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Papers by Juan Vitali (Office of Science And Technology- The White House)

Journal of Molecular and Cellular Cardiology, Oct 1, 2006

Cardiac sensitization is the term used for malignant ventricular arrhythmias associated with expo... more Cardiac sensitization is the term used for malignant ventricular arrhythmias associated with exposure to inhaled halocarbons in the presence of catecholamines. We investigated the electrophysiological changes associated with cardiomyocyte exposure to epinephrine and a halocarbon known to be associated with cardiac sensitization (halon 1301, CF 3 Br). Cardiomyocytes (CMs) were isolated from neonatal rats and grown on multielectrode arrays (MEAs). Upon exposure to epinephrine, the CM inter-spike interval (ISI) was decreased 14% at 10 µg/L (P<0.05) and 27% at 100 µg/L (P<0.05) as compared to baseline. Halon alone (50 mg/L) mildly prolonged the field potential (FP) duration (7%). CMs exposed to combinations of epinephrine (100 µg/L) and halon (50 mg/L) for 15 min showed a blunted increase in the ISI (35±12%) and a 38% decrease in conduction velocity (P<0.05) when compared to epinephrine alone. There was no change in field potential properties, but dephosphorylated connexin 43 (Cx43) was increased 60±16% with the combination as compared to epinephrine alone (P<0.05). Treatment with okadaic acid, a phosphatase inhibitor, prevented the Cx43 dephosphorylation and the reduction in conduction velocity upon exposure to halon and epinephrine. Moreover, the electrophysiological changes induced by epinephrine and halon were indistinguishable from those seen with the gap junction inhibitor heptanol. In conclusion, the combination of a halocarbon and epinephrine results in a unique electrophysiological signature including slow conduction that may explain, in part, the basis for cardiac sensitization. The slowing of conduction is most likely related to changes in the phosphorylation state of Cx43.

The authors consider the gas phase formation of chlorinated benzenes and phenols as precursors of... more The authors consider the gas phase formation of chlorinated benzenes and phenols as precursors of chlorinated dioxins and furans from the combustion of solid fuels containing organically bound chlorine. The model investigated is intended to apply to the combustion of medical waste, municipal waste and coals containing chlorine. Assuming a temperature-time profile drawn from incinerator experiments, the authors use kinetic modeling with known reaction rates to further investigate four models of chlorinated benzene formation. Since reaction rates for most chlorination processes are now known, the authors choose simple systems of reaction rates that yield outputs that can be made approximately compatible with results of the Pittsfield-Vicon incinerator and Clean Combustion Technology Laboratory experiments. The authors also consider recent measurements of HCI emissions from crematoria and the implication of this work with respect to the benefits of material substitution in medical and municipal waste incineration. These benefits should also accompany the dechlorination of coals. The authors note the disparity between the prevailing USA position and the emerging position of Germany on the issue of halogenated plastics. The authors also note that Europe and Asia are beginning to address solid fuel issues as a consolidated discipline. This pattern should be helpful inmore » broadening the understanding of solid fuels combustion processes and in ferreting out erroneous data and conclusions. This is important in view of the recent concern about the role of low dioxin exposure levels on fetal development and the immune system.« less

Proceeding of Proceedings of Symposium on Energy Engineering in the 21st Century (SEE2000) Volume I-IV

03-28-102833-257. v UNCLASSIFIED transportation, and fuel availability. A DOD-led interagency tea... more 03-28-102833-257. v UNCLASSIFIED transportation, and fuel availability. A DOD-led interagency team approach offers the best chance of success for resolution of non-technical matters. The MNPP concept is based on new, advanced, and safe technology currently available from the commercial and government sectors which should be further refined within the DOD and at the interagency level. This study recommends the DCS G-4:  Present the MNPP concept through the Commander, Army Futures Command (AFC) and the Vice Chief of Staff, Army (VCSA) to the Chief of Staff, Army for further consideration.  Express Army support for a DOD prototyping effort by the Strategic Capabilities Office (SCO).  Identify MNPP for future Joint Requirements Oversight Council (JROC)/Army Requirements Oversight Council (AROC) consideration.

this paper, we present a chronological and historical overview of the various successful paths ta... more this paper, we present a chronological and historical overview of the various successful paths taken by the USAF to identify and develop halon alternatives, and the current status of the replacement work both for Halon 1211 and for Halon 1301. 2

Historically, fuel fire explosion has been a major cause of aircraft losses in combat. To increas... more Historically, fuel fire explosion has been a major cause of aircraft losses in combat. To increase survivability, various techniques are used to reduce the vulnerability of the aircraft’s fuel system to this significant threat effect. The F-16 weapon system relies on Halon 1301 to provide fuel cell inerting to protect the fuel system from explosions due to combat threats. Halon, the worst known ozone-depleting chemical, has been eliminated as part of an international agreement to cease man-made production of these types of chemicals. A ban on production that went into effect in 1994 has left only existing stocks of halon available to support halon use in essential applications such as aircraft fire and explosion suppression systems. As a result, all F-16s are dependent on a finite amount of halon available from Department of Defense stocks. However, these stocks may become useless as there are on-going preliminary discussions among some countries to ban the use of halon altogether.

In 1985, under the lead of the U.S. Air Force (USAF), and with the U.S. Navy as a co-sponsor, res... more In 1985, under the lead of the U.S. Air Force (USAF), and with the U.S. Navy as a co-sponsor, research was initiated on chemical replacements for halon fire and explosion protection agents. Under Project Reliance, a tri-service agreement to assign ‘‘leads’’ to different services to avoid overlap in R&D, the Air Force is now designated the lead military organization in development of Halon 121 1 replacements. However, in the early days of halon replacement work, the Air Force was involved in halon replacement research in general. This work, which emphasizes chemical substitutes for halons rather than just testing and certification of commercial industry announced solutions, has continued not only under USAF leadership, but in work sponsored by the US . Environmental Protection Agency, Advanced Agent Working Group (AAWG), CF3I Working Group, US . Army, U.S. Navy, and North Slope Oil and Gas Producers. Some chemical manufacturers have also participated in the working groups. More recen...

: Combining the proven technology of solid core reactors with uranium arc confinement and non-equ... more : Combining the proven technology of solid core reactors with uranium arc confinement and non-equilibrium dissociation and ionization by fission fragments can lead to an attractive power and propulsion system. The benefit ensues from using the high quality directed energy of fission fragments and associated radiation to obtain working fluid/propellant dissociation and ionization directly, without first degrading the energy to heat. The dissociation and ionization energies can be utilized in a nozzle, thruster or MHD accelerator/generator. Uranium arc technology is being developed for use in space nuclear thermal and electric propulsion reactors. In the Uranium Arc Fission Reactor, arcs are driven mainly by fission energy and require little electrical energy input. The arcs operate at 10,000 K, and transfer energy to the propellant or working fluid via optical radiation, thus avoiding material temperature limitations. The result is a propulsion afterburner that can elevate fluid temp...

: The design and development of an aerosol generator utilizing pyrotechnically activated EMAA is ... more : The design and development of an aerosol generator utilizing pyrotechnically activated EMAA is subject to two principal requirements; effective total-flooding of the protected area, and safe transfer of thermal energy derived from EMAA combustion. Because EMAA's are ineffective below a threshold airborne concentration the aerosol generator design must limit the potential for trapping excessive amounts of aerosol before it can be released into the protected area. This concern is coupled with designing a reliable system for transferring relatively large amounts of heat from EMAA combustion to both aid in the effectiveness of the aerosol suspension and prevent the possibility of secondary fires. In addition, the corrosivity potential of the various EMAA formulations on different commonly-used metals and metal alloys found in military equipment was tested and evaluated.

Mainstream Engineering Corporation has been performing research on halon replacements for several... more Mainstream Engineering Corporation has been performing research on halon replacements for several years [ 1-71, Our approach to the problem has been to apply the complex yet accurate techniques of computational chemistry to screen previously untested compounds as halon replacements. Computational chemistry techniques allowed for accurate prediction of the key fire suppression properties of a large list of compounds not previously considered as halon replacements. Compounds with a high probability for success were then evaluated in the laboratory to test the computational chemistry predictions.

Page 1. WL-TR-96-3139 EMAA AEROSOL GENERATOR DESIGN AND CORROSION STUDY Weilin P. Chang Charles J... more Page 1. WL-TR-96-3139 EMAA AEROSOL GENERATOR DESIGN AND CORROSION STUDY Weilin P. Chang Charles J. Kibert James Akers Juan Vitali Fire Testing and Research Center PO Box 115703 University of Florida ...

Combining the proven technology of solid core reactors with uranium arc confinement and non-equil... more Combining the proven technology of solid core reactors with uranium arc confinement and non-equilibrium ionization by fission fragments can lead to an attractive propulsion system which has a higher specific impulse than a solid core propulsion system and higher thrust than ...

Airborne Intelligence, Surveillance, Reconnaissance (ISR) Systems and Applications IV, 2007

Journal of Molecular and Cellular Cardiology, Oct 1, 2006

Cardiac sensitization is the term used for malignant ventricular arrhythmias associated with expo... more Cardiac sensitization is the term used for malignant ventricular arrhythmias associated with exposure to inhaled halocarbons in the presence of catecholamines. We investigated the electrophysiological changes associated with cardiomyocyte exposure to epinephrine and a halocarbon known to be associated with cardiac sensitization (halon 1301, CF 3 Br). Cardiomyocytes (CMs) were isolated from neonatal rats and grown on multielectrode arrays (MEAs). Upon exposure to epinephrine, the CM inter-spike interval (ISI) was decreased 14% at 10 µg/L (P<0.05) and 27% at 100 µg/L (P<0.05) as compared to baseline. Halon alone (50 mg/L) mildly prolonged the field potential (FP) duration (7%). CMs exposed to combinations of epinephrine (100 µg/L) and halon (50 mg/L) for 15 min showed a blunted increase in the ISI (35±12%) and a 38% decrease in conduction velocity (P<0.05) when compared to epinephrine alone. There was no change in field potential properties, but dephosphorylated connexin 43 (Cx43) was increased 60±16% with the combination as compared to epinephrine alone (P<0.05). Treatment with okadaic acid, a phosphatase inhibitor, prevented the Cx43 dephosphorylation and the reduction in conduction velocity upon exposure to halon and epinephrine. Moreover, the electrophysiological changes induced by epinephrine and halon were indistinguishable from those seen with the gap junction inhibitor heptanol. In conclusion, the combination of a halocarbon and epinephrine results in a unique electrophysiological signature including slow conduction that may explain, in part, the basis for cardiac sensitization. The slowing of conduction is most likely related to changes in the phosphorylation state of Cx43.

The authors consider the gas phase formation of chlorinated benzenes and phenols as precursors of... more The authors consider the gas phase formation of chlorinated benzenes and phenols as precursors of chlorinated dioxins and furans from the combustion of solid fuels containing organically bound chlorine. The model investigated is intended to apply to the combustion of medical waste, municipal waste and coals containing chlorine. Assuming a temperature-time profile drawn from incinerator experiments, the authors use kinetic modeling with known reaction rates to further investigate four models of chlorinated benzene formation. Since reaction rates for most chlorination processes are now known, the authors choose simple systems of reaction rates that yield outputs that can be made approximately compatible with results of the Pittsfield-Vicon incinerator and Clean Combustion Technology Laboratory experiments. The authors also consider recent measurements of HCI emissions from crematoria and the implication of this work with respect to the benefits of material substitution in medical and municipal waste incineration. These benefits should also accompany the dechlorination of coals. The authors note the disparity between the prevailing USA position and the emerging position of Germany on the issue of halogenated plastics. The authors also note that Europe and Asia are beginning to address solid fuel issues as a consolidated discipline. This pattern should be helpful inmore » broadening the understanding of solid fuels combustion processes and in ferreting out erroneous data and conclusions. This is important in view of the recent concern about the role of low dioxin exposure levels on fetal development and the immune system.« less

Proceeding of Proceedings of Symposium on Energy Engineering in the 21st Century (SEE2000) Volume I-IV

03-28-102833-257. v UNCLASSIFIED transportation, and fuel availability. A DOD-led interagency tea... more 03-28-102833-257. v UNCLASSIFIED transportation, and fuel availability. A DOD-led interagency team approach offers the best chance of success for resolution of non-technical matters. The MNPP concept is based on new, advanced, and safe technology currently available from the commercial and government sectors which should be further refined within the DOD and at the interagency level. This study recommends the DCS G-4:  Present the MNPP concept through the Commander, Army Futures Command (AFC) and the Vice Chief of Staff, Army (VCSA) to the Chief of Staff, Army for further consideration.  Express Army support for a DOD prototyping effort by the Strategic Capabilities Office (SCO).  Identify MNPP for future Joint Requirements Oversight Council (JROC)/Army Requirements Oversight Council (AROC) consideration.

this paper, we present a chronological and historical overview of the various successful paths ta... more this paper, we present a chronological and historical overview of the various successful paths taken by the USAF to identify and develop halon alternatives, and the current status of the replacement work both for Halon 1211 and for Halon 1301. 2

Historically, fuel fire explosion has been a major cause of aircraft losses in combat. To increas... more Historically, fuel fire explosion has been a major cause of aircraft losses in combat. To increase survivability, various techniques are used to reduce the vulnerability of the aircraft’s fuel system to this significant threat effect. The F-16 weapon system relies on Halon 1301 to provide fuel cell inerting to protect the fuel system from explosions due to combat threats. Halon, the worst known ozone-depleting chemical, has been eliminated as part of an international agreement to cease man-made production of these types of chemicals. A ban on production that went into effect in 1994 has left only existing stocks of halon available to support halon use in essential applications such as aircraft fire and explosion suppression systems. As a result, all F-16s are dependent on a finite amount of halon available from Department of Defense stocks. However, these stocks may become useless as there are on-going preliminary discussions among some countries to ban the use of halon altogether.

In 1985, under the lead of the U.S. Air Force (USAF), and with the U.S. Navy as a co-sponsor, res... more In 1985, under the lead of the U.S. Air Force (USAF), and with the U.S. Navy as a co-sponsor, research was initiated on chemical replacements for halon fire and explosion protection agents. Under Project Reliance, a tri-service agreement to assign ‘‘leads’’ to different services to avoid overlap in R&D, the Air Force is now designated the lead military organization in development of Halon 121 1 replacements. However, in the early days of halon replacement work, the Air Force was involved in halon replacement research in general. This work, which emphasizes chemical substitutes for halons rather than just testing and certification of commercial industry announced solutions, has continued not only under USAF leadership, but in work sponsored by the US . Environmental Protection Agency, Advanced Agent Working Group (AAWG), CF3I Working Group, US . Army, U.S. Navy, and North Slope Oil and Gas Producers. Some chemical manufacturers have also participated in the working groups. More recen...

: Combining the proven technology of solid core reactors with uranium arc confinement and non-equ... more : Combining the proven technology of solid core reactors with uranium arc confinement and non-equilibrium dissociation and ionization by fission fragments can lead to an attractive power and propulsion system. The benefit ensues from using the high quality directed energy of fission fragments and associated radiation to obtain working fluid/propellant dissociation and ionization directly, without first degrading the energy to heat. The dissociation and ionization energies can be utilized in a nozzle, thruster or MHD accelerator/generator. Uranium arc technology is being developed for use in space nuclear thermal and electric propulsion reactors. In the Uranium Arc Fission Reactor, arcs are driven mainly by fission energy and require little electrical energy input. The arcs operate at 10,000 K, and transfer energy to the propellant or working fluid via optical radiation, thus avoiding material temperature limitations. The result is a propulsion afterburner that can elevate fluid temp...

: The design and development of an aerosol generator utilizing pyrotechnically activated EMAA is ... more : The design and development of an aerosol generator utilizing pyrotechnically activated EMAA is subject to two principal requirements; effective total-flooding of the protected area, and safe transfer of thermal energy derived from EMAA combustion. Because EMAA's are ineffective below a threshold airborne concentration the aerosol generator design must limit the potential for trapping excessive amounts of aerosol before it can be released into the protected area. This concern is coupled with designing a reliable system for transferring relatively large amounts of heat from EMAA combustion to both aid in the effectiveness of the aerosol suspension and prevent the possibility of secondary fires. In addition, the corrosivity potential of the various EMAA formulations on different commonly-used metals and metal alloys found in military equipment was tested and evaluated.

Mainstream Engineering Corporation has been performing research on halon replacements for several... more Mainstream Engineering Corporation has been performing research on halon replacements for several years [ 1-71, Our approach to the problem has been to apply the complex yet accurate techniques of computational chemistry to screen previously untested compounds as halon replacements. Computational chemistry techniques allowed for accurate prediction of the key fire suppression properties of a large list of compounds not previously considered as halon replacements. Compounds with a high probability for success were then evaluated in the laboratory to test the computational chemistry predictions.

Page 1. WL-TR-96-3139 EMAA AEROSOL GENERATOR DESIGN AND CORROSION STUDY Weilin P. Chang Charles J... more Page 1. WL-TR-96-3139 EMAA AEROSOL GENERATOR DESIGN AND CORROSION STUDY Weilin P. Chang Charles J. Kibert James Akers Juan Vitali Fire Testing and Research Center PO Box 115703 University of Florida ...

Combining the proven technology of solid core reactors with uranium arc confinement and non-equil... more Combining the proven technology of solid core reactors with uranium arc confinement and non-equilibrium ionization by fission fragments can lead to an attractive propulsion system which has a higher specific impulse than a solid core propulsion system and higher thrust than ...

Airborne Intelligence, Surveillance, Reconnaissance (ISR) Systems and Applications IV, 2007