with a temperature-dependent versus a comparable constant-rate blood perfusion model. The same simulations reveal that the percentages of tumour volume at temperatures > 42 degrees C are between 0 and 68% higher with the temperature-dependent versus the constant-rate perfusion model over all seed combinations studied. In summary, a numerical method is presented which makes it possible to investigate temperature-dependent, continuous functions of blood perfusion in simulations of hyperthermia treatments. Simulations with this numerical method reveal that the use of constant-rate instead of temperature-dependent blood perfusion models can be a conservative approach in treatment planning of ferromagnetic hyperthermia.

Research paper thumbnail of Effects of localised, low-voltage pulsed electric fields on the development and inhibition ofPseudomonas aeruginosabiofilms

Biofouling, 2006

This work describes the use of low-voltage (0.5 - 5 V) pulsed electric fields to prevent Pseudomo... more This work describes the use of low-voltage (0.5 - 5 V) pulsed electric fields to prevent Pseudomonas aeruginosa biofilm development. Interdigitated electrodes (IDEs) with 29-mum spacing between 22-mum-wide electrodes, were used as a platform where the effect of localised, high-strength electric fields could be tested. Alternating current, square-wave pulses were applied to the IDEs in 1 sec intervals. A two-level, three-variable factorial design experiment was used to detect the effects of applied voltage, frequency, and pulse duty ratio (i.e. percentage of pulsing time over one cycle) on the inhibition of biofilm formation. The observations indicated that a pulse configuration of 1% duty ratio, 5 V, and 200 Hz frequency reduced the area of the electrodes covered by biofilm by 50%. In general, the application of low-duty ratio pulses had a positive effect on preventing biofouling. Comparatively, frequency and applied voltage were observed to have less influence on biofouling.

Research paper thumbnail of Photocatalytic oxidation of acetone vapor on TiO2/ZrO2 thin films

Applied Catalysis B-environmental, Oct 1, 1999

The photocatalytic oxidation of acetone vapor on TiO 2 /ZrO 2 thin films is presented in this stu... more The photocatalytic oxidation of acetone vapor on TiO 2 /ZrO 2 thin films is presented in this study. Acetone conversion data collected using a non-circulating tubular reactor are analyzed using a general power law model and a Langmuir-Hinshelwood-Hougen-Watson (LHHW) model; the LHHW model provides a slightly better fit than the 1/2 order power law model. The effects of reaction temperature and relative humidity on the rate of reaction are presented. Using either kinetic model, increasing the reaction temperature from 30 to 77 • C (in a dry feed stream) significantly increases the reaction rate constant at a 95% confidence level; however, increasing the temperature from 77 to 113 • C does not have a significant effect. The addition of water vapor (50% relative humidity) to the feed stream at 77 • C significantly increases the reaction rate constant at a 95% confidence level. Also, at three different temperatures and a single reaction condition, the conversion of acetone is enhanced in the presence of water vapor. No byproducts are detected in the effluent stream of the photocatalytically active reactor.

Research paper thumbnail of Use of Power-Temperature Data in Finite-Element Model of Ferromagnetic Thermoseeds

Radiation Research: A Twentieth-century Perspective, 1991

Research paper thumbnail of A device that converts aqueous ammonia into nitrogen gas

Aquacultural Engineering, 2009

Research paper thumbnail of A finite element heat transfer model of ferromagnetic thermoseeds and a physiologically-based objective function for pretreatment planning of ferromagnetic …

Browse by Title. MINDS@UW Home >; Browse by Title. Browse by Title. 0-9; A; B; C; D; E; F; G; ... more Browse by Title. MINDS@UW Home >; Browse by Title. Browse by Title. 0-9; A; B; C; D; E; F; G; H; I; J; K; L; M; N; O; P; Q; R; S; T; U; V; W; X; Y; Z. Or enter first few letters:Browse for items that begin with these letters. Sort by: issue date ...

Research paper thumbnail of Effect of Fluorescent Illumination on Bacteria Supported on Glass Slides

Journal of Advanced Oxidation Technologies, 1998

The photocidal effect of exposing S. aureus BC12041 to UVA-rich fluorescent light is demonstrated... more The photocidal effect of exposing S. aureus BC12041 to UVA-rich fluorescent light is demonstrated. In UVA-exposure studies with appropriate controls, CFUs of S. aureus BC 12041 are reduced by approximately two logarithms in a high humidity environment 85% RH) and by one logarithm in moderate humidity (~ 50% RH) over a 30-min treatment period. In similar studies at the high humidity, no differential effect was observed between test and control studies with B. subtilis ATCC 6633. Thus, it appears that UVA-rich fluorescent lighting may be a useful side effect obtained when employing an UVA-activated photocatalyst for the degradation of volatile organic compounds (VOCs) in indoor air.

Research paper thumbnail of Evaluation of photocatalysis for gas-phase air cleaning- Part 2: Economics and utilization. Discussion

Ashrae Transactions, 2005

... Third, a study based on a consortium of semi-conductor companies demonstrated that the cost o... more ... Third, a study based on a consortium of semi-conductor companies demonstrated that the cost of ownership of PCO for point-of-use (POU) applications is not likely to cost less on a “per CFM basis” than existing end-of-pipe (EOP) technologies. ... Marc A. Anderson, PhD ...

Research paper thumbnail of Methods for Removing Contaminants from Aqueous Solutions Using Photoelectrocatalytic Oxidization

Research paper thumbnail of Shedding light on photocatalysis. Discussion

Ashrae Transactions, 2005

Research paper thumbnail of Radiation therapy and ferromagnetic hyperthermia in the treatment of murine transgenic retinoblastoma

Archives of Ophthalmology, Nov 1, 1996

Combined modality therapy for childhood retinoblastoma holds the potential of decreasing treatmen... more Combined modality therapy for childhood retinoblastoma holds the potential of decreasing treatment-related morbidity while maintaining excellent tumor control rates. To evaluate the efficacy of external beam radiation therapy (EBRT), ferromagnetic hyperthermia (FMH), and the combination of both modalities in the control of ocular tumors in a transgenic murine model of retinoblastoma. One hundred sixty-six mouse eyes from 4-week-old animals transgenically positive for simian virus 40 large T antigen were treated with a total dose of 10, 15, 20, 30, 40, 45, or 50 Gy of EBRT in 5-Gy fractions twice daily, with 48 degrees C or 54 degrees C FMH for 20 minutes, or with combined EBRT at 10 or 30 Gy and 48 degrees C or 54 degrees C FMH for 20 minutes. Serial histologic sections, obtained 8 weeks after treatment, were examined for the presence of tumor. The tumor control dose for 50% of eyes (TCD50) treated with EBRT occurred at 27.6 Gy. Ferromagnetic hyperthermia at 48 degrees C cured 30% (6/20) of eyes, while 54 degrees C FMH resulted in a 100% (20/20) cure rate. Combined treatment with 48 degrees C FMH and EBRT exhibited a TCD50 at 3.3 Gy. The thermal enhancement ratio was 8.4. Ferromagnetic hyperthermia at 54 degrees C exhibited tumor cure in all animals, but 25% of eyes were lost owing to secondary treatment complications. This represents the first documentation of tumor control via EBRT, ocular FMH, and a combination of these treatment modalities in this murine transgenic retinoblastoma model. The extent of treatment synergy in this model suggests that combined treatment application may allow a reduction in total ocular and periocular radiation dose while maintaining excellent local tumor control.

Research paper thumbnail of Evaluation of photocatalysis for gas-phase air cleaning- Part 1: Process, technical, and sizing considerations

Ashrae Transactions, 2005

... Third, a study based on a consortium of semi-conductor companies demonstrated that the cost o... more ... Third, a study based on a consortium of semi-conductor companies demonstrated that the cost of ownership of PCO for point-of-use (POU) applications is not likely to cost less on a “per CFM basis” than existing end-of-pipe (EOP) technologies. ... Marc A. Anderson, PhD ...

Research paper thumbnail of Temperature Distributions During Thermoradiotherapy: A Sensitivity Study With a Transient Numerical Model of the Rabbit Eye

Journal of Biomechanical Engineering, 1997

An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromag... more An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromagnetic hyperthermia. The study herein discusses results with a numerical thermal model of a choroidal melanoma in the rabbit eye as treated with episcleral, thermoradiotherapy plaques. The sensitivity of a temperature–dependent blood perfusion model is investigated.

Research paper thumbnail of Thermoradiotherapy of intraocular tumors in an animal model: Concurrent vs. sequential brachytherapy and ferromagnetic hyperthermia

International Journal of Radiation Oncology*Biology*Physics, 1995

Purpose: To compare concurrent vs. sequentiai ferromagnetic tbermoradiotberapy in vivo. Methods a... more Purpose: To compare concurrent vs. sequentiai ferromagnetic tbermoradiotberapy in vivo. Methods and Materiak Greene melanomas were implanted subretinally in rabbits and observed until they were 3-S mm in diameter. Episclerai plaques were assembled with '*'I seeds for radiation therapy, or with ferromagnetic (FM) tbermoseeds and nonradioactive I seeds for bypertbermia. Rabbits were impbutted by centering a plaque over tbe intraocuiar melanoma. After a given dose of radiation bad heen deiivered, the plaque was removed and a nonradioactive piaque containing FM thermoseeds was h~rted into tbe same extrascierai space. One hour later, bypertbermia (46-47'C at the pbque-sclerai interface) was buthued and continued for a period of 1 b by placing the rabbits in a magnetic brduction COB powered to 1200 W. Tumor size was determined at l-to 2-week intervais by bulirect opbtbahnoscopy and by ultrasound. Resuits: Dose-response anaiysis of 27 treated eye mebmomas showed 50% iocai tumor control at 43 Gy for IsI aione and 29.4 Gy for '=I foiiowed by FM hypertbermia. The thermai enhancement ratio was 1.4. Concbtsion: Comparison with a previously pubiisbed tbermai enhancement ratio of 4.4 (for concurrent lzI and FM bypertbermia) leads us to conclude that thermai enhancement of '=I bracbytberapy is more efficient in this tumor model system when bypertbermia is deiivered during, rather than after, the irradiation process.